,,on ,,the ,,philosophy ,,of ,,discovery4 ,cambridge3 ,,printed ,,by ,c4 ,j4 ,,clay1 ,m4,a4 ,,at ,,the ,,university ,,press4 ,,on ,,the ,,philosophy ,,of ,,discovery1 ,,chapters ,,historical ,,and ,,critical2 ,,by ,,william ,,whewell1 ,d4,d4 ,,master ,,of ,,trinity ,,college1 ,,cambridge1 ,,and ,,corresponding ,,member ,,of ,,the ,,institute ,,of ,,france4 ,,including ,,the ,,completion ,,of ,,the ,,third ,,edition ,,of ,,the ,,philosophy ,,of ,,the ,,inductive ,,sciences4 ,illustration3 ,hand passing torch to hand ,,london3 ,,john ,w4 ,,parker ,,and ,,son1 ,,west ,,strand4 #ahfj4 ,the following are the latest editions of the series of works which has been published connected with the present subject3 ,history of the ,inductive ,sciences1 #c ,vols4 #aheg4 ,history of ,scientific ,ideas1 #b ,vols4 #aheh4 ,novum ,organon ,renovatum1 #a ,vol4 #aheh4 ,on the ,philosophy of ,discovery1 #a ,vol4 #ahfj4 ,to the ,history of the ,inductive ,sciences are appended two ,indexes 7in ,vol4 #a471 an ,index of ,proper ,names1 and an ,index of ,technical ,terms4 ,these ,indexes1 and the ,tables of ,contents of the other works1 will enable the reader to refer to any person or event included in this series4 ,,preface ,the two works which ,i entitled ,the ,history of the ,inductive ,sciences1 and ,the ,philosophy of the ,inductive ,sciences1 were intended to present to the reader a view of the steps by which those portions of human knowledge which are held to be most certain and stable have been acquired1 and of the philosophical principles which are involved in those steps4 ,each of these steps was a scientific ,discovery1 in which a new conception was applied in order to bind together observed facts4 ,and though the conjunction of the observed facts was in each case an example of logical ,induction1 it was not the inductive process merely1 but the novelty of the result in each case which gave its peculiar character to the ,history2 and the ,philosophy at which ,i aimed was not the ,philosophy of ,induction1 but the ,philosophy of ,discovery4 ,in the present edition ,i have described this as my object in my ,title4 ,a great part of the present volume consists of chapters which composed the twelfth ,book of the ,philosophy in former editions1 which ,book was then described as a ',review of ,opinions on the nature of ,knowledge and the ,method of seeking it4' ,i have added to this part several new chapters1 on ,plato1 ,aristotle1 the ,arabian ,philosophers1 ,francis ,bacon1 ,mr4 ,mill1 ,mr4 ,mansel1 the late ,sir ,william ,hamilton1 and the ,german philosophers ,kant1 ,fichte1 ,schelling and ,hegel4 ,i might1 if time had allowed1 have added a new chapter on ,roger ,bacon1 founded on his ,opus ,minus and other works1 recently published for the first time under the direction of the ,master of the ,rolls2 a valuable contribution to the history of philosophy4 ,but the review of this work would not materially alter the estimate of ,roger ,bacon which ,i had derived from the ,opus ,majus4 ,but besides these historical and critical surveys of the philosophy of others1 ,i have ventured to introduce some new views of my own2 namely1 views which bear upon the philosophy of religion4 ,i have done so under the conviction that no philosophy of the universe can satisfy the minds of thoughtful men which does not deal with such questions as inevitably force themselves on our notice1 respecting the ,author and the ,object of the universe2 and also under the conviction that every philosophy of the universe which has any consistency must suggest answers1 at least conjectural1 to such questions4 ,no ,cosmos is complete from which the question of ,deity is excluded2 and all ,cosmology has a side turned towards ,theology4 ,though ,i am aware therefore how easy it is1 on this subject1 to give offence and to incur obloquy1 ,i have not thought it right to abstain from following out my philosophical principles to their results in this department of speculation4 ,the results do not differ materially from those at which many pious and thoughtful speculators have arrived in previous ages of the world2 though they have here1 as seems to me1 something of novelty in their connection with the philosophy of science4 ,but this point ,i willingly leave to the calm decision of competent judges4 ,i have added in an ,appendix various ,essays1 previously published at different times1 which may serve perhaps to illustrate some points of the history and philosophy of science4 ,,trinity ,,lodge1 ,february #h1 #ahef4 ,,on ,,the ,,philosophy ,,of ,,discovery4 ,,contents4 ,the chapters marked thus 99 appear now for the first time4 ,the chapters marked thus have appeared in other works4 ,,chap4 ,i4 ,,introduction4 ,,chap4 ,,ii4 ,,plato4 ,,chap4 ,,iii4 99 ,,additional ,,remarks ,,on ,,plato4 #a4 ,the ,doctrine of ,ideas4 #b4 ,the ,doctrine of the ,one and ,many4 #c4 ,the notion of the nature and aim of ,science4 #d4 ,the ,survey of existing ,sciences4 #e4 ,the ,constitution of the human ,mind4 ,,chap4 ,,iv4 ,,aristotle4 ,,chap4 ,v4 99 ,,additional ,,remarks ,,on ,,aristotle4 #a4 ,induction4 #b4 ,invention4 #c4 ,the ,one in the ,many4 #d4 ,the ,five ,words4 #e4 ,aristotle's contribution to the ,physical ,sciences4 #f4 ,aristotle's ,astronomy4 #g4 ,aristotle on ,classification4 #h4 ,f4 ,bacon on ,aristotle4 #i4 ,discovery of ,causes4 #aj4 ,plato and ,aristotle4 #aa4 ,aristotle against ,plato's ,ideas4 ,,chap4 ,,vi4 ,,the ,,later ,,greeks4 ,,chap4 ,,vii4 ,,the ,,romans4 ,,chap4 ,,viii4 99 ,,arabian ,,philosophers4 ,,chap4 ,,ix4 ,,the ,,schoolmen ,,of ,,the ,,middle ,,ages4 ,,chap4 ,x4 ,,the ,,innovators ,,of ,,the ,,middle ,,ages4 ,raymond ,lully4 ,,chap4 ,,xi4 ,,the ,,innovators ,,of ,,the ,,middle ,,ages--continued4 ,roger ,bacon4 ,,chap4 ,,xii4 ,,the ,,revival ,,of ,,platonism4 #a4 ,causes of ,delay in the ,advance of ,knowledge4 #b4 ,causes of ,progress4 #c4 ,hermolaus ,barbarus1 c4 #d4 ,nicolaus ,cusanus4 #e4 ,manilius ,ficinus4 #f4 ,francis ,patricius4 #g4 ,picus1 ,agrippa1 c4 #h4 ,paracelsus1 ,fludd1 c4 ,,chap4 ,,xiii4 ,,the ,,theoretical ,,reformers ,,of ,,science4 #a4 ,bernardinus ,telesius4 #b4 ,thomas ,campanella4 #c4 ,andrew ,csalpinus4 #d4 ,giordano ,bruno4 #e4 ,peter ,ramus4 #f4 ,the ,reformers in ,general4 #g4 ,melancthon4 ,,chap4 ,,xiv4 ,,the ,,practical ,,reformers ,,of ,,science4 #a4 ,character of the ,practical ,reformers4 #b4 ,leonardo da ,vinci4 #c4 ,copernicus4 #d4 ,fabricius4 #e4 ,maurolycus4 #f4 ,benedetti4 #g4 ,gilbert4 #h4 ,galileo4 #i4 ,kepler4 #aj4 ,tycho4 ,,chap4 ,,xv4 ,,francis ,,bacon4 #a4 7,i47 ,general ,remarks4 #b4 ,common estimate of him4 #c4 ,we consider only ,physical ,science4 #d4 ,he is placed at the head of the change3 #e4 7,,ii47 ,he proclaims a ,new ,era2 #f4 7,,iii47 ,by a ,change of ,method2 #g4 ,including successive ,steps2 #h4 ,gradually ascending4 #i4 7,,iv47 ,he contrasts the ,old and the ,new ,method4 #aj4 7,v47 ,has he neglected ,ideas8 #aa4 ,no4 #ab4 ,examples of ,ideas treated by him4 #ac4 ,he has failed in applying his ,method2 #ad4 7,,vi47 ,to the ,cause of ,heat4 #ae4 ,he seeks ,causes before ,laws4 #af4 7,,vii47 ,his ,technical ,form worthless4 #ag4 ,he is confused by words4 #ah4 ,his ,instances4 #ai4 ,contain some good ,suggestions4 #bj4 7,,viii47 ,his ,idols4 #ba4 7,,ix47 ,his view of ,utility4 #bb4 7,x47 ,his ,hopefulness4 #bc4 7,,xi47 ,his ,piety4 ,,chap4 ,,xvi4 99 ,,additional ,,remarks ,,on ,,francis ,,bacon4 #a4 ,mr4 ,ellis's views4 #b4 ,mr4 ,spedding's views4 ,,chap4 ,,xvii4 ,,from ,,bacon ,,to ,,newton4 #a4 ,harvey4 #b4 ,descartes4 #c4 ,gassendi4 #d4 ,actual ,progress in ,science4 #e4 ,otto ,guericke1 c4 #f4 ,hooke4 #g4 ,royal ,society4 #h4 ,bacon's ,new ,atalantis4 #i4 ,cowley4 #aj4 ,barrow4 ,,chap4 ,,xviii4 ,,newton4 #a4 ,animating effect of his ,discoveries4 #b4 ,they confirm ,bacon's views4 #c4 ,newton shuns ,hypotheses4 #d4 ,his views of ,inductive ,philosophy4 #e4 ,his ,rules of ,philosophizing4 #f4 ,the ,first ,rule4 #g4 ,what is a ,true ,cause8 #h4 ,such as are real8 #i4 ,or those which are proved8 #aj4 ,use of the ,rule4 #aa4 ,rule otherwise expressed4 #ab4 ,the ,second ,rule4 #ac4 ,what are ,events of the same kind8 #ad4 ,the ,third ,rule3 #ae4 ,not safe4 #af4 ,the ,fourth ,rule4 #ag4 ,occult ,qualities4 #ah4 ,ridiculed4 #ai4 ,distinction of ,laws and ,causes4 ,,chap4 ,,xix4 ,,locke ,,and ,,his ,,french ,,followers4 #a4 ,cause of ,locke's popularity4 #b4 ,sensational ,school4 #c4 ,his inconsistencies4 #d4 ,condillac1 c4 #e4 ,importance of ,language4 #f4 ,ground of this4 #g4 ,the ,encyclopedists4 #h4 ,helvetius4 #i4 ,value of ,arts4 #aj4 ,tendency to ,reaction4 ,,chap4 ,,xx4 ,,the ,,reaction ,,against ,,the ,,sensational ,,school4 #a4 ,nisi intellectus ipse4 #b4 ,price's ,review4 #c4 ,stewart defends ,price4 #d4 ,archbishop ,whately4 #e4 ,laromiguire4 #f4 ,m4 ,cousin4 #g4 ,m4 ,ampre4 #h4 ,his ,classification of ,sciences4 #i4 ,kant's ,reform of ,philosophy4 #aj4 ,its ,effect in ,germany4 ,,chap4 ,,xxi4 ,,further ,,advance ,,of ,,the ,,sensational ,,school4 ,m4 ,auguste ,comte4 #a4 ,m4 ,comte on three ,states of ,science4 #b4 ,m4 ,comte rejects the ,search of ,causes4 #c4 ,causes in ,physics4 #d4 ,causes in other ,sciences4 #e4 ,m4 ,comte's ,practical ,philosophy4 #f4 ,m4 ,comte on ,hypotheses4 #g4 ,m4 ,comte's ,classification of ,sciences4 ,,chap4 ,,xxii4 ,,mr4 ,,mill',s ,,logic4 7,i47 ,what is ,induction8 #a-ad4 7,,ii47 ,induction or ,description1 #ae-bc4 7,,iii47 ,in ,discovery a new ,conception is introduced1 #bd-cg4 7,,iv47 ,mr4 ,mill's ,four ,methods of ,inquiry1 #ch-dj4 7,v47 ,his ,examples1 #da-dh4 7,,vi47 ,mr4 ,mill against ,hypotheses1 #di1 #ej4 7,,vii47 ,against prediction of ,facts1 #ea-ec4 7,,viii47 ,newton's ,vera ,causa1 #ed1 #ee4 7,,ix47 ,successive ,generalizations1 #ef-fb4 7,x47 ,mr4 ,mill's ,hope from ,deductions1 #fc-fg4 7,,xi47 ,fundamental opposition of our ,doctrines1 #fh-ga4 7,,xii47 ,absurdities in ,mr4 ,mill's ,logic1 #gb-gd4 ,,chap4 ,,xxiii4 99 ,,political ,,economy ,,as ,,an ,,inductive ,,science4 #a4 ,moral ,sciences4 #b4 ,political ,economy4 #c4 ,wages1 ,profits1 and ,rents4 #d4 ,premature ,generalizations4 #e4 ,correction of these by ,induction--,rent4 #f4 ,wages4 #g4 ,population4 ,,chap4 ,,xxiv4 ,,modern ,,german ,,philosophy4 7,i47 ,science is the ,idealization of ,facts1 #a-h4 7,,ii47 ,successive ,german ,philosophies4 ,kant1 ,fichte1 ,schelling1 ,hegel1 #i-af4 ,,chap4 ,,xxv4 ,,the ,,fundamental ,,antithesis ,,as ,,it ,,exists ,,in ,,the ,,moral ,,world4 ,moral ,progress is the ,realization of ,ideas4 ,,chap4 ,,xxvi4 99 ,,of ,,the ,,philosophy ,,of ,,the ,,infinite4 ,god is ,eternal4 ,,chap4 ,,xxvii4 99 ,,sir ,,william ,,hamilton ,,on ,,inertia ,,and ,,weight4 #a4 ,primary and ,secondary ,qualities4 #b4 ,meaning of the ,distinction4 #c4 ,sir ,w4 ,hamilton adds ,secundo-,primary4 #d4 ,inertia4 #e4 ,sir ,w4 ,hamilton's arguments and reply4 #f4 ,gravity4 ,sir ,w4 ,hamilton's arguments and reply4 ,,chap4 ,,xxviii4 ,,influence ,,of ,,german ,,systems ,,of ,,philosophy ,,in ,,britain4 #a4 ,stewart on ,kant4 #b4 ,mr4 ,g4 ,h4 ,lewes on ,kant4 #d-f4 ,mr4 ,mansel on ,kant4 ,his objection to our ,fundamental ,ideas1 and ,reply4 #g-aj4 ,new ,axioms are possible4 #aa-ac4 ,mr4 ,mansel's ,kantianism4 #ad-af4 ,axioms are not from experience4 ,,chap4 ,,xxix4 99 ,,necessary ,,truth ,,is ,,progressive4 ,objections considered4 ,,chap4 ,,xxx4 99 ,,the ,,theological ,,bearing ,,of ,,the ,,philosophy ,,of ,,discovery4 #a-d4 ,how can necessary truths be actual8 #e1 #f4 ,small extent of necessary truth4 #g4 ,how did things come to be as they are8 #h4 ,view of the ,theist4 #i-ab4 ,is this ,platonism8 #ac4 ,idea of ,time4 #ad1 #ae4 ,ideas of ,force and ,matter4 #af4 ,creation of ,matter4 #ag4 ,platonic ,ideas4 #ah-ba4 ,idea of ,kind4 #bb4 ,idea of ,substance4 #bc4 ,idea of ,final ,cause4 #bd1 #be4 ,human immeasurably inferior to ,divine4 #bf4 ,science advances towards the ,divine ,ideas4 #bg4 ,recapitulation4 ,,chap4 ,,xxxi4 99 ,,man',s ,,knowledge ,,of ,,god4 #a1 #b4 ,opinions4 #c4 ,from ,nature we learn something of ,god4 #d-f4 ,though but little4 #g1 #h4 ,from ourselves we learn something concerning ,god4 #i-aa4 ,objections answered4 #ab4 ,creation4 #ac4 ,end of the ,world4 #ad4 ,moral and ,theological views enter4 ,,chap4 ,,xxxii4 99 ,,analogies ,,of ,,physical ,,and ,,religious ,,philosophy4 #a1 #b4 ,idealization of ,facts and ,realization of ,ideas2 #c1 #d4 ,both imperfect4 #e1 #f4 ,divine ,ideas perfect4 #g-i4 ,realization of ,divine ,love4 #aj-ac4 ,realization of ,divine ,justice4 #ad4 ,analogy of ,physical and ,moral ,philosophy4 #ae1 #af4 ,supernatural ,beginning1 ,middle1 and ,end indicated4 #ag4 ,suggestion of a ,future ,state4 #ah-bj4 ,confirmation from the ,intellect of ,man4 #ba4 ,from the ,moral ,nature of ,man4 ,,appendix4 ,,page ,,append4 ,a4 ,,of ,,the ,,platonic ,,theory ,,of ,,ideas #djc ,b4 ,,on ,,plato',s ,,survey ,,of ,,the ,,sciences #dag ,,bb4 ,,on ,,plato',s ,,notion ,,of ,,dialectic #dbi ,c4 ,,of ,,the ,,intellectual ,,powers ,,according ,,to ,,plato #ddj ,d4 ,,criticism ,,of ,,aristotle',s ,,account ,,of ,,induction #ddi ,e4 ,,on ,,the ,,fundamental ,,antithesis ,,of ,,philosophy #dfb ,f4 ,,remarks ,,on ,a ,,review ,,of ,,the ,,philosophy ,,of ,,the ,,inductive ,,sciences #dhb ,g4 ,,on ,,the ,,transformation ,,of ,,hypotheses ,,in ,,the ,,history ,,of ,,science #dib ,h4 ,,on ,,hegel',s ,,criticism ,,of ,,newton',s ,,principia #ejd ,appendix to the ,memoir on ,hegel's ,criticism of ,newton's ,principia #eac ,k4 ,,demonstration ,,that ,,all ,,matter ,,is ,,heavy #ebb ,,on ,,the ,,philosophy ,,of ,,discovery4 ,wr' nicht das ,auge sonnenhaft ,wie knnten wir das ,licht erblicken8 ,lebt' nicht in uns des ,gottes eigne ,kraft ,wie knnte uns das ,gttliche entzcken8 ,,goethe4 ,were nothing sunlike in the ,eye ,how could we ,light itself descry8 ,were nothing godlike in the ,mind ,how could we ,god in ,nature find8 ,,chapter ,i4 ,,introduction4 ,by the examination of the elements of human thought in which ,i have been engaged1 and by a consideration of the history of the most clear and certain parts of our knowledge1 ,i have been led to doctrines respecting the progress of that exact and systematic knowledge which we call ,science2 and these doctrines ,i have endeavoured to lay before the reader in the ,history of the ,sciences and of ,scientific ,ideas4 ,the questions on which ,i have thus ventured to pronounce have had a strong interest for man from the earliest period of his intellectual progress1 and have been the subjects of lively discussion and bold speculation in every age4 ,i conceive that in the doctrines to which these researches have conducted us1 we have a far better hope that we possess a body of permanent truths than the earlier essays on the same subjects could furnish4 ,for we have not taken our examples of knowledge at hazard1 as earlier speculators did1 and were almost compelled to do2 but have drawn our materials from the vast store of unquestioned truths which modern science offers to us3 and we have formed our judgment concerning the nature and progress of knowledge by considering what such science is1 and how it has reached its present condition4 ,but though we have thus pursued our speculations concerning knowledge with advantages which earlier writers did not possess1 it is still both interesting and instructive for us to regard the opinions upon this subject which have been delivered by the philosophers of past times4 ,it is especially interesting to see some of the truths which we have endeavoured to expound1 gradually dawning in men's minds1 and assuming the clear and permanent form in which we can now contemplate them4 ,i shall therefore1 in the ensuing chapters1 pass in review many of the opinions of the writers of various ages concerning the mode by which man best acquires the truest knowledge2 and ,i shall endeavour1 as we proceed1 to appreciate the real value of such judgments1 and their place in the progress of sound philosophy4 ,in this estimate of the opinions of others1 ,i shall be guided by those general doctrines which ,i have1 as ,i trust1 established in the histories already published4 ,and without attempting here to give any summary of these doctrines1 ,i may remark that there are two main principles by which speculations on such subjects in all ages are connected and related to each other2 namely1 the opposition of ,ideas and ,sensations1 and the distinction of practical and speculative knowledge4 ,the opposition of ,ideas and ,sensations is exhibited to us in the antithesis of ,theory and ,fact1 which are necessarily considered as distinct and of opposite natures1 and yet necessarily identical1 and constituting ,science by their identity4 ,in like manner1 although practical knowledge is in substance identical with speculative1 7for all knowledge is speculation17 there is a distinction between the two in their history1 and in the subjects by which they are exemplified1 which distinction is quite essential in judging of the philosophical views of the ancients4 ,the alternatives of identity and diversity1 in these two antitheses1--the successive separation1 opposition1 and reunion of principles which thus arise1--have produced1 7as they may easily be imagined capable of doing17 a long and varied series of systems concerning the nature of knowledge2 among which we shall have to guide our course by the aid of the views already presented4 ,i am far from undertaking1 or wishing1 to review the whole series of opinions which thus come under our notice2 and ,i do not even attempt to examine all the principal authors who have written on such subjects4 ,i merely wish to select some of the most considerable forms which1 such opinions have assumed1 and to point out in some measure the progress of truth from age to age4 ,in doing this1 ,i can only endeavour to seize some of the most prominent features of each time and of each step1 and ,i must pass rapidly from classical antiquity to those which we have called the dark ages1 and from them to modern times4 ,at each of these periods the modifications of opinion1 and the speculations with which they were connected1 formed a vast and tangled maze1 the byways of which our plan does not allow us to enter4 ,we shall esteem ourselves but too fortunate1 if we can discover the single track by which ancient led to modern philosophy4 ,i must also repeat that my survey of philosophical writers is here confined to this one point1--their opinions on the nature of knowledge and the method of science4 ,i with some effort avoid entering upon other parts of the philosophy of those authors of whom ,i speak2 ,i knowingly pass by those portions of their speculations which are in many cases the most interesting and celebrated2--their opinions concerning the human soul1 the ,divine ,governor of the world1 the foundations or leading doctrines of politics1 religion1 and general philosophy4 ,i am desirous that my reader should bear this in mind1 since he must otherwise be offended with the scanty and partial view which ,i give in this place of the philosophers whom ,i enumerate4 ,,chapter ,,ii4 ,,plato4 ,there would be small advantage in beginning our examination earlier than the period of the ,socratic ,school at ,athens2 for although the spirit of inquiry on such subjects had awakened in ,greece at an earlier period1 and although the peculiar aptitude of the ,grecian mind for such researches had shown itself repeatedly in subtle distinctions and acute reasonings1 all the positive results of these early efforts were contained in a more definite form in the reasonings of the ,platonic age4 ,before that time1 the ,greeks did not possess plain and familiar examples of exact knowledge1 such as the truths of ,arithmetic1 ,geometry1 ,astronomy and ,optics became in the school of ,plato2 nor were the antitheses of which we spoke above1 so distinctly and fully unfolded as we find them in ,plato's works4 ,the question which hinges upon one of these antitheses1 occupies a prominent place in several of the ,platonic dialogues2 namely1 whether our knowledge be obtained by means of ,sensation or of ,ideas4 ,one of the doctrines which ,plato most earnestly inculcated upon his countrymen was1 that we do not know concerning sensible objects1 but concerning ideas4 ,the first attempts of the ,greeks at metaphysical analysis had given rise to a school which maintained that material objects are the only realities4 ,in opposition to this1 arose another school1 which taught that material objects have no permanent reality1 but are ever waxing and waning1 constantly changing their substance4 ,and hence1 as ,aristotle says#a1 arose the doctrine of ideas which the ,platonists held4 ,for they assented to the opinion of ,heraclitus1 that all sensible objects are in a constant state of flux4 ,so that if there is to be any knowledge and science1 it must be concerning some permanent natures1 different from the sensible natures of objects2 for there can be no permanent science respecting that which is perpetually changing4 ,it happened that ,socrates turned his speculations to the moral virtues1 and was the first philosopher who endeavoured to give universal definitions of such matters4 ,he wished to reason systematically1 and therefore he tried to establish definitions1 for definitions are the basis of systematic reasoning4 ,there are two things which may justly be looked upon as steps in philosophy due to ,socrates2 inductive reasonings1 and universal definitions2--both of them steps which belong to the foundations of science4 ,socrates1 however1 did not make universals1 or definitions separable from the objects2 but his followers separated them1 and these essences they termed ,ideas4 ,and the same account is given by other writers#b4 ,some existences are sensible1 some intelligible3 and according to ,plato1 if we wish to understand the principles of things1 we must first separate the ideas from the things1 such as the ideas of ,similarity1 ,unity1 ,number1 ,magnitude1 ,position1 ,motion3 second1 that we must assume an absolute ,fair1 ,good1 ,just1 and the like3 third1 that we must consider the ideas of relation1 as ,knowledge1 ,power3 recollecting that the ,things which we perceive have this or that appellation applied to them because they partake of this or that ,idea2 those things being just which participate in the idea of ,the ,just1 those being beautiful1 which contain the idea of ,the ,beautiful4 ,and many of the arguments by which this doctrine was maintained are to be found in the ,platonic dialogues4 ,thus the opinion that true knowledge consists in sensation1 which had been asserted by ,protagoras and others1 is refuted in the ,thetetus3 and1 we may add1 so victoriously refuted1 that the arguments there put forth have ever since exercised a strong influence upon the speculative world4 ,it may be remarked that in the minds of ,plato and of those who have since pursued the same paths of speculation1 the interest of such discussions as those we are now referring to1 was by no means limited to their bearing upon mere theory2 but was closely connected with those great questions of morals which have always a practical import4 ,those who asserted that the only foundation of knowledge was sensation1 asserted also that the only foundation of virtue was the desire of pleasure4 ,and in ,plato1 the metaphysical part of the disquisitions concerning knowledge in general1 though independent in its principles1 always seems to be subordinate in its purpose to the questions concerning the knowledge of our duty4 ,since ,plato thus looked upon the ,ideas which were involved in each department of knowledge as forming its only essential part1 it was natural that he should look upon the study of ,ideas as the true mode of pursuing knowledge4 ,this he himself describes in the ,philebus#c4 ,the best way of arriving at truth is not very difficult to point out1 but most hard to pursue4 ,all the arts which have ever been discovered1 were revealed in this manner4 ,it is a gift of the gods to man1 which1 as ,i conceive1 they sent down by some ,prometheus1 as by ,prometheus they gave us the light of fire2 and the ancients1 more clear-sighted than we1 and less removed from the gods1 handed down this traditionary doctrine3 that whatever is said to be1 comes of ,one and of ,many1 and comprehends in itself the ,finite and the ,infinite in coalition 7being ,one ,kind1 and consisting of ,infinite ,individuals74 ,and this being the state of things1 we must1 in each case1 endeavour to seize the ,one ,idea 7the idea of the ,kind7 as the chief point2 for we shall find that it is there4 ,and when we have seized this one thing1 we may then consider how it comprehends in itself two1 or three1 or any other number2 and1 again1 examine each of these ramifications separately2 till at last we perceive1 not only that ,one is at the same time ,one and ,many1 but also how many4 ,and when we have thus filled up the interval between the ,infinite and the ,one1 we may consider that we have done with each one4 ,the gods then1 as ,i have said1 taught us by tradition thus to contemplate1 and to learn1 and to teach one another4 ,but the philosophers of the present day seize upon the ,one1 at hazard1 too soon or too late1 and then immediately snatch at the ,infinite2 but the intermediate steps escape them1 in which resides the distinction between a truly logical and a mere disputatious discussion4 ,it would seem that what the author here describes as the most perfect form of exposition1 is that which refers each object to its place in a classification containing a complete series of subordinations1 and which gives a definition of each class4 ,we have repeatedly remarked that1 in sciences of classification1 each new definition which gives a tenable and distinct separation of classes is an important advance in our knowledge2 but that such definitions are rather the last than the first step in each advance4 ,in the progress of real knowledge1 these definitions are always the results of a laborious study of individual cases1 and are never arrived at by a pure effort of thought1 which is what ,plato appears to have imagined as the true mode of philosophizing4 ,and still less do the advances of other sciences consist in seizing at once upon the highest generality1 and filling in afterwards all the intermediate steps between that and the special instances4 ,on the contrary1 as we have seen1 the ascents from particular to general are all successive2 and each step of this ascent requires time1 and labour1 and a patient examination of actual facts and objects4 ,it would1 of course1 be absurd to blame ,plato for having inadequate views of the nature of progressive knowledge1 at the time when knowledge could hardly be said to have begun its progress4 ,but we already find in his speculations1 as appears in the passages just quoted from his writings1 several points brought into view which will require our continued attention as we proceed4 ,in overlooking the necessity of a gradual and successive advance from the less general to the more general truths1 ,plato shared in a dimness of vision#d which prevailed among philosophers to the time of ,francis ,bacon4 ,in thinking too slightly of the study of actual nature1 he manifested a bias from which the human intellect freed itself in the vigorous struggles which terminated the dark ages4 ,in pointing out that all knowledge implies a unity of what we observe as manifold1 which unity is given by the mind1 ,plato taught a lesson which has of late been too obscurely acknowledged1 the recoil by which men repaired their long neglect of facts having carried them for a while so far as to think that facts were the whole of our knowledge4 ,and in analysing this principle of ,unity1 by which we thus connect sensible things1 into various ,ideas1 such as ,number1 ,magnitude1 ,position1 ,motion1 he made a highly important step1 which it has been the business of philosophers in succeeding times to complete and to follow out4 ,but the efficacy of ,plato's speculations in their bearing upon physical science1 and upon theory in general1 was much weakened by the confusion of practical with theoretical knowledge1 which arose from the ethical propensities of the ,socratic school4 ,in the ,platonic ,dialogues1 ,art and ,science are constantly spoken of indiscriminately4 ,the skill possessed by the ,painter1 the ,architect1 the ,shoemaker1 is considered as a just example of human science1 no less than the knowledge which the geometer or the astronomer possesses of the theoretical truths with which he is conversant4 ,not only so2 but traditionary and mythological tales1 mystical imaginations and fantastical etymologies1 are mixed up1 as no less choice ingredients1 with the most acute logical analyses1 and the most exact conduct of metaphysical controversies4 ,there is no distinction made between the knowledge possessed by the theoretical psychologist and the physician1 the philosophical teacher of morals and the legislator or the administrator of law4 ,this1 indeed1 is the less to be wondered at1 since even in our own time the same confusion is very commonly made by persons not otherwise ignorant or uncultured4 ,on the other hand1 we may remark finally1 that ,plato's admiration of ,ideas was not a barren imagination1 even so far as regarded physical science4 ,for1 as we have seen#e1 he had a very important share in the introduction of the theory of epicycles1 having been the first to propose to astronomers in a distinct form1 the problem of which that theory was the solution2 namely1 to explain the celestial phenomena by the combination of equable circular motions4 ,this demand of an ideal hypothesis which should exactly express the phenomena 7as well as they could then be observed71 and from which1 by the interposition of suitable steps1 all special cases might be deduced1 falls in well with those views respecting the proper mode of seeking knowledge which we have quoted from the ,philebus4 ,and the ,idea which could thus represent and replace all the particular ,facts1 being not only sought but found1 we may readily suppose that the philosopher was1 by this event1 strongly confirmed in his persuasion that such an ,idea was indeed what the inquirer ought to seek4 ,in this conviction all his genuine followers up to modern times have participated2 and thus1 though they have avoided the error of those who hold that facts alone are valuable as the elements of our knowledge1 they have frequently run into the opposite error of too much despising and neglecting facts1 and of thinking that the business of the inquirer after truth was only a profound and constant contemplation of the conceptions of his own mind4 ,but of this hereafter4 ,,footnotes3 ,footnote #a3 ,metaph4 xii4 #d4 ,footnote #b3 ,diog4 ,laert4 ,vit4 ,plat4 ,footnote #c3 ,t4 ii4 p4 #af1 c1 d4 ed4 ,bekker1 t4 v4 p4 #dcg4 ,footnote #d3 ,see the remarks on this phrase in the next chapter4 ,footnote #e3 ,hist4 ,ind4 ,sc4 b4 iii4 c4 ii4 ,,chapter ,,iii4 ,,additional ,,remarks ,,on ,,plato4 ,the leading points in ,plato's writings which bear upon the philosophy of discovery are these3 #a4 ,the ,doctrine of ,ideas4 #b4 ,the ,doctrine of the ,one and the ,many4 #c4 ,the notion of the nature and aim of ,science4 #d4 ,the survey of existing ,sciences4 #a4 ,the ,doctrine of ,ideas is an attempt to solve a problem which in all ages forces itself upon the notice of thoughtful men2 namely1 ,how can certain and permanent knowledge be possible for man1 since all his knowledge must be derived from transient and fluctuating sensations8 ,and the answer given by this doctrine is1 that certain and permanent knowledge is not derived from ,sensations1 but from ,ideas4 ,there are in the mind certain elements of knowledge which are not derived from sensation1 and are only imperfectly exemplified in sensible objects2 and when we reason concerning sensible things so as to obtain real knowledge1 we do so by considering such things as partaking of the qualities of the ,ideas concerning which there can be truth4 ,the sciences of ,geometry and ,arithmetic show that there are truths which man can know2 and the ,doctrine of ,ideas explains how this is possible4 ,so far the ,doctrine of ,ideas answers its primary purpose1 and is a reply 7by no means the least intelligible and satisfactory reply7 to a question still agitated among philosophers3 ,what is the ground of geometrical 7and other necessary7 truth8 ,but ,plato seems1 in many of his writings1 to extend this doctrine much further2 and to assume1 not only ,ideas of ,space and its properties1 from which geometrical truths are derived2 but of ,relations1 as the ,relations of ,like and ,unlike1 ,greater and ,less2 and of mere material objects1 as ,tables and ,chairs4 ,now to assume ,ideas of such things as these solves no difficulty and is supported by no argument4 ,in this respect the ,ideal theory is of no value in ,science4 ,it is curious that we have a very acute refutation of the ,ideal theory in this sense1 not only in ,aristotle1 the open opponent of ,plato on this subject1 but in the ,platonic writings themselves3 namely1 in the ,dialogue entitled ,parmenides2 which1 on this and on other accounts1 ,i consider to be the work not of ,plato1 but of an opponent of ,plato#f4 #b4 ,i have spoken1 in the preceding chapter1 of ,plato's doctrine that truth is to be obtained by discerning the ,one in the ,many4 ,this expression is used1 it would seem1 in a somewhat large and fluctuating way1 to mean several things2 as for instance1 finding the one kind in many individuals 7for instance1 the one idea of dog in many dogs72 or the one law in many phenomena 7for instance1 the eccentrics and epicycles in many planets74 ,in any interpretation1 it is too loose and indefinite a rule to be of much value in the formation of sciences1 though it has been recently again propounded as important in modern times4 #c4 ,i have said1 in the preceding chapter1 that ,plato1 though he saw that scientific truths of great generality might be obtained and were to be arrived at by philosophers1 overlooked the necessity of a gradual and successive advance from the less general to the more general2 and ,i have described this as a 'dimness of vision4' ,i must now acknowledge that this is not a very appropriate phrase2 for not only no acuteness of vision could have enabled ,plato to see that gradual generalization in science of which1 as yet1 no example had appeared2 but it was very fortunate for the progress of truth1 at that time1 that ,plato had imagined to himself the object of science to be general and sublime truths which prove themselves to be true by the light of their own generality and symmetry4 ,it is worth while to illustrate this notice of ,plato by some references to his writings4 ,in the ,sixth ,book of the ,republic1 ,plato treats of the then existing sciences as the instruments of a philosophical education4 ,among the most conspicuous of these is astronomy4 ,he there ridicules the notion that astronomy is a sublime science because it makes men look upward4 ,he asserts that the really sublime science is that which makes men look at the realities1 which are suggested by the appearances seen in the heavens3 namely1 the spheres which revolve and carry the luminaries in their revolutions4 ,now it was no doubt the determined search for such realities as these which gave birth to the ,greek ,astronomy1 that first and critical step in the progress of science4 ,plato1 by his exhortations1 if not by his suggestions1 contributed effectually1 as ,i conceive1 to this step in science4 ,in the same manner he requires a science of ,harmonics which shall be free from the defects and inaccuracies which occur in actual instruments4 ,this belief that the universe was full of mathematical relations1 and that these were the true objects of scientific research1 gave a vigour1 largeness of mind1 and confidence to the ,greek speculators which no more cautious view of the problem of scientific discovery could have supplied4 ,it was well that this advanced guard in the army of discoverers was filled with indomitable courage1 boundless hopes1 and creative minds4 ,but we must not forget that this disposition to what ,bacon calls anticipation was full of danger as well as of hope4 ,it led ,plato into error1 as it led ,kepler afterwards1 and many others in all ages of scientific activity4 ,it led ,plato into error1 for instance1 when it led him to assert 7in the ,timus7 that the four elements1 ,earth1 ,air1 ,fire and ,water1 have1 for the forms of their particles respectively1 the ,cube1 the ,icosahedron1 the ,pyramid1 and the ,octahedron2 and again1 when it led him to despise the practical controversies of the musicians of his time2 which controversies were1 in fact1 the proof of the truth of the mathematical theory of ,harmonics4 ,and in like manner it led ,kepler into error when it led him to believe that he had found the reason of the number1 size and motion of the planetary orbits in the application of the five regular solids to the frame of the universe#g4 ,how far the caution in forming hypotheses which ,bacon's writings urge upon us is more severe than suits the present prospects of science1 we may hereafter consider2 but it is plainly very conceivable that a boldness in the invention and application of hypotheses which was propitious to science in its infancy1 may be one of the greatest dangers of its more mature period3 and further1 that the happy effect of such a temper depended entirely upon the candour1 skill and labour with which the hypotheses were compared with the observed phenomena4 #d4 ,plato has given a survey of the sciences of his time as ,francis ,bacon has of his4 ,indeed ,plato has given two such surveys3 one1 in the ,republic1 in reviewing1 as ,i have said1 the elements of a philosophical education2 the other in the ,timus1 as the portions of a theological view of the universe--such as has been called a ,theodica1 a justification of ,god4 ,in the former passage of ,plato1 the sciences enumerated are ,arithmetic1 ,plane ,geometry1 ,solid ,geometry1 ,astronomy and ,harmonics#h4 ,in the ,timus we have a further notice of many other subjects1 in a way which is intended1 ,i conceive1 to include such knowledge as ,plato had then arrived at on the various parts of the universe4 ,the subjects there referred to are1 as ,i have elsewhere stated#i1 these3 light and heat1 water1 ice1 gold1 gems1 rust and other natural objects3--odours1 taste1 hearing1 lights1 colour1 and the powers of sense in general3--the parts and organs of the body1 as the bones1 the marrow1 the brain1 flesh1 muscles1 tendons1 ligaments and nerves2 the skin1 the hair1 the nails2 the veins and arteries2 respiration2 generation2 and in short1 every obvious point of physiology4 ,but the opinions thus delivered in the ,timus on the latter subject have little to do with the progress of real knowledge4 ,the doctrines1 on the other hand1 which depend upon geometrical and arithmetical relations are portions or preludes of the sciences which the fulness of time brought forth4 #e4 ,i may1 as further bearing upon the ,platonic notion of science1 notice ,plato's view of the constitution of the human mind4 ,according to him the ,ideas which are the constituents of science form an ,intelligible ,world1 while the visible and tangible things which we perceive by our senses form the ,visible ,world4 ,in the visible world we have shadows and reflections of actual objects1 and by these shadows and reflections we may judge of the objects1 even when we cannot do so directly2 as when men in a dark cavern judge of external objects by the shadows which they cast into the cavern4 ,in like manner in the ,intelligible ,world there are conceptions which are the usual objects of human thought1 and about which we reason2 but these are only shadows and reflections of the ,ideas which are the real sources of truth4 ,and the ,reasoning ,faculty1 the ,discursive ,reason1 the ,logos1 which thus deals with conceptions1 is subordinate to the ,intuitive ,faculty1 the ,intuitive ,reason1 the ,nous1 which apprehends ,ideas#aj4 ,this recognition of a ,faculty in man which contemplates the foundations--the ,fundamental ,ideas--of science1 and by apprehending such ,ideas1 makes science possible1 is consentaneous to the philosophy which ,i have all along presented1 as the view taught us by a careful study of the history and nature of science4 ,that new ,fundamental ,ideas are unfolded1 and the ,intuitive ,faculty developed and enlarged by the progress of science and by an intimate acquaintance with its reasonings1 ,plato appears to have discerned in some measure1 though dimly4 ,and this is the less wonderful1 inasmuch as this gradual and successive extension of the field of ,intuitive ,truth1 in proportion as we become familiar with a larger amount of derived truth1 is even now accepted by few1 though proved by the reasonings of the greatest scientific discoverers in every age4 ,the leading defect in ,plato's view of the nature of real science is his not seeing fully the extent to which experience and observation are the basis of all our knowledge of the universe4 ,he considers the luminaries which appear in the heavens to be not the true objects of astronomy1 but only some imperfect adumbration of them2--mere diagrams which may assist us in the study of a higher truth1 as beautiful diagrams might illustrate the truths of geometry1 but would not prove them4 ,this notion of an astronomy which is an astronomy of ,theories and not of ,facts1 is not tenable1 for ,theories are ,facts4 ,theories and ,facts are equally real2 true ,theories are ,facts1 and ,facts are familiar ,theories4 ,but when ,plato says that astronomy is a series of problems suggested by visible things1 he uses expressions quite conformable to the true philosophy of science2 and the like is true of all other sciences4 ,,footnotes3 ,footnote #f3 ,this matter is further discussed in the ,appendix1 ,essay ,a4 ,footnote #g3 ,these matters are further discussed in the ,appendix1 ,essay ,b4 ,footnote #h3 ,see ,appendix1 ,essay ,b4 ,footnote #i3 ,hist4 ,ind4 ,sc4 b4 ii4 ,additions to #crd ,ed4 ,footnote #aj3 ,see these views further discussed in the ,appendix1 ,essay ,c4 ,,chapter ,,iv4 ,,aristotle4 ,the views of ,aristotle with regard to the foundations of human knowledge are very different from those of his tutor ,plato1 and are even by himself put in opposition to them4 ,he dissents altogether from the ,platonic doctrine that ,ideas are the true materials of our knowledge2 and after giving1 respecting the origin of this doctrine1 the account which we quoted in the last chapter1 he goes on to reason against it4 ,thus1 he says#aa1 they devised ,ideas of all things which are spoken of as universals3 much as if any one having to count a number of objects1 should think that he could not do it while they were few1 and should expect to count them by making them more numerous4 ,for the kinds of things are almost more numerous than the special sensible objects1 by seeking the causes of which they were led to their ,ideas4 ,he then goes on to urge several other reasons against the assumption of ,ideas and the use of them in philosophical researches4 ,aristotle himself establishes his doctrines by trains of reasoning4 ,but reasoning must proceed from certain ,first ,principles2 and the question then arises1 ,whence are these ,first ,principles obtained8 ,to this he replies1 that they are the result of ,experience1 and he even employs the same technical expression by which we at this day describe the process of collecting these principles from observed facts2--that they are obtained by ,induction4 ,i have already quoted passages in which this statement is made#ab4 ,the way of reasoning1 he says#ac1 is the same in philosophy1 and in any art or science3 we must collect the facts 7 71 and the things to which the facts happen1 and must have as large a supply of these as possible1 and then we must examine them according to the terms of our syllogisms4 444 ,there are peculiar principles in each science2 and in each case these principles must be obtained from experience4 ,thus astronomical observation supplies the principles of astronomical science4 ,for the phenomena being rightly taken1 the demonstrations of astronomy were discovered2 and the same is the case with any other ,art or ,science4 ,so that if the facts in each case be taken1 it is our business to construct the demonstrations4 ,for if in our natural history 7 7 we have omitted none of the facts and properties which belong to the subject1 we shall learn what we can demonstrate and what we cannot4 ,and again#ad1 ,it is manifest that if any sensation be wanting1 there must be some knowledge wanting1 which we are thus prevented from having4 ,for we acquire knowledge either by ,induction 77 or by ,demonstration3 and ,demonstration is from universals1 but ,induction from particulars4 ,it is impossible to have universal theoretical propositions except by ,induction3 and we cannot make inductions without having sensation2 for sensation has to do with particulars4 ,it is easy to show that ,aristotle uses the term ,induction1 as we use it1 to express the process of collecting a general proposition from particular cases in which it is exemplified4 ,thus in a passage which we have already quoted#ae1 he says1 ,induction1 and ,syllogism from ,induction1 is when we attribute one extreme term to the middle by means of the other4 ,the import of this technical phraseology will further appear by the example which he gives3 ,we find that several animals which are deficient in bile are long-lived1 as man1 the horse1 the mule2 hence we infer that all animals which are deficient in bile are long-lived4 ,we may observe1 however1 that both ,aristotle's notion of induction1 and many other parts of his philosophy1 are obscure and imperfect1 in consequence of his refusing to contemplate ideas as something distinct from sensation4 ,it thus happens that he always assumes the ideas which enter into his proposition as given2 and considers it as the philosopher's business to determine whether such propositions are true or not3 whereas the most important feature in induction is1 as we have said1 the introduction of a new idea1 and not its employment when once introduced4 ,that the mind in this manner gives unity to that which is manifold1--that we are thus led to speculative principles which have an evidence higher than any others1--and that a peculiar sagacity in some men seizes upon the conceptions by which the facts may be bound into true propositions1--are doctrines which form no essential part of the philosophy of the ,stagirite1 although such views are sometimes recognized1 more or less clearly1 in his expressions4 ,thus he says#af1 ,there can be no knowledge when the sensation does not continue in the mind4 ,for this purpose1 it is necessary both to perceive1 and to have some unity in the mind 7 #ag 72 and many such perceptions having taken place1 some difference is then perceived3 and from the remembrance of these arises ,reason4 ,thus from ,sensation comes ,memory1 and from ,memory of the same thing often repeated comes ,experience3 for many acts of ,memory make up one ,experience4 ,and from ,experience1 or from any ,universal ,notion which takes a permanent place in the mind1--from the unity in the manifold1 the same some one thing being found in many facts1--springs the first principle of ,art and of ,science2 of ,art1 if it be employed about production2 of ,science1 if about existence4 ,i will add to this1 ,aristotle's notice of ,sagacity2 since1 although little or no further reference is made to this quality in his philosophy1 the passage fixes our attention upon an important step in the formation of knowledge4 ,sagacity 771 he says#ah1 is a hitting by guess 7 7 upon the middle term 7the conception common to two cases7 in an inappreciable time4 ,as for example1 if any one seeing that the bright side of the moon is always towards the sun1 suddenly perceives why this is2 namely1 because the moon shines by the light of the sun3--or if he sees a person talking with a rich man1 he guesses that he is borrowing money2--or conjectures that two persons are friends1 because they are enemies of the same person4--,to consider only the first of these examples2--the conception here introduced1 that of a body shining by the light which another casts upon it1 is not contained in the observed facts1 but introduced by the mind4 ,it is1 in short1 that conception which1 in the act of induction1 the mind superadds to the phenomena as they are presented by the senses3 and to invent such appropriate conceptions1 such eustochies1 is1 indeed1 the precise office of inductive sagacity4 ,at the end of this work 7the ,later ,analytics7 ,aristotle ascribes our knowledge of principles to ,intellect 771 or1 as it appears necessary to translate the word1 ,intuition#ai4 ,since1 of our intellectual habits by which we aim at truth1 some are always true1 but some admit of being false1 as ,opinion and ,reasoning1 but ,science and ,intuition are always true2 and since there is nothing which is more certain than ,science except ,intuition2 and since ,principles are better known to us than the ,deductions from them2 and since all ,science is connected by reasoning1 we cannot have ,science respecting ,principles4 ,considering this then1 and that the beginning of ,demonstration cannot be ,demonstration1 nor the beginning of ,science1 ,science2 and since1 as we have said1 there is no other kind of truth1 ,intuition must be the beginning of ,science4 ,what is here said1 is1 no doubt1 in accordance with the doctrines which we have endeavoured to establish respecting the nature of ,science1 if by this ,intuition we understand that contemplation of certain ,fundamental ,ideas1 which is the basis of all rigorous knowledge4 ,but notwithstanding this apparent approximation1 ,aristotle was far from having an habitual and practical possession of the principles which he thus touches upon4 ,he did not1 in reality1 construct his philosophy by giving ,unity to that which was manifold1 or by seeking in ,intuition principles which might be the basis of ,demonstration2 nor did he collect1 in each subject1 fundamental propositions by an induction of particulars4 ,he rather endeavoured to divide than to unite2 he employed himself1 not in combining facts1 but in analysing notions2 and the criterion to which he referred his analysis was1 not the facts of our experience1 but our habits of language4 ,thus his opinions rested1 not upon sound inductions1 gathered in each case from the phenomena by means of appropriate ,ideas2 but upon the loose and vague generalizations which are implied in the common use of speech4 ,yet ,aristotle was so far consistent with his own doctrine of the derivation of knowledge from experience1 that he made in almost every province of human knowledge1 a vast collection of such special facts as the experience of his time supplied4 ,these collections are almost unrivalled1 even to the present day1 especially in ,natural ,history2 in other departments1 when to the facts we must add the right ,inductive ,idea1 in order to obtain truth1 we find little of value in the ,aristotelic works4 ,but in those parts which refer to ,natural ,history1 we find not only an immense and varied collection of facts and observations1 but a sagacity and acuteness in classification which it is impossible not to admire4 ,this indeed appears to have been the most eminent faculty in ,aristotle's mind4 ,the influence of ,aristotle in succeeding ages will come under our notice shortly4 ,,footnotes3 ,footnote #aa3 ,metaph4 xii4 #d4 ,footnote #ab3 ,hist4 ,ind4 ,sc4 b4 i4 c4 iii4 sect4 #b4 ,footnote #ac3 ,analyt4 ,prior4 i4 #cj4 ,footnote #ad3 ,analyt4 ,post4 i4 #ah4 ,footnote #ae3 ,analyt4 ,prior4 ii4 #bc1 4 ,footnote #af3 ,analyt4 ,post4 ii4 #ai4 ,footnote #ag3 ,but the best reading seems to be not but 3 and the clause must be rendered both to perceive and to retain the perception in the mind4 ,this correction does not disturb the general sense of the passage1 that the first principles of science are obtained by finding the ,one in the ,many4 ,footnote #ah3 ,analyt4 ,post4 i4 #cd4 ,footnote #ai3 ,ibid4 ii4 #ai4 ,,chapter ,v4 ,,additional ,,remarks ,,on ,,aristotle4 #a4 ,one of the most conspicuous points in ,aristotle's doctrines as bearing upon the philosophy of ,science is his account of that mode of attaining truth which is called ,induction2 for we are accustomed to consider ,induction as the process by which our ,sciences have been formed2 and we call them collectively the ,inductive ,sciences4 ,aristotle often speaks of ,induction1 as for instance1 when he says that ,socrates introduced the frequent use of it4 ,but the cardinal passage on this subject is in his ,analytics1 in which he compares ,syllogism and ,induction as two modes of drawing conclusions#bj4 ,he there says that all belief arises either from ,syllogism or from ,induction3 and adds that ,induction is1 when by means of one extreme term we infer the other extreme to be true of the middle term4 ,the example which he gives is this3 knowing that particular animals are long-lived1 as elephant1 horse1 mule2 and finding that these animals agree in having no gall-bladder2 we infer1 by ,induction1 that all animals which have no gall-bladder are long-lived4 ,this may be done1 he says1 if the middle and the second extreme are convertible3 as the following formal statement may show4 ,elephant1 horse1 mule1 c4 are long-lived4 ,elephant1 horse1 mule1 c4 are all gall-less4 ,if we might convert this proposition1 and say ,all gall-less animals are as elephant1 horse1 mule1 c43 we might infer syllogistically that ,all gall-less animals are long-lived4 ,and though we cannot infer this syllogistically1 we infer it by ,induction1 when we have a sufficient amount of instances#ba4 ,i have already elsewhere given this account of ,induction1 as a process employed in the formation of our knowledge#bb4 ,what ,i have now to remark concerning ,aristotle is1 that it does not appear to have occurred to him1 that in establishing such a proposition as that which he gives as his instance1 the main difficulty is the discovery of a middle term which will allow us to frame such a proposition as we need4 ,the zoologist who wanted to know what kind of animals are long-lived1 might guess long before he guessed that the absence of the gall-bladder supplied the requisite middle term2 7if the proposition were true2 which it is not47 ,and in like manner in other cases1 it is difficult to find a middle term1 which enables us to collect a proposition by ,induction4 ,and herein consists the imperfection of his view of the subject2 which considers the main point to be the proof of the proposition when the conceptions are given1 whereas the main point really is1 the discovery of conceptions which will make a true proposition possible4 #b4 ,since the main characteristic of the steps which have occurred in the formation of the physical sciences1 is not merely that they are propositions collected by ,induction1 but by the introduction of a new conception2 it has been suggested that it is not a characteristic designation of these ,sciences to call them ,inductive ,sciences4 ,almost every discovery involves in it the introduction of a new conception1 as the element of a new proposition2 and the novelty of the conception is more characteristic of the stages of discovery than the inductive application of it4 ,hence as bearing upon the ,philosophy of ,discovery1 the statements of ,aristotle concerning ,induction1 though acute and valuable1 are not so valuable as they might seem4 ,even ,francis ,bacon1 it has been asserted1 erred in the same way 7and of course with less excuse7 in asserting ,induction1 of a certain kind1 to be the great instrument for the promotion of knowledge1 and in overlooking the necessity of the ,invention which gives ,induction its value4 #c4 ,the invention or discovery of a conception by which many facts of observation are conjoined so as to make them the materials of a proposition1 is called in ,plato1 as we have seen1 finding the ,one in the ,many4 ,in the passage quoted from the ,later ,analytics1 ,aristotle uses the same expression1 and speaks very justly respecting the formation of knowledge4 ,indeed the ,titles of the chapters of this and many parts of ,aristotle's works would lead us to expect just such a ,philosophy of ,discovery as is the object of our study at present4 ,thus we have1 ,anal4 ,post4 ,b4 ,,ii4 chap4 #ac3 ,how we are to hunt 77 the predications of a ,definition4 ,chap4 #ad3 ,precepts for the invention of ,problems and of a ,middle ,term3 and the like4 ,but when we come to read these chapters1 they contain little that is of value1 and resolve themselves mostly into permutations of ,aristotle's logical phraseology4 #d4 ,the part of the ,aristotelian philosophy which has most permanently retained its place in modern ,sciences is a part of which a use has been made quite different from that which was originally contemplated4 ,the ,five words which are explained in the ,introduction to ,aristotle's ,categories3 namely1 the words ,genus1 ,species1 ,difference1 ,property1 ,accident1 were introduced mainly that they might be used in the propositions of which ,syllogisms consist1 and might thus be the elements of reasoning4 ,but it has so happened that these words are rarely used in ,sciences of ,reasoning1 but are abundantly and commonly used in the ,sciences of ,classification1 as ,i have explained in speaking of the ,classificatory ,sciences#bc4 #e4 ,of ,aristotle's actual contributions to the ,physical ,sciences ,i have spoken in the ,history of those ,sciences#bd4 ,i have#be stated that he conceived the globular form of the earth so clearly and gave so forcibly the arguments for that doctrine1 that we may look upon him as the most effective teacher of it4 ,also in the ,appendix to that ,history1 published in the third edition1 ,i have given ,aristotle's account of the ,rainbow1 as a further example of his industrious accumulation of facts1 and of his liability to error in his facts4 #f4 ,we do not find ,aristotle so much impressed as we might have expected by that great monument of ,grecian ingenuity1 the theory of epicycles and excentrics which his predecessor ,plato urged so strongly upon the attention of his contemporaries4 ,aristotle proves1 as ,i have said1 the globular form of the earth by good and sufficient arguments4 ,he also proves by arguments which seem to him quite conclusive#bf1 that the earth is in the center of the universe1 and immoveable4 ,as to the motions of the rest of the planets1 he says little4 ,the questions of their order1 and their distances1 and the like1 belong1 he says1 to ,astrology#bg4 ,he remarks only that the revolution of the heaven itself1 the outermost revolution1 is simple and the quickest of all3 that the revolutions of the others are slower1 each moving in a direction opposite to the heaven in its own circle3 and that it is reasonable that those which are nearest to the first revolution should take the longest time in describing their own circle1 and those that are furthest off1 the least time1 and the intermediate ones in the order of their distances1 as also the mathematicians show4 ,in the ,metaphysics#bh he enumerates the circular movements which had been introduced by the astronomers ,eudoxus and ,calippus for the explanation of the phenomena presented by the sun1 moon and planets4 ,these1 he says1 amount to fifty-five2 and this1 he says1 must be the number of essences and principles which exist in the universe4 #g4 ,in the ,sciences of ,classification1 and especially in the classification of animals1 higher claims have been made for ,aristotle1 which ,i have discussed in the ,history#bi4 ,i have there attempted to show that ,aristotle's classification1 inasmuch as it enumerates all the parts of animals1 may be said to contain the materials of every subsequent classification3 but that it cannot be said to anticipate any modern system1 because the different grades of classification are not made subordinate to one another as a system of classification requires4 ,i have the satisfaction of finding ,mr4 ,owen agreeing with me in these views#cj4 #h4 ,francis ,bacon's criticism on ,aristotle which ,i have quoted in the ,appendix to the ,history#ca1 is severe1 and ,i think evidently the result of prejudice4 ,he disparages ,aristotle in comparison with the other philosophers of ,greece4 ',their systems1' he says1 'had some savour of experience1 and nature1 and bodily things2 while the ,physics of ,aristotle1 in general1 sound only of ,logical ,terms4 ',nor let anyone be moved by this3 that in his books ,of ,animals1 and in his ,problems1 and in others of his tracts1 there is often a quoting of experiments4 ,for he had made up his mind beforehand2 and did not consult experience in order to make right propositions and axioms1 but when he had settled his system to his will1 he twisted experience round and made her bend to his system4' ,i do not think that this can be said with any truth4 ,i know no instances in which ,aristotle has twisted experience round1 and made her bend to his system4 ,in his ,problems1 he is so far from giving dogmatical solutions of the questions proposed1 that in most cases1 he propounds two or three solutions as mere suggestions and conjectures4 ,and both in his ,history of ,animals1 as ,i have said1 and in others of his works1 the want of system gives them an incoherent and tumultuary character1 which even a false system would have advantageously removed2 for1 as ,i have said elsewhere1 it is easier to translate a false system into a true one1 than to introduce system into a mass of confusion4 #i4 ,it is curious that a fundamental error into which ,aristotle fell in his view of the conditions which determine the formation of ,science is very nearly the same as one of ,francis ,bacon's leading mistakes4 ,aristotle says1 that ,science consists in knowing the causes of things1 as ,bacon aims at acquiring a knowledge of the forms or essences of things and their qualities4 ,but the history of all the sciences teaches us that sciences do not begin with such knowledge1 and that in few cases only do they ever attain to it4 ,sciences begin by a knowledge of the laws of phenomena1 and proceed by the discovery of the scientific ideas by which the phenomena are colligated1 as ,i have shown in other works#cb4 ,the discovery of causes is not beyond the human powers1 as some have taught4 ,those who thus speak disregard the lessons taught by the history of ,physical ,astronomy1 of ,geology1 of ,physical ,optics1 ,thermotics and other sciences4 ,but the discovery of causes1 and of the essential forms of qualities1 is a triumph reserved for the later stages of each ,science1 when the knowledge of the laws of phenomena has already made great progress4 ,it was not to be expected that ,aristotle would discern this truth1 when1 as yet1 there was no ,science extant in which it had been exemplified4 ,yet in ,astronomy1 the theory of epicycles and excentrics had immense value1 and even has still1 as representing the laws of phenomena2 while the attempt to find in it1 as ,aristotle wished to do1 the ultimate causes of the motions of the universe1 could only mislead4 ,the ,aristotelian maxim1 which sounds so plausible1 and has been so generally accepted1 that to know truly is to know the causes of things1 is a bad guide in scientific research4 ,instead of it we might substitute this3 that though we may aspire to know at last why things are1 we must be content for a long time with knowing how they are4 #aj4 ,hence if we are asked whether ,plato or ,aristotle had the truer views of the nature and property of ,science1 we must give the preference to ,plato2 for though his notion of a real ,intelligible ,world1 of which the ,visible world was a fleeting and changeable shadow1 was extravagant1 yet it led him to seek to determine the forms of the ,intelligible ,things1 which are really the laws of visible phenomena2 while ,aristotle was led to pass lightly over such laws1 because they did not at once reveal the causes which produced the phenomena4 #aa4 ,aristotle1 throughout his works1 takes numerous occasions to argue against ,plato's doctrine of ,ideas4 ,yet these ,ideas1 so far as they were the ,intelligible ,forms of ,visible ,things1 were really fit objects of philosophical research2 and the search after them had a powerful influence in promoting the progress of ,science4 ,and we may see in the effect of this search the answer to many of ,aristotle's strongest arguments4 ,for instance1 ,aristotle says that ,plato1 by way of explaining things1 adds to them as many ,ideas1 and that this is just as if a man having to reckon a large number1 were to begin by adding to it another large number4 ,it is plain that to this we may reply1 that the adopting the ,ideas of ,cycles1 along with the motions of the ,planets1 does really explain the motions2 and that the ,cycles are not simply added to the phenomena1 but include and supersede the phenomena3 a finite number of ,cycles include and represent an infinite number of separate phenomena4 ,to ,aristotle's argument that ,ideas cannot be the ,causes or ,principles of ,things1 we should reply1 that though they cannot be this1 they may nevertheless be1 and must be1 the ,conditions and ,principles of our ,knowledge1 which is what we want them to be4 ,i have given an account of the main features of ,aristotle's philosophy1 so far as it concerns the ,physical ,sciences1 in the ,history of the ,inductive ,sciences1 ,book ,i4 ,,footnotes3 ,footnote #bj3 ,analyt4 ,prior4 ii4 #be4 ,footnote #ba3 ,see on this subject ,appendix1 ,essay ,d4 ,footnote #bb3 ,see the chapter on ,certain ,characteristics of ,scientific ,induction in the ,phil4 ,ind4 ,sc4 or in the ,nov4 ,org4 ,renov4 ,footnote #bc3 ,phil4 ,ind4 ,sc4 b4 viii4 c4 i4 art4 #aa1 or ,hist4 ,sc4 ,id4 b4 viii4 ,footnote #bd3 ,b4 i4 c4 xi4 sect4 #b4 ,footnote #be3 ,b4 iii4 c4 i4 sect4 #i4 ,footnote #bf3 ,de ,clo1 ii4 #ac4 ,footnote #bg3 ,ibid4 ii4 #aj4 ,footnote #bh3 xii4 #h4 ,footnote #bi3 ,b4 xvi4 c4 vi4 ,footnote #cj3 ,on the ,classification of ,mammalia1 c43 a ,lecture delivered at ,cambridge1 ,may #aj1 #ahei1 p4 #c4 ,footnote #ca3 ,b4 i4 c4 xi4 ,footnote #cb3 ,history of ,scientific ,ideas1 and ,novum ,organum ,renovatum4 ,,chapter ,,vi4 ,,the ,,later ,,greeks4 ,thus while ,plato was disposed to seek the essence of our knowledge in ,ideas alone1 ,aristotle1 slighting this source of truth1 looked to ,experience as the beginning of ,science2 and he attempted to obtain1 by division and deduction1 all that ,experience did not immediately supply4 ,and thus1 with these two great names1 began that struggle of opposite opinions which has ever since that time agitated the speculative world1 as men have urged the claims of ,ideas or of ,experience to our respect1 and as alternately each of these elements of knowledge has been elevated above its due place1 while the other has been unduly depressed4 ,we shall see the successive turns of this balanced struggle in the remaining portions of this review4 ,but we may observe that practically the influence of ,plato predominated rather than that of ,aristotle1 in the remaining part of the history of ancient philosophy4 ,it was1 indeed1 an habitual subject of dispute among men of letters1 whether the sources of true knowledge are to be found in the ,senses or in the ,mind2 the ,epicureans taking one side of this alternative1 and the ,academics another1 while the ,stoics in a certain manner included both elements in their view4 ,but none of these sects showed their persuasion that the materials of knowledge were to be found in the domain of ,sense1 by seeking them there4 ,no one appears to have thought of following the example of ,aristotle1 and gathering together a store of observed facts4 ,we may except1 perhaps1 assertions belonging to some provinces of ,natural ,history1 which were collected by various writers3 but in these1 the mixed character of the statements1 the want of discrimination in the estimate of evidence1 the credulity and love of the marvellous which the authors for the most part displayed1 showed that instead of improving upon the example of ,aristotle1 they were wandering further and further from the path of real knowledge4 ,and while they thus collected1 with so little judgment1 such statements as offered themselves1 it hardly appears to have occurred to any one to enlarge the stores of observation by the aid of experiment2 and to learn what the laws of nature were1 by trying what were their results in particular cases4 ,they used no instruments for obtaining an insight into the constitution of the universe1 except logical distinctions and discussions2 and proceeded as if the phenomena familiar to their predecessors must contain all that was needed as a basis for natural philosophy4 ,by thus contenting themselves with the facts which the earlier philosophers had contemplated1 they were led also to confine themselves to the ideas which those philosophers had put forth4 ,for all the most remarkable alternatives of hypothesis1 so far as they could be constructed with a slight and common knowledge of phenomena1 had been promulgated by the acute and profound thinkers who gave the first impulse to philosophy3 and it was not given to man to add much to the original inventions of their minds till he had undergone anew a long discipline of observation1 and of thought employed upon observation4 ,thus the later authors of the ,greek ,schools became little better than commentators on the earlier2 and the commonplaces with which the different schools carried on their debates1--the constantly recurring argument1 with its known attendant answer1--the distinctions drawn finer and finer and leading to nothing1--render the speculations of those times a scholastic philosophy1 in the same sense in which we employ the term when we speak of the labours of the middle ages4 ,it will be understood that ,i now refer to that which is here my subject1 the opinions concerning our knowledge of nature1 and the methods in use for the purpose of obtaining such knowledge4 ,whether the moral speculations of the ancient world were of the same stationary kind1 going their round in a limited circle1 like their metaphysics and physics1 must be considered on some other occasion4 #cc ,mr4 ,grote1 in his very interesting discussion of ,socrates's teaching1 notices also#cd the teaching of ,hippocrates1 which he conceives to have in one respect the same tendency as the philosophy of ,socrates2 namely1 to turn away from the vague aggregate of doctrines and guesses which constituted the ,physical ,philosophy of that time1 and to pursue instead a special and more practical course of inquiry3 ,hippocrates selecting ,medicine and ,socrates selecting ,ethics4 ,by this limitation of their subject1 they avoided some of the errors of their predecessors4 ,for1 as ,mr4 ,grote has also remarked1 the earlier speculators1 ,anaxagoras1 ,empedocles1 ,democritus1 the ,pythagoreans1 all had still present to their minds the vast and undivided problems which have been transmitted down from the old poets2 bending their minds to the invention of some system which would explain them all at once1 or assist the imagination in conceiving both how the ,kosmos first began and how it continued to move on4 ,there could be no better remedy for this ambitious error of the human mind than to have a definite subject of study1 such as the diseases and the health of the human body4 ,accordingly1 we see that the study of medicine did draw its cultivators away from this ancient but unprofitable field4 ,hippocrates#ce condemns those who1 as ,empedocles1 set themselves to make out what man was from the beginning1 how he began first to exist1 and in what manner he was constructed4 ,this is1 he says1 no part of medicine4 ,in like manner he blames and refutes those who make some simple element1 ,hot1 or ,cold1 or ,moist1 or ,dry1 the cause of diseases1 and give medical precepts professing to be founded on this hypothesis4 ,these passages are marked by the prudence which practical study suggests to a calm and clear-sighted man4 ,they can hardly be said to have opened the way to a ,science of ,medicine2 for in the sense in which we here use the word ,science1 namely1 a collection of general truths inferred from facts by successive discoverers1 we have even yet no ,science of ,medicine4 ,the question with regard to the number and nature of the ,elements of which bodies are composed began to be agitated1 as we have seen1 at a very early period of ,greek philosophy1 and continued long to be regarded as a chief point of physiological doctrine4 ,in ,galen's work we have a treatise entitled1 ,on the ,elements according to ,hippocrates2 and the writer explains#cf that though ,hippocrates has not written any work with the title ,on the ,elements1 yet that he has in his ,treatise on the ,nature of ,man shown his opinion on that subject4 ,that the doctrine of the ,four ,elements1 ,hot1 ,cold1 ,moist1 ,dry1 subsisted long in the schools1 we have evidence in ,galen4 ,he tells us#cg that when he was a student of nineteen years old a teacher urged this lore upon him1 and regarded him as very contentious and perverse1 because he offered objections to it4 ,his account of the ,dialogue between him and the teacher is curious4 ,but in ,hippocrates the doctrine of these four elements is replaced1 in a great measure1 by the doctrine of the ,four ,humours of which the human body is constituted2 namely1 ,blood1 ,phlegm1 ,yellow ,bile and ,black ,bile4 ,galen dwells with emphasis upon ,hippocrates's proof that there must be more than one such element#ch4 ,what1 he asks1 is the method of finding the ,elements of bodies8 ,there can1 in my opinion1 be no other than that which was introduced by ,hippocrates2 namely1 we must inquire whether there be only one element1 everywhere the same in kind1 or whether there are more than one1 various and unlike each other4 ,and if the ,element be not one only1 but several1 various and dissimilar1 we must inquire in the second place1 how many elements there are1 and what1 and of what kind they are1 and how related in their association4 ,now that the ,first ,element is not one only of which both our bodies and those of all other creatures were produced1 ,hippocrates shows from these considerations4 ,and it is better first to put down his own expressions and then to expound them4 ',i assert that if man consisted of one element only he could not fall sick2 for there would be nothing which could derange his health1 if he were all of one ,element4' ,the doctrine of ,one ,element did not prevail much after the time of ,hippocrates3 the doctrine of ,four ,elements continued1 as ,i have said1 long to hold possession of the ,schools1 but does not appear as an important part of the doctrine of ,hippocrates4 ,the doctrine of the ,four ,humours 7,blood1 ,phlegm1 ,yellow ,bile and ,black ,bile7 is more peculiarly his1 and long retained its place as a principle of physiological ,science4 ,but we are here not so much concerned with his discoveries in medicine as with his views respecting the method of acquiring sound knowledge1 and in this respect1 as has been said1 he recommends by his practice a prudent limitation of the field of inquiry1 a rejection of wide1 ambitious1 general assertions1 and a practical study of his proper field4 ,in ascribing these merits to ,hippocrates's medical speculations as to the ethical speculations of his contemporary ,socrates1 we assign considerable philosophical value to ,hippocrates1 no less than to ,socrates4 ,these merits were at that time the great virtues of physical as well as of ethical philosophy4 ,but1 as ,mr4 ,grote well observes1 the community of character which then subsisted between the physical and ethical speculations prevailing at that time1 ceased to obtain in later times4 ,indeed1 it ceased to exist just at that time1 in consequence of the establishment of scientific astronomy by the exertions of ,plato and his contemporaries4 ,from that time the ,common ,sense 7as we call it7 of a man like ,socrates1 though it might be a good guide in ethics1 was not a good guide in physics4 ,i have shown elsewhere#ci how the ,common ,sense of ,socrates was worthless in matters of astronomy4 ,from that time one of the great intellectual lessons was1 that in order to understand the external world1 we must indeed observe carefully1 but we must also guess boldly4 ,discovery here required an inventive mind like ,plato's to deal with and arrange new and varied facts4 ,but in ethics all the facts were old and familiar1 and the generalizations of language by which they were grouped as ,virtues and ,vices1 and the like1 were common and well-known words4 ,here was no room for invention2 and thus in the ethical speculations of ,socrates or of any other moral teacher1 we are not to look for any contributions to the ,philosophy of ,discovery4 ,nor do ,i find anything on this subject among later ,greek writers1 beyond the commendation of such intellectual virtues as ,hippocrates and ,galen1 and other medical writers1 schooled by the practice of their art1 enjoined and praised4 ,but before we quit the ancients ,i will point out some peculiarities which may be noticed in the ,roman disciples of the ,greek philosophy4 ,,footnotes3 ,footnote #cc3 ,the remainder of this chapter is new in the present edition4 ,footnote #cd3 ,hist4 of ,greece1 ,part ii4 chap4 #fh4 ,footnote #ce3 ,de ,antiqua ,medicina1 c4 #bj4 ,footnote #cf3 ,lib4 i4 c4 #i4 ,footnote #cg3 ,de ,elem4 i4 #f4 ,footnote #ch3 ,in former editions ,i have not done justice to this passage4 ,footnote #ci3 ,hist4 ,ind4 ,sc4 ,addition to ,introduction in ,third ,edition4 ,,chapter ,,vii4 ,,the ,,romans4 ,the ,romans had no philosophy but that which they borrowed from the ,greeks2 and what they thus received1 they hardly made entirely their own4 ,the vast and profound question of which we have been speaking1 the relation between ,existence and our ,knowledge of what exists1 they never appear to have fathomed1 even so far as to discern how wide and deep it is4 ,in the development of the ideas by which nature is to be understood1 they went no further than their ,greek masters had gone1 nor indeed was more to be looked for4 ,and in the practical habit of accumulating observed facts as materials for knowledge1 they were much less discriminating and more credulous than their ,greek predecessors4 ,the descent from ,aristotle to ,pliny1 in the judiciousness of the authors and the value of their collections of facts1 is immense4 ,since the ,romans were thus servile followers of their ,greek teachers1 and little acquainted with any example of new truths collected from the world around them1 it was not to be expected that they could have any just conception of that long and magnificent ascent from one set of truths to others of higher order and wider compass1 which the history of science began to exhibit when the human mind recovered its progressive habits4 ,yet some dim presentiment of the splendid career thus destined for the intellect of man appears from time to time to have arisen in their minds4 ,perhaps the circumstance which most powerfully contributed to suggest this vision1 was the vast intellectual progress which they were themselves conscious of having made1 through the introduction of the ,greek philosophy2 and to this may be added1 perhaps1 some other features of national character4 ,their temper was too stubborn to acquiesce in the absolute authority of the ,greek philosophy1 although their minds were not inventive enough to establish a rival by its side4 ,and the wonderful progress of their political power had given them a hope in the progress of man which the ,greeks never possessed4 ,the ,roman1 as he believed the fortune of his ,state to be destined for eternity1 believed also in the immortal destiny and endless advance of that ,intellectual ,republic of which he had been admitted a denizen4 ,it is easy to find examples of such feelings as ,i have endeavoured to describe4 ,the enthusiasm with which ,lucretius and ,virgil speak of physical knowledge1 manifestly arises in a great measure from the delight which they had felt in becoming acquainted with the ,greek theories4 ,me vero primum dulces ante omnia ,mus ,quarum sacra fero ingenti perculsus amore ,accipiant1 clique vias et sidera monstrent1 ,defectus ,solis varios1 ,lunque labores6444 ,felix qui potuit rerum cognoscere causas6 ,ye sacred ,muses1 with whose beauty fir'd1 ,my soul is ravisht and my brain inspir'd3 ,whose ,priest ,i am1 whose holy fillets wear1 ,would you your ,poet's first petition hear1 ,give me the ways of wand'ring stars to know1 ,the depth of ,heaven above and ,earth below2 ,teach me the various labours of the ,moon1 ,and whence proceed th' eclipses of the ,sun2 ,why flowing ,tides prevail upon the main1 ,and in what dark abyss they shrink again2 ,what shakes the solid ,earth2 what cause delays ,the ,summer ,nights2 and shortens ,winter ,days4444 ,happy the man who1 studying ,nature's ,laws1 ,through known effects can trace the secret cause6 ,ovid#dj expresses a similar feeling4 ,felices animos quibus hc cognoscere primis ,inque domos superas scandere cura fuit6444 ,admovere oculis distantia sidera nostris theraque ingenio supposuere suo4 ,sic petitur clum3 non ut ferat ,ossam ,olympus ,summaque ,peliacus sidera tanget apex4 ,thrice happy souls6 to whom 'twas given to rise ,to truths like these1 and scale the spangled skies6 ,far distant stars to clearest view they brought1 ,and girdled ether with their chain of thought4 ,so heaven is reached3--not as of old they tried ,by mountains piled on mountains in their pride4 ,and from the whole tenour of these and similar passages1 it is evident that the intellectual pleasure which arises from our first introduction to a beautiful physical theory had a main share in producing this enthusiasm at the contemplation of the victories of science2 although undoubtedly the moral philosophy1 which was never separated from the natural philosophy1 and the triumph over superstitious fears1 which a knowledge of nature was supposed to furnish1 added warmth to the feeling of exultation4 ,we may trace a similar impression in the ardent expressions which ,pliny#da makes use of in speaking of the early astronomers1 and which we have quoted in the ,history4 ,great men6 elevated above the common standard of human nature1 by discovering the laws which celestial occurrences obey1 and by freeing the wretched mind of man from the fears which eclipses inspired4 ,this exulting contemplation of what science had done1 naturally led the mind to an anticipation of further achievements still to be performed4 ,expressions of this feeling occur in ,seneca1 and are of the most remarkable kind1 as the following example will show#db3 ,why do we wonder that comets1 so rare a phenomenon1 have not yet had their laws assigned8--that we should know so little of their beginning and their end1 when their recurrence is at wide intervals8 ,it is not yet fifteen hundred years since ,greece1 ,stellis numeros et nomina fecit1 'reckoned the stars1 and gave them names4' ,there are still many nations which are acquainted with the heavens by sight only2 which do not yet know why the moon disappears1 why she is eclipsed4 ,it is but lately that among us philosophy has reduced these matters to a certainty4 ,the day shall come when the course of time and the labour of a maturer age shall bring to light what is yet concealed4 ,one generation1 even if it devoted itself to the skies1 is not enough for researches so extensive4 ,how then can it be so1 when we divide this scanty allowance of years into no equal shares between our studies and our vices8 ,these things then must be explained by a long succession of inquiries4 ,we have but just begun to know how arise the morning and evening appearances1 the stations1 the progressions1 and the retrogradations of the fixed stars which put themselves in our way2--which appearing perpetually in another and another place compel us to be curious4 ,some one will hereafter demonstrate in what region the comets wander2 why they move so far asunder from the rest2 of what size and nature they are4 ,let us be content with what we have discovered3 let posterity contribute its share to truth4 ,again he adds#dc in the same strain3 ,let us not wonder that what lies so deep is brought out so slowly4 ,how many animals have become known for the first time in this age6 ,and the members of future generations shall know many of which we are ignorant4 ,many things are reserved for ages to come1 when our memory shall have passed away4 ,the world would be a small thing indeed1 if it did not contain matter of inquiry for all the world4 ,eleusis reserves something for the second visit of the worshipper4 ,so too ,nature does not at once disclose all ,,her mysteries4 ,we think ourselves initiated2 we are but in the vestibule4 ,the arcana are not thrown open without distinction and without reserve4 ,this age will see some things2 that which comes after us1 others4 ,while we admire the happy coincidence of these conjectures with the soundest views which the history of science teaches us1 we must not forget that they are merely conjectures1 suggested by very vague impressions1 and associated with very scanty conceptions of the laws of nature4 ,seneca's ,natural ,questions1 from which the above extract is taken1 contains a series of dissertations on various subjects of ,natural ,philosophy2 as ,meteors1 ,rainbows1 ,lightnings1 ,springs1 ,rivers1 ,snow1 ,hail1 ,rain1 ,wind1 ,earthquakes and ,comets4 ,in the whole of these dissertations1 the statements are loose1 and the explanations of little or no value4 ,perhaps it may be worth our while to notice a case in which he refers to an observation of his own1 although his conclusion from it be erroneous4 ,he is arguing#dd against the opinion that ,springs arise from the water which falls in rain4 ,in the first place1 he says1 ,i1 a very diligent digger in my vineyard1 affirm that no rain is so heavy as to moisten the earth to the depth of more than ten feet4 ,all the moisture is consumed in this outer crust1 and descends not to the lower part4 ,we have here something of the nature of an experiment2 and indeed1 as we may readily conceive1 the instinct which impels man to seek truth by experiment can never be altogether extinguished4 ,seneca's experiment was deprived of its value by the indistinctness of his ideas1 which led him to rest in the crude conception of the water being consumed in the superficial crust of the earth4 ,it is unnecessary to pursue further the reasonings of the ,romans on such subjects1 and we now proceed to the ages which succeeded the fall of their empire4 ,,footnotes3 ,footnote #dj3 ,lib4 i4 ,fast4 ,footnote #da3 ,hist4 ,nat4 i4 #ge4 ,footnote #db3 ,qust4 ,nat4 vii4 #be4 ,footnote #dc3 ,qust4 ,nat4 vii4 #cj1 #ca4 ,footnote #dd3 ,ibid4 iii4 #g4 ,,chapter ,,viii4 ,,arabian ,,philosophers4 ,i have noticed certain additions to ,physical ,science made by the ,arabians2 namely1 in ,astronomy#de4 ,the discovery of the motion of the ,sun's ,apogee by ,albategnius1 and the discovery of the ,moon's ,variation by ,aboul-,wefa2 and in ,optics#df the assertion of ,alhazen that the angle of refraction is not proportional to the angle of incidence1 as ,ptolemy had supposed3 and certain steps in the philosophy of vision4 ,we must also suppose1 as the ,arabic word alkali reminds us1 that the ,arabians contributed to lay the foundations of chemistry4 ,the question which we have here to ask is1 whether the ,arabians made any steps beyond their predecessors in the philosophy of discovery4 ,and to this question1 ,i conceive the answer must be this3 that among them as among the ,greeks1 those who practically observed nature1 and especially those who made discoveries in ,science1 must have had a practical acquaintance with some of the maxims which are exemplified in the formation of ,science4 ,to discover that the ,apogee of the ,sun was #ag degrees distant from the point where ,ptolemy had placed it1 ,albategnius made careful observations1 and referred them to the theory of the eccentric1 so as to verify or correct that theory4 ,and when1 in the eleventh century1 ,arzachel found the ,apogee to be less advanced than ,albategnius had found it1 he proceeded again to correct the theory by introducing a new movement of the equinoctial points1 which was called the ,trepidation4 ,it appeared afterwards1 however1 that1 in doing this1 he had had too much confidence in the observations of his predecessors1 and that no such movement as the ,trepidation really existed4 ,in like manner to correct ,ptolemy's law of refraction1 ,alhazen had recourse to experiment3 but he did not put his experiments in the form of a ,table1 as ,ptolemy had done4 ,if he had done this1 he might possibly have discovered the law of sines1 which ,snell afterwards discovered4 ,but though the ,arabian philosophers thus1 in some cases1 observed facts1 and referred those facts to general mathematical laws1 it does not appear that they were led to put in any new or striking general form such maxims as this3 ,that the progress of ,science consists in the exact observation of facts and in colligating them by ideas4 ,those of them who were dissatisfied with the existing philosophy as barren and useless 7for instance ,algazel#dg71 were led to point at the faults and contradictions of that philosophy1 but did not attempt1 so far as ,i know1 to substitute for it anything better4 ,if they rejected ,aristotle's ,organon1 they did not attempt to construct a new ,organon for themselves4 ,indeed they do not appear even to have had sufficient confidence in the real truth of the astronomical theories which they had adopted from the ,greeks1 always to correct and extend those where their observations showed that they required correction and extension4 ,sometimes they did this1 but not generally enough4 ,when ,arzachel found by observation the ,apogee of the ,sun to be situated too far back1 he ventured to correct ,ptolemy's statement of its motion4 ,but when ,aboul-,wefa had really discovered the ,variation of the ,moon's motion1 he did not express it by means of an epicycle4 ,if he had done so1 he would have made it unnecessary for ,tycho ,brahe at a later period to make the same discovery4 ,the moral of this incident is the same moral which we have perpetually to note as taught us at every step by the history of ,science3--namely1 the necessity of constant1 careful and exact observation of ,facts2 and the advantage of devising a ,theory1 7even if it have to be afterwards rejected17 by which the ,facts shall be bound together into a coherent whole4 ,,footnotes3 ,footnote #de3 ,hist4 ,ind4 ,sc4 b4 iii4 c4 iv4 sect4 #h4 ,footnote #df3 ,ibid4 b4 ix4 c4 ii4 ,footnote #dg3 ,see ,hist4 ,ind4 ,sc4 b4 iv4 c4 i4 ,,chapter ,,ix4 ,,the ,,schoolmen ,,of ,,the ,,middle ,,ages4 ,in the ,history of the ,sciences ,i have devoted a ,book to the state of ,science in the middle ages1 and have endeavoured to analyse the intellectual defects of that period4 ,among the characteristic features of the human mind during those times1 ,i have noticed ,indistinctness of ,ideas1 a ,commentatorial ,spirit1 ,mysticism1 and ,dogmatism4 ,the account there given of this portion of the history of man belongs1 in reality1 rather to the ,history of ,ideas than to the ,history of ,progressive ,science4 ,for1 as we have there remarked1 theoretical ,science was1 during the period of which we speak1 almost entirely stationary2 and the investigation of the causes of such a state of things may be considered as a part of that review in which we are now engaged1 of the vicissitudes of man's acquaintance with the methods of discovery4 ,but when we offered to the world a history of science1 to leave so large a chasm unexplained1 would have made the series of events seem defective and broken2 and the survey of the ,middle ,ages was therefore inserted4 ,i would beg to refer to that portion of the former work the reader who wishes for information in addition to what is here given4 ,the ,indistinctness of ,ideas and the ,commentatorial ,disposition of those ages have already been here brought under our notice4 ,viewed with reference to the opposition between ,experience and ,ideas1 on which point1 as we have said1 the succession of opinions in a great measure turns1 it is clear that the commentatorial method belongs to the ideal side of the question3 for the commentator seeks for such knowledge as he values1 by analysing and illustrating what his author has said2 and1 content with this material of speculation1 does not desire to add to it new stores of experience and observation4 ,and with regard to the two other features in the character which we gave to those ages1 we may observe that ,dogmatism demands for philosophical theories the submission of mind1 due to those revealed religious doctrines which are to guide our conduct and direct our hopes3 while ,mysticism elevates ideas into realities1 and offers them to us as the objects of our religious regard4 ,thus the ,mysticism of the middle ages and their ,dogmatism alike arose from not discriminating the offices of theoretical and practical philosophy4 ,mysticism claimed for ideas the dignity and reality of principles of moral action and religious hope3 ,dogmatism imposed theoretical opinions respecting speculative points with the imperative tone of rules of conduct and faith4 ,if1 however1 the opposite claims of theory and practice interfered with the progress of science by the confusion they thus occasioned1 they did so far more by drawing men away altogether from mere physical speculations4 ,the ,christian religion1 with its precepts1 its hopes1 and its promises1 became the leading subject of men's thoughts2 and the great active truths thus revealed1 and the duties thus enjoined1 made all inquiries of mere curiosity appear frivolous and unworthy of man4 ,the ,fathers of the ,church sometimes philosophized ill2 but far more commonly they were too intent upon the great lessons which they had to teach1 respecting man's situation in the eyes of his ,heavenly ,master1 to philosophize at all respecting things remote from the business of life and of no importance in man's spiritual concerns4 ,yet man has his intellectual as well as his spiritual wants4 ,he has faculties which demand systems and reasons1 as well as precepts and promises4 ,the ,christian doctor1 who knew so much more than the heathen philosopher respecting the ,creator and ,governor of the universe1 was not long content to know or to teach less1 respecting the universe itself4 ,while it was still maintained that ,theology was the only really important study1 ,theology was so extended and so fashioned as to include all other knowledge3 and after no long time1 the ,fathers of the ,church themselves became the authors of systems of universal knowledge4 ,but when this happened1 the commentatorial spirit was still in its full vigour4 ,the learned ,christians could not1 any more than the later ,greeks or the ,romans1 devise1 by the mere force of their own invention1 new systems1 full1 comprehensive1 and connected1 like those of the heroic age of philosophy4 ,the same mental tendencies which led men to look for speculative coherence and completeness in the view of the universe1 led them also to admire and dwell upon the splendid and acute speculations of the ,greeks4 ,they were content to find1 in those immortal works1 the answers to the questions which their curiosity prompted2 and to seek what further satisfaction they might require1 in analysing and unfolding the doctrines promulgated by those great masters of knowledge4 ,thus the ,christian doctors became1 as to general philosophy1 commentators upon the ancient ,greek teachers4 ,among these1 they selected ,aristotle as their peculiar object of admiration and study4 ,the vast store1 both of opinions and facts1 which his works contain1 his acute distinctions1 his cogent reasons in some portions of his speculations1 his symmetrical systems in almost all1 naturally commended him to the minds of subtle and curious men4 ,we may add that ,plato1 who taught men to contemplate ,ideas separate from ,things1 was not so well fitted for general acceptance as ,aristotle1 who rejected this separation4 ,for although the due apprehension of this opposition of ,ideas and ,sensations is a necessary step in the progress of true philosophy1 it requires a clearer view and a more balanced mind than the common herd of students possess2 and ,aristotle1 who evaded the necessary perplexities in which this antithesis involves us1 appeared1 to the temper of those times1 the easier and the plainer guide of the two4 ,the ,doctors of the middle ages having thus adopted ,aristotle as their master in philosophy1 we shall not be surprised to find them declaring1 after him1 that experience is the source of our knowledge of the visible world4 ,but though1 like the ,greeks1 they thus talked of experiment1 like the ,greeks1 they showed little disposition to discover the laws of nature by observation of facts4 ,this barren and formal recognition of experience or sensation as one source of knowledge1 not being illustrated by a practical study of nature1 and by real theoretical truths obtained by such a study1 remained ever vague1 wavering1 and empty4 ,such a mere acknowledgment cannot1 in any times1 ancient or modern1 be considered as indicating a just apprehension of the true basis and nature of science4 ,in imperfectly perceiving how1 and how far1 experience is the source of our knowledge of the external world1 the teachers of the middle ages were in the dark2 but so1 on this subject1 have been almost all the writers of all ages1 with the exception of those who in recent times have had their minds enlightened by contemplating philosophically the modern progress of science4 ,the opinions of the doctors of the middle ages on such subjects generally had those of ,aristotle for their basis2 but the subject was often still further analysed and systematized1 with an acute and methodical skill hardly inferior to that of ,aristotle himself4 ,the ,stagirite1 in the beginning of his ,physics1 had made the following remarks4 ,in all bodies of doctrine which involve principles1 causes1 or elements1 ,science and ,knowledge arise from the knowledge of these2 7for we then consider ourselves to know respecting any subject1 when we know its first cause1 its first principles1 its ultimate elements47 ,it is evident1 therefore1 that in seeking a knowledge of nature1 we must first know what are its principles4 ,but the course of our knowledge is1 from the things which are better known and more manifest to us1 to the things which are more certain and evident in nature4 ,for those things which are most evident in truth1 are not most evident to us4 ,and consequently we must advance from things obscure in nature1 but manifest to us1 towards the things which are really in nature more clear and certain4 ,the things which are first obvious and apparent to us are complex2 and from these we obtain1 by analysis1 principles and elements4 ,we must proceed from universals to particulars4 ,for the whole is better known to our senses than the parts1 and for the same reason1 the universal better known than the particular4 ,and thus words signify things in a large and indiscriminate way1 which is afterwards analysed by definition2 as we see that the children at first call all men father1 and all women mother1 but afterwards learn to distinguish4 ,there are various assertions contained in this extract which came to be considered as standard maxims1 and which occur constantly in the writers of the middle ages4 ,such are1 for instance1 the maxim1 ,ver scire est per causas scire2 the remark1 that compounds are known to us before their parts1 and the illustration from the expressions used by children4 ,of the mode in which this subject was treated by the schoolmen1 we may judge by looking at passages of ,thomas ,aquinas which treat of the subject of the human understanding4 ,in the ,summa ,theologi1 the eighty-fifth ,question is ,on the manner and order of understanding1 which subject he considers in eight ,articles2 and these must1 even now1 be looked upon as exhibiting many of the most important and interesting points of the subject4 ,they are1 ,first1 ,whether our understanding understands by abstracting ideas 7species7 from appearances2 ,second1 ,whether intelligible species abstracted from appearances are related to our understanding as that which we understand1 or that by which we understand2 ,third1 ,whether our understanding does naturally understand universals first2 ,fourth1 ,whether our understanding can understand many things at once2 ,fifth1 ,whether our understanding understands by compounding and dividing2 ,sixth1 ,whether the understanding can err2 ,seventh1 ,whether one person can understand the same thing better than another2 ,eighth1 ,whether our understanding understands the indivisible sooner than the divisible4 ,and in the discussion of the last point1 for example1 reference is made to the passage of ,aristotle which we have already quoted4 ,it may seem1 he says1 that we understand the indivisible before the divisible2 for the ,philosopher says that we understand and know by knowing principles and elements2 but indivisibles are the principles and elements of divisible things4 ,but to this we may reply1 that in our receiving of science1 principles and elements are not always first2 for sometimes from the sensible effects we go on to the knowledge of intelligible principles and causes4 ,we see that both the objection and the answer are drawn from ,aristotle4 ,we find the same close imitation of ,aristotle in ,albertus ,magnus1 who1 like ,aquinas1 flourished in the thirteenth century4 ,albertus1 indeed1 wrote treatises corresponding to almost all those of the ,stagirite1 and was called the ,ape of ,aristotle4 ,in the beginning of his ,physics1 he says1 ,knowledge does not always begin from that which is first according to the nature of things1 but from that of which the knowledge is easiest4 ,for the human intellect1 on account of its relation to the senses 7propter reflexionem quam habet ad sensum71 collects science from the senses2 and thus it is easier for our knowledge to begin from that which we can apprehend by sense1 imagination1 and intellect1 than from that which we apprehend by intellect alone4 ,we see that he has somewhat systematized what he has borrowed4 ,this disposition to dwell upon and systematize the leading doctrines of metaphysics assumed a more definite and permanent shape in the opposition of the ,realists and ,nominalists4 ,the opposition involved in this controversy is1 in fact1 that fundamental antithesis of ,sense and ,ideas about which philosophy has always been engaged2 and of which we have marked the manifestation in ,plato and ,aristotle4 ,the question1 ,what is the object of our thoughts when we reason concerning the external world8 must occur to all speculative minds3 and the difficulties of the answer are manifest4 ,we must reply1 either that our own ,ideas1 or that ,sensible ,things1 are the elements of our knowledge of nature4 ,and then the scruples again occur1--how we have any general knowledge if our thoughts are fixed on particular objects2 and1 on the other hand1--how we can attain to any true knowledge of nature by contemplating ideas which are not identical with objects in nature4 ,the two opposite opinions maintained on this subject were1 on the one side1--that our general propositions refer to objects which are real1 though divested of the peculiarities of individuals2 and1 on the other side1--that in such propositions1 individuals are not represented by any reality1 but bound together by a name4 ,these two views were held by the ,realists and ,nominalists respectively3 and thus the ,realist manifested the adherence to ,ideas1 and the ,nominalist the adherence to the impressions of ,sense1 which have always existed as opposite yet correlative tendencies in man4 ,the ,realists were the prevailing sect in the ,scholastic times3 for example1 both ,thomas ,aquinas and ,duns ,scotus1 the ,angelical and the ,subtle ,doctor1 held this opinion1 although opposed to each other in many of their leading doctrines on other subjects4 ,and as the ,nominalist1 fixing his attention upon sensible objects1 is obliged to consider what is the principle of generalization1 in order that the possibility of any general proposition may be conceivable2 so on the other hand1 the ,realist1 beginning with the contemplation of universal ideas1 is compelled to ask what is the principle of individuation1 in order that he may comprehend the application of general propositions in each particular instance4 ,this inquiry concerning the principle of individuation was accordingly a problem which occupied all the leading minds among the ,schoolmen#dh4 ,it will be apparent from what has been said1 that it is only one of the many forms of the fundamental antithesis of the ,ideas and the ,senses1 which we have constantly before us in this review4 ,the recognition of the derivation of our knowledge1 in part at least1 from ,experience1 though always loose and incomplete1 appears often to be independent of the ,peripatetic traditions4 ,thus ,richard of ,st4 ,victor1 a writer of contemplative theology in the twelfth century1 says#di1 that there are three sources of knowledge1 experience1 reason1 faith4 ,some things we prove by experiment1 others we collect by reasoning1 the certainty of others we hold by believing4 ,and with regard to temporal matters1 we obtain our knowledge by actual experience2 the other guides belong to divine knowledge4 ,richard also propounds a division of human knowledge which is clearly not derived directly from the ancients1 and which shows that considerable attention must have been paid to such speculations4 ,he begins by laying down clearly and broadly the distinction1 which1 as we have seen1 is of primary importance1 between practice and theory4 ,practice1 he says1 includes seven mechanical arts2 those of the clothier1 the armourer1 the navigator1 the hunter1 the physician1 and the player4 ,theory is threefold1 divine1 natural1 doctrinal2 and is thus divided into ,theology1 ,physics1 and ,mathematics4 ,mathematics1 he adds1 treats of the invisible forms of visible things4 ,we have seen that by many profound thinkers this word forms has been selected as best fitted to describe those relations of things which are the subject of mathematics4 ,again1 ,physics discovers causes from their effects and effects from their causes4 ,it would not be easy at the present day to give a better account of the object of physical science4 ,but ,richard of ,st4 ,victor makes this account still more remarkably judicious1 by the examples to which he alludes2 which are earthquakes1 the tides1 the virtues of plants1 the instincts of animals1 the classification of minerals1 plants and reptiles4 ,unde tremor terris1 qu vi maria alta tumescant1 ,herbarum vires1 animos irasque ferarum1 ,omne genus fruticum1 lapidum quoque1 reptiliumque4 ,he further adds#ej1 ,physical science ascends from effects to causes1 and descends again from causes to effects4 ,this declaration ,francis ,bacon himself might have adopted4 ,it is true1 that ,richard would probably have been little able to produce any clear and definite instances of knowledge1 in which this ascent and descent were exemplified2 but still the statement1 even considered as a mere conjectural thought1 contains a portion of that sagacity and comprehensive power which we admire so much in ,bacon4 ,richard of ,st4 ,victor1 who lived in the twelfth century1 thus exhibits more vigour and independence of speculative power than ,thomas ,aquinas1 ,albertus ,magnus1 and ,duns ,scotus1 in the thirteenth4 ,in the interval1 about the end of the twelfth century1 the writings of ,aristotle had become generally known in the ,west2 and had been elevated into the standard of philosophical doctrine1 by the divines mentioned above1 who felt a reverent sympathy with the systematizing and subtle spirit of the ,stagirite as soon as it was made manifest to them4 ,these doctors1 following the example of their great forerunner1 reduced every part of human knowledge to a systematic form2 the systems which they thus framed were presented to men's minds as the only true philosophy1 and dissent from them was no longer considered to be blameless4 ,it was an offence against religion as well as reason to reject the truth1 and the truth could be but one4 ,in this manner arose that claim which the ,doctors of the ,church put forth to control men's opinions upon all subjects1 and which we have spoken of in the ,history of ,science as the ,dogmatism of the ,middle ,ages4 ,there is no difficulty in giving examples of this characteristic4 ,we may take for instance a ,statute of the ,university of ,paris1 occasioned by a ,bull of ,pope ,john ,,xxi41 in which it is enacted1 that no ,master or ,bachelor of any faculty1 shall presume to read lectures upon any author in a private room1 on account of the many perils which may arise therefrom2 but shall read in public places1 where all may resort1 and may faithfully report what is there taught2 excepting only books of ,grammar and ,logic1 in which there can be no presumption4 ,and certain errors of ,brescian are condemned in a ,rescript#ea of the papal ,legate ,odo1 with the following expressions3 ,whereas1 as we have been informed1 certain ,logical professors treating of ,theology in their disputations1 and ,theologians treating of ,logic1 contrary to the command of the law are not afraid to mix and confound the lots of the ,lord's heritage2 we exhort and admonish your ,university1 all and singular1 that they be content with the landmarks of the ,sciences and ,faculties which our ,fathers have fixed2 and that having due fear of the curse pronounced in the law against him who removeth his neighbour's landmark1 you hold such sober wisdom according to the ,apostles1 that ye may by no means incur the blame of innovation or presumption4 ,the account which1 in the ,history of ,science1 ,i gave of ,dogmatism as a characteristic of the middle ages1 has been indignantly rejected by a very pleasing modern writer1 who has1 with great feeling and great diligence1 brought into view the merits and beauties of those times1 termed by him ,ages of ,faith4 ,he urges#eb that religious authority was never claimed for physical science3 and he quotes from ,thomas ,aquinas1 a passage in which the author protests against the practice of confounding opinions of philosophy with doctrines of faith4 ,we might quote in return the ,rescript#ec of ,stephen1 bishop of ,paris1 in which he declares that there can be but one truth1 and rejects the distinction of things being true according to philosophy and not according to the ,catholic faith2 and it might be added1 that among the errors condemned in this document are some of ,thomas ,aquinas himself4 ,we might further observe1 that if no physical doctrines were condemned in the times of which we now speak1 this was because1 on such subjects1 no new opinions were promulgated1 and not because opinion was free4 ,as soon as new opinions1 even on physical subjects1 attracted general notice1 they were prohibited by authority1 as we see in the case of ,galileo#ed4 ,but this disinclination to recognize philosophy as independent of religion1 and this disposition to find in new theories1 even in physical ones1 something contrary to religion or scripture1 are1 it would seem1 very natural tendencies of theologians2 and it would be unjust to assert that these propensities were confined to the periods when the authority of papal ,rome was highest2 or that the spirit which has in a great degree controlled and removed such habits was introduced by the ,reformation of religion in the sixteenth century4 ,we must trace to other causes1 the clear and general recognition of ,philosophy1 as distinct from ,theology1 and independent of her authority4 ,in the earlier ages of the ,church1 indeed1 this separation had been acknowledged4 ,st4 ,augustin says1 ,a ,christian should beware how he speaks on questions of natural philosophy1 as if they were doctrines of ,holy ,scripture2 for an infidel who should hear him deliver absurdities could not avoid laughing4 ,thus the ,christian would be confused1 and the infidel but little edified2 for the infidel would conclude that our authors really entertained these extravagant opinions1 and therefore they would despise them1 to their own eternal ruin4 ,therefore the opinions of philosophers should never be proposed as dogmas of faith1 or rejected as contrary to faith1 when it is not certain that they are so4 ,these words are quoted with approbation by ,thomas ,aquinas1 and it is said#ee1 are cited in the same manner in every encyclopedical work of the middle ages4 ,this warning of genuine wisdom was afterwards rejected1 as we have seen2 and it is only in modern times that its value has again been fully recognized4 ,and this improvement we must ascribe1 mainly1 to the progress of physical science4 ,for a great body of undeniable truths on physical subjects being accumulated1 such as had no reference to nor connexion with the truths of religion1 and yet such as possessed a strong interest for most men's minds1 it was impossible longer to deny that there were wide provinces of knowledge which were not included in the dominions of ,theology1 and over which she had no authority4 ,in the fifteenth and sixteenth centuries1 the fundamental doctrines of mechanics1 hydrostatics1 optics1 magnetics1 chemistry1 were established and promulgated2 and along with them1 a vast train of consequences1 attractive to the mind by the ideal relations which they exhibited1 and striking to the senses by the power which they gave man over nature4 ,here was a region in which philosophy felt herself entitled and impelled to assert her independence4 ,from this region1 there is a gradation of subjects in which philosophy advances more and more towards the peculiar domain of religion2 and at some intermediate points there have been1 and probably will always be1 conflicts respecting the boundary line of the two fields of speculation4 ,for the limit is vague and obscure1 and appears to fluctuate and shift with the progress of time and knowledge4 ,our business at present is not with the whole extent and limits of philosophy1 but with the progress of physical science more particularly1 and the methods by which it may be attained3 and we are endeavouring to trace historically the views which have prevailed respecting such methods1 at various periods of man's intellectual progress4 ,among the most conspicuous of the revolutions which opinions on this subject have undergone1 is the transition from an implicit trust in the internal powers of man's mind to a professed dependence upon external observation2 and from an unbounded reverence for the wisdom of the past1 to a fervid expectation of change and improvement4 ,the origin and progress of this disposition of mind2--the introduction of a state of things in which men not only obtained a body of indestructible truths from experience1 and increased it from generation to generation1 but professedly1 and we may say1 ostentatiously1 declared such to be the source of their knowledge1 and such their hopes of its destined career2--the rise1 in short1 of ,experimental ,philosophy1 not only as a habit1 but as a ,philosophy of ,experience1 is what we must now endeavour to exhibit4 ,,footnotes3 ,footnote #dh3 ,see the opinion of ,aquinas1 in ,degerando1 ,hist4 ,com4 des ,syst4 iv4 #dii2 of ,duns ,scotus1 ibid4 iv4 #ebc4 ,footnote #di3 ,liber ,excerptionum1 ,lib4 i4 c4 i4 ,footnote #ej3 ,tr4 ,ex4 ,lib4 i4 c4 vii4 ,footnote #ea3 ,tenneman1 viii4 #dfa4 ,footnote #eb3 ,mores ,catholici1 or ,ages of ,faith1 viii4 p4 #bdg4 ,footnote #ec3 ,tenneman1 viii4 #dfj4 ,footnote #ed3 ,if there were any doubt on this subject1 we might refer to the writers who afterwards questioned the supremacy of ,aristotle1 and who with one voice assert that an infallible authority had been claimed for him4 ,thus ,laurentius ,valla3 ,quo minus ferendi sunt recentes ,peripatetici1 qui nullius sect hominibus interdicunt libertate ab ,aristotele dissentiendi1 quasi sophos hic1 non philosophus4 ,pref4 in ,dial4 7,tenneman1 ix4 #bi47 ,so ,ludovicus ,vives3 ,sunt ex philosophis et ex theologis qui non solum quo ,aristoteles pervenit extremum esse aiunt natur1 sed qu pervenit eam rectissimam esse omnium et certissimam in natura viam4 7,tenneman1 ix4 #dc47 ,we might urge too1 the evasions practised by philosophical ,reformers1 through fear of the dogmatism to which they had to submit2 for example1 the protestation of ,telesius at the end of the ,proem to his work1 ,de ,rerum ,natura3 ,nec tamen1 si quid eorum qu nobis posita sunt1 sacris literis1 ,catholicve ecclesi decretis non cohreat1 tenendum id1 quin penitus rejiciendum asseveramus contendimusque4 ,neque enim humana modo ratio quvis1 sed ipse etiam sensus illis posthabendus1 et si illis non congruat1 abnegandus omnino et ipse etiam est sensus4 ,footnote #ee3 ,ages of ,faith1 viii4 #bdg3 to the author of which ,i am obliged for this quotation4 ,,chapter ,x4 ,,the ,,innovators ,,of ,,the ,,middle ,,ages4 ,raymond ,lully4 #a4 ,general ,remarks4--,in the rise of ,experimental ,philosophy1 understanding the term in the way just now stated1 two features have already been alluded to3 the disposition to cast off the prevalent reverence for the opinions and methods of preceding teachers with an eager expectation of some vast advantage to be derived from a change2 and the belief that this improvement must be sought by drawing our knowledge from external observation rather than from mere intellectual efforts2--the ,insurrection against ,authority1 and the ,appeal to ,experience4 ,these two movements were closely connected2 but they may easily be distinguished1 and in fact1 persons were very prominent in the former part of the task1 who had no comprehension of the latter principle1 from which alone the change derives its value4 ,there were many ,malcontents who had not the temper1 talent or knowledge1 which fitted them to be ,reformers4 ,the authority which was questioned1 in the struggle of which we speak1 was that of the ,scholastic ,system1 the combination of ,philosophy with ,theology2 of which ,aristotle1 presented in the form and manner which the ,doctors of the ,church had imposed upon him1 is to be considered the representative4 ,when there was demanded of men a submission of the mind1 such as this system claimed1 the natural love of freedom in man's bosom1 and the speculative tendencies of his intellect1 rose in rebellion1 from time to time1 against the ruling oppression4 ,we find in all periods of the scholastic ages examples of this disposition of man to resist overstrained authority2 the tendency being mostly1 however1 combined with a want of solid thought1 and showing itself in extravagant pretensions and fantastical systems put forwards by the insurgents4 ,we have pointed out one such opponent#ef of the established systems1 even among the ,arabian schoolmen1 a more servile race than ever the ,europeans were4 ,we may here notice more especially an extraordinary character who appeared in the thirteenth century1 and who may be considered as belonging to the ,prelude of the ,reform in ,philosophy1 although he had no share in the ,reform itself4 #b4 ,raymond ,lully4--,raymond ,lully is perhaps traditionally best known as an ,alchemist1 of which art he appears to have been a cultivator4 ,but this was only one of the many impulses of a spirit ardently thirsty of knowledge and novelty4 ,he had#eg1 in his youth1 been a man of pleasure1 but was driven by a sudden shock of feeling to resolve on a complete change of life4 ,he plunged into solitude1 endeavoured to still the remorse of his conscience by prayer and penance1 and soon had his soul possessed by visions which he conceived were vouchsafed to him4 ,in the feeling of religious enthusiasm thus excited1 he resolved to devote his life to the diffusion of ,christian truth among ,heathens and ,mahomedans4 ,for this purpose1 at the age of thirty he betook himself to the study of ,grammar1 and of the ,arabic language4 ,he breathed earnest supplications for an illumination from above2 and these were answered by his receiving from heaven1 as his admirers declare1 his ,ars ,magna by which he was able without labour or effort to learn and apply all knowledge4 ,the real state of the case is1 that he put himself in opposition to the established systems1 and propounded a ,new ,art1 from which he promised the most wonderful results2 but that his ,art really is merely a mode of combining ideal conceptions without any reference to real sources of knowledge1 or any possibility of real advantage4 ,in a ,treatise addressed1 in ,a4,d4 #acaj1 to ,king ,philip of ,france1 entitled ,liber ,lamentationis ,duodecim ,principiorum ,philosophi contra ,averroistas1 ,lully introduced ,philosophy1 accompanied by her twelve ,principles1 7,matter1 ,form1 ,generation1 c47 uttering loud complaints against the prevailing system of doctrine2 and represents her as presenting to the king a petition that she may be upheld and restored by her favourite1 the ,author4 ,his ,tabula ,generalis ad omnes ,scientias applicabilis was begun the #aeth ,september1 #abib1 in the ,harbour of ,tunis1 and finished in #abic1 at ,naples4 ,in order to frame an ,art of thus tabulating all existing sciences1 and indeed all possible knowledge1 he divides into various classes the conceptions with which he has to deal4 ,the first class contains nine ,absolute ,conceptions3 ,goodness1 ,greatness1 ,duration1 ,power1 ,wisdom1 ,will1 ,virtue1 ,truth1 ,majesty4 ,the second class has nine ,relative ,conceptions3 ,difference1 ,identity1 ,contrariety1 ,beginning1 ,middle1 ,end1 ,majority1 ,equality1 ,minority4 ,the third class contains nine ,questions3 ,whether8 ,what8 ,whence8 ,why8 ,how great8 ,how circumstanced8 ,when8 ,where8 and ,how8 ,the fourth class contains the nine ,most ,general ,subjects3 ,god1 ,angel1 ,heaven1 ,man1 ,imaginativum1 ,sensitivum1 ,vegetativum1 ,elementativum1 ,instrumentativum4 ,then come nine ,prdicaments1 nine ,moral ,qualities1 and so on4 ,these conceptions are arranged in the compartments of certain concentric moveable circles1 and give various combinations by means of triangles and other figures1 and thus propositions are constructed4 ,it must be clear at once1 that real knowledge1 which is the union of facts and ideas1 can never result from this machinery for shifting about1 joining and disjoining1 empty conceptions4 ,this1 and all similar schemes1 go upon the supposition that the logical combinations of notions do of themselves compose knowledge2 and that really existing things may be arrived at by a successive system of derivation from our most general ideas4 ,it is imagined that by distributing the nomenclature of abstract ideas according to the place which they can hold in our propositions1 and by combining them according to certain conditions1 we may obtain formul including all possible truths1 and thus fabricate a science in which all sciences are contained4 ,we thus obtain the means of talking and writing upon all subjects1 without the trouble of thinking3 the revolutions of the emblematical figures are substituted for the operations of the mind4 ,both exertion of thought1 and knowledge of facts1 become superfluous4 ,and this reflection1 adds an intelligent author#eh1 explains the enormous number of books which ,lully is said to have written2 for he might have written those even during his sleep1 by the aid of a moving power which should keep his machine in motion4 ,having once devised this invention for manufacturing science1 ,lully varied it in a thousand ways1 and followed it into a variety of developments4 ,besides ,synoptical ,tables1 he employs ,genealogical ,trees1 each of which he dignifies with the name of the ,tree of ,science4 ,the only requisite for the application of his ,system was a certain agreement in the numbers of the classes into which different subjects were distributed2 and as this symmetry does not really exist in the operations of our thoughts1 some violence was done to the natural distinction and subordination of conceptions1 in order to fit them for the use of the system4 ,thus ,lully1 while he professed to teach an ,art which was to shed new light upon every part of science1 was in fact employed in a pedantic and trifling repetition of known truths or truisms2 and while he complained of the errors of existing methods1 he proposed in their place one which was far more empty1 barren1 and worthless1 than the customary processes of human thought4 ,yet his method is spoken of#ei with some praise by ,leibnitz1 who indeed rather delighted in the region of ideas and words1 than in the world of realities4 ,but ,francis ,bacon speaks far otherwise and more justly on this subject#fj4 ,it is not to be omitted that some men1 swollen with emptiness rather than knowledge1 have laboured to produce a certain ,method1 not deserving the name of a legitimate ,method1 since it is rather a method of imposture3 which yet is doubtless highly grateful to certain would-be philosophers4 ,this method scatters about certain little drops of science in such a manner that a smatterer may make a perverse and ostentatious use of them with a certain show of learning4 ,such was the art of ,lully1 which consisted of nothing but a mass and heap of the words of each science2 with the intention that he who can readily produce the words of any science shall be supposed to know the science itself4 ,such collections are like a rag shop1 where you find a patch of everything1 but nothing which is of any value4 ,,footnotes3 ,footnote #ef3 ,algazel4 ,see ,hist4 ,ind4 ,sc4 b4 iv4 c4 i4 ,footnote #eg3 ,tenneman1 viii4 #hcj4 ,footnote #eh3 ,degerando1 iv4 #ece4 ,footnote #ei3 ,leibnitz's expressions are1 7,op4 t4 vi4 p4 #af73 ,quand j'tais jeune1 je prenois quelque a l',art de ,lulle1 mais je crus y entrevoir bien des dfectuosits1 dont j'ai dit quelque chose dans un petit ,essai d'colier intitul ,de ,arte ,combinatoria1 publi en #afff1 et qui a t rimprim aprs malgr moi4 ,mais comme je ne mprise rien facilement1 except les arts divinatoires que ne sont que des tromperies toutes pures1 j'ai trouv quelque chose d'estimable encore dans l',art de ,lulle4 ,footnote #fj3 ,works1 vii4 #bif4 ,,chapter ,,xi4 ,,the ,,innovators ,,of ,,the ,,middle ,,ages--,,continued4 ,roger ,bacon4 ,we now come to a philosopher of a very different character1 who was impelled to declare his dissent from the reigning philosophy by the abundance of his knowledge1 and by his clear apprehension of the mode in which real knowledge had been acquired and must be increased4 ,roger ,bacon was born in #abad1 near ,ilchester1 in ,somersetshire1 of an old family4 ,in his youth he was a student at ,oxford1 and made extraordinary progress in all branches of learning4 ,he then went to the ,university of ,paris1 as was at that time the custom of learned ,englishmen1 and there received the degree of ,doctor of ,theology4 ,at the persuasion of ,robert ,grostte1 bishop of ,lincoln1 he entered the brotherhood of ,franciscans in ,oxford1 and gave himself up to study with extraordinary fervour4 ,he was termed by his brother monks ,doctor ,mirabilis4 ,we know from his own works1 as well as from the traditions concerning him1 that he possessed an intimate acquaintance with all the science of his time which could be acquired from books2 and that he had made many remarkable advances by means of his own experimental labours4 ,he was acquainted with ,arabic1 as well as with the other languages common in his time4 ,in the title of his works1 we find the whole range of science and philosophy1 ,mathematics and ,mechanics1 ,optics1 ,astronomy1 ,geography1 ,chronology1 ,chemistry1 ,magic1 ,music1 ,medicine1 ,grammar1 ,logic1 ,metaphysics1 ,ethics1 and ,theology2 and judging from those which are published1 these works are full of sound and exact knowledge4 ,he is1 with good reason1 supposed to have discovered1 or to have had some knowledge of1 several of the most remarkable inventions which were made generally known soon afterwards2 as gunpowder1 lenses1 burning specula1 telescopes1 clocks1 the correction of the calendar1 and the explanation of the rainbow4 ,thus possessing1 in the acquirements and habits of his own mind1 abundant examples of the nature of knowledge and of the process of invention1 ,roger ,bacon felt also a deep interest in the growth and progress of science1 a spirit of inquiry respecting the causes which produced or prevented its advance1 and a fervent hope and trust in its future destinies2 and these feelings impelled him to speculate worthily and wisely respecting a ,reform of the ,method of ,philosophizing4 ,the manuscripts of his works have existed for nearly six hundred years in many of the libraries of ,europe1 and especially in those of ,england2 and for a long period the very imperfect portions of them which were generally known1 left the character and attainments of the author shrouded in a kind of mysterious obscurity4 ,about a century ago1 however1 his ,opus ,majus was published#fa by ,dr4 ,s4 ,jebb1 principally from a manuscript in the ,library of ,trinity ,college1 ,dublin2 and this contained most or all of the separate works which were previously known to the public1 along with others still more peculiar and characteristic4 ,we are thus able to judge of ,roger ,bacon's knowledge and of his views1 and they are in every way well worthy our attention4 ,the ,opus ,majus is addressed to ,pope ,clement the ,fourth1 whom ,bacon had known when he was legate in ,england as ,cardinal-bishop of ,sabina1 and who admired the talents of the monk1 and pitied him for the persecutions to which he was exposed4 ,on his elevation to the papal chair1 this account of ,bacon's labours and views was sent1 at the earnest request of the pontiff4 ,besides the ,opus ,majus1 he wrote two others1 the ,opus ,minus and ,opus ,tertium2 which were also sent to the pope1 as the author says#fb1 on account of the danger of roads1 and the possible loss of the work4 ,these works still exist unpublished1 in the ,cottonian and other libraries4 ,the ,opus ,majus is a work equally wonderful with regard to its general scheme1 and to the special treatises with which the outlines of the plan are filled up4 ,the professed object of the work is to urge the necessity of a reform in the mode of philosophizing1 to set forth the reasons why knowledge had not made a greater progress1 to draw back attention to the sources of knowledge which had been unwisely neglected1 to discover other sources which were yet almost untouched1 and to animate men in the undertaking1 by a prospect of the vast advantages which it offered4 ,in the development of this plan1 all the leading portions of science are expounded in the most complete shape which they had at that time assumed2 and improvements of a very wide and striking kind are proposed in some of the principal of these departments4 ,even if the work had had no leading purpose1 it would have been highly valuable as a treasure of the most solid knowledge and soundest speculations of the time2 even if it had contained no such details1 it would have been a work most remarkable for its general views and scope4 ,it may be considered as1 at the same time1 the ,encyclopedia and the ,novum ,organon of the thirteenth century4 ,since this work is thus so important in the history of ,inductive ,philosophy ,i shall give1 in a note1 a view#fc of its divisions and contents4 ,but ,i must now endeavour to point out more especially the way in which the various principles1 which the reform of scientific method involved1 are here brought into view4 ,one of the first points to be noticed for this purpose1 is the resistance to authority2 and at the stage of philosophical history with which we here have to do1 this means resistance to the authority of ,aristotle1 as adopted and interpreted by the ,doctors of the ,schools4 ,bacon's work#fd is divided into ,six ,parts2 and of these ,parts1 the ,first is1 ,of the four universal ,causes of all ,human ,ignorance4 ,the causes thus enumerated#fe are3--the force of unworthy authority2--traditionary habit2--the imperfection of the undisciplined senses2--and the disposition to conceal our ignorance and to make an ostentatious show of our knowledge4 ,these influences involve every man1 occupy every condition4 ,they prevent our obtaining the most useful and large and fair doctrines of wisdom1 the secret of all sciences and arts4 ,he then proceeds to argue1 from the testimony of philosophers themselves1 that the authority of antiquity1 and especially of ,aristotle1 is not infallible4 ,we find#ff their books full of doubts1 obscurities1 and perplexities4 ,they scarce agree with each other in one empty question or one worthless sophism1 or one operation of science1 as one man agrees with another in the practical operations of medicine1 surgery1 and the like arts of ,secular men4 ,indeed1 he adds1 not only the philosophers1 but the saints have fallen into errors which they have afterwards retracted1 and this he instances in ,augustin1 ,jerome1 and others4 ,he gives an admirable sketch#fg of the progress of philosophy from the ,ionic ,school to ,aristotle2 of whom he speaks with great applause4 ,yet1 he adds#fh1 those who came after him corrected him in some things1 and added many things to his works1 and shall go on adding to the end of the world4 ,aristotle1 he adds1 is now called peculiarly#fi the ,philosopher1 yet there was a time when his philosophy was silent and unregarded1 either on account of the rarity of copies of his works1 or their difficulty1 or from envy2 till after the time of ,mahomet1 when ,avicenna and ,averroes1 and others1 recalled this philosophy into the full light of exposition4 ,and although the ,logic and some other works were translated by ,boethius from the ,greek1 yet the philosophy of ,aristotle first received a quick increase among the ,latins at the time of ,michael ,scot2 who1 in the year of our ,lord #abcj1 appeared1 bringing with him portions of the books of ,aristotle on ,natural ,philosophy and ,mathematics4 ,and yet a small part only of the works of this author is translated1 and a still smaller part is in the hands of common students4 ,he adds further#gj 7in the ,third ,part of the ,opus ,majus1 which is a ,dissertation on language71 that the translations which are current of these writings1 are very bad and imperfect4 ,with these views1 he is moved to express himself somewhat impatiently#ga respecting these works3 ,if ,i had1 he says1 power over the works of ,aristotle1 ,i would have them all burnt2 for it is only a loss of time to study in them1 and a cause of error1 and a multiplication of ignorance beyond expression4 ,the common herd of students1 he says1 with their heads1 have no principle by which they can be excited to any worthy employment2 and hence they mope and make asses of themselves over their bad translations1 and lose their time1 and trouble1 and money4 ,the remedies which he recommends for these evils1 are1 in the first place1 the study of that only perfect wisdom which is to be found in the sacred ,scripture#gb1 in the next place1 the study of mathematics and the use of experiment#gc4 ,by the aid of these methods1 ,bacon anticipates the most splendid progress for human knowledge4 ,he takes up the strain of hope and confidence which we have noticed as so peculiar in the ,roman writers2 and quotes some of the passages of ,seneca which we adduced in illustration of this3--that the attempts in science were at first rude and imperfect1 and were afterwards improved2--that the day will come1 when what is still unknown shall be brought to light by the progress of time and the labours of a longer period2--that one age does not suffice for inquiries so wide and various2--that the people of future times shall know many things unknown to us2--and that the time shall arrive when posterity will wonder that we overlooked what was so obvious4 ,bacon himself adds anticipations more peculiarly in the spirit of his own time4 ,we have seen1 he says1 at the end of the work1 how ,aristotle1 by the ways which wisdom teaches1 could give to ,alexander the empire of the world4 ,and this the ,church ought to take into consideration against the infidels and rebels1 that there may be a sparing of ,christian blood1 and especially on account of the troubles that shall come to pass in the days of ,antichrist2 which by the grace of ,god1 it would be easy to obviate1 if prelates and princes would encourage study1 and join in searching out the secrets of nature and art4 ,it may not be improper to observe here that this belief in the appointed progress of knowledge1 is not combined with any overweening belief in the unbounded and independent power of the human intellect4 ,on the contrary1 one of the lessons which ,bacon draws from the state and prospects of knowledge1 is the duty of faith and humility4 ,to him1 he says#gd1 who denies the truth of the faith because he is unable to understand it1 ,i will propose in reply the course of nature1 and as we have seen it in examples4 ,and after giving some instances1 he adds1 ,these1 and the like1 ought to move men and to excite them to the reception of divine truths4 ,for if1 in the vilest objects of creation1 truths are found1 before which the inward pride of man must bow1 and believe though it cannot understand1 how much more should man humble his mind before the glorious truths of ,god6 ,he had before said#ge3 ,man is incapable of perfect wisdom in this life2 it is hard for him to ascend towards perfection1 easy to glide downwards to falsehoods and vanities3 let him then not boast of his wisdom1 or extol his knowledge4 ,what he knows is little and worthless1 in respect of that which he believes without knowing2 and still less1 in respect of that which he is ignorant of4 ,he is mad who thinks highly of his wisdom2 he most mad1 who exhibits it as something to be wondered at4 ,he adds1 as another reason for humility1 that he has proved by trial1 he could teach in one year1 to a poor boy1 the marrow of all that the most diligent person could acquire in forty years' laborious and expensive study4 ,to proceed somewhat more in detail with regard to ,roger ,bacon's views of a ,reform in ,scientific ,inquiry1 we may observe that by making ,mathematics and ,experiment the two great points of his recommendation1 he directed his improvement to the two essential parts of all knowledge1 ,ideas and ,facts1 and thus took the course which the most enlightened philosophy would have suggested4 ,he did not urge the prosecution of experiment1 to the comparative neglect of the existing mathematical sciences and conception2 a fault which there is some ground for ascribing to his great namesake and successor ,francis ,bacon3 still less did he content himself with a mere protest against the authority of the schools1 and a vague demand for change1 which was almost all that was done by those who put themselves forward as reformers in the intermediate time4 ,roger ,bacon holds his way steadily between the two poles of human knowledge2 which1 as we have seen1 it is far from easy to do4 ,there are two modes of knowing1 says he#gf2 by argument1 and by experiment4 ,argument concludes a question2 but it does not make us feel certain1 or acquiesce in the contemplation of truth1 except the truth be also found to be so by experience4 ,it is not easy to express more decidedly the clearly seen union of exact conceptions with certain facts1 which1 as we have explained1 constitutes real knowledge4 ,one large division of the ,opus ,majus is ,on the ,usefulness of ,mathematics1 which is shown by a copious enumeration of existing branches of knowledge1 as ,chronology1 ,geography1 the ,calendar and 7in a separate ,part7 ,optics4 ,there is a chapter#gg1 in which it is proved by reason1 that all science requires mathematics4 ,and the arguments which are used to establish this doctrine1 show a most just appreciation of the office of mathematics in science4 ,they are such as follows3--,that other sciences use examples taken from mathematics as the most evident3--,that mathematical knowledge is1 as it were1 innate in us1 on which point he refers to the well-known dialogue of ,plato1 as quoted by ,cicero3--,that this science1 being the easiest1 offers the best introduction to the more difficult3--,that in mathematics1 things as known to us are identical with things as known to nature3--,that we can here entirely avoid doubt and error1 and obtain certainty and truth3--,that mathematics is prior to other sciences in nature1 because it takes cognizance of quantity1 which is apprehended by intuition1 7intuitu intellectus74 ,moreover1 he adds#gh1 there have been found famous men1 as ,robert1 bishop of ,lincoln1 and ,brother ,adam ,marshman 7de ,marisco71 and many others1 who by the power of mathematics have been able to explain the causes of things2 as may be seen in the writings of these men1 for instance1 concerning the ,rainbow and ,comets1 and the generation of heat1 and climates1 and the celestial bodies4 ,but undoubtedly the most remarkable portion of the ,opus ,majus is the ,sixth and last ,part1 which is entitled ,de ,scientia experimentali4 ,it is indeed an extraordinary circumstance to find a writer of the thirteenth century1 not only recognizing experiment as one source of knowledge1 but urging its claims as something far more important than men had yet been aware of1 exemplifying its value by striking and just examples1 and speaking of its authority with a dignity of diction which sounds like a foremurmur of the ,baconian sentences uttered nearly four hundred years later4 ,yet this is the character of what we here find#gi4 ,experimental science1 the sole mistress of speculative sciences1 has three great ,prerogatives among other parts of knowledge3 ,first she tests by experiment the noblest conclusions of all other sciences3 ,next she discovers respecting the notions which other sciences deal with1 magnificent truths to which these sciences of themselves can by no means attain3 her ,third dignity is1 that she by her own power and without respect of other sciences1 investigates the secret of nature4 ,the examples which ,bacon gives of these ,prerogatives are very curious1 exhibiting1 among some error and credulity1 sound and clear views4 ,his leading example of the ,first ,prerogative1 is the ,rainbow1 of which the cause1 as given by ,aristotle1 is tested by reference to experiment with a skill which is1 even to us now1 truly admirable4 ,the examples of the ,second ,prerogative are three3--first1 the art of making an artificial sphere which shall move with the heavens by natural influences1 which ,bacon trusts may be done1 though astronomy herself cannot do it--et tunc1 he says1 thesaurum unius regis valeret hoc instrumentum2--secondly1 the art of prolonging life1 which experiment may teach1 though medicine has no means of securing it except by regimen#hj2--thirdly1 the art of making gold finer than fine gold1 which goes beyond the power of alchemy4 ,the ,third ,prerogative of experimental science1 arts independent of the received sciences1 is exemplified in many curious examples1 many of them whimsical traditions4 ,thus it is said that the character of a people may be altered by altering the air#ha4 ,alexander1 it seems1 applied to ,aristotle to know whether he should exterminate certain nations which he had discovered1 as being irreclaimably barbarous2 to which the philosopher replied1 ,if you can alter their air1 permit them to live1 if not1 put them to death4 ,in this part1 we find the suggestion that the fire-works made by children1 of saltpetre1 might lead to the invention of a formidable military weapon4 ,it could not be expected that ,roger ,bacon1 at a time when experimental science hardly existed1 could give any precepts for the discovery of truth by experiment4 ,but nothing can be a better example of the method of such investigation1 than his inquiry concerning the cause of the ,rainbow4 ,neither ,aristotle1 nor ,avicenna1 nor ,seneca1 he says1 have given us any clear knowledge of this matter1 but experimental science can do so4 ,let the experimenter 7experimentator7 consider the cases in which he finds the same colours1 as the hexagonal crystals from ,ireland and ,india2 by looking into these he will see colours like those of the rainbow4 ,many think that this arises from some special virtue of these stones and their hexagonal figure2 let therefore the experimenter go on1 and he will find the same in other transparent stones1 in dark ones as well as in light-coloured4 ,he will find the same effect also in other forms than the hexagon1 if they be furrowed in the surface1 as the ,irish crystals are4 ,let him consider too1 that he sees the same colours in the drops which are dashed from oars in the sunshine2--and in the spray thrown by a millwheel2--and in the dew-drops which lie on the grass in a meadow on a summer-morning2--and if a man takes water in his mouth and projects it on one side into a sunbeam2--and if in an oil-lamp hanging in the air1 the rays fall in certain positions upon the surface of the oil2--and in many other ways1 are colours produced4 ,we have here a collection of instances1 which are almost all examples of the same kind as the phenomenon under consideration2 and by the help of a principle collected by induction from these facts1 the colours of the rainbow were afterwards really explained4 ,with regard to the form and other circumstances of the bow he is still more precise4 ,he bids us measure the height of the bow and of the sun1 to show that the center of the bow is exactly opposite to the sun4 ,he explains the circular form of the bow1--its being independent of the form of the cloud1 its moving when we move1 its flying when we follow1--by its consisting of the reflections from a vast number of minute drops4 ,he does not1 indeed1 trace the course of the rays through the drop1 or account for the precise magnitude which the bow assumes2 but he approaches to the verge of this part of the explanation2 and must be considered as having given a most happy example of experimental inquiry into nature1 at a time when such examples were exceedingly scanty4 ,in this respect1 he was more fortunate than ,francis ,bacon1 as we shall hereafter see4 ,we know but little of the biography of ,roger ,bacon1 but we have every reason to believe that his influence upon his age was not great4 ,he was suspected of magic1 and is said to have been put into close confinement in consequence of this charge4 ,in his work he speaks of ,astrology as a science well worth cultivating4 ,but1 says he1 ,theologians and ,decretists1 not being learned in such matters and seeing that evil as well as good may be done1 neglect and abhor such things1 and reckon them among ,magic ,arts4 ,we have already seen1 that at the very time when ,bacon was thus raising his voice against the habit of blindly following authority1 and seeking for all science in ,aristotle1 ,thomas ,aquinas was employed in fashioning ,aristotle's tenets into that fixed form in which they became the great impediment to the progress of knowledge4 ,it would seem1 indeed1 that something of a struggle between the progressive and stationary powers of the human mind was going on at this time4 ,bacon himself says#hb1 ,never was there so great an appearance of wisdom1 nor so much exercise of study in so many ,faculties1 in so many regions1 as for this last forty years4 ,doctors are dispersed everywhere1 in every castle1 in every burgh1 and especially by the students of two ,orders1 7he means the ,franciscans and ,dominicans1 who were almost the only religious orders that distinguished themselves by an application to study#hc17 which has not happened except for about forty years4 ,and yet there was never so much ignorance1 so much error4 ,and in the part of his work which refers to ,mathematics1 he says of that study#hd1 that it is the door and the key of the sciences2 and that the neglect of it for thirty or forty years has entirely ruined the studies of the ,latins4 ,according to these statements1 some change1 disastrous to the fortunes of science1 must have taken place about #abcj1 soon after the foundation of the ,dominican and ,franciscan ,orders#he4 ,nor can we doubt that the adoption of the ,aristotelian philosophy by these two ,orders1 in the form in which the ,angelical ,doctor had systematized it1 was one of the events which most tended to defer1 for three centuries1 the reform which ,roger ,bacon urged as a matter of crying necessity in his own time4 ,,footnotes3 ,footnote #fa3 ,fratris ,rogeri ,bacon1 ,ordinis ,minorum1 ,opus ,majus1 ad ,clementem ,quartum1 ,pontificem ,romanum1 ex ,,ms4 ,codice ,dubliniensi cum aliis quibusdam collato1 nunc primum edidit ,s4 ,jebb1 ,m4,d4 ,londini1 #agcc4 ,footnote #fb3 ,opus ,majus1 ,prf4 ,footnote #fc3 ,contents of ,roger ,bacon's ,opus ,majus4 ,part ,i4 ,on the four causes of human ignorance3--,authority1 ,custom1 ,popular ,opinion1 and the ,pride of supposed ,knowledge4 ,part ,,ii4 ,on the source of perfect wisdom in the ,sacred ,scripture4 ,part ,,iii4 ,on the ,usefulness of ,grammar4 ,part ,,iv4 ,on the ,usefulness of ,mathematics4 7#a7 ,the necessity of ,mathematics in ,human ,things 7published separately as the ,specula ,mathematica74 7#b7 ,the necessity of ,mathematics in ,divine ,things4--#a4 ,this study has occupied holy men3 #b4 ,geography3 #c4 ,chronology3 #d4 ,cycles2 the ,golden ,number1 c43 #e4 ,natural ,phenomena1 as the ,rainbow3 #f4 ,arithmetic3 #g4 ,music4 7#c7 ,the necessity of ,mathematics in ,ecclesiastical ,things4--#a4 ,the ,certification of ,faith3 #b4 ,the ,correction of the ,calendar4 7#d7 ,the necessity of ,mathematics in the ,state4--#a4 ,of ,climates3 #b4 ,hydrography3 #c4 ,geography3 #d4 ,astrology4 ,part ,v4 ,on ,perspective 7published separately as ,perspectiva74 7#a7 ,the organs of vision4 7#b7 ,vision in straight lines4 7#c7 ,vision reflected and refracted4 7#d7 ,de multiplicatione specierum 7on the propagation of the impressions of light1 heat1 c47 ,part ,,vi4 ,on ,experimental ,science4 ,footnote #fd3 ,op4 ,maj4 p4 #a4 ,footnote #fe3 ,ibid4 p4 #b4 ,footnote #ff3 ,ibid4 p4 #aj4 ,footnote #fg3 ,i will give a specimen4 ,opus ,majus1 c4 viii4 p4 #ce3 ,these two kinds of philosophers1 the ,ionic and ,italic1 ramified through many sects and various successors1 till they came to the doctrine of ,aristotle1 who corrected and changed the propositions of all his predecessors1 and attempted to perfect philosophy4 ,in the ,italic succession1 ,pythagoras1 ,archytas ,tarentinus and ,timus are most prominently mentioned4 ,but the principal philosophers1 as ,socrates1 ,plato1 and ,aristotle1 did not descend from this line1 but were ,ionics and true ,greeks1 of whom the first was ,thales ,milesius4444 ,socrates1 according to ,augustine in his #hth book1 is related to have been a disciple of ,archelaus4 ,this ,socrates is called the father of the great philosophers1 since he was the master of ,plato and ,aristotle1 from whom all the sects of philosophers descended4444 ,plato1 first learning what ,socrates and ,greece could teach1 made a laborious voyage to ,egypt1 to ,archytas of ,tarentum and ,timus1 as says ,jerome to ,paulinus4 ,and this ,plato is1 according to holy men1 preferred to all philosophers1 because he has written many excellent things concerning ,god1 and morality1 and a future life1 which agree with the divine wisdom of ,god4 ,and ,aristotle was born before the death of ,socrates1 since he was his hearer for three years1 as we read in the life of ,aristotle4444 ,this ,aristotle1 being made the master of ,alexander the ,great1 sent two thousand men into all regions of the earth1 to search out the nature of things1 as ,pliny relates in the #hth book of his ,naturalia1 and composed a thousand books1 as we read in his life4 ,footnote #fh3 ,ibid4 p4 #cf4 ,footnote #fi3 ,autonomatic4 ,footnote #gj3 ,op4 ,maj4 p4 #df4 ,footnote #ga3 ,see ,pref4 to ,jebb's edition4 ,the passages1 there quoted1 however1 are not extracts from the ,opus ,majus1 but 7apparently7 from the ,opus ,minus 7,,ms4 ,cott4 ,tib4 c4 #e47 ,si haberem potestatem supra libros ,aristotelis1 ego facerem omnes cremari2 quia non est nisi temporis amissio studere in illis1 et causa erroris1 et multiplicatio ignoranti ultra id quod valeat explicari4444 ,vulgus studentum cum capitibus suis non habet unde excitetur ad aliquid dignum1 et ideo languet et asininat circa male translata1 et tempus et studium amittit in omnibus et expensas4 ,footnote #gb3 ,part ii4 ,footnote #gc3 ,parts iv4 v4 and vi4 ,footnote #gd3 ,op4 ,maj4 p4 #dgf4 ,footnote #ge3 ,op4 ,maj4 p4 #ae4 ,footnote #gf3 ,ibid4 p4 #dde1 see also p4 #ddh4 ,scienti ali sciunt sua principia invenire per experimenta1 sed conclusiones per argumenta facta ex principiis inventis4 ,si vero debeant habere experientiam conclusionum suarum particularem et completam1 tunc oportet quod habeant per adjutorium istius scienti nobilis 7experimentalis74 ,footnote #gg3 ,op4 ,maj4 p4 #fj4 ,footnote #gh3 ,ibid4 p4 #fd4 ,footnote #gi3 ,veritates magnificas in terminis aliarum scientiarum in quas per nullam viam possunt ill scienti1 hc sola scientiarum domina speculativarum1 potest dare4 ,op4 ,maj4 p4 #dfe4 ,footnote #hj3 ,one of the ingredients of a preparation here mentioned1 is the flesh of a dragon1 which it appears is used as food by the ,ethiopians4 ,the mode of preparing this food cannot fail to amuse the reader4 ,where there are good flying dragons1 by the art which they possess1 they draw them out of their dens1 and have bridles and saddles in readiness1 and they ride upon them1 and make them bound about in the air in a violent manner1 that the hardness and toughness of the flesh may be reduced1 as boars are hunted and bulls are baited before they are killed for eating4 ,op4 ,maj4 p4 #dgj4 ,footnote #ha3 ,op4 ,maj4 p4 #dgc4 ,footnote #hb3 ,quoted by ,jebb1 ,pref4 to ,op4 ,maj4 ,footnote #hc3 ,mosheim1 ,hist4 iii4 #afa4 ,footnote #hd3 ,op4 ,maj4 p4 #eg4 ,footnote #he3 ,mosheim1 iii4 #afa4 ,,chapter ,,xii4 ,,the ,,revival ,,of ,,platonism4 #a4 ,causes of ,delay in the ,advance of ,knowledge4--,in the insight possessed by learned men into the method by which truth was to be discovered1 the fourteenth and fifteenth centuries went backwards1 rather than forwards1 from the point which had been reached in the thirteenth4 ,roger ,bacon had urged them to have recourse to experiment2 but they returned with additional and exclusive zeal to the more favourite employment of reasoning upon their own conceptions4 ,he had called upon them to look at the world without2 but their eyes forthwith turned back upon the world within4 ,in the constant oscillation of the human mind between ,ideas and ,facts1 after having for a moment touched the latter1 it seemed to swing back more impetuously to the former4 ,not only was the philosophy of ,aristotle firmly established for a considerable period1 but when men began to question its authority1 they attempted to set up in its place a philosophy still more purely ideal1 that of ,plato4 ,it was not till the actual progress of experimental knowledge for some centuries had given it a vast accumulation of force1 that it was able to break its way fully into the circle of speculative science4 ,the new ,platonist schoolmen had to run their course1 the practical discoverers had to prove their merit by their works1 the ,italian innovators had to utter their aspirations for a change1 before the second ,bacon could truly declare that the time for a fundamental reform was at length arrived4 ,it cannot but seem strange1 to any one who attempts to trace the general outline of the intellectual progress of man1 and who considers him as under the guidance of a ,providential sway1 that he should thus be permitted to wander so long in a wilderness of intellectual darkness2 and even to turn back1 by a perverse caprice as it might seem1 when on the very border of the brighter and better land which was his destined inheritance4 ,we do not attempt to solve this difficulty3 but such a course of things naturally suggests the thought1 that a progress in physical science is not the main object of man's career1 in the eyes of the ,power who directs the fortunes of our race4 ,we can easily conceive that it may have been necessary to man's general welfare that he should continue to turn his eyes inwards upon his own heart and faculties1 till ,law and ,duty1 ,religion and ,government1 ,faith and ,hope1 had been fully incorporated with all the past acquisitions of human intellect2 rather than that he should have rushed on into a train of discoveries tending to chain him to the objects and operations of the material world4 ,the systematic ,law#hf and philosophical ,theology which acquired their ascendancy in men's minds at the time of which we speak1 kept them engaged in a region of speculations which perhaps prepared the way for a profounder and wider civilization1 for a more elevated and spiritual character1 than might have been possible without such a preparation4 ,the great ,italian poet of the fourteenth century speaks with strong admiration of the founders of the system which prevailed in his time4 ,thomas1 ,albert1 ,gratian1 ,peter ,lombard1 occupy distinguished places in the ,paradise4 ,the first1 who is the poet's instructor1 says1-- ,io fui degli agni della santa greggia ,che ,domenico mena per cammino ,u' ben s'impingua se non si vaneggia4 ,questo che m' a destra piu vicino ,frate e maestro fummi2 ed esso ,alberto ,e di ,cologna1 ed io ,tomas d',aquino4444 ,quell' altro fiammeggiar esce del riso ,de ,grazian1 che l'uno et l'altro foro ,ajut si che piace in ,paradiso4 ,i1 then1 was of the lambs that ,dominic ,leads1 for his saintly flock1 along the way ,where well they thrive not swoln with vanity4 ,he nearest on my right-hand brother was ,and master to me2 ,albert of ,cologne ,is this2 and of ,aquinum ,thomas1 ,i4444 ,that next resplendence issues from the smile ,of ,gratian1 who to either forum lent ,such help as favour wins in ,paradise4 ,it appears probable that neither poetry1 nor painting1 nor the other arts which require for their perfection a lofty and spiritualized imagination1 would have appeared in the noble and beautiful forms which they assumed in the fourteenth and fifteenth century1 if men of genius had1 at the beginning of that period1 made it their main business to discover the laws of nature1 and to reduce them to a rigorous scientific form4 ,yet who can doubt that the absence of these touching and impressive works would have left one of the best and purest parts of man's nature without its due nutriment and development8 ,it may perhaps be a necessary condition in the progress of man1 that the ,arts which aim at beauty should reach their excellence before the ,sciences which seek speculative truth2 and if this be so1 we inherit1 from the middle ages1 treasures which may well reconcile us to the delay which took place in their cultivation of experimental science4 ,however this may be1 it is our business at present to trace the circumstances of this very lingering advance4 ,we have already noticed the contest of the ,nominalists and ,realists1 which was one form1 though1 with regard to scientific methods1 an unprofitable one1 of the antithesis of ,ideas and ,things4 ,though1 therefore1 this struggle continued1 we need not dwell upon it4 ,the ,nominalists denied the real existence of ,ideas1 which doctrine was to a great extent implied in the prevailing systems2 but the controversy in which they thus engaged1 did not lead them to seek for knowledge in a new field and by new methods4 ,the arguments which ,occam the ,nominalist opposes to those of ,duns ,scotus the ,realist1 are marked with the stamp of the same system1 and consist only in permutations and combinations of the same elementary conceptions4 ,it was not till the impulse of external circumstances was added to the discontent1 which the more stirring intellects felt towards the barren dogmatism of their age1 that the activity of the human mind was again called into full play1 and a new career of progression entered upon1 till then undreamt of1 except by a few prophetic spirits4 #b4 ,causes of ,progress4--,these circumstances were principally the revival of ,greek and ,roman literature1 the invention of ,printing1 the ,protestant ,reformation1 and a great number of curious discoveries and inventions in the arts1 which were soon succeeded by important steps in speculative physical science4 ,connected with the first of these events1 was the rise of a party of learned men who expressed their dissatisfaction with the ,aristotelian philosophy1 as it was then taught1 and manifested a strong preference for the views of ,plato4 ,it is by no means suitable to our plan to give a detailed account of this new ,platonic school2 but we may notice a few of the writers who belong to it1 so far at least as to indicate its influence upon the ,methods of pursuing science4 ,in the fourteenth century#hg1 the frequent intercourse of the most cultivated persons of the ,eastern and ,western ,empire1 the increased study of the ,greek language in ,italy1 the intellectual activity of the ,italian ,states1 the discovery of manuscripts of the classical authors1 were circumstances which excited or nourished a new and zealous study of the works of ,greek and ,roman genius4 ,the genuine writings of the ancients1 when presented in their native life and beauty1 instead of being seen only in those lifeless fragments and dull transformations which the scholastic system had exhibited1 excited an intense enthusiasm4 ,europe1 at that period1 might be represented by ,plato's beautiful allegory1 of a man who1 after being long kept in a dark cavern1 in which his knowledge of the external world is gathered from the images which stream through the chinks of his prison1 is at last led forth into the full blaze of day4 ,it was inevitable that such a change should animate men's efforts and enlarge their faculties4 ,greek literature became more and more known1 especially by the influence of learned men who came from ,constantinople into ,italy3 these teachers1 though they honoured ,aristotle1 reverenced ,plato no less1 and had never been accustomed to follow with servile submission of thought either these or any other leaders4 ,the effect of such influences soon reveals itself in the works of that period4 ,dante has woven into his ,divina ,commedia some of the ideas of ,platonism4 ,petrarch1 who had formed his mind by the study of ,cicero1 and had thus been inspired with a profound admiration for the literature of ,greece1 learnt ,greek from ,barlaam1 a monk who came as ambassador from the ,emperor of the ,east to the ,pope1 in #acci4 ,with this instructor1 the poet read the works of ,plato2 struck by their beauty1 he contributed1 by his writings and his conversation1 to awake in others an admiration and love for that philosopher1 which soon became strongly and extensively prevalent among the learned in ,italy4 #c4 ,hermolaus ,barbarus1 c4--,along with the feeling there prevailed also1 among those who had learnt to relish the genuine beauties of the ,greek and ,latin writers1 a strong disgust for the barbarisms in which the scholastic philosophy was clothed4 ,hermolaus ,barbarus#hh1 who was born in #aded1 at ,venice1 and had formed his taste by the study of classical literature1 translated1 among other learned works1 ,themistius's paraphrastic expositions of the ,physics of ,aristotle2 with the view of trying whether the ,aristotelian ,natural ,philosophy could not be presented in good ,latin1 which the scholastic teachers denied4 ,in his ,preface he expresses great indignation against those philosophers who have written and disputed on philosophical subjects in barbarous ,latin1 and in an uncultured style1 so that all refined minds are repelled from these studies by weariness and disgust4 ,they have1 he says1 by this barbarism1 endeavoured to secure to themselves1 in their own province1 a supremacy without rivals or opponents4 ,hence they maintain that mathematics1 philosophy1 jurisprudence1 cannot be expounded in correct ,latin2--that between these sciences and the genuine ,latin language there is a great gulf1 as between things that cannot be brought together3 and on this ground they blame those who combine the study of philology and eloquence with that of science4 ,this opinion1 adds ,hermolaus1 perverts and ruins our studies2 and is highly prejudicial and unworthy in respect to the state4 ,hermolaus awoke in others1 as for instance1 in ,john ,picus of ,mirandula1 the same dislike to the reigning school philosophy4 ,as an opponent of the same kind1 we may add ,marius ,nizolius of ,bersallo1 a scholar who carried his admiration of ,cicero to an exaggerated extent1 and who was led1 by a controversy with the defenders of the scholastic philosophy1 to publish 7#aeec7 a work ,on the ,true ,principles and ,true ,method of ,philosophizing4 ,in the title of this work1 he professes to give the true principles of almost all arts and sciences1 refuting and rejecting almost all the false principles of the ,logicians and ,metaphysicians4 ,but although1 in the work1 he attacks the scholastic philosophy1 he does little or nothing to justify the large pretensions of his title2 and he excited1 it is said1 little notice4 ,it is therefore curious that ,leibnitz should have thought it worth his while to re-edit this work1 which he did in #afgj1 adding remarks of his own4 #d4 ,nicolaus ,cusanus4--,without dwelling upon this opposition to the scholastic system on the ground of taste1 ,i shall notice somewhat further those writers who put forwards ,platonic views1 as fitted to complete or to replace the doctrines of ,aristotle4 ,among these1 ,i may place ,nicolaus ,cusanus1 7so called from ,cus1 a village on the ,moselle1 where he was born in #adja27 who was afterwards raised to the dignity of cardinal4 ,we might1 indeed1 at first be tempted to include ,cusanus among those persons who were led to reject the old philosophy by being themselves agents in the progressive movement of physical science4 ,for he published1 before ,copernicus1 and independently of him1 the doctrine that the earth is in motion#hi4 ,but it should be recollected that in order to see the possibility of this doctrine1 and its claims to acceptance1 no new reference to observation was requisite4 ,the ,heliocentric ,system was merely a new mode of representing to the mind facts1 with which all astronomers had long been familiar4 ,the system might very easily have been embraced and inculcated by ,plato himself2 as indeed it is said to have been actually taught by ,pythagoras4 ,the mere adoption of the ,heliocentric view1 therefore1 without attempting to realize the system in detail1 as ,copernicus did1 cannot entitle a writer of the fifteenth century to be looked upon as one of the authors of the discoveries of that period2 and we must consider ,cusanus as a speculative anti-,aristotelian1 rather than as a practical reformer4 ,the title of ,cusanus's book1 ,de ,doct ,ignoranti1 shows how far he was from agreeing with those who conceived that1 in the works of ,aristotle1 they had a full and complete system of all human knowledge4 ,at the outset of this book#ij1 he says1 after pointing out some difficulties in the received philosophy1 ,if1 therefore1 the case be so1 7as even the very profound ,aristotle1 in his ,first ,philosophy1 affirms17 that in things most manifest by nature1 there is a difficulty1 no less than for an owl to look at the sun2 since the appetite of knowledge is not implanted in us in vain1 we ought to desire to know that we are ignorant4 ,if we can fully attain to this1 we shall arrive at ,instructed ,ignorance4 ,how far he was from placing the source of knowledge in experience1 as opposed to ideas1 we may see in the following passage#ia from another work of his1 ,on ,conjectures4 ,conjectures must proceed from our mind1 as the real world proceeds from the infinite ,divine ,reason4 ,for since the human mind1 the lofty likeness of ,god1 participates1 as it may1 in the fruitfulness of the creative nature1 it doth from itself1 as the image of the ,omnipotent ,form1 bring forth reasonable thoughts which have a similitude to real existences4 ,thus the ,human ,mind exists as a conjectural form of the world1 as the ,divine ,mind is its real form4 ,we have here the ,platonic or ideal side of knowledge put prominently and exclusively forwards4 #e4 ,marsilius ,ficinus1 c4--,a person who had much more influence on the diffusion of ,platonism was ,marsilius ,ficinus1 a physician of ,florence4 ,in that city there prevailed1 at the time of which we speak1 the greatest enthusiasm for ,plato4 ,george ,gemistius ,pletho1 when in attendance upon the ,council of ,florence1 had imparted to many persons the doctrines of the ,greek philosopher2 and1 among others1 had infused a lively interest on this subject into the elder ,cosmo1 the head of the family of the ,medici4 ,cosmo formed the plan of founding a ,platonic academy4 ,ficinus#ib1 well instructed in the works of ,plato1 ,plotinus1 ,proclus1 and other ,platonists1 was selected to further this object1 and was employed in translating the works of these authors into ,latin4 ,it is not to our present purpose to consider the doctrines of this school1 except so far as they bear upon the nature and methods of knowledge2 and therefore ,i must pass by1 as ,i have in other instances done1 the greater part of their speculations1 which related to the nature of ,god1 the immortality of the soul1 the principles of ,goodness and ,beauty1 and other points of the same order4 ,the object of these and other ,platonists of this school1 however1 was not to expel the authority of ,aristotle by that of ,plato4 ,many of them had come to the conviction that the highest ends of philosophy were to be reached only by bringing into accordance the doctrines of ,plato and of ,aristotle4 ,of this opinion was ,john ,picus1 ,count of ,mirandula and ,concordia2 and under this persuasion he employed the whole of his life in labouring upon a work1 ,de ,concordi ,platonis et ,aristotelis1 which was not completed at the time of his death1 in #adid2 and has never been published4 ,but about a century later1 another writer of the same school1 ,francis ,patricius#ic1 pointing out the discrepancies between the two ,greek teachers1 urged the propriety of deposing ,aristotle from the supremacy he had so long enjoyed4 ,now all these doctrines1 and others not a few1 he says#id1 since they are ,platonic doctrines1 philosophically most true1 and consonant with the ,catholic faith1 whilst the ,aristotelian tenets are contrary to the faith1 and philosophically false1 who will not1 both as a ,christian and a ,philosopher1 prefer ,plato to ,aristotle8 ,and why should not hereafter1 in all the colleges and monasteries of ,europe1 the reading and study of ,plato be introduced8 ,why should not the philosophy of ,aristotle be forthwith exiled from such places8 ,why must men continue to drink the mortal poison of impiety from that source8 with much more in the same strain4 ,the ,platonic school1 of which we have spoken1 had1 however1 reached its highest point of prosperity before this time1 and was already declining4 ,about #aejj1 the ,platonists appeared to triumph over the ,peripatetics#ie2 but the death of their great patron1 ,cardinal ,bessarion1 about this time1 and we may add1 the hollowness of their system in many points1 and its want of fitness for the wants and expectations of the age1 turned men's thoughts partly back to the established ,aristotelian doctrines1 and partly forwards to schemes of bolder and fresher promise4 #f4 ,francis ,patricius4--,patricius1 of whom we have just spoken1 was one of those who had arrived at the conviction that the formation of a new philosophy1 and not merely the restoration of an old one1 was needed4 ,in #aeic1 appeared his ,nova de ,universis ,philosophia2 and the mode in which it begins#if can hardly fail to remind us of the expressions which ,francis ,bacon soon afterwards used in the opening of a work of the same nature4 ,francis ,patricius1 being about to found anew the true philosophy of the universe1 dared to begin by announcing the following indisputable principles4 ,here1 however1 the resemblance between ,patricius and true inductive philosophers ends4 ,his principles are barren priori axioms2 and his system has one main element1 ,light1 7,lux1 or ,lumen17 to which all operations of nature are referred4 ,in general cultivation1 and practical knowledge of nature1 he was distinguished among his contemporaries4 ,in various passages of his works he relates#ig observations which he had made in the course of his travels1 in ,cyprus1 ,corfu1 ,spain1 the mountains of the ,modenese1 and ,dalmatia1 which was his own country2 his observations relate to light1 the saltness of the sea1 its flux and reflux1 and other points of astronomy1 meteorology1 and natural history4 ,he speaks of the sex of plants#ih2 rejects judicial astrology2 and notices the astronomical systems of ,copernicus1 ,tycho1 ,fracastoro1 and ,torre4 ,but the mode in which he speaks of experiments proves1 what indeed is evident from the general scheme of his system1 that he had no due appreciation of the place which observation must hold in real and natural philosophy4 #g4 ,picus1 ,agrippa1 c4--,it had been seen in the later philosophical history of ,greece1 how readily the ideas of the ,platonic school lead on to a system of unfathomable and unbounded mysticism4 ,john ,picus1 of ,mirandula#ii1 added to the study of ,plato and the ,neoplatonists1 a mass of allegorical interpretations of the ,scriptures1 and the dreams of the ,cabbala1 a ,jewish system#ajj1 which pretends to explain how all things are an emanation of the ,deity4 ,to this his nephew1 ,francis ,picus1 added a reference to inward illumination#aja1 by which knowledge is obtained1 independently of the progress of reasoning4 ,john ,reuchlin1 or ,capnio1 born #adee2 ,john ,baptist ,helmont1 born #aegg2 ,francis ,mercurius ,helmont1 born #afah1 and others1 succeeded ,john ,picus in his admiration of the ,cabbala3 while others1 as ,jacob ,bhmen1 rested upon internal revelations like ,francis ,picus4 ,and thus we have a series of mystical writers1 continued into modern times1 who may be considered as the successors of the ,platonic school2 and who all exhibit views altogether erroneous with regard to the nature and origin of knowledge4 ,among the various dreams of this school are certain wide and loose analogies of terrestrial and spiritual things4 ,thus in the writings of ,cornelius ,agrippa 7who was born #adhg1 at ,cologne7 we have such systems as the following#ajb3--,since there is a threefold world1 elemental1 celestial1 and intellectual1 and each lower one is governed by that above it1 and receives the influence of its powers3 so that the very ,archetype and ,supreme ,author transfuses the virtues of his omnipotence into us through angels1 heavens1 stars1 elements1 animals1 plants1 stones1--into us1 ,i say1 for whose service he has framed and created all these things2--the ,magi do not think it irrational that we should be able to ascend by the same degrees1 the same worlds1 to this ,archetype of the world1 the ,author and ,first ,cause of all1 of whom all things are1 and from whom they proceed2 and should not only avail ourselves of those powers which exist in the nobler works of creation1 but also should be able to attract other powers1 and add them to these4 ,agrippa's work1 ,de ,vanitate ,scientiarum1 may be said rather to have a skeptical and cynical1 than a ,platonic1 character4 ,it is a declamation#ajc1 in a melancholy mood1 against the condition of the sciences in his time4 ,his indignation at the worldly success of men whom he considered inferior to himself1 had1 he says1 metamorphosed him into a dog1 as the poets relate of ,hecuba of ,troy1 so that his impulse was to snarl and bark4 ,his professed purpose1 however1 was to expose the dogmatism1 the servility1 the self-conceit1 and the neglect of religious truth which prevailed in the reigning ,schools of philosophy4 ,his views of the nature of science1 and the modes of improving its cultivation1 are too imperfect and vague to allow us to rank him among the reformers of science4 #h4 ,paracelsus1 ,fludd1 c4--,the celebrated ,paracelsus#ajd put himself forwards as a reformer in philosophy1 and obtained no small number of adherents4 ,he was1 in most respects1 a shallow and impudent pretender2 and had small knowledge of the literature or science of his time3 but by the tone of his speaking and writing he manifestly belongs to the mystical school of which we are now speaking4 ,perhaps by the boldness with which he proposed new systems1 and by connecting these with the practical doctrines of medicine1 he contributed something to the introduction of a new philosophy4 ,we have seen in the ,history of ,chemistry that he was the author of the system of ,three ,principles1 7salt1 sulphur1 and mercury17 which replaced the ancient doctrine of ,four ,elements1 and prepared the way for a true science of chemistry4 ,but the salt1 sulphur1 and mercury of ,paracelsus were not1 he tells his disciples1 the visible bodies which we call by those names1 but certain invisible1 astral1 or sidereal elements4 ,the astral salt is the basis of the solidity and incombustible parts in bodies2 the astral sulphur is the source of combustion and vegetation2 the astral mercury is the origin of fluidity and volatility4 ,and again1 these three elements are analogous to the three elements of man1--,body1 ,spirit1 and ,soul4 ,a writer of our own country1 belonging to this mystical school1 is ,robert ,fludd1 or ,de ,fluctibus1 who was born in #aega1 in ,kent1 and after pursuing his studies at ,oxford1 travelled for several years4 ,of all the ,theosophists and ,mystics1 he is by much the most learned2 and was engaged in various controversies with ,mersenne1 ,gassendi1 ,kepler1 and others4 ,he thus brings us in contact with the next class of philosophers whom we have to consider1 the practical reformers of philosophy2--those who furthered the cause of science by making1 promulgating1 or defending the great discoveries which now began to occupy men4 ,he adopted the principle1 which we have noticed elsewhere#aje1 of the analogy of the ,macrocosm and ,microcosm1 the world of nature and the world of man4 ,his system contains such a mixture and confusion of physical and metaphysical doctrines as might be expected from his ground-plan1 and from his school4 ,indeed his object1 the general object of mystical speculators1 is to identify physical with spiritual truths4 ,yet the influence of the practical experimental philosophy which was now gaining ground in the world may be traced in him4 ,thus he refers to experiments on distillation to prove the existence and relation of the regions of water1 air1 and fire1 and of the spirits which correspond to them2 and is conceived1 by some persons#ajf1 to have anticipated ,torricelli in the invention of the ,barometer4 ,we need no further follow the speculations of this school4 ,we see already abundant reason why the reform of the methods of pursuing science could not proceed from the ,platonists4 ,instead of seeking knowledge by experiment1 they immersed themselves deeper than even the ,aristotelians had done in traditionary lore1 or turned their eyes inwards in search of an internal illumination4 ,some attempts were made to remedy the defects of philosophy by a recourse to the doctrines of other sects of antiquity1 when men began to feel more distinctly the need of a more connected and solid knowledge of nature than the established system gave them4 ,among these attempts were those of ,berigard#ajg1 ,magernus1 and especially ,gassendi1 to bring into repute the philosophy of the ,ionian school1 of ,democritus and of ,epicurus4 ,but these endeavours were posterior in time to the new impulse given to knowledge by ,copernicus1 ,kepler1 and ,galileo1 and were influenced by views arising out of the success of these discoveries1 and they must1 therefore1 be considered hereafter4 ,in the mean time1 some independent efforts 7arising from speculative rather than practical reformers7 were made to cast off the yoke of the ,aristotelian dogmatism1 and to apprehend the true form of that new philosophy which the most active and hopeful minds saw to be needed2 and we must give some account of these attempts1 before we can commit ourselves to the full stream of progressive philosophy4 ,,footnotes3 ,footnote #hf3 ,gratian published the ,decretals in the twelfth century2 and the ,canon and ,civil ,law became a regular study in the universities soon afterwards4 ,footnote #hg3 ,tenneman1 ix4 #d4 ,footnote #hh3 ,tenneman1 ix4 #be4 ,footnote #hi3 ,jam nobis manifestum est terram istam in veritate moveri1 c4--,de ,doct ,ignoranti1 lib4 ii4 c4 xii4 ,footnote #ij3 ,de ,doct4 ,ignor4 lib4 i4 c4 i4 ,footnote #ia3 ,de ,conjecturis1 lib4 i4 c4 iii4 iv4 ,footnote #ib3 ,born in #adcc4 ,footnote #ic3 ,born #aebi1 died #aeig4 ,footnote #id3 ,aristoteles ,exotericus1 p4 #ej4 ,footnote #ie3 ,tiraboschi1 t4 vii4 pt4 ii4 p4 #daa4 ,footnote #if3 ,franciscus ,patricius1 novam veram integram de universis conditurus philosophiam1 sequentia uti verissima prnuntiare est ausus4 ,prnunciata ordine persecutus1 divinis oraculis1 geometricis rationibus1 clarissimisque experimentis comprobavit4 ,ante primum nihil1 ,post primum omnia1 ,a principio omnia1 c4 ,his other works are ,panaugia1 ,pancosmia1 ,dissertations ,peripatetic4 ,footnote #ig3 ,tiraboschi1 t4 vii4 pt4 ii4 p4 #daa4 ,footnote #ih3 ,dissert4 ,perip4 t4 ii4 lib4 v4 sub fin4 ,footnote #ii3 ,tenneman1 ix4 #adh4 ,footnote #ajj3 ,tenneman1 ix4 #afg4 ,footnote #aja3 ,ibid4 #aeh4 ,footnote #ajb3 ,agrippa1 ,de ,occult4 ,phil4 lib4 i4 c4 l4 ,footnote #ajc3 ,written in #aebf4 ,footnote #ajd3 ,philip ,aurelius ,theophrastus ,bombastus von ,hohenheim1 also called ,paracelsus ,eremita1 born at ,einsiedlen in ,switzerland1 in #adic4 ,footnote #aje3 ,hist4 ,sc4 ,id4 b4 ix4 c4 #b4 sect4 #a4 ,the ,mystical ,school of ,biology4 ,footnote #ajf3 ,tenneman1 ix4 #bba4 ,footnote #ajg3 ,tenneman1 ix4 #bfe4 ,,chapter ,,xiii4 ,,the ,,theoretical ,,reformers ,,of ,,science4 ,we have already seen that ,patricius1 about the middle of the sixteenth century1 announced his purpose of founding anew the whole fabric of philosophy2 but that1 in executing this plan1 he ran into wide and baseless hypotheses1 suggested by priori conceptions rather than by external observation2 and that he was further misled by fanciful analogies resembling those which the ,platonic mystics loved to contemplate4 ,the same time1 and the period which followed it1 produced several other essays which were of the same nature1 with the exception of their being free from the peculiar tendencies of the ,platonic school3 and these insurrections against the authority of the established dogmas1 although they did not directly substitute a better positive system in the place of that which they assailed1 shook the authority of the ,aristotelian system1 and led to its overthrow2 which took place as soon as these theoretical reformers were aided by practical reformers4 #a4 ,bernardinus ,telesius4--,italy1 always1 in modern times1 fertile in the beginnings of new systems1 was the soil on which these innovators arose4 ,the earliest and most conspicuous of them is ,bernardinus ,telesius1 who was born in #aejh1 at ,cosenza1 in the kingdom of ,naples4 ,his studies1 carried on with great zeal and ability1 first at ,milan and then at ,rome1 made him well acquainted with the knowledge of his times2 but his own reflections convinced him that the basis of science1 as then received1 was altogether erroneous2 and led him to attempt a reform1 with which view1 in #aefe1 he published1 at ,rome1 his work#ajh1 ,bernardinus ,telesius1 of ,cosenza1 on the ,nature of ,things1 according to principles of his own4 ,in the preface of this work he gives a short account#aji of the train of reflection by which he was led to put himself in opposition to the ,aristotelian philosophy4 ,this kind of autobiography occurs not unfrequently in the writings of theoretical reformers2 and shows how livelily they felt the novelty of their undertaking4 ,after the storm and sack of ,rome in #aebg1 ,telesius retired to ,padua1 as a peaceful seat of the muses2 and there studied philosophy and mathematics1 with great zeal1 under the direction of ,jerome ,amalthus and ,frederic ,delphinus4 ,in these studies he made great progress2 and the knowledge which he thus acquired threw a new light upon his view of the ,aristotelian philosophy4 ,he undertook a closer examination of the ,physical ,doctrines of ,aristotle2 and as the result of this1 he was astonished how it could have been possible that so many excellent men1 so many nations1 and even almost the whole human race1 should1 for so long a time1 have allowed themselves to be carried away by a blind reverence for a teacher1 who had committed errors so numerous and grave as he perceived to exist in the philosopher4 ,along with this view of the insufficiency of the ,aristotelian philosophy1 arose1 at an early period1 the thought of erecting a better system in its place4 ,with this purpose he left ,padua1 when he had received the degree of ,doctor1 and went to ,rome1 where he was encouraged in his design by the approval and friendly exhortations of distinguished men of letters1 amongst whom were ,ubaldino ,bandinelli and ,giovanni della ,casa4 ,from ,rome he went to his native place1 when the incidents and occupations of a married life for a while interrupted his philosophical project4 ,but after his wife was dead1 and his eldest son grown to manhood1 he resumed with ardour the scheme of his youth2 again studied the works of ,aristotle and other philosophers1 and composed and published the first two books of his treatise4 ,the opening to this work sufficiently exhibits the spirit in which it was conceived4 ,its object is stated in the title to be to show1 that the construction of the world1 the magnitude and nature of the bodies contained in it1 are not to be investigated by reasoning1 which was done by the ancients1 but are to be apprehended by the senses1 and collected from the things themselves4 ,and the ,proem is in the same strain4 ,they who before us have inquired concerning the construction of this world and of the things which it contains1 seem indeed to have prosecuted their examination with protracted vigils and great labour1 but never to have looked at it4 ,and thus1 he observes1 they found nothing but error4 ,this he ascribes to their presumption4 ,for1 as it were1 attempting to rival ,god in wisdom1 and venturing to seek for the principles and causes of the world by the light of their own reason1 and thinking they had found what they had only invented1 they made an arbitrary world of their own4 ,we then1 he adds1 not relying on ourselves1 and of a duller intellect than they1 propose to ourselves to turn our regards to the world itself and its parts4 ,the execution of the work1 however1 by no means corresponds to the announcement4 ,the doctrines of ,aristotle are indeed attacked2 and the objections to these1 and to other received opinions1 form a large part of the work4 ,but these objections are supported by priori reasoning1 and not by experiments4 ,and thus1 rejecting the ,aristotelian physics1 he proposes a system at least equally baseless2 although1 no doubt1 grateful to the author from its sweeping and apparently simple character4 ,he assumes three principles1 ,heat1 ,cold1 and ,matter3 ,heat is the principle of motion1 ,cold of immobility1 and ,matter is the corporeal substratum1 in which these incorporeal and active principles produce their effects4 ,it is easy to imagine that1 by combining and separating these abstractions in various ways1 a sort of account of many natural phenomena may be given2 but it is impossible to ascribe any real value to such a system4 ,the merit of ,telesius must be considered to consist in his rejection of the ,aristotelian errors1 in his perception of the necessity of a reform in the method of philosophizing1 and in his persuasion that this reform must be founded on experiments rather than on reasoning4 ,when he said#aaj1 ,we propose to ourselves to turn our eyes to the world itself1 and its parts1 their passions1 actions1 operations1 and species1 his view of the course to be followed was right2 but his purpose remained but ill fulfilled1 by the arbitrary edifice of abstract conceptions which his system exhibits4 ,francis ,bacon1 who1 about half a century later1 treated the subject of a reform of philosophy in a far more penetrating and masterly manner1 has given us his judgment of ,telesius4 ,in his view1 he takes ,telesius as the restorer of the ,atomic philosophy1 which ,democritus and ,parmenides taught among the ancients2 and according to his custom1 he presents an image of this philosophy in an adaptation of a portion of ancient mythology#aaa4 ,the ,celestial ,cupid1 who with ,clus1 was the parent of the ,gods and of the ,universe1 is exhibited as a representation of matter and its properties1 according to the ,democritean philosophy4 ,concerning ,telesius1 says ,bacon1 we think well1 and acknowledge him as a lover of truth1 a useful contributor to science1 an amender of some tenets1 the first of recent men4 ,but we have to do with him as the restorer of the philosophy of ,parmenides1 to whom much reverence is due4 ,with regard to this philosophy1 he pronounces a judgment which very truly expresses the cause of its rashness and emptiness4 ,it is1 he says1 such a system#aab as naturally proceeds from the intellect1 abandoned to its own impulse1 and not rising from experience to theory continuously and successively4 ,accordingly1 he says that1 ,telesius1 although learned in the ,peripatetic philosophy 7if that were anything71 which indeed1 he has turned against the teachers of it1 is hindered by his affirmations1 and is more successful in destroying than in building4 ,the work of ,telesius excited no small notice1 and was placed in the ,index ,expurgatorius4 ,it made many disciples1 a consequence probably due to its spirit of system-making1 no less than to its promise of reform1 or its acuteness of argument2 for till trial and reflection have taught man modesty and moderation1 he can never be content to receive knowledge in the small successive instalments in which nature gives it forth to him4 ,it is the makers of large systems1 arranged with an appearance of completeness and symmetry1 who1 principally1 give rise to ,schools of philosophy4 #b4 7,thomas ,campanella74--,accordingly1 ,telesius may be looked upon as the founder of a ,school4 ,his most distinguished successor was ,thomas ,campanella1 who was born in #aefh1 at ,stilo1 in ,calabria4 ,he showed great talents at an early age1 prosecuting his studies at ,cosenza1 the birth-place of the great opponent of ,aristotle and reformer of philosophy4 ,he1 too1 has given us an account#aac of the course of thought by which he was led to become an innovator4 ,being afraid that not genuine truth1 but falsehood in the place of truth1 was the tenant of the ,peripatetic ,school1 ,i examined all the ,greek1 ,latin1 and ,arabic commentators of ,aristotle1 and hesitated more and more1 as ,i sought to learn whether what they have said were also to be read in the world itself1 which ,i had been taught by learned men was the living book of ,god4 ,and as my doctors could not satisfy my scruples1 ,i resolved to read all the books of ,plato1 ,pliny1 ,galen1 the ,stoics1 and the ,democriteans1 and especially those of ,telesius2 and to compare them with that first and original writing1 the world2 that thus from the primary autograph1 ,i might learn if the copies contained anything false4 ,campanella probably refers here to an expression of ,plato1 who says1 the world is ,god's epistle to mankind4 ,and this image1 of the natural world as an original manuscript1 while human systems of philosophy are but copies1 and may be false ones1 became a favourite thought of the reformers1 and appears repeatedly in their writings from this time4 ,when ,i held my public disputation at ,cosenza1 ,campanella proceeds1 and still more1 when ,i conversed privately with the brethren of the monastery1 ,i found little satisfaction in their answers2 but ,telesius delighted me1 on account of his freedom in philosophizing1 and because he rested upon the nature of things1 and not upon the assertions of men4 ,with these views and feelings1 it is not wonderful that ,campanella1 at the early age of twenty-two 7#aeij17 published a work remarkable for the bold promise of its title3 ,thomas ,campanella's ,philosophy demonstrated to the senses1 against those who have philosophized in an arbitrary and dogmatical manner1 not taking nature for their guide2 in which the errors of ,aristotle and his followers are refuted from their own assertions and the laws of nature3 and all the imaginations feigned in the place of nature by the ,peripatetics are altogether rejected2 with a true defence of ,bernardin ,telesius of ,cosenza1 the greatest of philosophers2 confirmed by the opinions of the ancients1 here elucidated and defended1 especially those of the ,platonists4 ,this work was written in answer to a book published against ,telesius by a ,neapolitan professor named ,marta2 and it was the boast of the young author that he had only employed eleven months in the composition of his defence1 while his adversary had been engaged eleven years in preparing his attack4 ,campanella found a favourable reception in the house of the ,marchese ,lavelli1 and there employed himself in the composition of an additional work1 entitled ,on the ,sense of ,things and ,magic1 and in other literary labours4 ,these1 however1 are full of the indications of an enthusiastic temper1 inclined to mystical devotion1 and of opinions bearing the cast of pantheism4 ,for instance1 the title of the book last quoted sets forth as demonstrated in the course of the work1 that the world is the living and intelligent statue of ,god2 and that all its parts1 and particles of parts1 are endowed some with a clearer1 some with a more obscure sense1 such as suffices for the preservation of each and of the whole4 ,besides these opinions1 which could not fail to make him obnoxious to the religious authorities1 ,campanella#aad engaged in schemes of political revolution1 which involved him in danger and calamity4 ,he took part in a conspiracy1 of which the object was to cast off the tyranny of ,spain1 and to make ,calabria a republic4 ,this design was discovered2 and ,campanella1 along with others1 was thrown into prison and subjected to torture4 ,he was kept in confinement twenty-seven years2 and at last obtained his liberation by the interposition of ,pope ,urban ,,viii4 ,he was1 however1 still in danger from the ,neapolitan ,inquisition2 and escaped in disguise to ,paris1 where he received a pension from the king1 and lived in intercourse with the most eminent men of letters4 ,he died there in #afci4 ,campanella was a contemporary of ,francis ,bacon1 whom we must consider as belonging to an epoch to which the ,calabrian school of innovators was only a prelude4 ,i shall not therefore further follow the connexion of writers of this order4 ,tobias ,adami1 a ,saxon writer1 an admirer of ,campanella's works1 employed himself1 about #afbj1 in adapting them to the ,german public1 and in recommending them strongly to ,german philosophers4 ,descartes1 and even ,bacon1 may be considered as successors of ,campanella2 for they too were theoretical reformers2 but they enjoyed the advantage of the light which had1 in the mean time1 been thrown upon the philosophy of science1 by the great practical advances of ,kepler1 ,galileo1 and others4 ,to these practical reformers we must soon turn our attention3 but we may first notice one or two additional circumstances belonging to our present subject4 ,campanella remarks that both the ,peripatetics and the ,platonists conducted the learner to knowledge by a long and circuitous path1 which he wished to shorten by setting out from the sense4 ,without speaking of the methods which he proposed1 we may notice one maxim#aae of considerable value which he propounds1 and to which we have already been led4 ,we begin to reason from sensible objects1 and definition is the end and epilogue of science4 ,it is not the beginning of our knowing1 but only of our teaching4 #c4 7,andrew ,csalpinus47--,the same maxim had already been announced by ,csalpinus1 a contemporary of ,telesius2 7he was born at ,arezzo in #aebj1 and died at ,rome in #afjc74 ,csalpinus is a great name in science1 though professedly an ,aristotelian4 ,it has been seen in the ,history of ,science#aaf1 that he formed the first great epoch of the science of botany by his systematic arrangement of plants1 and that in this task he had no successor for nearly a century4 ,he also approached near to the great discovery of the circulation of the blood#aag4 ,he takes a view of science which includes the remark that we have just quoted from ,campanella3 ,we reach perfect knowledge by three steps3 ,induction1 ,division1 ,definition4 ,by ,induction1 we collect likeness and agreement from observation2 by ,division1 we collect unlikeness and disagreement2 by ,definition1 we learn the proper substance of each object4 ,induction makes universals from particulars1 and offers to the mind all intelligible matter2 ,division discovers the difference of universals1 and leads to species2 ,definition resolves species into their principles and elements#aah4 ,without asserting this to be rigorously correct1 it is incomparably more true and philosophical than the opposite view1 which represents definition as the beginning of our knowledge2 and the establishment of such a doctrine is a material step in inductive philosophy#aai4 #d4 7,giordano ,bruno47--,among the ,italian innovators of this time we must notice the unfortunate ,giordano ,bruno1 who was born at ,nola about #aeej and burnt at ,rome in #afjj4 ,he is1 however1 a reformer of a different school from ,campanella2 for he derives his philosophy from ,ideas and not from ,observation4 ,he represents himself as the author of a new doctrine1 which he terms the ,nolan ,philosophy4 ,he was a zealous promulgator and defender of the ,copernican system of the universe1 as we have noticed in the ,history of ,science#abj4 ,campanella also wrote in defence of that system4 ,it is worthy of remark that a thought which is often quoted from ,francis ,bacon1 occurs in ,bruno's ,cena di ,cenere1 published in #aehd2 ,i mean1 the notion that the later times are more aged than the earlier4 ,in the course of the dialogue1 the ,pedant1 who is one of the interlocutors1 says1 ,in antiquity is wisdom2 to which the ,philosophical ,character replies1 ,if you knew what you were talking about1 you would see that your principle leads to the opposite result of that which you wish to infer2--,i mean1 that we are older1 and have lived longer1 than our predecessors4 ,he then proceeds to apply this1 by tracing the course of astronomy through the earlier astronomers up to ,copernicus4 #e4 7,peter ,ramus47--,i will notice one other reformer of this period1 who attacked the ,aristotelian system on another side1 on which it was considered to be most impregnable4 ,this was ,peter ,ramus17born in ,picardy in #aeae17 who ventured to denounce the ,logic of ,aristotle as unphilosophical and useless4 ,after showing an extraordinary aptitude for the acquirement of knowledge in his youth1 when he proceeded to the degree of ,master of ,arts1 he astonished his examiners by choosing for the subject of the requisite disputation the thesis#aba1 that what ,aristotle has said is all wrong4 ,this position1 so startling in #aece1 he defended for the whole day1 without being defeated4 ,this was1 however1 only a formal academical exercise1 which did not necessarily imply any permanent conviction of the opinion thus expressed4 ,but his mind was really labouring to detect and remedy the errors which he thus proclaimed4 ,from him1 as from the other reformers of this time1 we have an account of this mental struggle#abb4 ,he says1 in a work on this subject1 ,i will candidly and simply explain how ,i was delivered from the darkness of ,aristotle4 ,when1 according to the laws of our university1 ,i had spent three years and a half in the ,aristotelian philosophy1 and was now invested with the philosophical laurel as a ,master of ,arts1 ,i took an account of the time which ,i had consumed in this study1 and considered on what subjects ,i should employ this logical art of ,aristotle1 which ,i had learnt with so much labour and noise1 ,i found it made me not more versed in history or antiquities1 more eloquent in discourse1 more ready in verse1 more wise in any subject4 ,alas for me6 how was ,i overpowered1 how deeply did ,i groan1 how did ,i deplore my lot and my nature1 how did ,i deem myself to be by some unhappy and dismal fate and frame of mind abhorrent from the ,muses1 when ,i found that ,i was one who1 after all my pains1 could reap no benefit from that wisdom of which ,i heard so much1 as being contained in the ,logic of ,aristotle4 ,he then relates that he was led to the study of the ,dialogues of ,plato1 and was delighted with the kind of analysis of the subjects discussed which ,socrates is there represented as executing4 ,well1 he adds1 ,i began thus to reflect within myself--7,i should have thought it impious to say it to another7--,what1 ,i pray you1 prevents me from socratizing2 and from asking1 without regard to ,aristotle's authority1 whether ,aristotle's ,logic be true and correct8 ,it may be that that philosopher leads us wrong2 and if so1 no wonder that ,i cannot find in his books the treasure which is not there4 ,what if his dogmas be mere figments8 ,do ,i not tease and torment myself in vain1 trying to get a harvest from a barren soil8 ,he convinced himself that the ,aristotelian logic was worthless3 and constructed a new system of ,logic1 founded mainly on the ,platonic process of exhausting a subject by analytical classification of its parts4 ,both works1 his ,animadversions on ,aristotle1 and his ,logic1 appeared in #aedc4 ,the learned world was startled and shocked to find a young man1 on his first entrance into life1 condemning as faulty1 fallacious1 and useless1 that part of ,aristotle's works which had always hitherto been held as a masterpiece of philosophical acuteness1 and as the ,organon of scientific reasoning4 ,and in truth1 it must be granted that ,ramus does not appear to have understood the real nature and object of ,aristotle's ,logic2 while his own system could not supply the place of the old one1 and was not of much real value4 ,this dissent from the established doctrines was1 however1 not only condemned but punished4 ,the printing and selling of his books was forbidden through ,france2 and ,ramus was stigmatized by a sentence#abc which declared him rash1 arrogant1 impudent1 and ignorant1 and prohibited from teaching logic and philosophy4 ,he was1 however1 afterwards restored to the office of professor3 and though much attacked1 persisted in his plan of reforming1 not only ,logic but ,physics and ,metaphysics4 ,he made his position still more dangerous by adopting the reformed religion2 and during the unhappy civil wars of ,france1 he was deprived of his professorship1 driven from ,paris1 and had his library plundered4 ,he endeavoured1 but in vain1 to engage a ,german professor1 ,schegk1 to undertake the reform of the ,aristotelian ,physics2 a portion of knowledge in which he felt himself not to be strong4 ,unhappily for himself1 he afterwards returned to ,paris1 where he perished in the massacre of ,st4 ,bartholomew in #aegb4 ,ramus's main objection to the ,aristotelian ,logic is1 that it is not the image of the natural process of thought2 an objection which shows little philosophical insight2 for the course by which we obtain knowledge may well differ from the order in which our knowledge1 when obtained1 is exhibited4 ,we have already seen that ,ramus's contemporaries1 ,csalpinus and ,campanella1 had a wiser view2 placing definition as the last step in knowing1 but the first in teaching4 ,but the effect which ,ramus produced was by no means slight4 ,he aided powerfully in turning the minds of men to question the authority of ,aristotle on all points2 and had many followers1 especially among the ,protestants4 ,among the rest1 ,milton1 our great poet1 published ,artis ,logic plenior ,institutio ad ,petri ,rami methodum concinnata2 but this work1 appearing in #afgb1 belongs to a succeeding period4 #f4 7,the ,reformers in general74--,it is impossible not to be struck with the series of misfortunes which assailed the reformers of philosophy of the period we have had to review4 ,roger ,bacon was repeatedly condemned and imprisoned2 and1 not to speak of others who suffered under the imputation of magical arts1 ,telesius is said#abd to have been driven from ,naples to his native city by calumny and envy2 ,csalpinus was accused of atheism#abe2 ,campanella was imprisoned for twenty-seven years and tortured2 ,giordano ,bruno was burnt at ,rome as a heretic2 ,ramus was persecuted during his life1 and finally murdered by his personal enemy ,jacques ,charpentier1 in a massacre of which the plea was religion4 ,it is true1 that for the most part these misfortunes were not principally due to the attempts at philosophical reform1 but were connected rather with politics or religion4 ,but we cannot doubt that the spirit which led men to assail the received philosophy1 might readily incline them to reject some tenets of the established religion2 since the boundary line of these subjects is difficult to draw4 ,and as we have seen1 there was in most of the persons of whom we have spoken1 not only a well-founded persuasion of the defects of existing systems1 but an eager spirit of change1 and a sanguine anticipation of some wide and lofty philosophy1 which was soon to elevate the minds and conditions of men4 ,the most unfortunate were1 for the most part1 the least temperate and judicious reformers4 ,patricius1 who1 as we have seen1 declared himself against the ,aristotelian philosophy1 lived and died at ,rome in peace and honour#abf4 #g4 7,melancthon47--,it is not easy to point out with precision the connexion between the efforts at a ,reform in ,philosophy1 and the great ,reformation of ,religion in the sixteenth century4 ,the disposition to assert 7practically at least7 a freedom of thinking1 and to reject the corruptions which tradition had introduced and authority maintained1 naturally extended its influence from one subject to another2 and especially in subjects so nearly connected as theology and philosophy4 ,the ,protestants1 however1 did not reject the ,aristotelian system2 they only reformed it1 by going back to the original works of the author1 and by reducing it to a conformity with ,scripture4 ,in this reform1 ,melancthon was the chief author1 and wrote works on ,logic1 ,physics1 ,morals1 and ,metaphysics1 which were used among ,protestants4 ,on the subject of the origin of our knowledge1 his views contained a very philosophical improvement of the ,aristotelian doctrines4 ,he recognized the importance of ,ideas1 as well as of ,experience4 ,we could not1 he says#abg1 proceed to reason at all1 except there were by nature innate in man certain fixed points1 that is1 principles of science2--as ,number1 the recognition of ,order and ,proportion1 logical1 geometrical1 physical and moral ,principles4 ,physical principles are such as these1--everything which exists proceeds from a cause1--a body cannot be in two places at once1--time is a continued series of things or of motions1--and the like4 ,it is not difficult to see that such ,principles partake of the nature of the ,fundamental ,ideas which we have attempted to arrange and enumerate in a previous part of this work4 ,before we proceed to the next chapter1 which treats of the ,practical ,reformers of ,scientific ,method1 let us for an instant look at the strong persuasion implied in the titles of the works of this period1 that the time of a philosophical revolution was at hand4 ,telesius published ,de ,rerum ,natura juxta propria principia2 ,francis ,helmont1 ,philosophia vulgaris refutata2 ,patricius1 ,nova de ,universis ,philosophia2 ,campanella1 ,philosophia sensibus demonstrata1 adversus errores ,aristotelis2 ,bruno professed himself the author of a ,nolan ,philosophy2 and ,ramus of a ,new ,logic4 ,the age announced itself pregnant2 and the eyes of all who took an interest in the intellectual fortunes of the race1 were looking eagerly for the expected offspring4 ,,footnotes3 ,footnote #ajh3 ,bernardini ,telesii ,consentini ,de ,rerum ,natura juxta propria ,principia4 ,footnote #aji3 ,i take this account from ,tenneman3 this ,proem was omitted in subsequent editions of ,telesius1 and is not in the one which ,i have consulted4 ,tenneman1 ,gesch4 d4 ,phil4 ix4 #bhj4 ,footnote #aaj3 ,proem4 ,footnote #aaa3 ,de ,principiis atque ,originibus secundum fabulas ,cupidinis et ,cli3 sive ,parmenidis et ,telesii et prcipu ,democriti ,philosophia tractata in ,fabula de ,cupidine4 ,footnote #aab3 ,talia sunt qualia possunt esse ea qu ab intellectu sibi permisso1 nec ab experimentis continenter et gradatim sublevato1 profecta videntur4 ,footnote #aac3 ,thom4 ,campanella de ,libris propriis1 as quoted in ,tenneman1 ix4 #bia4 ,footnote #aad3 ,economisti ,italiani1 t4 i4 p4 xxxiii4 ,footnote #aae3 ,tenneman1 ix4 #cje4 ,footnote #aaf3 ,hist4 ,ind4 ,sc4 b4 xvi4 c4 iii4 sect4 #b4 ,footnote #aag3 ,ibid4 b4 xvii4 c4 ii4 sect4 #a4 ,footnote #aah3 ,qust4 ,peripat4 i4 #a4 ,footnote #aai3 ,tenneman1 ix4 #ajh4 ,footnote #abj3 ,hist4 ,ind4 ,sc4 b4 v4 c4 iii4 sect4 #b4 ,footnote #aba3 ,tenneman1 ix4 #dbj4 ,qucunque ab ,aristotele dicta essent commenticia esse4 ,freigius1 ,vita ,petri ,rami1 p4 #aj4 ,footnote #abb3 ,rami1 ,animadv4 ,aristot4 i4 iv4 ,footnote #abc3 ,see ,hist4 ,ind4 ,sc4 b4 iv4 c4 iv4 sect4 #d4 ,footnote #abd3 ,tenneman1 ix4 #bcj4 ,footnote #abe3 ,ibid4 #ajh4 ,footnote #abf3 ,tenneman1 ix4 #bdf4 ,footnote #abg3 ,melancthon1 ,de ,anima1 p4 #bjg1 quoted in ,tenneman1 ix4 #aba4 ,,chapter ,,xiv4 ,,the ,,practical ,,reformers ,,of ,,science4 #a4 ,character of the ,practical ,reformers4--,we now come to a class of speculators who had perhaps a greater share in bringing about the change from stationary to progressive knowledge1 than those writers who so loudly announced the revolution4 ,the mode in which the philosophers of whom we now speak produced their impressions on men's minds1 was very different from the procedure of the theoretical reformers4 ,what these talked of1 they did2 what these promised1 they performed4 ,while the theorists concerning knowledge proclaimed that great advances were to be made1 the practical discoverers went steadily forwards4 ,while one class spoke of a complete ,reform of scientific ,methods1 the other1 boasting little1 and often thinking little of ,method1 proved the novelty of their instrument by obtaining new results4 ,while the metaphysicians were exhorting men to consult experience and the senses1 the physicists were examining nature by such means with unparalleled success4 ,and while the former1 even when they did for a moment refer to facts1 soon rushed back into their own region of ideas1 and tried at once to seize the widest generalizations1 the latter1 fastening their attention upon the phenomena1 and trying to reduce them to laws1 were carried forwards by steps measured and gradual1 such as no conjectural view of scientific method had suggested2 but leading to truths as profound and comprehensive as any which conjecture had dared to anticipate4 ,the theoretical reformers were bold1 self-confident1 hasty1 contemptuous of antiquity1 ambitious of ruling all future speculations1 as they whom they sought to depose had ruled the past4 ,the practical reformers were cautious1 modest1 slow1 despising no knowledge1 whether borrowed from tradition or observation1 confident in the ultimate triumph of science1 but impressed with the conviction that each single person could contribute a little only to its progress4 ,yet though thus working rather than speculating1--dealing with particulars more than with generals1--employed mainly in adding to knowledge1 and not in defining what knowledge is1 or how additions are to be made to it1--these men1 thoughtful1 curious1 and of comprehensive minds1 were constantly led to important views on the nature and methods of science4 ,and these views1 thus suggested by reflections on their own mental activity1 were gradually incorporated with the more abstract doctrines of the metaphysicians1 and had a most important influence in establishing an improved philosophy of science4 ,the indications of such views we must now endeavour to collect from the writings of the discoverers of the times preceding the seventeenth century4 ,some of the earliest of these indications are to be found in those who dealt with ,art rather than with ,science4 ,i have already endeavoured to show that the advance of the arts which give us a command over the powers of nature1 is generally prior to the formation of exact and speculative knowledge concerning those powers4 ,but ,art1 which is thus the predecessor of ,science1 is1 among nations of acute and active intellects1 usually its parent4 ,there operates1 in such a case1 a speculative spirit1 leading men to seek for the reasons of that which they find themselves able to do4 ,how slowly1 and with what repeated deviations men follow this leading1 when under the influence of a partial and dogmatical philosophy1 the late birth and slow growth of sound physical theory shows4 ,but at the period of which we now speak1 we find men1 at length1 proceeding in obedience to the impulse which thus drives them from practice to theory2--from an acquaintance with phenomena to a free and intelligent inquiry concerning their causes4 #b4 ,leonardo da ,vinci4--,i have already noted1 in the ,history of ,science1 that the ,indistinctness of ,ideas1 which was long one main impediment to the progress of science in the middle ages1 was first remedied among architects and engineers4 ,these men1 so far at least as mechanical ideas were concerned1 were compelled by their employments to judge rightly of the relations and properties of the materials with which they had to deal2 and would have been chastised by the failure of their works1 if they had violated the laws of mechanical truth4 ,it was not wonderful1 therefore1 that these laws became known to them first4 ,we have seen1 in the ,history1 that ,leonardo da ,vinci1 the celebrated painter1 who was also an engineer1 is the first writer in whom we find the true view of the laws of equilibrium of the lever in the most general case4 ,this artist1 a man of a lively and discursive mind1 is led to make some remarks#abh on the formation of our knowledge1 which may show the opinions on that subject that already offered themselves at the beginning of the sixteenth century#abi4 ,he expresses himself as follows3--,theory is the general1 ,experiments are the soldiers4 ,the interpreter of the artifices of nature is ,experience3 she is never deceived4 ,our judgment sometimes is deceived1 because it expects effects which ,experience refuses to allow4 ,and again1 ,we must consult ,experience1 and vary the circumstances till we have drawn from them general rules2 for it is she who furnishes true rules4 ,but of what use1 you ask1 are these rules2 ,i reply1 that they direct us in the researches of nature and the operations of art4 ,they prevent our imposing upon ourselves and others by promising ourselves results which we cannot obtain4 ,in the study of the sciences which depend on mathematics1 those who do not consult nature but authors1 are not the children of nature1 they are only her grandchildren4 ,she is the true teacher of men of genius4 ,but see the absurdity of men6 ,they turn up their noses at a man who prefers to learn from nature herself rather than from authors who are only her clerks4 ,in another place1 in reference to a particular case1 he says1 ,nature begins from the ,reason and ends in ,experience2 but for all that1 we must take the opposite course2 begin from the ,experiment and try to discover the ,reason4 ,leonardo was born forty-six years before ,telesius2 yet we have here an estimate of the value of experience far more just and substantial than the ,calabrian school ever reached4 ,the expressions contained in the above extracts1 are well worthy our notice2--that experience is never deceived2--that we must vary our experiments1 and draw from them general rules2--that nature is the original source of knowledge1 and books only a derivative substitute2--with a lively image of the sons and grandsons of nature4 ,some of these assertions have been deemed1 and not without reason1 very similar to those made by ,bacon a century later4 ,yet it is probable that the import of such expressions1 in ,leonardo's mind1 was less clear and definite than that which they acquired by the progress of sound philosophy4 ,when he says that theory is the general and experiments the soldiers1 he probably meant that theory directs men what experiments to make2 and had not in his mind the notion of a theoretical ,idea ordering and brigading the ,facts4 ,when he says that ,experience is the interpreter of ,nature1 we may recollect1 that in a more correct use of this image1 ,experience and ,nature are the writing1 and the ,intellect of man the interpreter4 ,we may add1 that the clear apprehension of the importance of ,experience led1 in this as in other cases1 to an unjust depreciation of the value of what science owed to books4 ,leonardo would have made little progress1 if he had attempted to master a complex science1 astronomy for instance1 by means of observation alone1 without the aid of books4 ,but in spite of such criticism1 ,leonardo's maxims show extraordinary sagacity and insight2 and they appear to us the more remarkable1 when we see how rare such views are for a century after his time4 #c4 ,copernicus4--,for we by no means find1 even in those practical discoverers to whom1 in reality1 the revolution in science1 and consequently in the philosophy of science1 was due1 this prompt and vigorous recognition of the supreme authority of observation as a ground of belief2 this bold estimate of the probable worthlessness of traditional knowledge2 and this plain assertion of the reality of theory founded upon experience4 ,among such discoverers1 ,copernicus must ever hold a most distinguished place4 ,the heliocentric theory of the universe1 established by him with vast labour and deep knowledge1 was1 for the succeeding century1 the field of discipline and exertion of all the most active speculative minds4 ,men1 during that time1 proved their freedom of thought1 their hopeful spirit1 and their comprehensive view1 by adopting1 inculcating1 and following out the philosophy which this theory suggested4 ,but in the first promulgation of the theory1 in the works of ,copernicus himself1 we find a far more cautious and reserved temper4 ,he does not1 indeed1 give up the reality of his theory1 but he expresses himself so as to avoid shocking those who might 7as some afterwards did7 think it safe to speak of it as an hypothesis rather than a truth4 ,in his preface addressed to the ,pope#acj1 after speaking of the difficulties in the old and received doctrines1 by which he was led to his own theory1 he says1 ,hence ,i began to think of the mobility of the earth2 and although the opinion seemed absurd1 yet because ,i knew that to others before me this liberty had been conceded1 of imagining any kinds of circles in order to explain the phenomena of the stars1 ,i thought it would also be readily granted me1 that ,i might try whether1 by supposing the earth to be in motion1 ,i might not arrive at a better explanation than theirs1 of the revolutions of the celestial orbs4 ,nor does he anywhere assert that the seeming absurdity had become a certain truth1 or betray any feeling of triumph over the mistaken belief of his predecessors4 ,and1 as ,i have elsewhere shown1 his disciples#aca indignantly and justly defended him from the charge of disrespect towards ,ptolemy and other ancient astronomers4 ,yet ,copernicus is far from compromising the value or evidence of the great truths which he introduced to general acceptance2 and from sinking in his exposition of his discoveries below the temper which had led to them4 ,his quotation from ,ptolemy1 that ,he who is to follow philosophy must be a freeman in mind1 is a grand and noble maxim1 which it well became him to utter4 #d4 ,fabricius4--,in another of the great discoverers of this period1 though employed on a very different subject1 we discern much of the same temper4 ,fabricius of ,acquapendente#acb1 the tutor and forerunner of our ,harvey1 and one of that illustrious series of ,paduan professors who were the fathers of anatomy#acc1 exhibits something of the same respect for antiquity1 in the midst of his original speculations4 ,thus in a dissertation#acd ,on the ,action of the ,joints1 he quotes ,aristotle's ,mechanical ,problems to prove that in all animal motion there must be some quiescent fulcrum2 and finds merit even in ,aristotle's ignorance4 ,aristotle1 he says#ace1 did not know that motion was produced by the muscle2 and after staggering about from one supposition to another1 at last is compelled by the facts themselves to recur to an innate spirit1 which1 he conceives1 is contrasted1 and which pulls and pushes4 ,and here we cannot help admiring the genius of ,aristotle1 who1 though ignorant of the muscle1 invents something which produces nearly the same effect as the muscle1 namely1 contraction and pulling4 ,he then1 with great acuteness1 points out the distinction between ,aristotle's opinions1 thus favourably interpreted1 and those of ,galen4 ,in all this1 we see something of the wish to find all truths in the writings of the ancients1 but nothing which materially interferes with freedom of inquiry4 ,the anatomists have in all ages and countries been practically employed in seeking knowledge from observation4 ,facts have ever been to them a subject of careful and profitable study2 while the ideas which enter into the wider truths of the science1 are1 as we have seen1 even still involved in obscurity1 doubt1 and contest4 #e4 ,maurolycus4--,francis ,maurolycus of ,messana1 whose mathematical works were published in #aege1 was one of the great improvers of the science of optics in his time4 ,in his ,preface to his ,treatise on the ,spheres1 he speaks of previous writers on the same subject2 and observes that as they have not superseded one another1 they have not rendered it unfit for any one to treat the subject afresh4 ,yet1 he says1 it is impossible to amend the errors of all who have preceded us4 ,this would be a task too hard for ,atlas1 although he supports the heavens4 ,even ,copernicus is tolerated1 who makes the sun to be fixed1 and the earth to move round it in a circle1 and who is more worthy of a whip or a scourge than of a refutation4 ,the mathematicians and astronomers of that time were not the persons most sensible of the progress of physical knowledge2 for the basis of their science1 and a great part of its substance1 were contained in the writings of the ancients2 and till the time of ,kepler1 ,ptolemy's work was1 very justly1 looked upon as including all that was essential in the science4 #f4 ,benedetti4--,but the writers on ,mechanics were naturally led to present themselves as innovators and experimenters2 for all that the ancients had taught concerning the doctrine of motion was erroneous2 while those who sought their knowledge from experiment1 were constantly led to new truths4 ,john ,baptist ,benedetti1 a ,venetian nobleman1 in #aeii1 published his ,speculationum ,liber1 containing1 among other matter1 a treatise on ,mechanics1 in which several of the ,aristotelian errors were refuted4 ,in the ,preface to this ,treatise1 he says1 ,many authors have written much1 and with great ability1 on ,mechanics2 but since nature is constantly bringing to light something either new1 or before unnoticed1 ,i too wished to put forth a few things hitherto unattempted1 or not sufficiently explained4 ,in the doctrine of motion he distinctly and at some length condemns and argues against all the ,aristotelian doctrines concerning motion1 weight1 and many other fundamental principles of physics4 ,benedetti is also an adherent of the ,copernican doctrine4 ,he states#acf the enormous velocity which the heavenly bodies must have1 if the earth be the centre of their motions2 and adds1 which difficulty does not occur according to the beautiful theory of the ,samian ,aristarchus1 expounded in a divine manner by ,nicolas ,copernicus2 against which the reasons alleged by ,aristotle are of no weight4 ,benedetti throughout shows no want of the courage or ability which were needed in order to rise in opposition against the dogmas of the ,peripatetics4 ,he does not1 however1 refer to experiment in a very direct manner2 indeed most of the facts on which the elementary truths of mechanics rest1 were known and admitted by the ,aristotelians2 and therefore could not be adduced as novelties4 ,on the contrary1 he begins with priori maxims1 which experience would not have confirmed4 ,since1 he says#acg1 we have undertaken the task of proving that ,aristotle is wrong in his opinions concerning motion1 there are certain absolute truths1 the objects of the intellect known of themselves1 which we must lay down in the first place4 ,and then1 as an example of these truths1 he states this3 ,any two bodies of equal size and figure1 but of different materials1 will have their natural velocities in the same proportion as their weights2 where by their natural velocities1 he means the velocities with which they naturally fall downwards4 #g4 ,gilbert4--,the greatest of these practical reformers of science is our countryman1 ,william ,gilbert2 if1 indeed1 in virtue of the clear views of the prospects which were then opening to science1 and of the methods by which her future progress was to be secured1 while he exemplified those views by physical discoveries1 he does not rather deserve the still higher praise of being at the same time a theoretical and a practical reformer4 ,gilbert's physical researches and speculations were employed principally upon subjects on which the ancients had known little or nothing2 and on which therefore it could not be doubtful whether tradition or observation was the source of knowledge4 ,such was magnetism2 for the ancients were barely acquainted with the attractive property of the magnet4 ,its polarity1 including repulsion as well as attraction1 its direction towards the north1 its limited variation from this direction1 its declination from the horizontal position1 were all modern discoveries4 ,gilbert's work#ach on the magnet and on the magnetism of the earth1 appeared in #afjj2 and in this1 he repeatedly maintains the superiority of experimental knowledge over the physical philosophy of the ancients4 ,his preface opens thus3 ,since in making discoveries and searching out the hidden causes of things1 stronger reasons are obtained from trustworthy experiments and demonstrable arguments1 than from probable conjectures and the dogmas of those who philosophize in the usual manner1 he has1 he says1 endeavoured to proceed from common magnetical experiments to the inward constitution of the earth4 ,as ,i have stated in the ,history of ,magnetism#aci1 ,gilbert's work contains all the fundamental facts of that science1 so fully stated1 that we have1 at this day1 little to add to them4 ,he is not1 however1 by the advance which he thus made1 led to depreciate the ancients1 but only to claim for himself the same liberty of philosophizing which they had enjoyed#adj4 ,to those ancient and first parents of philosophy1 ,aristotle1 ,theophrastus1 ,ptolemy1 ,hippocrates1 ,galen1 be all due honour2 from them it was that the stream of wisdom has been derived down to posterity4 ,but our age has discovered and brought to light many things which they1 if they were yet alive1 would gladly embrace4 ,wherefore we also shall not hesitate to expound1 by probable hypotheses1 those things which by long experience we have ascertained4 ,in this work the author not only adopts the ,copernican doctrine of the earth's motion1 but speaks#ada of the contrary supposition as utterly absurd1 founding his argument mainly on the vast velocities which such a supposition requires us to ascribe to the celestial bodies4 ,dr4 ,gilbert was physician to ,queen ,elizabeth and to ,james the ,first1 and died in #afjc4 ,some time after his death the executors of his brother published another work of his1 ,de ,mundo nostro ,sublunari ,philosophia ,nova1 in which similar views are still more comprehensively presented4 ,in this he says1 ,the two lords of philosophy1 ,aristotle and ,galen1 are held in worship like gods1 and rule the schools2--the former by some destiny obtained a sway and influence among philosophers1 like that of his pupil ,alexander among the kings of the earth2--,galen1 with like success1 holds his triumph among the physicians of ,europe4 ,this comparison of ,aristotle to ,alexander was also taken hold of by ,bacon4 ,nor is ,gilbert an unworthy precursor of ,bacon in the view he gives of the ,history of ,science1 which occupies the first three chapters of his ,philosophy4 ,he traces this history from the simplicity and ignorance of the ancients1 through the fabrication of the fable of the four elements1 to ,aristotle and ,galen4 ,he mentions with due disapproval the host of commentators which succeeded1 the alchemists1 the shipwreck of science in the deluge of the ,goths1 and the revival of letters and genius in the time of our grandfathers4 ,this later age1 he says1 has exploded the ,barbarians1 and restored the ,greeks and ,latins to their pristine grace and honour4 ,it remains1 that if they have written aught in error1 this should be remedied by better and more productive processes 7frugiferis institutis71 not to be contemned for their novelty2 7for nothing which is true is really new1 but is perfect from eternity1 though to weak man it may be unknown27 and that thus ,philosophy may bear her fruit4 ,the reader of ,bacon will not fail to recognize1 in these references to fruit-bearing knowledge1 a similarity of expression with the ,novum ,organon4 ,bacon does not appear to me to have done justice to his contemporary4 ,he nowhere recognizes in the labours of ,gilbert a community of purpose and spirit with his own4 ,on the other hand1 he casts upon him a reflection which he by no means deserves4 ,in the ,advancement of ,learning#adb1 he says1 ,another error is1 that men have used to infect their meditations1 opinions1 and doctrines1 with some conceits which they have most admired1 or some sciences to which they have most applied2 and given all things else a tincture according to them1 utterly untrue and improper4444 ,so have the alchemists made a philosophy out of a few experiments of the furnace2 and ,gilbertus1 our countryman1 hath made a philosophy out of the observations of a loadstone1 7in the ,latin1 philosophiam etiam e magnete elicuit74 ,and in the same manner he mentions him in the ,novum ,organon#adc1 as affording an example of an empirical kind of philosophy1 which appears to those daily conversant with the experiments1 probable1 but to other persons incredible and empty4 ,but instead of blaming ,gilbert for disturbing and narrowing science by a too constant reference to magnetical rules1 we might rather censure ,bacon1 for not seeing how important in all natural philosophy are those laws of attraction and repulsion of which magnetical phenomena are the most obvious illustration4 ,we may find ground for such a judgment in another passage in which ,bacon speaks of ,gilbert4 ,in the ,second ,book#add of the ,novum ,organon1 having classified motions1 he gives1 as one kind1 what he calls1 in his figurative language1 motion for gain1 or motion of need1 by which a body shuns heterogeneous1 and seeks cognate bodies4 ,and he adds1 ,the ,electrical operation1 concerning which ,gilbert and others since him have made up such a wonderful story1 is nothing less than the appetite of a body1 which1 excited by friction1 does not well tolerate the air1 and prefers another tangible body if it be found near4 ,bacon's notion of an appetite in the body is certainly much less philosophical than ,gilbert's1 who speaks of light bodies as drawn towards amber by certain material radii#ade2 and we might perhaps venture to say that ,bacon here manifests a want of clear mechanical ideas4 ,bacon1 too1 showed his inferior aptitude for physical research in rejecting the ,copernican doctrine which ,gilbert adopted4 ,in the ,advancement of ,learning#adf1 suggesting a history of the opinions of philosophers1 he says that he would have inserted in it even recent theories1 as those of ,paracelsus2 of ,telesius1 who restored the philosophy of ,parmenides2 or ,patricius1 who resublimed the fumes of ,platonism2 or ,gilbert1 who brought back the dogmas of ,philolaus4 ,but ,bacon quotes#adg with pleasure ,gilbert's ridicule of the ,peripatetics' definition of heat4 ,they had said1 that heat is that which separates heterogeneous and unites homogeneous matter2 which1 said ,gilbert1 is as if any one were to define man as that which sows wheat and plants vines4 ,galileo1 another of ,gilbert's distinguished contemporaries1 had a higher opinion of him4 ,he says#adh1 ,i extremely admire and envy this author4 ,i think him worthy of the greatest praise for the many new and true observations which he has made1 to the disgrace of so many vain and fabling authors2 who write1 not from their own knowledge only1 but repeat everything they hear from the foolish and vulgar1 without attempting to satisfy themselves of the same by experience2 perhaps that they may not diminish the size of their books4 #h4 ,galileo4--,galileo was content with the active and successful practice of experimental inquiry2 and did not demand that such researches should be made expressly subservient to that wider and more ambitious philosophy1 on which the author of the ,novum ,organon employed his powers4 ,but still it now becomes our business to trace those portions of ,galileo's views which have reference to the theory1 as well as the practice1 of scientific investigation4 ,on this subject1 ,galileo did not think more profoundly1 perhaps1 than several of his contemporaries2 but in the liveliness of expression and illustration with which he recommended his opinions on such topics1 he was unrivalled4 ,writing in the language of the people1 in the attractive form of dialogue1 with clearness1 grace1 and wit1 he did far more than any of his predecessors had done to render the new methods1 results1 and prospects of science familiar to a wide circle of readers1 first in ,italy1 and soon1 all over ,europe4 ,the principal points inculcated by him were already becoming familiar to men of active and inquiring minds2 such as1--that knowledge was to be sought from observation1 and not from books2--that it was absurd to adhere to1 and debate about1 the physical tenets of ,aristotle and the rest of the ancients4 ,on persons who followed this latter course1 ,galileo fixed the epithet of ,paper ,philosophers#adi2 because1 as he wrote in a letter to ,kepler1 this sort of men fancied that philosophy was to be studied like the neid or ,odyssey1 and that the true reading of nature was to be detected by the collation of texts4 ,nothing so much shook the authority of the received system of ,physics as the experimental discoveries1 directly contradicting it1 which ,galileo made4 ,by experiment1 as ,i have elsewhere stated#aej1 he disproved the ,aristotelian doctrine that bodies fall quickly or slowly in proportion to their weight4 ,and when he had invented the telescope1 a number of new discoveries of the most striking kind 7the inequalities of the moon's surface1 the spots in the sun1 the moon-like phases of ,venus1 the satellites of ,jupiter1 the ring of ,saturn17 showed1 by the evidence of the eyes1 how inadequate were the conceptions1 and how erroneous the doctrines of the ancients1 respecting the constitution of the universe4 ,how severe the blow was to the disciples of the ancient schools1 we may judge by the extraordinary forms of defence in which they tried to intrench themselves4 ,they would not look through ,galileo's glasses2 they maintained that what was seen was an illusion of witchcraft2 and they tried1 as ,galileo says#aea1 with logical arguments1 as if with magical incantations1 to charm the new planets out of the sky4 ,no one could be better fitted than ,galileo for such a warfare4 ,his great knowledge1 clear intellect1 gaiety1 and light irony1 7with the advantage of being in the right17 enabled him to play with his adversaries as he pleased4 ,thus when an ,aristotelian#aeb rejected the discovery of the irregularities in the moon's surface1 because1 according to the ancient doctrine1 her form was a perfect sphere1 and held that the apparent cavities were filled with an invisible crystal substance1 ,galileo replied1 that he had no objection to assent to this1 but that then he should require his adversary in return to believe that there were on the same surface invisible crystal mountains ten times as high as those visible ones which he had actually observed and measured4 ,we find in ,galileo many thoughts which have since become established maxims of modern philosophy4 ,philosophy1 he says#aec1 is written in that great book1 ,i mean the ,universe1 which is constantly open before our eyes2 but it cannot be understood1 unless we first know the language and learn the characters in which it is written4 ,with this thought he combines some other lively images4 ,one of his interlocutors says concerning another1 ,sarsi perhaps thinks that philosophy is a book made up of the fancies of men1 like the ,iliad or ,orlando ,furioso1 in which the matter of least importance is1 that what is written be true4 ,and again1 with regard to the system of authority1 he says1 ,i think ,i discover in him a firm belief that1 in philosophizing1 it is necessary to lean upon the opinion of some celebrated author2 as if our mind must necessarily remain unfruitful and barren till it be married to another man's reason4--,no1 he says1 the case is not so4--,when we have the decrees of ,nature1 authority goes for nothing2 reason is absolute#aed4 ,in the course of ,galileo's controversies1 questions of the logic of science came under discussion4 ,vincenzio di ,grazia objected to a proof from induction which ,galileo adduced1 because all the particulars were not enumerated2 to which the latter justly replies#aee1 that if induction were required to pass through all the cases1 it would be either useless or impossible2--impossible when the cases are innumerable2 useless when they have each already been verified1 since then the general proposition adds nothing to our knowledge4 ,one of the most novel of the characters which ,science assumes in ,galileo's hands is1 that she becomes cautious4 ,she not only proceeds leaning upon ,experience1 but she is content to proceed a little way at a time4 ,she already begins to perceive that she must rise to the heights of knowledge by many small and separate steps4 ,the philosopher is desirous to know much1 but resigned to be ignorant for a time of that which cannot yet be known4 ,thus when ,galileo discovered the true law of the motion of a falling body#aef1 that the velocity increases proportionally to the time from the beginning of the fall1 he did not insist upon immediately assigning the cause of this law4 ,the cause of the acceleration of the motions of falling bodies is not1 he says1 a necessary part of the investigation4 ,yet the conception of this acceleration1 as the result of the continued action of the force of gravity upon the falling body1 could hardly fail to suggest itself to one who had formed the idea of force4 ,in like manner1 the truth that the velocities1 acquired by bodies falling down planes of equal heights1 are all equal1 was known to ,galileo and his disciples1 long before he accounted for it#aeg1 by the principle1 apparently so obvious1 that the momentum generated is as the moving force which generates it4 ,he was not tempted to rush at once1 from an experimental truth to a universal system4 ,science had learnt that she must move step by step2 and the gravity of her pace already indicated her approaching maturity and her consciousness of the long path which lay before her4 ,but besides the genuine philosophical prudence which thus withheld ,galileo from leaping hastily from one inference to another1 he had perhaps a preponderating inclination towards facts2 and did not feel1 so much as some other persons of his time1 the need of reducing them to ideas4 ,he could bear to contemplate laws of motion without being urged by an uncontrollable desire to refer them to conceptions of force4 #i4 ,kepler4--,in this respect his friend ,kepler differed from him2 for ,kepler was restless and unsatisfied till he had reduced facts to laws1 and laws to causes2 and never acquiesced in ignorance1 though he tested with the most rigorous scrutiny that which presented itself in the shape of knowledge to fill the void4 ,it may be seen in the ,history of ,astronomy#aeh with what perseverance1 energy1 and fertility of invention1 ,kepler pursued his labours1 7enlivened and relieved by the most curious freaks of fancy17 with a view of discovering the rules which regulate the motions of the planet ,mars4 ,he represents this employment under the image of a warfare2 and describes#aei his object to be to triumph over ,mars1 and to prepare for him1 as for one altogether vanquished1 tabular prisons and equated eccentric fetters2 and when1 the enemy1 left at home a despised captive1 had burst all the chains of the equations1 and broken forth of the prisons of the tables2--when it was buzzed here and there that the victory is vain1 and that the war is raging anew as violently as before2--that is1 when the rules which he had proposed did not coincide with the facts2--he by no means desisted from his attempts1 but suddenly sent into the field a reserve of new physical reasonings on the rout and dispersion of the veterans1 that is1 tried new suppositions suggested by such views as he then entertained of the celestial motions4 ,his efforts to obtain the formal laws of the planetary motions resulted in some of the most important discoveries ever made in astronomy2 and if his physical reasonings were for the time fruitless1 this arose only from the want of that discipline in mechanical ideas which the minds of mathematicians had still to undergo2 for the great discoveries of ,newton in the next generation showed that1 in reality1 the next step of the advance was in this direction4 ,among all ,kepler's fantastical expressions1 the fundamental thoughts were sound and true2 namely1 that it was his business1 as a physical investigator1 to discover a mathematical rule which governed and included all the special facts2 and that the rules of the motions of the planets must conform to some conception of causation4 ,the same characteristics1--the conviction of rule and cause1 perseverance in seeking these1 inventiveness in devising hypotheses1 love of truth in trying and rejecting them1 and a lively ,fancy playing with the ,reason without interrupting her1--appear also in his work on ,optics2 in which he tried to discover the exact law of optical refraction#afj4 ,in this undertaking he did not succeed entirely2 nor does he profess to have done so4 ,he ends his numerous attempts by saying1 ,now1 reader1 you and ,i have been detained sufficiently long while ,i have been attempting to collect into one fagot the measures of different refractions4 ,in this and in other expressions1 we see how clearly he apprehended that colligation of facts which is the main business of the practical discoverer4 ,and by his peculiar endowments and habits1 ,kepler exhibits an essential portion of this process1 which hardly appears at all in ,galileo4 ,in order to bind together facts1 theory is requisite as well as observation1--the cord as well as the fagots4 ,and the true theory is often1 if not always1 obtained by trying several and selecting the right4 ,now of this portion of the discoverer's exertions1 ,kepler is a most conspicuous example4 ,his fertility in devising suppositions1 his undaunted industry in calculating the results of them1 his entire honesty and candour in resigning them if these results disagreed with the facts1 are a very instructive spectacle2 and are fortunately exhibited to us in the most lively manner in his own garrulous narratives4 ,galileo urged men by precept as well as example to begin their philosophy from observation2 ,kepler taught them by his practice that they must proceed from observation by means of hypotheses4 ,the one insisted upon facts2 the other dealt no less copiously with ideas4 ,in the practical1 as in the speculative portion of our history1 this antithesis shows itself2 although in the practical part we cannot have the two elements separated1 as in the speculative we sometimes have4 ,in the ,history of ,science#afa1 ,i have devoted several pages to the intellectual character of ,kepler1 inasmuch as his habit of devising so great a multitude of hypotheses1 so fancifully expressed1 had led some writers to look upon him as an inquirer who transgressed the most fixed rules of philosophical inquiry4 ,this opinion has arisen1 ,i conceive1 among those who have forgotten the necessity of ,ideas as well as ,facts for all theory2 or who have overlooked the impossibility of selecting and explicating our ideas without a good deal of spontaneous play of the mind4 ,it must1 however1 always be recollected that ,kepler's genius and fancy derived all their scientific value from his genuine and unmingled love of truth4 ,these qualities appeared1 not only in the judgment he passed upon hypotheses1 but also in matters which more immediately concerned his reputation4 ,thus when ,galileo's discovery of the telescope disproved several opinions which ,kepler had published and strenuously maintained1 he did not hesitate a moment to retract his assertions and range himself by the side of ,galileo1 whom he vigorously supported in his warfare against those who were incapable of thus cheerfully acknowledging the triumph of new facts over their old theories4 #aj4 ,tycho4--,there remains one eminent astronomer1 the friend and fellow-labourer of ,kepler1 whom we must not separate from him as one of the practical reformers of science4 ,i speak of ,tycho ,brahe1 who is1 ,i think1 not justly appreciated by the literary world in general1 in consequence of his having made a retrograde step in that portion of astronomical theory which is most familiar to the popular mind4 ,though he adopted the ,copernican view of the motion of the planets about the sun1 he refused to acknowledge the annual and diurnal motion of the earth4 ,but notwithstanding this mistake1 into which he was led by his interpretation of ,scripture rather than of nature1 ,tycho must ever be one of the greatest names in astronomy4 ,in the philosophy of science also1 the influence of what he did is far from inconsiderable2 and especially its value in bringing into notice these two points3--that not only are observations the beginning of science1 but that the progress of science may often depend upon the observer's pursuing his task regularly and carefully for a long time1 and with well devised instruments2 and again1 that observed facts offer a succession of laws which we discover as our observations become better1 and as our theories are better adapted to the observations4 ,with regard to the former point1 ,tycho's observatory was far superior to all that had preceded it#afb1 not only in the optical1 but in the mechanical arrangements2 a matter of almost equal consequence4 ,and hence it was that his observations inspired in ,kepler that confidence which led him to all his labours and all his discoveries4 ,since1 he says#afc1 the divine goodness has given us in ,tycho ,brahe an exact observer1 from whose observations this error of eight minutes in the calculations of the ,ptolemaic hypothesis is detected1 let us acknowledge and make use of this gift of ,god3 and since this error cannot be neglected1 these eight minutes alone have prepared the way for an entire reform of ,astronomy1 and are to be the main subject of this work4 ,with regard to ,tycho's discoveries respecting the moon1 it is to be recollected that besides the first inequality of the moon's motion1 7the equation of the centre1 arising from the elliptical form of her orbit17 ,ptolemy had discovered a second inequality1 the evection1 which1 as we have observed in the ,history of this subject#afd1 might have naturally suggested the suspicion that there were still other inequalities4 ,in the middle ages1 however1 such suggestions1 implying a constant progress in science1 were little attended to2 and1 we have seen1 that when an ,arabian astronomer#afe had really discovered another inequality of the moon1 it was soon forgotten1 because it had no place in the established systems4 ,tycho not only rediscovered the lunar inequality1 7the variation17 thus once before won and lost1 but also two other inequalities2 namely#aff1 the change of inclination of the moon's orbit as the line of nodes moves round1 and an inequality in the motion of the line of nodes4 ,thus1 as ,i have elsewhere said1 it appeared that the discovery of a rule is a step to the discovery of deviations from that rule1 which require to be expressed in other rules4 ,it became manifest to astronomers1 and through them to all philosophers1 that in the application of theory to observation1 we find1 not only the stated phenomena1 for which the theory does account1 but also residual phenomena1 which are unaccounted for1 and remain over and above the calculation4 ,and it was seen further1 that these residual phenomena might be1 altogether or in part1 exhausted by new theories4 ,these were valuable lessons2 and the more valuable inasmuch as men were now trying to lay down maxims and methods for the conduct of science4 ,a revolution was not only at hand1 but had really taken place1 in the great body of real cultivators of science4 ,the occasion now required that this revolution should be formally recognized2--that the new intellectual power should be clothed with the forms of government2--that the new philosophical republic should be acknowledged as a sister state by the ancient dynasties of ,aristotle and ,plato4 ,there was needed some great ,theoretical ,reformer1 to speak in the name of the ,experimental ,philosophy2 to lay before the world a declaration of its rights and a scheme of its laws4 ,and thus our eyes are turned to ,francis ,bacon1 and others who like him attempted this great office4 ,we quit those august and venerable names of discoverers1 whose appearance was the prelude and announcement of the new state of things then opening2 and in doing so1 we may apply to them the language which ,bacon applies to himself#afg3-- 4 ,hail1 ,heralds1 ,messengers of ,gods and ,men6 ,,footnotes3 ,footnote #abh3 ,his works have never been published1 and exist in manuscript in the library of the ,institute at ,paris4 ,some extracts were published by ,venturi1 ,essai sur les ,ouvrages de ,leonard da ,vinci4 ,paris1 #agig4 ,footnote #abi3 ,leonardo died in #aebj1 at the age of #gh4 ,footnote #acj3 ,paul ,,iii4 in #aedc4 ,footnote #aca3 ,hist4 ,ind4 ,sc4 b4 v4 c4 ii4 ,footnote #acb3 ,born #aecg1 died #afai4 ,footnote #acc3 ,hist4 ,ind4 ,sc4 b4 xvii4 c4 ii4 sect4 #a4 ,footnote #acd3 ,fabricius1 ,de ,motu ,locali1 p4 #ahb4 ,footnote #ace3 p4 #aii4 ,footnote #acf3 ,speculationum ,liber1 p4 #aie4 ,footnote #acg3 ,ibid4 p4 #afi4 ,footnote #ach3 ,gulielmi ,gilberti1 ,colcestriensis1 ,medici ,londinensis1 ,de ,magnete1 ,magneticisque ,corporibus1 et de ,magno ,magnete ,tellure1 ,physiologia ,nova1 plurimis et ,argumentis et ,experimentis demonstrata4 ,footnote #aci3 ,hist4 ,ind4 ,sc4 b4 xii4 c4 i4 ,footnote #adj3 ,pref4 ,footnote #ada3 ,de ,magnete1 lib4 vi4 c4 #c1 #d4 ,footnote #adb3 ,nov4 ,org4 b4 i4 ,footnote #adc3 ,b4 i4 ,aph4 #fd4 ,footnote #add3 ,vol4 ix4 #ahe4 ,footnote #ade3 ,de ,magnete1 p4 #fj4 ,footnote #adf3 ,b4 iii4 c4 #d4 ,footnote #adg3 ,nov4 ,org4 b4 ii4 ,aph4 #dh4 ,footnote #adh3 ,drinkwater's ,life of ,galileo1 p4 #ah4 ,footnote #adi3 ,life of ,galileo1 p4 #i4 ,footnote #aej3 ,hist4 ,ind4 ,sc4 b4 vi4 c4 ii4 sect4 #e4 ,footnote #aea3 ,life of ,galileo1 p4 #bi4 ,footnote #aeb3 ,ibid4 p4 #cc4 ,footnote #aec3 ,il ,saggiatore1 ii4 #bdg4 ,footnote #aed3 ,il ,saggiatore1 ii4 #bjj4 ,footnote #aee3 ,ibid4 i4 #eja4 ,footnote #aef3 ,hist4 ,ind4 ,sc4 b4 vi4 c4 ii4 sect4 #b4 ,footnote #aeg3 ,hist4 ,ind4 ,sc4 b4 vi4 c4 ii4 sect4 #d4 ,footnote #aeh3 ,ibid4 b4 v4 c4 iv4 sect4 #a4 ,footnote #aei3 ,de ,stell4 ,mart4 p4 iv4 c4 #ea 7#afji72 ,drinkwater's ,kepler1 p4 #cc4 ,footnote #afj3 ,published #afjd4 ,hist4 ,ind4 ,sc4 b4 ix4 c4 ii4 ,footnote #afa3 ,hist4 ,ind4 ,sc4 b4 v4 c4 iv4 sect4 #a4 ,footnote #afb3 ,hist4 ,ind4 ,sc4 b4 vii4 c4 vi4 sect #a4 ,footnote #afc3 ,de ,stell4 ,mart4 p4 #aa4 c4 #ai4 ,footnote #afd3 ,hist4 ,ind4 ,sc4 b4 ii4 c4 iv4 sect4 #f4 ,footnote #afe3 ,ibid4 sect4 #h4 ,footnote #aff3 ,montucla1 i4 #eff4 ,footnote #afg3 ,de ,augm4 lib4 iv4 c4 #a4 ,,chapter ,,xv4 ,,francis ,,bacon4 7,i47 #a4 ,general ,remarks4--,it is a matter of some difficulty to speak of the character and merits of this illustrious man1 as regards his place in that philosophical history with which we are here engaged4 ,if we were to content ourselves with estimating him according to the office which1 as we have just seen1 he claims for himself#afh1 as merely the harbinger and announcer of a sounder method of scientific inquiry than that which was recognized before him1 the task would be comparatively easy4 ,for we might select from his writings those passages in which he has delivered opinions and pointed out processes1 then novel and strange1 but since confirmed by the experience of actual discoverers1 and by the judgments of the wisest of succeeding philosophers2 and we might pass by1 without disrespect1 but without notice1 maxims and proposals which have not been found available for use2--views so indistinct and vague1 that we are even yet unable to pronounce upon their justice2--and boundless anticipations1 dictated by the sanguine hopes of a noble and comprehensive intellect4 ,but if we thus reduce the philosophy of ,bacon to that portion which the subsequent progress of science has rigorously verified1 we shall have to pass over many of those declarations which have excited most notice in his writings1 and shall lose sight of many of those striking thoughts which his admirers most love to dwell upon4 ,for he is usually spoken of1 at least in this country1 as a teacher who not only commenced1 but in a great measure completed1 the ,philosophy of ,induction4 ,he is considered1 not only as having asserted some general principles1 but laid down the special rules of scientific investigation2 as not only one of the ,founders1 but the supreme ,legislator of the modern ,republic of ,science2 not only the ,hercules who slew the monsters that obstructed the earlier traveller1 but the ,solon who established a constitution fitted for all future time4 #b4 ,nor is it our purpose to deny that of such praise he deserves a share which1 considering the period at which he lived1 is truly astonishing4 ,but it is necessary for us in this place to discriminate and select that portion of his system which1 bearing upon physical science1 has since been confirmed by the actual history of science4 ,many of ,bacon's most impressive and captivating passages contemplate the extension of the new methods of discovering truth to intellectual1 to moral1 to political1 as well as to physical science4 ,and how far1 and how1 the advantages of the inductive method may be secured for those important branches of speculation1 it will at some future time be a highly interesting task to examine4 ,but our plan requires us at present to omit the consideration of these2 for our purpose is to learn what the genuine course of the formation of science is1 by tracing it in those portions of human knowledge1 which1 by the confession of all1 are most exact1 most certain1 most complete4 ,hence we must here deny ourselves the dignity and interest which float about all speculations in which the great moral and political concerns of men are involved4 ,it cannot be doubted that the commanding position which ,bacon occupies in men's estimation arises from his proclaiming a reform in philosophy of so comprehensive a nature2--a reform which was to infuse a new spirit into every part of knowledge4 ,physical ,science has tranquilly and noiselessly adopted many of his suggestions2 which were1 indeed1 her own natural impulses1 not borrowed from him2 and she is too deeply and satisfactorily absorbed in contemplating her results1 to talk much about the methods of obtaining them which she has thus instinctively pursued4 ,but the philosophy which deals with mind1 with manners1 with morals1 with polity1 is conscious still of much obscurity and perplexity2 and would gladly borrow aid from a system in which aid is so confidently promised4 ,the aphorisms and phrases of the ,novum ,organon are far more frequently quoted by metaphysical1 ethical1 and even theological writers1 than they are by the authors of works on physics4 #c4 ,again1 even as regards physics1 ,bacon's fame rests upon something besides the novelty of the maxims which he promulgated4 ,that a revolution in the method of scientific research was going on1 all the greatest physical investigators of the sixteenth century were fully aware1 as we have shown in the last chapter4 ,but their writings conveyed this conviction to the public at large somewhat slowly4 ,men of letters1 men of the world1 men of rank1 did not become familiar with the abstruse works in which these views were published2 and above all1 they did not1 by such occasional glimpses as they took of the state of physical science1 become aware of the magnitude and consequences of this change4 ,but ,bacon's lofty eloquence1 wide learning1 comprehensive views1 bold pictures of the coming state of things1 were fitted to make men turn a far more general and earnest gaze upon the passing change4 ,when a man of his acquirements1 of his talents1 of his rank and position1 of his gravity and caution1 poured forth the strongest and loftiest expressions and images which his mind could supply1 in order to depict the ,great ,instauration which he announced2--in order to contrast the weakness1 the blindness1 the ignorance1 the wretchedness1 under which men had laboured while they followed the long beaten track1 with the light1 the power1 the privileges1 which they were to find in the paths to which he pointed2--it was impossible that readers of all classes should not have their attention arrested1 their minds stirred1 their hopes warmed2 and should not listen with wonder and with pleasure to the strains of prophetic eloquence in which so great a subject was presented4 ,and when it was found that the prophecy was verified2 when it appeared that an immense change in the methods of scientific research really had occurred2--that vast additions to man's knowledge and power had been acquired1 in modes like those which had been spoken of2--that further advances might be constantly looked for2--and that a progress1 seemingly boundless1 was going on in the direction in which the seer had thus pointed2--it was natural that men should hail him as the leader of the revolution2 that they should identify him with the event which he was the first to announce2 that they should look upon him as the author of that which he had1 as they perceived1 so soon and so thoroughly comprehended4 #d4 ,for we must remark1 that although 7as we have seen7 he was not the only1 nor the earliest writer1 who declared that the time was come for such a change1 he not only proclaimed it more emphatically1 but understood it1 in its general character1 much more exactly1 than any of his contemporaries4 ,among the maxims1 suggestions and anticipations which he threw out1 there were many of which the wisdom and the novelty were alike striking to his immediate successors2--there are many which even now1 from time to time1 we find fresh reason to admire1 for their acuteness and justice4 ,bacon stands far above the herd of loose and visionary speculators who1 before and about his time1 spoke of the establishment of new philosophies4 ,if we must select some one philosopher as the ,hero of the revolution in scientific method1 beyond all doubt ,francis ,bacon must occupy the place of honour4 ,we shall1 however1 no longer dwell upon these general considerations1 but shall proceed to notice some of the more peculiar and characteristic features of ,bacon's philosophy2 and especially those views1 which1 occurring for the first time in his writings1 have been fully illustrated and confirmed by the subsequent progress of science1 and have become a portion of the permanent philosophy of our times4 7,,ii47 #e4 ,a ,new ,era announced4--,the first great feature which strikes us in ,bacon's philosophical views is that which we have already noticed2--his confident and emphatic announcement of a ,new ,era in the progress of science1 compared with which the advances of former times were poor and trifling4 ,this was with ,bacon no loose and shallow opinion1 taken up on light grounds and involving only vague1 general notions4 ,he had satisfied himself of the justice of such a view by a laborious course of research and reflection4 ,in #afje1 at the age of forty-four1 he published his ,treatise of the ,advancement of ,learning1 in which he takes a comprehensive and spirited survey of the condition of all branches of knowledge which had been cultivated up to that time4 ,this work was composed with a view to that reform of the existing philosophy which ,bacon always had before his eyes2 and in the ,latin edition of his works1 forms the ,first ,part of the ,instauratio ,magna4 ,in the ,second ,part of the ,instauratio1 the ,novum ,organon1 published in #afbj1 he more explicitly and confidently states his expectations on this subject4 ,he points out how slightly and feebly the examination of nature had been pursued up to his time1 and with what scanty fruit4 ,he notes the indications of this in the very limited knowledge of the ,greeks who had till then been the teachers of ,europe1 in the complaints of authors concerning the subtilty and obscurity of the secrets of nature1 in the dissensions of sects1 in the absence of useful inventions resulting from theory1 in the fixed form which the sciences had retained for two thousand years4 ,nor1 he adds#afi1 is this wonderful2 for how little of his thought and labour has man bestowed upon science6 ,out of twenty-five centuries scarce six have been favourable to the progress of knowledge4 ,and even in those favoured times1 natural philosophy received the smallest share of man's attention2 while the portion so given was marred by controversy and dogmatism2 and even those who have bestowed a little thought upon this philosophy1 have never made it their main study1 but have used it as a passage or drawbridge to serve other objects4 ,and thus1 he says1 the great ,mother of the ,sciences is thrust down with indignity to the offices of a handmaid2 is made to minister to the labours of medicine or mathematics1 or to give the first preparatory tinge to the immature minds of youth4 ,for these and similar considerations of the errors of past time1 he draws hope for the future1 employing the same argument which ,demosthenes uses to the ,athenians3 ,that which is worst in the events of the past1 is the best as a ground of trust in the future4 ,for if you had done all that became you1 and still had been in this condition1 your case might be desperate2 but since your failure is the result of your own mistakes1 there is good hope that1 correcting the error of your course1 you may reach a prosperity yet unknown to you4 7,,iii47 #f4 ,a change of existing ,method4--,all ,bacon's hope of improvement indeed was placed in an entire change of the ,method by which science was pursued2 and the boldness1 and at the same time 7the then existing state of science being considered71 the definiteness of his views of the change that was requisite1 are truly remarkable4 ,that all knowledge must begin with observation1 is one great principle of ,bacon's philosophy2 but ,i hardly think it necessary to notice the inculcation of this maxim as one of his main services to the cause of sound knowledge1 since it had1 as we have seen1 been fully insisted upon by others before him1 and was growing rapidly into general acceptance without his aid4 ,but if he was not the first to tell men that they must collect their knowledge from observation1 he had no rival in his peculiar office of teaching them how science must thus be gathered from experience4 ,it appears to me that by far the most extraordinary parts of ,bacon's works are those in which1 with extreme earnestness and clearness1 he insists upon a graduated and successive induction1 as opposed to a hasty transit from special facts to the highest generalizations4 ,the nineteenth ,axiom of the ,first ,book of the ,novum ,organon contains a view of the nature of true science most exact and profound1 and1 so far as ,i am aware1 at the time perfectly new4 ,there are two ways1 and can only be two1 of seeking and finding truth4 ,the one1 from sense and particulars1 takes a flight to the most general axioms1 and from those principles and their truth1 settled once for all1 invents and judges of intermediate axioms4 ,the other method collects axioms from sense and particulars1 ascending continuously and by degrees1 so that in the end it arrives at the most general axioms2 this latter way is the true one1 but hitherto untried4 ,it is to be remarked1 that in this passage ,bacon employs the term axioms to express any propositions collected from facts by induction1 and thus fitted to become the starting-point of deductive reasonings4 ,how far propositions so obtained may approach to the character of axioms in the more rigorous sense of the term1 we have already in some measure examined2 but that question does not here immediately concern us4 ,the truly remarkable circumstance is to find this recommendation of a continuous advance from observation1 by limited steps1 through successive gradations of generality1 given at a time when speculative men in general had only just begun to perceive that they must begin their course from experience in some way or other4 ,how exactly this description represents the general structure of the soundest and most comprehensive physical theories1 all persons who have studied the progress of science up to modern times can bear testimony2 but perhaps this structure of science cannot in any other way be made so apparent as by those ,tables of successive generalizations in which we have exhibited the history and constitution of some of the principal physical sciences1 in the ,chapter of a preceding work which treats of the ,logic of ,induction4 ,and the view which ,bacon thus took of the true progress of science was not only new1 but1 so far as ,i am aware1 has never been adequately illustrated up to the present day4 #g4 ,it is true1 as ,i observed in the last chapter1 that ,galileo had been led to see the necessity1 not only of proceeding from experience in the pursuit of knowledge1 but of proceeding cautiously and gradually2 and he had exemplified this rule more than once1 when1 having made one step in discovery1 he held back his foot1 for a time1 from the next step1 however tempting4 ,but ,galileo had not reached this wide and commanding view of the successive subordination of many steps1 all leading up at last to some wide and simple general truth4 ,in catching sight of this principle1 and in ascribing to it its due importance1 ,bacon's sagacity1 so far as ,i am aware1 wrought unassisted and unrivalled4 #h4 ,nor is there any wavering or vagueness in ,bacon's assertion of this important truth4 ,he repeats it over and over again2 illustrates it by a great number of the most lively metaphors and emphatic expressions4 ,thus he speaks of the successive floors 7tabulata7 of induction2 and speaks of each science as a pyramid#agj which has observation and experience for its basis4 ,no images can better exhibit the relation of general and particular truths1 as our own ,inductive ,tables may serve to show4 7,,iv47 #i4 ,comparison of the ,new and ,old ,method4 ,again2 not less remarkable is his contrasting this true ,method of ,science 7while it was almost1 as he says1 yet untried7 with the ancient and vicious ,method1 which began1 indeed1 with facts of observation1 but rushed at once and with no gradations1 to the most general principles4 ,for this was the course which had been actually followed by all those speculative reformers who had talked so loudly of the necessity of beginning our philosophy from experience4 ,all these men1 if they attempted to frame physical doctrines at all1 had caught up a few facts of observation1 and had erected a universal theory upon the suggestions which these offered4 ,this process of illicit generalization1 or1 as ,bacon terms it1 ,anticipation of ,nature 7anticipatio natur71 in opposition to the ,interpretation of ,nature1 he depicts with singular acuteness1 in its character and causes4 ,these two ways1 he says#aga1 both begin from sense and particulars2 but their discrepancy is immense4 ,the one merely skims over experience and particulars in a cursory transit2 the other deals with them in a due and orderly manner4 ,the one1 at its very outset1 frames certain general abstract principles1 but useless2 the other gradually rises to those principles which have a real existence in nature4 ,the former path1 he adds#agb1 that of illicit and hasty generalization1 is one which the intellect follows when abandoned to its own impulse2 and this it does from the requisitions of logic4 ,for the mind has a yearning which makes it dart forth to generalities1 that it may have something to rest in2 and after a little dallying with experience1 becomes weary of it2 and all these evils are augmented by logic1 which requires these generalities to make a show with in its disputations4 ,in a sober1 patient1 grave intellect1 he further adds1 the mind1 by its own impulse1 7and more especially if it be not impelled by the sway of established opinions7 attempts in some measure that other and true way1 of gradual generalization2 but this it does with small profit2 for the intellect1 except it be regulated and aided1 is a faculty of unequal operation1 and altogether unapt to master the obscurity of things4 ,the profound and searching wisdom of these remarks appears more and more1 as we apply them to the various attempts which men have made to obtain knowledge2 when they begin with the contemplation of a few facts1 and pursue their speculations1 as upon most subjects they have hitherto generally done2 for almost all such attempts have led immediately to some process of illicit generalization1 which introduces an interminable course of controversy4 ,in the physical sciences1 however1 we have the further inestimable advantage of seeing the other side of the contrast exemplified3 for many of them1 as our inductive ,tables show us1 have gone on according to the most rigorous conditions of gradual and successive generalization2 and in consequence of this circumstance in their constitution1 possess1 in each part of their structure1 a solid truth1 which is always ready to stand the severest tests of reasoning and experiment4 ,we see how justly and clearly ,bacon judged concerning the mode in which facts are to be employed in the construction of science4 ,this1 indeed1 has ever been deemed his great merit3 insomuch that many persons appear to apprehend the main substance of his doctrine to reside in the maxim that facts of observation1 and such facts alone1 are the essential elements of all true science4 7,v47 #aj4 ,ideas are necessary4--,yet we have endeavoured to establish the doctrine that facts are but one of two ingredients of knowledge both equally necessary2--that ,ideas are no less indispensable than facts themselves2 and that except these be duly unfolded and applied1 facts are collected in vain4 ,has ,bacon then neglected this great portion of his subject8 ,has he been led by some partiality of view1 or some peculiarity of circumstances1 to leave this curious and essential element of science in its pristine obscurity8 ,was he unaware of its interest and importance8 ,we may reply that ,bacon's philosophy1 in its effect upon his readers in general1 does not give due weight or due attention to the ideal element of our knowledge4 ,he is considered as peculiarly and eminently the asserter of the value of experiment and observation4 ,he is always understood to belong to the experiential1 as opposed to the ideal school4 ,he is held up in contrast to ,plato and others who love to dwell upon that part of knowledge which has its origin in the intellect of man4 #aa4 ,nor can it be denied that ,bacon has1 in the finished part of his ,novum ,organon1 put prominently forwards the necessary dependence of all our knowledge upon ,experience1 and said little of its dependence1 equally necessary1 upon the ,conceptions which the intellect itself supplies4 ,it will appear1 however1 on a close examination1 that he was by no means insensible or careless of this internal element of all connected speculation4 ,he held the balance1 with no partial or feeble hand1 between phenomena and ideas4 ,he urged the ,colligation of ,facts1 but he was not the less aware of the value of the ,explication of ,conceptions4 #ab4 ,this appears plainly from some remarkable ,aphorisms in the ,novum ,organon4 ,thus1 in noticing the causes of the little progress then made by science#agc1 he states this3--,in the current ,notions1 all is unsound1 whether they be logical or physical4 ,substance1 quality1 action1 passion1 even being1 are not good ,conceptions2 still less are heavy1 light1 dense1 rare1 moist1 dry1 generation1 corruption1 attraction1 repulsion1 element1 matter1 form1 and others of that kind2 all are fantastical and ill-defined4 ,and in his attempt to exemplify his own system1 he hesitates#agd in accepting or rejecting the notions of elementary1 celestial1 rare1 as belonging to fire1 since1 as he says1 they are vague and ill-defined notions 7notiones vag nec bene terminat74 ,in that part of his work which appears to be completed1 there is not1 so far as ,i have noticed1 any attempt to fix and define any notions thus complained of as loose and obscure4 ,but yet such an undertaking appears to have formed part of his plan2 and in the ,abecedarium ,natur#age1 which consists of the heads of various portions of his great scheme1 marked by letters of the alphabet1 we find the titles of a series of dissertations ,on the ,conditions of ,being1 which must have had for their object the elucidation of divers ,notions essential to science1 and which would have been contributions to the ,explication of ,conceptions1 such as we have attempted in a former part of this work4 ,thus some of the subjects of these dissertations are2--,of ,much and ,little2--,of ,durable and ,transitory2--,of ,natural and ,monstrous2--,of ,natural and ,artificial4 ,when the philosopher of induction came to discuss these1 considered as conditions of existence1 he could not do otherwise than develope1 limit1 methodize1 and define the ,ideas involved in these ,notions1 so as to make them consistent with themselves1 and a fit basis of demonstrative reasoning4 ,his task would have been of the same nature as ours has been1 in that part of this work which treats of the ,fundamental ,ideas of the various classes of sciences4 #ac4 ,thus ,bacon1 in his speculative philosophy1 took firmly hold of both the handles of science2 and if he had completed his scheme1 would probably have given due attention to ,ideas1 no less than to ,facts1 as an element of our knowledge2 while in his view of the general method of ascending from facts to principles1 he displayed a sagacity truly wonderful4 ,but we cannot be surprised1 that in attempting to exemplify the method which he recommended1 he should have failed4 ,for the method could be exemplified only by some important discovery in physical science2 and great discoveries1 even with the most perfect methods1 do not come at command4 ,moreover1 although the general structure of his scheme was correct1 the precise import of some of its details could hardly be understood1 till the actual progress of science had made men somewhat familiar with the kind of steps which it included4 7,,vi47 #ad4 ,bacon's ,example4--,accordingly1 ,bacon's ,inquisition into the ,nature of ,heat1 which is given in the ,second ,book of the ,novum ,organon as an example of the mode of interrogating ,nature1 cannot be looked upon otherwise than as a complete failure4 ,this will be evident if we consider that1 although the exact nature of heat is still an obscure and controverted matter1 the science of ,heat now consists of many important truths2 and that to none of these truths is there any approximation in ,bacon's essay4 ,from his process he arrives at this1 as the forma or true definition of heat2--that it is an expansive1 restrained motion1 modified in certain ways1 and exerted in the smaller particles of the body4 ,but the steps by which the science of ,heat really advanced were 7as may be seen in the history#agf of the subject7 these2--,the discovery of a measure of heat or temperature 7the thermometer72 the establishment of the laws of conduction and radiation2 of the laws of specific heat1 latent heat1 and the like4 ,such steps have led to ,ampre's hypothesis#agg1 that heat consists in the vibrations of an imponderable fluid2 and to ,laplace's hypothesis1 that temperature consists in the internal radiation of such a fluid4 ,these hypotheses cannot yet be said to be even probable2 but at least they are so modified as to include some of the preceding laws which are firmly established2 whereas ,bacon's hypothetical motion includes no laws of phenomena1 explains no process1 and is indeed itself an example of illicit generalization4 #ae4 ,one main ground of ,bacon's ill fortune in this undertaking appears to be1 that he was not aware of an important maxim of inductive science1 that we must first obtain the measure and ascertain the laws of phenomena1 before we endeavour to discover their causes4 ,the whole history of thermotics up to the present time has been occupied with the former step1 and the task is not yet completed3 it is no wonder1 therefore1 that ,bacon failed entirely1 when he so prematurely attempted the second4 ,his sagacity had taught him that the progress of science must be gradual2 but it had not led him to judge adequately how gradual it must be1 nor of what different kinds of inquiries1 taken in due order1 it must needs consist1 in order to obtain success4 ,another mistake1 which could not fail to render it unlikely that ,bacon should really exemplify his precepts by any actual advance in science1 was1 that he did not justly appreciate the sagacity1 the inventive genius1 which all discovery requires4 ,he conceived that he could supersede the necessity of such peculiar endowments4 ,our method of discovery in science1 he says#agh1 is of such a nature1 that there is not much left to acuteness and strength of genius1 but all degrees of genius and intellect are brought nearly to the same level4 ,and he illustrates this by comparing his method to a pair of compasses1 by means of which a person with no manual skill may draw a perfect circle4 ,in the same spirit he speaks of proceeding by due rejections2 and appears to imagine that when we have obtained a collection of facts1 if we go on successively rejecting what is false1 we shall at last find that we have1 left in our hands1 that scientific truth which we seek4 ,i need not observe how far this view is removed from the real state of the case4 ,the necessity of a conception which must be furnished by the mind in order to bind together the facts1 could hardly have escaped the eye of ,bacon1 if he had cultivated more carefully the ideal side of his own philosophy4 ,and any attempts which he could have made to construct such conceptions by mere rule and method1 must have ended in convincing him that nothing but a peculiar inventive talent could supply that which was thus not contained in the facts1 and yet was needed for the discovery4 7,,vii47 #af4 ,his ,failure4--,since ,bacon1 with all his acuteness1 had not divined circumstances so important in the formation of science1 it is not wonderful that his attempt to reduce this process to a ,technical ,form is of little value4 ,in the first place1 he says#agi1 we must prepare a natural and experimental history1 good and sufficient2 in the next place1 the instances thus collected are to be arranged in ,tables in some orderly way2 and then we must apply a legitimate and true induction4 ,and in his example#ahj1 he first collects a great number of cases in which heat appears under various circumstances1 which he calls a ,muster of ,instances before the intellect1 7comparentia instantiarum ad intellectum17 or a ,table of the ,presence of the thing sought4 ,he then adds a ,table of its ,absence in proximate cases1 containing instances where heat does not appear2 then a ,table of ,degrees1 in which it appears with greater or less intensity4 ,he then adds#aha1 that we must try to exclude several obvious suppositions1 which he does by reference to some of the instances he has collected2 and this step he calls the ,exclusive1 or the ,rejection of ,natures4 ,he then observes1 7and justly17 that whereas truth emerges more easily from error than from confusion1 we may1 after this preparation1 give play to the intellect1 7fiat permissio intellectus17 and make an attempt at induction1 liable afterwards to be corrected2 and by this step1 which he terms his ,first ,vindemiation1 or ,inchoate ,induction1 he is led to the proposition concerning heat1 which we have stated above4 #ag4 ,in all the details of his example he is unfortunate4 ,by proposing to himself to examine at once into the nature of heat1 instead of the laws of special classes of phenomena1 he makes1 as we have said1 a fundamental mistake2 which is the less surprising since he had before him so few examples of the right course in the previous history of science4 ,but further1 his collection of instances is very loosely brought together2 for he includes in his list the hot taste of aromatic plants1 the caustic effects of acids1 and many other facts which cannot be ascribed to heat without a studious laxity in the use of the word4 ,and when he comes to that point where he permits his intellect its range1 the conception of motion upon which it at once fastens1 appears to be selected with little choice or skill1 the suggestion being taken from flame#ahb1 boiling liquids1 a blown fire1 and some other cases4 ,if from such examples we could imagine heat to be motion1 we ought at least to have some gradation to cases of heat where no motion is visible1 as in a red-hot iron4 ,it would seem that1 after a large collection of instances had been looked at1 the intellect1 even in its first attempts1 ought not to have dwelt upon such an hypothesis as this4 #ah4 ,after these steps1 ,bacon speaks of several classes of instances which1 singling them out of the general and indiscriminate collection of facts1 he terms ,instances with ,prerogative3 and these he points out as peculiar aids and guides to the intellect in its task4 ,these ,instances with ,prerogative have generally been much dwelt upon by those who have commented on the ,novum ,organon4 ,yet1 in reality1 such a classification1 as has been observed by one of the ablest writers of the present day#ahc1 is of little service in the task of induction4 ,for the instances are1 for the most part1 classed1 not according to the ideas which they involve1 or to any obvious circumstance in the facts of which they consist1 but according to the extent or manner of their influence upon the inquiry in which they are employed4 ,thus we have ,solitary ,instances1 ,migrating ,instances1 ,ostensive ,instances1 ,clandestine ,instances1 so termed according to the degree in which they exhibit1 or seem to exhibit1 the property whose nature we would examine4 ,we have ,guide-,post ,instances1 7,instanti ,crucis17 ,instances of the ,parted ,road1 of the ,doorway1 of the ,lamp1 according to the guidance they supply to our advance4 ,such a classification is much of the same nature as if1 having to teach the art of building1 we were to describe tools with reference to the amount and place of the work which they must do1 instead of pointing out their construction and use3--as if we were to inform the pupil that we must have tools for lifting a stone up1 tools for moving it sideways1 tools for laying it square1 tools for cementing it firmly4 ,such an enumeration of ends would convey little instruction as to the means4 ,moreover1 many of ,bacon's classes of instances are vitiated by the assumption that the form1 that is1 the general law and cause of the property which is the subject of investigation1 is to be looked for directly in the instances2 which1 as we have seen in his inquiry concerning heat1 is a fundamental error4 #ai4 ,yet his phraseology in some cases1 as in the instantia crucis1 serves well to mark the place which certain experiments hold in our reasonings3 and many of the special examples which he gives are full of acuteness and sagacity4 ,thus he suggests swinging a pendulum in a mine1 in order to determine whether the attraction of the earth arises from the attraction of its parts2 and observing the tide at the same moment in different parts of the world1 in order to ascertain whether the motion of the water is expansive or progressive2 with other ingenious proposals4 ,these marks of genius may serve to counterbalance the unfavourable judgment of ,bacon's aptitude for physical science which we are sometimes tempted to form1 in consequence of his false views on other points2 as his rejection of the ,copernican system1 and his undervaluing ,gilbert's magnetical speculations4 ,most of these errors arose from a too ambitious habit of intellect1 which would not be contented with any except very wide and general truths2 and from an indistinctness of mechanical1 and perhaps1 in general1 of mathematical ideas3--defects which ,bacon's own philosophy was directed to remedy1 and which1 in the progress of time1 it has remedied in others4 7,,viii47 #bj4 ,his ,idols4--,having thus freely given our judgment concerning the most exact and definite portion of ,bacon's precepts1 it cannot be necessary for us to discuss at any length the value of those more vague and general ,warnings against prejudice and partiality1 against intellectual indolence and presumption1 with which his works abound4 ,his advice and exhortations of this kind are always expressed with energy and point1 often clothed in the happiest forms of imagery2 and hence it has come to pass1 that such passages are perhaps more familiar to the general reader than any other part of his writings4 ,nor are ,bacon's counsels without their importance1 when we have to do with those subjects in which prejudice and partiality exercise their peculiar sway4 ,questions of politics and morals1 of manners1 taste1 or history1 cannot be subjected to a scheme of rigorous induction2 and though on such matters we venture to assert general principles1 these are commonly obtained with some degree of insecurity1 and depend upon special habits of thought1 not upon mere logical connexion4 ,here1 therefore1 the intellect may be perverted1 by mixing1 with the pure reason1 our gregarious affections1 or our individual propensities2 the false suggestions involved in language1 or the imposing delusions of received theories4 ,in these dim and complex labyrinths of human thought1 the ,idol of the ,tribe1 or of the ,den1 of the ,forum1 or of the ,theatre1 may occupy men's minds with delusive shapes1 and may obscure or pervert their vision of truth4 ,but in that ,natural ,philosophy with which we are here concerned1 there is little opportunity for such influences4 ,as far as a physical theory is completed through all the steps of a just induction1 there is a clear daylight diffused over it which leaves no lurking-place for prejudice4 ,each part can be examined separately and repeatedly2 and the theory is not to be deemed perfect till it will bear the scrutiny of all sound minds alike4 ,although1 therefore1 ,bacon1 by warning men against the idols of fallacious images above spoken of1 may have guarded them from dangerous error1 his precepts have little to do with ,natural ,philosophy3 and we cannot agree with him when he says#ahd1 that the doctrine concerning these idols bears the same relation to the interpretation of nature as the doctrine concerning sophistical paralogisms bears to common logic4 7,,ix47 #ba4 ,his ,aim1 ,utility4--,there is one very prominent feature in ,bacon's speculations which we must not omit to notice2 it is a leading and constant object with him to apply his knowledge to ,use4 ,the insight which he obtains into nature1 he would employ in commanding nature for the service of man4 ,he wishes to have not only principles but works4 ,the phrase which best describes the aim of his philosophy is his own#ahe1 ,ascendendo ad axiomata1 descendendo ad opera4 ,this disposition appears in the first aphorism of the ,novum ,organon1 and runs through the work4 ,man1 the minister and interpreter of nature1 does and understands1 so far as he has1 in fact or in thought1 observed the course of nature2 and he cannot know or do more than this4 ,it is not necessary for us to dwell much upon this turn of mind2 for the whole of our present inquiry goes upon the supposition that an acquaintance with the laws of nature is worth our having for its own sake4 ,it may be universally true1 that ,knowledge is ,power2 but we have to do with it not as ,power1 but as ,knowledge4 ,it is the formation of ,science1 not of ,art1 with which we are here concerned4 ,it may give a peculiar interest to the history of science1 to show how it constantly tends to provide better and better for the wants and comforts of the body2 but that is not the interest which engages us in our present inquiry into the nature and course of philosophy4 ,the consideration of the means which promote man's material well-being often appears to be invested with a kind of dignity1 by the discovery of general laws which it involves2 and the satisfaction which rises in our minds at the contemplation of such cases1 men sometimes ascribe1 with a false ingenuity1 to the love of mere bodily enjoyment4 ,but it is never difficult to see that this baser and coarser element is not the real source of our admiration4 ,those who hold that it is the main business of science to construct instruments for the uses of life1 appear sometimes to be willing to accept the consequence which follows from such a doctrine1 that the first shoemaker was a philosopher worthy of the highest admiration#ahf4 ,but those who maintain such paradoxes1 often1 by a happy inconsistency1 make it their own aim1 not to devise some improved covering for the feet1 but to delight the mind with acute speculations1 exhibited in all the graces of wit and fancy4 ,it has been said#ahg that the key of the ,baconian doctrine consists in two words1 ,utility and ,progress4 ,with regard to the latter point1 we have already seen that the hope and prospect of a boundless progress in human knowledge had sprung up in men's minds1 even in the early times of imperial ,rome2 and were most emphatically expressed by that very ,seneca who disdained to reckon the worth of knowledge by its value in food and clothing4 ,and when we say that ,utility was the great business of ,bacon's philosophy1 we forget one-half of his characteristic phrase3 ,ascendendo ad aximomata1 no less than descendendo ad opera1 was1 he repeatedly declared1 the scheme of his path4 ,he constantly spoke1 we are told by his secretary#ahh1 of two kinds of experiments1 experimenta fructifera1 and experimenta lucifera4 ,again2 when we are told by modern writers that ,bacon merely recommended such induction as all men instinctively practise1 we ought to recollect his own earnest and incessant declarations to the contrary4 ,the induction hitherto practised is1 he says1 of no use for obtaining solid science4 ,there are two ways#ahi1 hc via in usu est1 altera vera1 sed intentata4 ,men have constantly been employed in anticipation2 in illicit induction4 ,the intellect left to itself rushes on in this road#aij2 the conclusions so obtained are persuasive#aia2 far more persuasive than inductions made with due caution#aib4 ,but still this method must be rejected if we would obtain true knowledge4 ,we shall then at length have ground of good hope for science when we proceed in another manner#aic4 ,we must rise1 not by a leap1 but by small steps1 by successive advances1 by a gradation of ascents1 trying our facts1 and clearing our notions at every interval4 ,the scheme of true philosophy1 according to ,bacon1 is not obvious and simple1 but long and technical1 requiring constant care and self-denial to follow it4 ,and we have seen that1 in this opinion1 his judgment is confirmed by the past history and present condition of science4 ,again2 it is by no means a just view of ,bacon's character to place him in contrast to ,plato4 ,plato's philosophy was the philosophy of ,ideas2 but it was not left for ,bacon to set up the philosophy of ,facts in opposition to that of ,ideas4 ,that had been done fully by the speculative reformers of the sixteenth century4 ,bacon had the merit of showing that ,facts and ,ideas must be combined2 and not only so1 but of divining many of the special rules and forms of this combination1 when as yet there were no examples of them1 with a sagacity hitherto quite unparalleled4 7,x47 #bb4 ,his ,perseverance4--,with ,bacon's unhappy political life we have here nothing to do4 ,but we cannot but notice with pleasure how faithfully1 how perseveringly1 how energetically he discharged his great philosophical office of a ,reformer of ,methods4 ,he had conceived the purpose of making this his object at an early period4 ,when meditating the continuation of his ,novum ,organon1 and speaking of his reasons for trusting that his work will reach some completeness of effect1 he says#aid1 ,i am by two arguments thus persuaded4 ,first1 ,i think thus from the zeal and constancy of my mind1 which has not waxed old in this design1 nor1 after so many years1 grown cold and indifferent2 ,i remember that about forty years ago ,i composed a juvenile work about these things1 which with great contrivance and a pompous title ,i called temporis partum maximum1 or the most considerable birth of time2 ,next1 that on account of its usefulness1 it may hope the ,divine blessing4 ,in stating the grounds of hope for future progress in the sciences1 he says#aie3 ,some hope may1 we conceive1 be ministered to men by our own example3 and this we say1 not for the sake of boasting1 but because it is useful to be said4 ,if any despond1 let them look at me1 a man among all others of my age most occupied with civil affairs1 nor of very sound health1 7which brings a great loss of time27 also in this attempt the first explorer1 following the footsteps of no man1 nor communicating on these subjects with any mortal2 yet1 having steadily entered upon the true road and made my mind submit to things themselves1 one who has1 in this undertaking1 made1 7as we think17 some progress4 ,he then proceeds to speak of what may be done by the combined and more prosperous labours of others1 in that strain of noble hope and confidence1 which rises again and again1 like a chorus1 at intervals in every part of his writings4 ,in the ,advancement of ,learning he had said1 ,i could not be true and constant to the argument ,i handle1 if ,i were not willing to go beyond others1 but yet not more willing than to have others go beyond me again4 ,in the ,preface to the ,instauratio ,magna1 he had placed among his postulates those expressions which have more than once warmed the breast of a philosophical reformer#aif4 ,concerning ourselves we speak not2 but as touching the matter which we have in hand1 this we ask2--that men be of good hope1 neither feign and imagine to themselves this our ,reform as something of infinite dimension and beyond the grasp of mortal man1 when in truth it is the end and true limit of infinite error2 and is by no means unmindful of the condition of mortality and humanity1 not confiding that such a thing can be carried to its perfect close in the space of a single age1 but assigning it as a task to a succession of generations4 ,in a later portion of the ,instauratio he says3 ,we bear the strongest love to the human republic our common country2 and we by no means abandon the hope that there will arise and come forth some man among posterity1 who will be able to receive and digest all that is best in what we deliver2 and whose care it will be to cultivate and perfect such things4 ,therefore1 by the blessing of the ,deity1 to tend to this object1 to open up the fountains1 to discover the useful1 to gather guidance for the way1 shall be our task2 and from this we shall never1 while we remain in life1 desist4 7,,xi47 #bc4 ,his ,piety4--,we may add1 that the spirit of piety as well as of hope which is seen in this passage1 appears to have been habitual to ,bacon at all periods of his life4 ,we find in his works several drafts of portions of his great scheme1 and several of them begin with a prayer4 ,one of these entitled1 in the edition of his works1 ,the ,student's ,prayer1 appears to me to belong probably to his early youth4 ,another1 entitled ,the ,writer's ,prayer1 is inserted at the end of the ,preface of the ,instauratio1 as it was finally published4 ,i will conclude my notice of this wonderful man by inserting here these two prayers4 ,to ,god the ,father1 ,god the ,word1 ,god the ,spirit1 we pour forth most humble and hearty supplications2 that he1 remembering the calamities of mankind1 and the pilgrimage of this our life1 in which we wear out days few and evil1 would please to open to us new refreshments out of the fountains of his goodness for the alleviating of our miseries4 ,this also we humbly and earnestly beg1 that human things may not prejudice such as are divine2 neither that1 from the unlocking of the gates of sense1 and the kindling of a greater natural light1 anything of incredulity1 or intellectual night1 may arise in our minds towards divine mysteries4 ,but rather1 that by our mind thoroughly cleansed and purged from fancy and vanities1 and yet subject and perfectly given up to the ,divine oracles1 there may be given unto faith the things that are faith's4 ,thou1 ,o ,father1 who gavest the visible light as the first-born of thy creatures1 and didst pour into man the intellectual light as the top and consummation of thy workmanship1 be pleased to protect and govern this work1 which coming from thy goodness1 returneth to thy glory4 ,thou1 after thou hadst reviewed the works which thy hands had made1 beheldest that everything was very good1 and thou didst rest with complacency in them4 ,but man1 reflecting on the works which he had made1 saw that all was vanity and vexation of spirit1 and could by no means acquiesce in them4 ,wherefore1 if we labour in thy works with the sweat of our brows1 thou wilt make us partakers of thy vision and thy ,sabbath4 ,we humbly beg that this mind may be steadfastly in us2 and that thou1 by our hands1 and also by the hands of others on whom thou shalt bestow the same spirit1 wilt please to convey a largess of new alms to thy family of mankind4 ,these things we commend to thy everlasting love1 by our ,jesus1 thy ,christ1 ,god with us4 ,amen4 ,,footnotes3 ,footnote #afh3 ,and in other passages3 thus1 ,ego enim buccinator tantum pugnam non ineo4 ,nov4 ,org4 lib4 iv4 c4 i4 ,footnote #afi3 ,lib4 #a4 ,aphor4 #gh et seq4 ,footnote #agj3 ,aug4 ,sc4 ,lib4 iii4 c4 #d4 p4 #aid4 ,so in other places1 as ,nov4 ,org4 i4 ,aph4 #ajd4 ,de scientiis tum demum bene sperandum est quando per scalam veram et per gradus continuos1 et non intermissos aut hiulcos a particularibus ascendetur ad axiomata minora1 et deinde ad media1 alia aliis superiora1 et postremo demum ad generalissima4 ,footnote #aga3 ,nov4 ,org4 #a4 ,aph4 #bb4 ,footnote #agb3 ,ib4 ,aph4 #bj4 ,footnote #agc3 #a ,ax4 #ae4 ,footnote #agd3 ,nov4 ,org4 lib4 ii4 ,aph4 #ai4 ,footnote #age3 ,inst4 ,mag4 par4 iii4 7vol4 viii4 p4 #bdd74 ,footnote #agf3 ,hist4 ,ind4 ,sc4 b4 x4 c4 i4 ,footnote #agg3 ,ib4 c4 iv4 ,footnote #agh3 ,nov4 ,org4 lib4 i4 ,aph4 #fa4 ,footnote #agi3 ,nov4 ,org4 lib4 ii4 ,aph4 #aj4 ,footnote #ahj3 ,aph4 #aa4 ,footnote #aha3 ,aph4 #ae1 p4 #aje4 ,footnote #ahb3 ,page #aaj4 ,footnote #ahc3 ,herschel1 ,on the ,study of ,nat4 ,phil4 ,art4 #aib4 ,footnote #ahd3 ,nov4 ,org4 lib4 i4 ,aph4 #dj4 ,footnote #ahe3 ,nov4 ,org4 lib4 i4 ,ax4 #ajc4 ,footnote #ahf3 ,edinb4 ,rev4 ,no4 cxxxii4 p4 #fe4 ,footnote #ahg3 ,ib4 ,footnote #ahh3 ,pref4 to the ,nat4 ,hist4 i4 #bdc4 ,footnote #ahi3 ,nov4 ,org4 lib4 i4 ,aph4 #ai4 ,footnote #aij3 ,ibid4 lib4 i4 ,aph4 #bj4 ,footnote #aia3 ,aph4 #bg4 ,footnote #aib3 ,ib4 #bh4 ,footnote #aic3 ,aph4 #ajd4 ,so ,aph4 #aje4 ,in constituendo axiomate forma inductionis alia quam adhuc in usu fuit excogitanda est1 c4 ,footnote #aid3 ,ep4 ad ,p4 ,fulgentium4 ,op4 x4 #ccj4 ,footnote #aie3 ,nov4 ,org4 i4 ,aph4 #aac4 ,footnote #aif3 ,see the motto to ,kant's ,kritik der ,reinen ,vernunft4 ,,chapter ,,xvi4 ,,additional ,,remarks ,,on ,,francis ,,bacon4 ,francis ,bacon and his works have recently been discussed and examined by various writers in ,france and ,germany as well as ,england#aig4 ,not to mention smaller essays1 ,m4 ,bouillet has published a valuable edition of his philosophical works2 ,count ,joseph de ,maistre wrote a severe critique of his philosophy1 which has been published since the death of the author2 ,m4 ,charles ,remusat has written a lucid and discriminating ,essay on the subject2 and in ,england we have had a new edition of the works published1 with a careful and thoughtful examination of the philosophy which they contain1 written by one of the editors3 a person especially fitted for such an examination by an acute intellect1 great acquaintance with philosophical literature1 and a wide knowledge of modern science4 ,robert ,leslie ,ellis1 the editor of whom ,i speak1 died during the publication of the edition1 and before he had done full justice to his powers2 but he had already written various dissertations on ,bacon's philosophy1 which accompany the different ,treatises in the new edition4 ,mr4 ,ellis has given a more precise view than any of his predecessors had done of the nature of ,bacon's induction and of his philosophy of discovery4 ,bacon's object was to discover the 'natures' or essences of things1 in order that he might reproduce these natures or essences at will2 he conceived that these natures were limited in number1 and manifested in various combinations in the bodies which exist in the universe2 so that by accumulating observations of them in a multitude of cases1 we may learn by induction in what they do and in what they do not consist2 the ,induction which is to be used for this purpose consists in a great measure of excluding the cases which do not exhibit the 'nature' in question2 and by such exclusion1 duly repeated1 we have at last left in our hands the elements of which the proposed nature consists4 ,and the knowledge which is thus obtained may be applied to reproduce the things so analysed4 ,as exhibiting this view clearly we may take a passage in the ,sylva ,sylvarum3 ,gold has these natures3 greatness of weight1 closeness of parts1 fixation1 pliantness or softness1 immunity from rust1 colour or tincture of yellow4 ,therefore the sure way1 though most about1 to make gold1 is to know the causes of the several natures before rehearsed1 and the axioms concerning the same4 ,for if a man can make a metal1 that hath all these properties1 let men dispute whether it be gold or no4 ,he means that however they dispute1 it is gold for all practical purposes4 ,for such an ,induction as this1 ,bacon claims the merit both of being certain1 and of being nearly independent of the ingenuity of the inquirer4 ,it is a method which enables all men to make exact discoveries1 as a pair of compasses enables all men to draw an exact circle4 ,now it is necessary for us1 who are exploring the progress of the true philosophy of discovery1 to say plainly that this part of ,bacon's speculation is erroneous and valueless4 ,no scientific discovery ever has been made in this way4 ,men have not obtained truths concerning the natural world by seeking for the natures of things1 and by extracting them from phenomena by rejecting the cases in which they were not4 ,on the contrary1 they have begun by ascertaining the laws of the phenomena2 and have then gone on1 not by a mechanical method which levels all intellect1 but by special efforts of the brightest intellects to catch hold of the ideas by which these laws of phenomena might be interpreted and expressed in more general terms4 ,these two steps1 the finding the laws of phenomena1 and finding the conceptions by which those laws can be expressed1 are really the course of discovery1 as the history of science exhibits it to us4 ,bacon1 therefore1 according to the view now presented1 was wrong both as to his object and as to his method4 ,he was wrong in taking for his object the essences of things1--the causes of abstract properties3 for these man cannot1 or can very rarely discover2 and all ,bacon's ingenuity in enumerating and classifying these essences and abstract properties has led1 and could lead1 to no result4 ,the vast results of modern science have been obtained1 not by seeking and finding the essences of things1 but by exploring the laws of phenomena and the causes of those laws4 ,and ,bacon's method1 as well as his object1 is vitiated by a pervading error3--the error of supposing that to be done by method which must be done by mind2--that to be done by rule which must be done by a flight beyond rule2--that to be mainly negative which is eminently positive2--that to depend on other men which must depend on the discoverer himself2--that to be mere prose which must have a dash of poetry2--that to be a work of mere labour which must be also a work of genius4 ,mr4 ,ellis has seen very clearly and explained very candidly that this method thus recommended by ,bacon has not led to discovery4 ,it is1 he says1 neither to the technical part of his method nor to the details of his view of the nature and progress of science1 that his great fame is justly owing4 ,his merits are of another kind4 ,they belong to the spirit rather than to the positive precepts of his philosophy4 ,as the reader of the last chapter will see1 this amounts to much the same as the account which ,i had given of the positive results of ,bacon's method1 and the real value of that portion of his philosophy which he himself valued most4 ,but still there remain1 as ,i have also noted1 portions of ,bacon's speculations which have a great and enduring value1 namely1 his doctrine that ,science is the ,interpretation of ,nature1 his distinction of this ,interpretation of ,nature from the vicious and premature ,anticipation of ,nature which had generally prevailed till then2 and the recommendation of a graduated and successive induction by which alone the highest and most general truths were to be reached4 ,these are points which he urges with great clearness and with great earnestness2 and these are important points in the true philosophy of discovery4 ,i may add that ,mr4 ,ellis agrees with me in noting the invention of the conception by which the laws of phenomena are interpreted as something additional to ,induction1 both in the common and in the ,baconian sense of the word4 ,he says 7,general ,preface1 ,art4 #i71 ,in all cases this process scientific discovery involves an element to which nothing corresponds in the ,tables of ,comparence and ,exclusion2 namely the application to the facts of a principle of arrangement1 an idea1 existing in the mind of the discoverer antecedently to the act of induction4 ,it may be said that this principle or idea is aimed at in the ,baconian analysis4 ,and this is in one sense true3 but it must be added1 that this analysis1 if it be thought right to call it so1 is of the essence of the discovery which results from it4 ,to take for granted that it has been already effected is simply a petitio principii4 ,in most cases the mere act of induction follows as a matter of course as soon as the appropriate idea has been introduced4 ,and as an example he takes ,kepler's invention of the ellipse1 as the idea by which ,mars's motions could be reduced to law2 making the same use of this example which we have repeatedly made of it4 ,mr4 ,ellis may at first sight appear to express himself more favourably than ,i have done1 with regard to the value of ,bacon's ,inquisitio in ,naturam ,calidi in the ,second ,book of the ,novum ,organon4 ,he says of one part of it#aih3 ,bacon here anticipates not merely the essential character of the most recent theory of heat1 but also the kind of evidence by which it has been established4444 ,the merit of having perceived the true significance of the production of heat by friction belongs of right to ,bacon4 ,but notwithstanding this1 ,mr4 ,ellis's general judgment on this specimen of ,bacon's application of his own method does not differ essentially from mine4 ,he examines the ,inquisitio at some length1 and finally says3 ,if it were affirmed that ,bacon1 after having had a glimpse of the truth suggested by some obvious phenomena1 had then recourse1 as he himself expresses it1 to certain 'differenti inanes' in order to save the phenomena1 ,i think it would be hard to dispute the truth of the censure4 ,another of the ,editors of this edition 7,mr4 ,spedding7 fixes his attention upon another of the features of the method of discovery proposed by ,bacon1 and is disposed to think that the proposed method has never yet had justice done it1 because it has not been tried in the way and on the scale that ,bacon proposes#aii4 ,bacon recommended that a great collection of facts should be at once made and accumulated1 regarding every branch of human knowledge2 and conceived that1 when this had been done by common observers1 philosophers might extract scientific truths from this mass of facts by the application of a right method4 ,this separation of the offices of the observer and discoverer1 ,mr4 ,spedding thinks is shown to be possible by such practical examples as meteorological observations1 made by ordinary observers1 and reduced to tables and laws by a central calculator2 by hydrographical observations made by ships provided with proper instructions1 and reduced to general laws by the man of science in his study2 by magnetical observations made by many persons in every part of the world1 and reduced into subservience to theory by mathematicians at home4 ,and to this our reply will be1 in the terms which the history of all the ,sciences has taught us1 that such methods of procedure as this do not belong to the ,epoch of ,discovery1 but to the ,period of verification and application of the discovery which follows4 ,when a theory has been established in its general form1 our knowledge of the distribution of its phenomena in time and space can be much promoted by ordinary observers scattered over the earth1 and succeeding each other in time1 provided they are furnished with instruments and methods of observation1 duly constructed on the principles of science2 but such observers cannot in any degree supersede the discoverer who is first to establish the theory1 and to introduce into the facts a new principle of order4 ,when the laws of nature have been caught sight of1 much may be done1 even by ordinary observers1 in verifying and exactly determining them2 but when a real discovery is to be made1 this separation of the observer and the theorist is not possible4 ,in those cases1 the questioning temper1 the busy suggestive mind1 is needed at every step1 to direct the operating hand or the open gaze4 ,no possible accumulation of facts about mixture and heat1 collected in the way of blind trial1 could have led to the doctrines of chemistry1 or crystallography1 or the atomic theory1 or voltaic and chemical and magnetic polarity1 or physiology1 or any other science4 ,indeed not only is an existing theory requisite to supply the observer with instruments and methods1 but without theory he cannot even describe his observations4 ,he says that he mixes an acid and an alkali2 but what is an acid8 ,what is an alkali8 ,how does he know them8 ,he classifies crystals according to their forms3 but till he has learnt what is distinctive in the form of a crystal1 he cannot distinguish a cube from a square prism1 even if he had a goniometer and could use it4 ,and the like impossibility hangs over all the other subjects4 ,to report facts for scientific purposes without some aid from theory1 is not only useless1 but impossible4 ,when ,mr4 ,spedding says1 ,i could wish that men of science would apply themselves earnestly to the solution of this practical problem3 ,what measures are to be taken in order that the greatest variety of judicious observations of nature all over the world may be carried on in concert upon a common plan and brought to a common centre3--he is urging upon men of science to do what they have always done1 so far as they have had any power1 and in proportion as the state of science rendered such a procedure possible and profitable to science4 ,in ,astronomy1 it has been done from the times of the ,greeks and even of the ,chaldeans1 having been begun as soon as the heavens were reduced to law at all4 ,in meteorology1 it has been done extensively1 though to little purpose1 because the weather has not yet been reduced to rule4 ,men of science have shown how barometers1 thermometers1 hygrometers1 and the like1 may be constructed2 and these may be now read by any one as easily as a clock2 but of ten thousand meteorological registers thus kept by ordinary observers1 what good has come to science8 ,again3 ,the laws of the tides have been in a great measure determined by observations in all parts of the globe1 because theory pointed out what was to be observed4 ,in like manner the facts of terrestrial magnetism were ascertained with tolerable completeness by extended observations1 then1 and then only1 when a most recondite and profound branch of mathematics had pointed out what was to be observed1 and most ingenious instruments had been devised by men of science for observing4 ,and even with these1 it requires an education to use the instruments4 ,but in many cases no education in the use of instruments devised by others can supersede the necessity of a theoretical and suggestive spirit in the inquirer himself4 ,he must devise his own instruments and his own methods1 if he is to make any discovery4 ,what chemist1 or inquirer about polarities1 or about optical laws yet undiscovered1 can make any progress by using another man's experiments and observations8 ,he must invent at every step of his observation2 and the observer and theorist can no more be dissevered1 than the body and soul of the inquirer4 ,that persons of moderate philosophical powers may1 when duly educated1 make observations which may be used by greater discoverers than themselves1 is true4 ,we have examples of such a subordination of scientific offices in astronomy1 in geology1 and in many other departments4 ,but still1 as ,i have said1 a very considerable degree of scientific education is needed even for the subordinate labourers in science2 and the more considerable in proportion as science advances further and further2 since every advance implies a knowledge of what has already been done1 and requires a new precision or generality in the new points of inquiry4 ,,footnotes3 ,footnote #aig3 uvres ,philosophiques de ,bacon1 c4 par ,m4 ,n4 ,bouillet1 #c ,tomes4 ,examen de la ,philosophie de ,bacon 7uvres ,posthumes du ,comte ,j4 de ,maistre74 ,bacon1 sa ,vie1 son ,temps1 sa ,philosophie1 par ,charles de ,remusat4 ,histoire de la ,vie et des ,ouvrages de ,franois ,bacon1 par ,j4 ,b4 de ,vaugelles4 ,franz ,baco von ,verulam1 von ,kuno ,fischer4 ,the ,works of ,francis ,bacon1 collected and edited by ,james ,spedding1 ,robert ,leslie ,ellis1 and ,douglas ,denon ,heath4 ,footnote #aih3 ,note to ,aph4 xviii4 ,footnote #aii3 ,pref4 to the ,parasceue1 ,vol4 i4 p4 #chb4 ,,chapter ,,xvii4 ,,from ,,bacon ,,to ,,newton4 #a4 ,harvey4--,we have already seen that ,bacon was by no means the first mover or principal author of the revolution in the method of philosophizing which took place in his time2 but only the writer who proclaimed in the most impressive and comprehensive manner1 the scheme1 the profit1 the dignity1 and the prospects of the new philosophy4 ,those1 therefore1 who after him1 took up the same views are not to be considered as his successors1 but as his fellow-labourers2 and the line of historical succession of opinions must be pursued without special reference to any one leading character1 as the principal figure of the epoch4 ,i resume this line1 by noticing a contemporary and fellow-countryman of ,bacon1 ,harvey1 the discoverer of the circulation of the blood4 ,this discovery was not published and generally accepted till near the end of ,bacon's life2 but the anatomist's reflections on the method of pursuing science1 though strongly marked with the character of the revolution that was taking place1 belong to a very different school from the ,chancellor's4 ,harvey was a pupil of ,fabricius of ,acquapendente1 whom we noticed among the practical reformers of the sixteenth century4 ,he entertained1 like his master1 a strong reverence for the great names which had ruled in philosophy up to that time1 ,aristotle and ,galen2 and was disposed rather to recommend his own method by exhibiting it as the true interpretation of ancient wisdom1 than to boast of its novelty4 ,it is true1 that he assigns1 as his reason for publishing some of his researches#bjj1 that by revealing the method ,i use in searching into things1 ,i might propose to studious men1 a new and 7if ,i mistake not7 a surer path to the attainment of knowledge#bja2 but he soon proceeds to fortify himself with the authority of ,aristotle4 ,in doing this1 however1 he has the very great merit of giving a living and practical character to truths which exist in the ,aristotelian works1 but which had hitherto been barren and empty professions4 ,we have seen that ,aristotle had asserted the importance of experience as one root of knowledge2 and in this had been followed by the schoolmen of the middle ages3 but this assertion came with very different force and effect from a man1 the whole of whose life had been spent in obtaining1 by means of experience1 knowledge which no man had possessed before4 ,in ,harvey's general reflections1 the necessity of both the elements of knowledge1 sensations and ideas1 experience and reason1 is fully brought into view1 and rightly connected with the metaphysics of ,aristotle4 ,he puts the antithesis of these two elements with great clearness4 ,universals are chiefly known to us1 for science is begot by reasoning from universals to particulars2 yet that very comprehension of universals in the understanding springs from the perception of singulars in our sense4 ,again1 he quotes ,aristotle's apparently opposite assertions3--that made in his ,physics#bjb1 that we must advance from things which are first known to us1 though confusedly1 to things more distinctly intelligible in themselves2 from the whole to the part2 from the universal to the particular2 and that made in the ,analytics#bjc2 that ,singulars are more known to us and do first exist according to sense3 for nothing is in the understanding which was not before in the sense4 ,both1 he says1 are true1 though at first they seem to clash3 for though in knowledge we begin with sense1 sensation itself is a universal thing4 ,this he further illustrates2 and quotes ,seneca1 who says1 that ,art itself is nothing but the reason of the work1 implanted in the ,artist's mind3 and adds1 the same way by which we gain an ,art1 by the very same way we attain any kind of science or knowledge whatever2 for as ,art is a habit whose object is something to be done1 so ,science is a habit whose object is something to be known2 and as the former proceedeth from the imitation of examples1 so this latter1 from the knowledge of things natural4 ,the source of both is from sense and experience2 since but8 it is impossible that ,art should be rightly purchased by the one or ,science by the other without a direction from ideas4 ,without here dwelling on the relation of ,art and ,science1 7very justly stated by ,harvey1 except that ideas exist in a very different form in the mind of the ,artist and the ,scientist7 it will be seen that this doctrine1 of science springing from experience with a direction from ideas1 is exactly that which we have repeatedly urged1 as the true view of the subject4 ,from this view1 ,harvey proceeds to infer the importance of a reference to sense in his own subject1 not only for first discovering1 but for receiving knowledge3 ,without experience1 not other men's but our own1 no man is a proper disciple of any part of natural knowledge2 without experimental skill in anatomy1 he will no better apprehend what ,i shall deliver concerning generation1 than a man born blind can judge of the nature and difference of colours1 or one born deaf1 of sounds4 ,if we do otherwise1 we may get a humid and floating opinion1 but never a solid and infallible knowledge3 as is happenable to those who see foreign countries only in maps1 and the bowels of men falsely described in anatomical tables4 ,and hence it comes about1 that in this rank age1 we have many sophisters and bookwrights1 but few wise men and philosophers4 ,he had before declared how unsafe and degenerate a thing it is1 to be tutored by other men's commentaries1 without making trial of the things themselves2 especially since ,nature's book is so open and legible4 ,we are here reminded of ,galileo's condemnation of the paper philosophers4 ,the train of thought thus expressed by the practical discoverers1 spread rapidly with the spread of the new knowledge that had suggested it1 and soon became general and unquestioned4 #b4 ,descartes4--,such opinions are now among the most familiar and popular of those which are current among writers and speakers2 but we should err much if we were to imagine that after they were once propounded they were never resisted or contradicted4 ,indeed1 even in our own time1 not only are such maxims very often practically neglected or forgotten1 but the opposite opinions1 and views of science quite inconsistent with those we have been explaining1 are often promulgated and widely accepted4 ,the philosophy of pure ideas has its commonplaces1 as well as the philosophy of experience4 ,and at the time of which we speak1 the former philosophy1 no less than the latter1 had its great asserter and expounder2 a man in his own time more admired than ,bacon1 regarded with more deference by a large body of disciples all over ,europe1 and more powerful in stirring up men's minds to a new activity of inquiry4 ,i speak of ,descartes1 whose labours1 considered as a philosophical system1 were an endeavour to revive the method of obtaining knowledge by reasoning from our own ideas only1 and to erect it in opposition to the method of observation and experiment4 ,the ,cartesian philosophy contained an attempt at a counter-revolution4 ,thus in this author's ,principia ,philosophi#bjd1 he says that he will give a short account of the principal phenomena of the world1 not that he may use them as reasons to prove anything2 for1 adds he1 we desire to deduce effects from causes1 not causes from effects2 but only in order that out of the innumerable effects which we learn to be capable of resulting from the same causes1 we may determine our mind to consider some rather than others4 ,he had before said1 ,the principles which we have obtained by pure priori reasoning are so vast and so fruitful1 that many more consequences follow from them than we see contained in this visible world1 and even many more than our mind can ever take a full survey of4 ,and he professes to apply this method in detail4 ,thus in attempting to state the three fundamental laws of motion1 he employs only priori reasonings1 and is in fact led into error in the third law which he thus obtains#bje4 ,and in his ,dioptrics#bjf he pretends to deduce the laws of reflection and refraction of light from certain comparisons 7which are1 in truth1 arbitrary17 in which the radiation of light is represented by the motion of a ball impinging upon the reflecting or refracting body4 ,it might be represented as a curious instance of the caprice of fortune1 which appears in scientific as in other history1 that ,kepler1 professing to derive all his knowledge from experience1 and exerting himself with the greatest energy and perseverance1 failed in detecting the law of refraction2 while ,descartes1 who professed to be able to despise experiment1 obtained the true law of sines4 ,but as we have stated in the ,history#bjg1 ,descartes appears to have learnt this law from ,snell's papers4 ,and whether this be so or not1 it is certain that notwithstanding the profession of independence which his philosophy made1 it was in reality constantly guided and instructed by experience4 ,thus in explaining the ,rainbow 7in which his portion of the discovery merits great praise7 he speaks#bjh of taking a globe of glass1 allowing the sun to shine on one side of it1 and noting the colours produced by rays after two refractions and one reflection4 ,and in many other instances1 indeed in all that relates to physics1 the reasonings and explanations of ,descartes and his followers were1 consciously or unconsciously1 directed by the known facts1 which they had observed themselves or learnt from others4 ,but since ,descartes thus1 speculatively at least1 set himself in opposition to the great reform of scientific method which was going on in his time1 how1 it may be asked1 did he acquire so strong an influence over the most active minds of his time8 ,how is it that he became the founder of a large and distinguished school of philosophers8 ,how is it that he not only was mainly instrumental in deposing ,aristotle from his intellectual throne1 but for a time appeared to have established himself with almost equal powers1 and to have rendered the ,cartesian school as firm a body as the ,peripatetic had been8 ,the causes to be assigned for this remarkable result are1 ,i conceive1 the following4 ,in the first place1 the physicists of the ,cartesian school did1 as ,i have just stated1 found their philosophy upon experiment1 and did not practically1 or indeed1 most of them1 theoretically1 assent to their master's boast of showing what the phenomena must be1 instead of looking to see what they are4 ,and as ,descartes had really incorporated in his philosophy all the chief physical discoveries of his own and preceding times1 and had delivered1 in a more general and systematic shape than any one before him1 the principles which he thus established1 the physical philosophy of his school was in reality far the best then current2 and was an immense improvement upon the ,aristotelian doctrines1 which had not yet been displaced as a system4 ,another circumstance which gained him much favour1 was the bold and ostentatious manner in which he professed to begin his philosophy by liberating himself from all preconceived prejudice4 ,the first sentence of his philosophy contains this celebrated declaration3 ,since1 he says1 we begin life as infants1 and have contracted various judgments concerning sensible things before we possess the entire use of our reason1 we are turned aside from the knowledge of truth by many prejudices3 from which it does not appear that we can be any otherwise delivered1 than if once in our life we make it our business to doubt of everything in which we discern the smallest suspicion of uncertainty4 ,in the face of this sweeping rejection or unhesitating scrutiny of all preconceived opinions1 the power of the ancient authorities and masters in philosophy must obviously shrink away2 and thus ,descartes came to be considered as the great hero of the overthrow of the ,aristotelian dogmatism4 ,but in addition to these causes1 and perhaps more powerful than all in procuring the assent of men to his doctrines1 came the deductive and systematic character of his philosophy4 ,for although all knowledge of the external world is in reality only to be obtained from observation1 by inductive steps1--minute1 perhaps1 and slow1 and many1 as ,galileo and ,bacon had already taught2--the human mind conforms to these conditions reluctantly and unsteadily1 and is ever ready to rush to general principles1 and then to employ itself in deducing conclusions from these by synthetical reasonings2 a task grateful1 from the distinctness and certainty of the result1 and the accompanying feeling of our own sufficiency4 ,hence men readily overlooked the precarious character of ,descartes' fundamental assumptions1 in their admiration of the skill with which a varied and complex ,universe was evolved out of them4 ,and the complete and systematic character of this philosophy attracted men no less than its logical connexion4 ,i may quote here what a philosopher#bji of our own time has said of another writer3 ,he owed his influence to various causes2 at the head of which may be placed that genius for system which1 though it cramps the growth of knowledge1 perhaps finally atones for that mischief by the zeal and activity which it rouses among followers and opponents1 who discover truth by accident when in pursuit of weapons for their warfare4 ,a system which attempts a task so hard as that of subjecting vast provinces of human knowledge to one or two principles1 if it presents some striking instances of conformity to superficial appearances1 is sure to delight the framer2 and for a time to subdue and captivate the student too entirely for sober reflection and rigorous examination4 ,in the first instance consistency passes for truth4 ,when principles in some instances have proved sufficient to give an unexpected explanation of facts1 the delighted reader is content to accept as true all other deductions from the principles4 ,specious premises being assumed to be true1 nothing more can be required than logical inference4 ,mathematical forms pass current as the equivalent of mathematical certainty4 ,the unwary admirer is satisfied with the completeness and symmetry of the plan of his house1 unmindful of the need of examining the firmness of the foundation and the soundness of the materials4 ,the system-maker1 like the conqueror1 long dazzles and overawes the world2 but when their sway is past1 the vulgar herd1 unable to measure their astonishing faculties1 take revenge by trampling on fallen greatness4 ,bacon showed his wisdom in his reflections on this subject1 when he said that ,method1 carrying a show of total and perfect knowledge1 hath a tendency to generate acquiescence4 ,the main value of ,descartes' physical doctrines consisted in their being arrived at in a way inconsistent with his own professed method1 namely1 by a reference to observation4 ,but though he did in reality begin from facts1 his system was nevertheless a glaring example of that error which ,bacon had called ,anticipation2 that illicit generalization which leaps at once from special facts to principles of the widest and remotest kind2 such1 for instance1 as the ,cartesian doctrine1 that the world is an absolute plenum1 every part being full of matter of some kind1 and that all natural effects depend on the laws of motion4 ,against this fault1 to which the human mind is so prone1 ,bacon had lifted his warning voice in vain1 so far as the ,cartesians were concerned2 as indeed1 to this day1 one theorist after another pursues his course1 and turns a deaf ear to the ,verulamian injunctions2 perhaps even complacently boasts that he founds his theory upon observation2 and forgets that there are1 as the aphorism of the ,novum ,organon declares1 two ways by which this may be done2--the one hitherto in use and suggested by our common tendencies1 but barren and worthless2 the other almost untried1 to be pursued only with effort and self-denial1 but alone capable of producing true knowledge4 #c4 ,gassendi4--,thus the lessons which ,bacon taught were far from being generally accepted and applied at first4 ,the amount of the influence of these two men1 ,bacon and ,descartes1 upon their age1 has often been a subject of discussion4 ,the fortunes of the ,cartesian school have been in some measure traced in the ,history of ,science4 ,but ,i may mention the notice taken of these two philosophers by ,gassendi1 a contemporary and countryman of ,descartes4 ,gassendi1 as ,i have elsewhere stated#baj1 was associated with ,descartes in public opinion1 as an opponent of the ,aristotelian dogmatism2 but was not in fact a follower or profound admirer of that writer4 ,in a ,treatise on ,logic1 ,gassendi gives an account of the ,logic of various sects and authors2 treating1 in order1 of the ,logic of ,zeno 7the ,eleatic71 of ,euclid 7the ,megarean71 of ,plato1 of ,aristotle1 of the ,stoics1 of ,epicurus1 of ,lullius1 of ,ramus2 and to these he adds the ,logic of ,verulam1 and the ,logic of ,cartesius4 ,we must not1 he says1 on account of the celebrity it has obtained1 pass over the ,organon or ,logic of ,francis ,bacon ,lord ,verulam1 ,high ,chancellor of ,england1 whose noble purpose in our time it has been1 to make an ,instauration of the ,sciences4 ,he then gives a brief account of the ,novum ,organon1 noticing the principal features in its rules1 and especially the distinction between the vulgar induction which leaps at once from particular experiments to the more general axioms1 and the chastised and gradual induction1 which the author of the ,organon recommends4 ,in his account of the ,cartesian ,logic1 he justly observes1 that ,he too imitated ,verulam in this1 that being about to build up a new philosophy from the foundation1 he wished in the first place to lay aside all prejudice3 and having then found some solid principle1 to make that the groundwork of his whole structure4 ,but he proceeds by a very different path from that which ,verulam follows2 for while ,verulam seeks aid from things1 to perfect the cogitation of the intellect1 ,cartesius conceives1 that when we have laid aside all knowledge of things1 there is1 in our thoughts alone1 such a resource1 that the intellect may by its own power arrive at a perfect knowledge of all1 even the most abstruse things4 ,the writings of ,descartes have been most admired1 and his method most commended1 by those authors who have employed themselves upon metaphysical rather than physical subjects of inquiry4 ,perhaps we might say that1 in reference to such subjects1 this method is not so vicious as at first1 when contrasted with the ,baconian induction1 it seems to be3 for it might be urged that the thoughts from which ,descartes begins his reasonings are1 in reality1 experiments of the kind which the subject requires us to consider3 each such thought is a fact in the intellectual world2 and of such facts1 the metaphysician seeks to discover the laws4 ,i shall not here examine the validity of this plea2 but shall turn to the consideration of the actual progress of physical science1 and its effect on men's minds4 #d4 ,actual progress in ,science4--,the practical discoverers were indeed very active and very successful during the seventeenth century1 which opened with ,bacon's survey and exhortations4 ,the laws of nature1 of which men had begun to obtain a glimpse in the preceding century1 were investigated with zeal and sagacity1 and the consequence was that the foundations of most of the modern physical sciences were laid4 ,that mode of research by experiment and observation1 which had1 a little time ago1 been a strange1 and to many1 an unwelcome innovation1 was now become the habitual course of philosophers4 ,the revolution from the philosophy of tradition to the philosophy of experience was completed4 ,the great discoveries of ,kepler belonged to the preceding century4 ,they are not1 ,i believe1 noticed1 either by ,bacon or by ,descartes2 but they gave a strong impulse to astronomical and mechanical speculators1 by showing the necessity of a sound science of motion4 ,such a science ,galileo had already begun to construct4 ,at the time of which ,i speak1 his disciples#baa were still labouring at this task1 and at other problems which rapidly suggested themselves4 ,they had already convinced themselves that air had weight2 in #afdc ,torricelli proved this practically by the invention of the ,barometer2 in #afdg ,pascal proved it still further by sending the ,barometer to the top of a mountain4 ,pascal and ,boyle brought into clear view the fundamental laws of fluid equilibrium2 ,boyle and ,mariotte determined the law of the compression of air as regulated by its elasticity4 ,otto ,guericke invented the air-pump1 and by his ,madgeburg ,experiments on a vacuum1 illustrated still further the effects of the air4 ,guericke pursued what ,gilbert had begun1 the observation of electrical phenomena2 and these two physicists made an important step1 by detecting repulsion as well as attraction in these phenomena4 ,gilbert had already laid the foundations of the science of ,magnetism4 ,the law of refraction1 at which ,kepler had laboured in vain1 was1 as we have seen1 discovered by ,snell 7about #afba71 and published by ,descartes4 ,mersenne had discovered some of the more important parts of the theory of ,harmonics4 ,in sciences of a different kind1 the same movement was visible4 ,chemical doctrines tended to assume a proper degree of generality1 when ,sylvius in #afgi taught the opposition of acid and alkali1 and ,stahl1 soon after1 the phlogistic theory of combustion4 ,steno had remarked the most important law of crystallography in #affi1 that the angles of the same kind of crystals are always equal4 ,in the sciences of classification1 about #afhj1 ,ray and ,morison in ,england resumed the attempt to form a systematic botany1 which had been interrupted for a hundred years1 from the time of the memorable essay of ,csalpinus4 ,the grand discovery of the circulation of the blood by ,harvey about #afai1 was followed in #afea by ,pecquet's discovery of the course of the chyle4 ,there could now no longer be any question whether science was progressive1 or whether observation could lead to new truths4 ,among these cultivators of science1 such sentiments as have been already quoted became very familiar2--that knowledge is to be sought from nature herself by observation and experiment2--that in such matters tradition is of no force when opposed to experience1 and that mere reasonings without facts cannot lead to solid knowledge4 ,but ,i do not know that we find in these writers any more special rules of induction and scientific research which have since been confirmed and universally adopted4 ,perhaps too1 as was natural in so great a revolution1 the writers of this time1 especially the second-rate ones1 were somewhat too prone to disparage the labours and talents of ,aristotle and the ancients in general1 and to overlook the ideal element of our knowledge1 in their zealous study of phenomena4 ,they urged1 sometimes in an exaggerated manner1 the superiority of modern times in all that regards science1 and the supreme and sole importance of facts in scientific investigations4 ,there prevailed among them also a lofty and dignified tone of speaking of the condition and prospects of science1 such as we are accustomed to admire in the ,verulamian writings2 for this1 in a less degree1 is epidemic among those who a little after his time speak of the new philosophy4 #e4 ,otto ,guericke1 c4--,i need not illustrate these characteristics at any great length4 ,i may as an example notice ,otto ,guericke's ,preface to his ,experimenta ,magdeburgica 7#afgj74 ,he quotes a passage from ,kircher's ,treatise on the ,magnetic ,art1 in which the author says1 ,hence it appears how all philosophy1 except it be supported by experiments1 is empty1 fallacious1 and useless2 what monstrosities philosophers1 in other respects of the highest and subtlest genius1 may produce in philosophy by neglecting experiment4 ,thus ,experience alone is the ,dissolver of ,doubts1 the ,reconciler of ,difficulties1 the sole ,mistress of ,truth1 who holds a torch before us in obscurity1 unties our knots1 teaches us the true causes of things4 ,guericke himself reiterates the same remark1 adding that philosophers1 insisting upon their own thoughts and arguments merely1 cannot come to any sound conclusion respecting the natural constitution of the world4 ,nor were the ,cartesians slow in taking up the same train of reflection4 ,thus ,gilbert ,clark who1 in #affj1 published#bab a defence of ,descartes' doctrine of a plenum in the universe1 speaks in a tone which reminds us of ,bacon1 and indeed was very probably caught from him3 ,natural philosophy formerly consisted entirely of loose and most doubtful controversies1 carried on in high-sounding words1 fit rather to delude than to instruct men4 ,but at last 7by the favour of the ,deity7 there shone forth some more divine intellects1 who taking as their counsellors reason and experience together1 exhibited a new method of philosophizing4 ,hence has been conceived a strong hope that philosophers may embrace1 not a shadow or empty image of ,truth1 but ,truth herself3 and that ,physiology 7,physics7 scattering these controversies to the winds1 will contract an alliance with ,mathematics4 ,yet this is hardly the work of one age2 still less of one man4 ,yet let not the mind despond1 or doubt not that1 one party of investigators after another following the same method of philosophizing1 at last1 under good auguries1 the mysteries of nature being daily unlocked as far as human feebleness will allow1 ,truth may at last appear in full1 and these nuptial torches may be lighted4 ,as another instance of the same kind1 ,i may quote the preface to the ,first volume of the ,transactions of the ,academy of ,sciences at ,paris3 ,it is only since the present century1 says the writer1 that we can reckon the revival of ,mathematics and ,physics4 ,m4 ,descartes and other great men have laboured at this work with so much success1 that in this department of literature1 the whole face of things has been changed4 ,men have quitted a sterile system of physics1 which for several generations had been always at the same point2 the reign of words and terms is passed2 men will have things2 they establish principles which they understand1 they follow those principles2 and thus they make progress4 ,authority has ceased to have more weight than ,reason3 that which was received without contradiction because it had been long received1 is now examined1 and often rejected3 and philosophers have made it their business to consult1 respecting natural things1 ,nature herself rather than the ,ancients4 ,these had now become the commonplaces of those who spoke concerning the course and method of the ,sciences4 #f4 ,hooke4--,in ,england1 as might be expected1 the influence of ,francis ,bacon was more directly visible4 ,we find many writers1 about this time1 repeating the truths which ,bacon had proclaimed1 and in almost every case showing the same imperfections in their views which we have noticed in him4 ,we may take as an example of this ,hooke's ,essay1 entitled ,a ,general ,scheme or ,idea of the present state of ,natural ,philosophy1 and how its defects may be remedied by a ,methodical proceeding in the making ,experiments and collecting ,observations2 whereby to compile a ,natural ,history as a solid basis for the superstructure of true ,philosophy4 ,this ,essay may be looked upon as an attempt to adapt the ,novum ,organon to the age which succeeded its publication4 ,we have in this imitation1 as in the original1 an enumeration of various mistakes and impediments which had in preceding times prevented the progress of knowledge2 exhortations to experiment and observation as the only solid basis of ,science2 very ingenious suggestions of trains of inquiry1 and modes of pursuing them2 and a promise of obtaining scientific truths when facts have been duly accumulated4 ,this last part of his scheme the author calls a ,philosophical ,algebra2 and he appears to have imagined that it might answer the purpose of finding unknown causes from known facts1 by means of certain regular processes1 in the same manner as ,common ,algebra finds unknown from known quantities4 ,but this part of the plan appears to have remained unexecuted4 ,the suggestion of such a method was a result of the ,baconian notion that invention in a discoverer might be dispensed with4 ,we find ,hooke adopting the phrases in which this notion is implied3 thus he speaks of the understanding as being very prone to run into the affirmative way of judging1 and wanting patience to follow and prosecute the negative way of inquiry1 by rejection of disagreeing natures4 ,and he follows ,bacon also in the error of attempting at once to obtain from the facts the discovery of a nature1 instead of investigating first the measures and the laws of phenomena4 ,i return to more general notices of the course of men's thoughts on this subject4 #g4 ,royal ,society4--,those who associated themselves together for the prosecution of science quoted ,bacon as their leader1 and exulted in the progress made by the philosophy which proceeded upon his principles4 ,thus in ,oldenburg's ,dedication of the ,transactions of the ,royal ,society of ,london for #afgj1 to ,robert ,boyle1 he says2 ,i am informed by such as well remember the best and worst days of the famous ,lord ,bacon1 that though he wrote his ,advancement of ,learning and his ,instauratio ,magna in the time of his greatest power1 yet his greatest reputation rebounded first from the most intelligent foreigners in many parts of ,christendom3 and after speaking of his practical talents and his public employments1 he adds1 much more justly still may we wonder how1 without any great skill in ,chemistry1 without much pretence to the ,mathematics or ,mechanics1 without optic aids or other engines of late invention1 he should so much transcend the philosophers then living1 in judicious and clear instructions1 in so many useful observations and discoveries1 ,i think ,i may say beyond the records of many ages4 ,and in the end of the ,preface to the same volume1 he speaks with great exultation of the advance of science all over ,europe1 referring undoubtedly to facts then familiar4 ,and now let envy snarl1 it cannot stop the wheels of active philosophy1 in no part of the known world2--not in ,france1 either in ,paris or in ,caen2--not in ,italy1 either in ,rome1 ,naples1 ,milan1 ,florence1 ,venice1 ,bononia or ,padua2--in none of the ,universities either on this or on that side of the seas1 ,madrid and ,lisbon1 all the best spirits in ,spain and ,portugal1 and the spacious and remote dominions to them belonging2--the ,imperial ,court and the ,princes of ,germany2 the ,northern ,kings and their best luminaries2 and even the frozen ,muscovite and ,russian have all taken the operative ferment3 and it works high and prevails every way1 to the encouragement of all sincere lovers of knowledge and virtue4 ,again1 in the ,preface for #afgb1 he pursues the same thought into detail3 ,we must grant that in the last age1 when operative philosophy began to recover ground1 and to tread on the heels of triumphant ,philology2 emergent adventures and great successes were encountered by dangerous oppositions and strong obstructions4 ,galilus and others in ,italy suffered extremities for their celestial discoveries2 and here in ,england ,sir ,walter ,raleigh1 when he was in his greatest lustrous1 was notoriously slandered to have erected a school of atheism1 because he gave countenance to chemistry1 to practical arts1 and to curious mechanical operations1 and designed to form the best of them into a college4 ,and ,queen ,elizabeth's ,gilbert was a long time esteemed extravagant for his magnetisms2 and ,harvey for his diligent researches in pursuance of the circulation of the blood4 ,but when our renowned ,lord ,bacon had demonstrated the methods for a perfect restoration of all parts of real knowledge2 and the generous and philosophical ,peireskius had1 soon after1 agitated in all parts to redeem the most instructive antiquities1 and to excite experimental essays and fresh discoveries2 the success became on a sudden stupendous2 and effective philosophy began to sparkle1 and even to flow into beams of shining light all over the world4 ,the formation of the ,royal ,society of ,london and of the ,academy of ,sciences of ,paris1 from which proceeded the declamations just quoted1 were among many indications1 belonging to this period1 of the importance which states as well as individuals had by this time begun to attach to the cultivation of science4 ,the ,english ,society was established almost immediately when the restoration of the monarchy appeared to give a promise of tranquillity to the nation 7in #affj71 and the ,french ,academy very soon afterwards 7in #afff74 ,these measures were very soon followed by the establishment of the ,observatories of ,paris and ,greenwich 7in #affg and #afge72 which may be considered to be a kind of public recognition of the astronomy of observation1 as an object on which it was the advantage and the duty of nations to bestow their wealth4 #h4 ,bacon's ,new ,atalantis4--,when philosophers had their attention turned to the boundless prospect of increase to the knowledge and powers and pleasures of man which the cultivation of experimental philosophy seemed to promise1 it was natural that they should think of devising institutions and associations by which such benefits might be secured4 ,bacon had drawn a picture of a society organized with a view to such purpose1 in his fiction of the ,new ,atalantis4 ,the imaginary teacher who explains this institution to the inquiring traveller1 describes it by the name of ,solomon's ,house2 and says#bac1 ,the end of our foundation is the knowledge of causes and secret motions of things2 and the enlarging the bounds of the human empire to effecting of things possible4 ,and1 as parts of this ,house1 he describes caves and wells1 chambers and towers1 baths and gardens1 parks and pools1 dispensatories and furnaces1 and many other contrivances1 provided for the purpose of making experiments of many kinds4 ,he describes also the various employments of the ,fellows of this ,college1 who take a share in its researches4 ,there are merchants of light1 who bring books and inventions from foreign countries2 depredators1 who gather the experiments which exist in books2 mystery-men1 who collect the experiments of the mechanical arts2 pioneers or miners1 who invent new experiments2 and compilers1 who draw the experiments of the former into titles and tables1 to give the better light for the drawing of observations and axioms out of them4 ,there are also dowry-men or benefactors1 that cast about how to draw out of the experiments of their fellows things of use and practice for man's life2 lamps1 that direct new experiments of a more penetrating light than the former2 inoculators1 that execute the experiments so directed4 ,finally1 there are the interpreters of nature1 that raise the former discoveries by experiments into greater observations 7that is1 more general truths71 axioms and aphorisms4 ,upon this scheme we may remark1 that fictitious as it undisguisedly is1 it still serves to exhibit very clearly some of the main features of the author's philosophy3--namely1 his steady view of the necessity of ascending from facts to the most general truths by several stages2--an exaggerated opinion of the aid that could be derived in such a task from technical separation of the phenomena and a distribution of them into tables2--a belief1 probably incorrect1 that the offices of experimenter and interpreter may be entirely separated1 and pursued by different persons with a certainty of obtaining success6--and a strong determination to make knowledge constantly subservient to the uses of life4 #i4 ,cowley4--,another project of the same kind1 less ambitious but apparently more directed to practice1 was published a little later 7#afeg7 by another eminent man of letters in this country4 ,i speak of ,cowley's ,proposition for the ,advancement of ,experimental ,philosophy4 ,he suggests that a ,college should be established at a short distance from ,london1 endowed with a revenue of four thousand pounds1 and consisting of twenty professors with other members4 ,the objects of the labours of these professors he describes to be1 first1 to examine all knowledge of nature delivered to us from former ages and to pronounce it sound or worthless2 second1 to recover the lost inventions of the ancients2 third1 to improve all arts that we now have2 lastly1 to discover others that we yet have not4 ,in this proposal we cannot help marking the visible declension from ,bacon's more philosophical view4 ,for we have here only a very vague indication of improving old arts and discovering new1 instead of the two clear ,verulamian antitheses1 ,experiments and ,axioms deduced from them1 on the one hand1 and on the other an ascent to general ,laws1 and a derivation1 from these1 of ,arts for daily use4 ,moreover the prominent place which ,cowley has assigned to the verifying the knowledge of former ages and recovering the lost inventions and drowned lands of the ancients1 implies a disposition to think too highly of traditionary knowledge2 a weakness which ,bacon's scheme shows him to have fully overcome4 ,and thus it has been up to the present day1 that with all ,bacon's mistakes1 in the philosophy of scientific method few have come up to him1 and perhaps none have gone beyond him4 ,cowley exerted himself to do justice to the new philosophy in verse as well as prose1 and his ,poem to the ,royal ,society expresses in a very noble manner those views of the history and prospects of philosophy which prevailed among the men by whom the ,royal ,society was founded4 ,the fertility and ingenuity of comparison which characterize ,cowley's poetry are well known2 and these qualities are in this instance largely employed for the embellishment of his subject4 ,many of the comparisons which he exhibits are apt and striking4 ,philosophy is a ward whose estate 7human knowledge7 is1 in his nonage1 kept from him by his guardians and tutors2 7a case which the ancient rhetoricians were fond of taking as a subject of declamation27 and these wrong-doers retain him in unjust tutelage and constraint for their own purposes2 until ,bacon at last1 a mighty man1 arose1 7,whom a wise ,king1 and ,nature1 chose ,lord ,chancellor of both their laws17 ,and boldly undertook the injured pupil's cause4 ,again1 ,bacon is one who breaks a scarecrow ,priapus which stands in the garden of knowledge4 ,again1 ,bacon is one who1 instead of a picture of painted grapes1 gives us real grapes from which we press the thirsty soul's refreshing wine4 ,again1 ,bacon is like ,moses1 who led the ,hebrews forth from the barren wilderness1 and ascended ,pisgah2-- ,did on the very border stand ,of the blest promised land1 ,and from the mountain's top of his exalted wit ,saw it himself and showed us it4 ,the poet however adds1 that ,bacon discovered1 but did not conquer this new world2 and that the men whom he addresses must subdue these regions4 ,these champions are then ingeniously compared to ,gideon's band3 ,their old and empty pitchers first they brake1 ,and with their hands then lifted up the light4 ,there were still at this time some who sneered at or condemned the new philosophy2 but the tide of popular opinion was soon strongly in its favour4 ,i have elsewhere#bad noticed a pasquinade of the poet ,boileau in #afhb1 directed against the ,aristotelians4 ,at this time1 and indeed for long afterwards1 the philosophers of ,france were ,cartesians4 ,the ,english men of science1 although partially and for a time they accepted some of ,descartes' opinions1 for the most part carried on the reform independently1 and in pursuance of their own views4 ,and they very soon found a much greater leader than ,descartes to place at their head1 and to take as their authority1 so far as they acknowledged authority1 in their speculations4 ,i speak of ,newton1 whose influence upon the philosophy of science ,i must now consider4 #aj4 ,barrow4--,i will1 however1 first mention one other writer who may1 in more than one way1 be regarded as the predecessor of ,newton4 ,i speak of ,isaac ,barrow1 whom ,newton succeeded as ,professor of ,mathematics in the ,university of ,cambridge1 and who in his mathematical speculations approached very near to ,newton's method of ,fluxions4 ,he afterwards 7in #afgc7 became ,master of ,trinity ,college1 which office he held till his death in #afgg4 ,but the passages which ,i shall quote belong to an earlier period1 7when ,barrow was about #bb years old17 and may be regarded as expressions of the opinions which were then current among active-minded and studious young men4 ,they manifest a complete familiarity with the writings both of ,bacon and of ,descartes1 and a very just appreciation of both4 ,the discourse of which ,i speak is an academical exercise delivered in #afeb1 on the thesis ,cartesiana hypothesis haud satisfacit prcipuis natur phnomenis4 ,by the ,cartesian hypothesis1 he does not mean the hypothesis that the planets are moved by vortices of etherial matter3 ,i believe that this ,cartesian tenet never had any disciples in ,england2 it certainly never took any hold of ,cambridge4 ,by the ,cartesian hypothesis1 ,barrow means the doctrine that all the phenomena of nature can be accounted for by matter and motion2 and allowing that the motions of the planets are to be so accounted for1 7which is ,newtonian as well as ,cartesian doctrine17 he denies that the ,cartesian hypothesis accounts for the generations1 properties1 and specific operations of animals1 plants1 minerals1 stones1 and other natural bodies1 in doing which he shows a sound philosophical judgment4 ,but among the parts of this discourse most bearing on our present purpose are those where he mentions ,bacon4 ,against ,cartesius1 he says1 ,i pit the chymists and others1 but especially as the foremost champion of this battle1 our ,verulam1 a man of great name and of great judgment1 who condemned this philosophy before it was born4 ,he1 adds ,barrow1 several times in his ,organon1 warned men against all hypotheses of this kind1 and noticed beforehand that there was not much to be expected from those principles which are brought into being by violent efforts of argumentation from the brains of particular men3 for that1 as upon the phenomena of the stars1 various constructions of the heavens may be devised1 so also upon the phenomena of the ,universe1 still more dogmas may be founded and constructed2 and yet all such are mere inventions3 and as many philosophies of this kind as are or shall be extant1 so many fictitious and theatrical worlds are made4 ,the reference is doubtless to ,aphorism ,,lxii4 of the ,first ,book of the ,novum ,organon1 in which ,bacon is speaking of his ,idols of the ,theatre4 ,after making the remark which ,barrow has adopted1 ,bacon adds1 ,such theatrical fables have also this in common with those of dramatic poets1 that the dramatic story is more regular and elegant than true histories are1 and is made so as to be agreeable4 ,barrow1 having this in his mind1 goes on to say3 ,and though ,cartesius has dressed up the stage of his theatre more prettily than any other person1 and made his drama more like history1 still he is not exempt from the like censure4 ,and he then refers to ,cartesius's own declaration1 that he did not learn his system from things themselves1 but tried to impose his own laws upon things2 thus inverting the order of true philosophy4 ,other parts of ,bacon's work to which ,barrow refers are those where he speaks of the ,form1 or ,formal ,cause of a body1 and says that in comparison with that1 the ,efficient ,cause and the ,material ,cause are things unimportant and superficial1 and contribute little to true and active science#bae4 ,and again1 his classification of the various kinds of motions#baf1--the motus libertatis1 motus nexus1 motus continuitatis1 motus ad lucrum1 fug1 unionis1 congregationis2 and the explanation of electrical attraction 7about which ,gilbert and others had written7 as motus ad lucrum4 ,these passages show that ,barrow had read the ,novum ,organon in a careful and intelligent manner1 and presumed his ,cambridge hearers to be acquainted with the work4 ,nor is his judgment of ,descartes less wise and philosophical4 ,he rejects1 as we have seen1 his system as a true scheme of the universe1 and condemns altogether his priori mode of philosophizing2 but this does not prevent his accepting ,descartes' real discoveries1 and admiring the boldness and vigour of his attempts to reform philosophy4 ,there is1 in ,barrow's works1 academic verse1 as well as prose1 on the subject of the ,cartesian hypothesis4 ,in this1 ,descartes himself is highly praised1 though his doctrines are very partially accepted4 ,the writer says3 ,pardon us1 great ,cartesius1 if the ,muse resists you4 ,pardon6 ,we follow you1 ,inquiring ,spirit that you are1 while we reject your system4 ,as you have taught us free thought1 and broken down the rule of tyranny1 we undauntedly speculate1 even in opposition to you4 ,descartes is even yet spoken of1 especially by ,french writers1 as the person who first asserted and established the freedom of inquiry which is the boast of modern philosophy2 but this is said with reference to metaphysics1 not to physics4 ,in physical philosophy1 though he caught hold of some of the discoveries which were then coming into view1 the method in which he reasoned or professed to reason was altogether vicious2 and was1 as ,i have already said1 an attempt to undo what the reformers1 both theoretical and practical1 had been doing3--to discredit the philosophy of experience1 and to restore the reign of priori systems4 ,it was1 however1 now1 too late to make any such attempt2 and nothing came of it to interrupt the progress of a better philosophy of discovery4 ,,footnotes3 ,footnote #bjj3 ,anatomical ,exercitations concerning the ,generation of ,living ,creatures1 #afec4 ,preface4 ,footnote #bja3 ,he used similar expressions in conversation4 ,george ,ent1 who edited his ,generation of ,animals1 visited him1 at that time residing not far from the city2 and found him very intent upon the perscrutation of nature's works1 and with a countenance as cheerful1 as mind unperturbed2 ,democritus-like1 chiefly searching into the cause of natural things4 ,in the course of conversation the writer said1 ,it hath always been your choice about the secrets of ,nature1 to consult ,nature herself4 ',tis true1 replied he2 and ,i have constantly been of opinion that from thence we might acquire not only the knowledge of those less considerable secrets of ,nature1 but even a certain admiration of that ,supreme ,essence1 the ,creator4 ,and though ,i have ever been ready to acknowledge1 that many things have been discovered by learned men of former times2 yet do ,i still believe that the number of those which remain yet concealed in the darkness of impervestigable ,nature is much greater4 ,nay1 ,i cannot forbear to wonder1 and sometimes smile at those1 who persuade themselves1 that all things were so consummately and absolutely delivered by ,aristotle1 ,galen1 or some other great name1 as that nothing was left to the superaddition of any that succeeded4 ,footnote #bjb3 ,lib4 i4 c4 #b1 #c4 ,footnote #bjc3 ,anal4 ,post4 ii4 ,footnote #bjd3 ,pars iii4 p4 #de4 ,footnote #bje3 ,see ,hist4 ,ind4 ,sc4 b4 vi4 c4 ii4 ,footnote #bjf3 ,cap4 i4 ii4 ,footnote #bjg3 ,hist4 ,ind4 ,sc4 b4 ix4 c4 ii4 ,footnote #bjh3 ,meteorum1 c4 viii4 p4 #ahg4 ,footnote #bji3 ,mackintosh1 ,dissertation on ,ethical ,science4 ,footnote #baj3 ,hist4 ,ind4 ,sc4 b4 vii4 c4 i4 ,footnote #baa3 ,castelli1 ,torricelli1 ,viviani1 ,baliani1 ,gassendi1 ,mersenne1 ,borelli1 ,cavalleri4 ,footnote #bab3 ,de ,plenitudine ,mundi1 in qua defenditur ,cartesiana ,philosophia contra sententias ,francisci ,baconi1 ,th4 ,hobbii et ,sethi ,wardi4 ,footnote #bac3 ,bacon's ,works1 vol4 ii4 #aaa4 ,footnote #bad3 ,hist4 ,ind4 ,sc4 b4 vii4 c4 i4 ,footnote #bae3 ,nov4 ,org4 lib4 ii4 ,aph4 #b4 ,footnote #baf3 ,ib4 lib4 ii4 ,aph4 #de4 ,,chapter ,,xviii4 ,,newton4 #a4 ,bold and extensive as had been the anticipations of those whose minds were excited by the promise of the new philosophy1 the discoveries of ,newton respecting the mechanics of the universe1 brought into view truths more general and profound than those earlier philosophers had hoped or imagined4 ,with these vast accessions to human knowledge1 men's thoughts were again set in action2 and philosophers made earnest and various attempts to draw1 from these extraordinary advances in science1 the true moral with regard to the conduct and limits of the human understanding4 ,they not only endeavoured to verify and illustrate1 by these new portions of science1 what had recently been taught concerning the methods of obtaining sound knowledge2 but they were also led to speculate concerning many new and more interesting questions relating to this subject4 ,they saw1 for the first time1 or at least far more clearly than before1 the distinction between the inquiry into the laws1 and into the causes of phenomena4 ,they were tempted to ask1 how far the discovery of causes could be carried2 and whether it would soon reach1 or clearly point to1 the ultimate cause4 ,they were driven to consider whether the properties which they discovered were essential properties of all matter1 necessarily and primarily involved in its essence1 though revealed to us at a late period by their derivative effects4 ,these questions even now agitate the thoughts of speculative men4 ,some of them have already1 in this work1 been discussed1 or arranged in the places which our view of the philosophy of these subjects assigns to them4 ,but we must here notice them as they occurred to ,newton himself and his immediate followers4 #b4 ,the general ,baconian notion of the method of philosophizing1--that it consists in ascending from phenomena1 through various stages of generalization1 to truths of the highest order1--received1 in ,newton's discovery of the universal mutual gravitation of every particle of matter1 that pointed actual exemplification1 for want of which it had hitherto been almost overlooked1 or at least very vaguely understood4 ,that great truth1 and the steps by which it was established1 afford1 even now1 by far the best example of the successive ascent1 from one scientific truth to another1--of the repeated transition from less to more general propositions1--which we can yet produce2 as may be seen in the ,table which exhibits the relation of these steps in ,book ,,ii4 of the ,novum ,organon ,renovatum4 ,newton himself did not fail to recognize this feature in the truths which he exhibited4 ,thus he says#bag1 ,by the way of ,analysis we proceed from compounds to ingredients1 as from motions to the forces producing them2 and in general1 from effects to their causes1 and from particular causes to more general ones1 till the argument ends in the most general4 ,and in like manner in another ,query#bah3 ,the main business of natural philosophy is to argue from phenomena without feigning hypotheses1 and to deduce causes from effects1 till we come to the ,first ,cause1 which is certainly not mechanical4 #c4 ,newton appears to have had a horror of the term hypothesis1 which probably arose from his acquaintance with the rash and illicit general assumptions of ,descartes4 ,thus in the passage just quoted1 after declaring that gravity must have some other cause than matter1 he says1 ,later philosophers banish the consideration of such a cause out of ,natural ,philosophy1 feigning hypotheses for explaining all things mechanically1 and referring other causes to metaphysics4 ,in the celebrated ,scholium at the end of the ,principia he says1 ,whatever is not deduced from the phenomena1 is to be termed hypothesis2 and hypotheses1 whether metaphysical or physical1 or occult causes1 or mechanical1 have no place in experimental philosophy4 ,in this philosophy1 propositions are deduced from phenomena1 and rendered general by induction4 ,and in another place1 he arrests the course of his own suggestions1 saying1 ,verum hypotheses non fingo4 ,i have already attempted to show that this is1 in reality1 a superstitious and self-destructive spirit of speculation4 ,some hypotheses are necessary1 in order to connect the facts which are observed2 some new principle of unity must be applied to the phenomena1 before induction can be attempted4 ,what is requisite is1 that the hypothesis should be close to the facts1 and not connected with them by the intermediation of other arbitrary and untried facts2 and that the philosopher should be ready to resign it as soon as the facts refuse to confirm it4 ,we have seen in the ,history#bai1 that it was by such a use of hypotheses1 that both ,newton himself1 and ,kepler1 on whose discoveries those of ,newton were based1 made their discoveries4 ,the suppositions of a force tending to the sun and varying inversely as the square of the distance2 of a mutual force between all the bodies of the solar system2 of the force of each body arising from the attraction of all its parts2 not to mention others1 also propounded by ,newton1--were all hypotheses before they were verified as theories4 ,it is related that when ,newton was asked how it was that he saw into the laws of nature so much further than other men1 he replied1 that if it were so1 it resulted from his keeping his thoughts steadily occupied upon the subject which was to be thus penetrated4 ,but what is this occupation of the thoughts1 if it be not the process of keeping the phenomena clearly in view1 and trying1 one after another1 all the plausible hypotheses which seem likely to connect them1 till at last the true law is discovered8 ,hypotheses so used are a necessary element of discovery4 #d4 ,with regard to the details of the process of discovery1 ,newton has given us some of his views1 which are well worthy of notice1 on account of their coming from him2 and which are real additions to the philosophy of this subject4 ,he speaks repeatedly of the analysis and synthesis of observed facts2 and thus marks certain steps in scientific research1 very important1 and not1 ,i think1 clearly pointed out by his predecessors4 ,thus he says#bbj1 ,as in ,mathematics1 so in ,natural ,philosophy1 the investigation of difficult things by the method of analysis ought ever to precede the method of composition4 ,this analysis consists in making experiments and observations1 and in drawing general conclusions from them by induction1 and admitting of no objections against the conclusions1 but such as are taken from experiments or other certain truths4 ,and although the arguing from experiments and observations by induction be no demonstration of general conclusions2 yet it is the best way of arguing which the nature of things admits of1 and may be looked upon as so much the stronger1 by how much the induction is more general4 ,and he then observes1 as we have quoted above1 that by this way of analysis we proceed from compounds to ingredients1 from motions to forces1 from effects to causes1 and from less to more general causes4 ,the analysis here spoken of includes the steps which in our ,novum ,organon we call the decomposition of facts1 the exact observation and measurement of the phenomena1 and the colligation of facts2 the necessary intermediate step1 the selection and explication of the appropriate conception1 being passed over by ,newton1 in the fear of seeming to encourage the fabrication of hypotheses4 ,the synthesis of which ,newton here speaks consists of those steps of deductive reasoning1 proceeding from the conception once assumed1 which are requisite for the comparison of its consequences with the observed facts4 ,this1 his statement of the process of research1 is1 as far as it goes1 perfectly exact4 #e4 ,in speaking of ,newton's precepts on the subject1 we are naturally led to the celebrated ,rules of ,philosophizing1 inserted in the second edition of the ,principia4 ,these rules have generally been quoted and commented on with an almost unquestioning reverence4 ,such ,rules1 coming from such an authority1 cannot fail to be highly interesting to us2 but at the same time1 we cannot here evade the necessity of scrutinizing their truth and value1 according to the principles which our survey of this subject has brought into view4 ,the ,rules stand at the beginning of that part of the ,principia 7the ,third ,book7 in which he infers the mutual gravitation of the sun1 moon1 planets1 and all parts of each4 ,they are as follows3 ,rule ,i4 ,we are not to admit other causes of natural things than such as both are true1 and suffice for explaining their phenomena4 ,rule ,,ii4 ,natural effects of the same kind are to be referred to the same causes1 as far as can be done4 ,rule ,,iii4 ,the qualities of bodies which cannot be increased or diminished in intensity1 and which belong to all bodies in which we can institute experiments1 are to be held for qualities of all bodies whatever4 ,rule ,,iv4 ,in experimental philosophy1 propositions collected from phenomena by induction1 are to be held as true either accurately or approximately1 notwithstanding contrary hypotheses2 till other phenomena occur by which they may be rendered either more accurate or liable to exception4 ,in considering these ,rules1 we cannot help remarking1 in the first place1 that they are constructed with an intentional adaptation to the case with which ,newton has to deal1--the induction of ,universal ,gravitation2 and are intended to protect the reasonings before which they stand4 ,thus the first ,rule is designed to strengthen the inference of gravitation from the celestial phenomena1 by describing it as a vera causa1 a true cause2 the second ,rule countenances the doctrine that the planetary motions are governed by mechanical forces1 as terrestrial motions are2 the third rule appears intended to justify the assertion of gravitation1 as a universal quality of bodies2 and the fourth contains1 along with a general declaration of the authority of induction1 the author's usual protest against hypotheses1 levelled at the ,cartesian hypotheses especially4 #f4 ,of the ,first ,rule4--,we1 however1 must consider these ,rules in their general application1 in which point of view they have often been referred to1 and have had very great authority allowed them4 ,one of the points which has been most discussed1 is that maxim which requires that the causes of phenomena which we assign should be true causes1 ver caus4 ,of course this does not mean that they should be the true or right cause2 for although it is the philosopher's aim to discover such causes1 he would be little aided in his search of truth1 by being told that it is truth which he is to seek4 ,the rule has generally been understood to prescribe that in attempting to account for any class of phenomena1 we must assume such causes only1 as from other considerations1 we know to exist4 ,thus gravity1 which was employed in explaining the motions of the moon and planets1 was already known to exist and operate at the earth's surface4 ,now the ,rule thus interpreted is1 ,i conceive1 an injurious limitation of the field of induction4 ,for it forbids us to look for a cause1 except among the causes with which we are already familiar4 ,but if we follow this rule1 how shall we ever become acquainted with any new cause8 ,or how do we know that the phenomena which we contemplate do really arise from some cause which we already truly know8 ,if they do not1 must we still insist upon making them depend upon some of our known causes2 or must we abandon the study of them altogether8 ,must we1 for example1 resolve to refer the action of radiant heat to the air1 rather than to any peculiar fluid or ether1 because the former is known to exist1 the latter is merely assumed for the purpose of explanation8 ,but why should we do this8 ,why should we not endeavour to learn the cause from the effects1 even if it be not already known to us8 ,we can infer causes1 which are new when we first become acquainted with them4 ,chemical ,forces1 ,optical ,forces1 ,vital ,forces1 are known to us only by chemical and optical and vital phenomena2 must we1 therefore1 reject their existence or abandon their study8 ,they do not conform to the double condition1 that they shall be sufficient and also real3 they are true1 only so far as they explain the facts1 but are they1 therefore1 unintelligible or useless8 ,are they not highly important and instructive subjects of speculation8 ,and if the gravitation which rules the motions of the planets had not existed at the earth's surface2--if it had been there masked and concealed by the superior effect of magnetism1 or some other extraneous force1--might not ,newton still have inferred1 from ,kepler's laws1 the tendency of the planets to the sun2 and from their perturbations1 their tendency to each other8 ,his discoveries would still have been immense1 if the cause which he assigned had not been a vera causa in the sense now contemplated4 #g4 ,but what do we mean by calling gravity a true cause8 ,how do we learn its reality8 ,of course1 by its effects1 with which we are familiar2--by the weight and fall of bodies about us4 ,these strike even the most careless observer4 ,no one can fail to see that all bodies which we come in contact with are heavy2--that gravity acts in our neighbourhood here upon earth4 ,hence1 it may be said1 this cause is at any rate a true cause1 whether it explains the celestial phenomena or not4 ,but if this be what is meant by a vera causa1 it appears strange to require that in all cases we should find such a one to account for all classes of phenomena4 ,is it reasonable or prudent to demand that we shall reduce every set of phenomena1 however minute1 or abstruse1 or complicated1 to causes so obviously existing as to strike the most incurious1 and to be familiar among men8 ,how can we expect to find such ver caus for the delicate and recondite phenomena which an exact and skilful observer detects in chemical1 or optical1 or electrical experiments8 ,the facts themselves are too fine for vulgar apprehension2 their relations1 their symmetries1 their measures require a previous discipline to understand them4 ,how then can their causes be found among those agencies with which the common unscientific herd of mankind are familiar8 ,what likelihood is there that causes held for real by such persons1 shall explain facts which such persons cannot see or cannot understand8 ,again3 if we give authority to such a rule1 and require that the causes by which science explains the facts which she notes and measures and analyses1 shall be causes which men1 without any special study1 have already come to believe in1 from the effects which they casually see around them1 what is this1 except to make our first rude and unscientific persuasions the criterion and test of our most laborious and thoughtful inferences8 ,what is it1 but to give to ignorance and thoughtlessness the right of pronouncing upon the convictions of intense study and long-disciplined thought8 ,electrical atmospheres surrounding electrized bodies1 were at one time held to be a true cause of the effects which such bodies produce4 ,these atmospheres1 it was said1 are obvious to the senses2 we feel them like a spider's web on the hands and face4 pinus had to answer such persons1 by proving that there are no atmospheres1 no effluvia1 but only repulsion4 ,he thus1 for a true cause in the vulgar sense of the term1 substituted an hypothesis2 yet who doubts that what he did was an advance in the science of electricity8 #h4 ,perhaps some persons may be disposed to say1 that ,newton's ,rule does not enjoin us to take those causes only which we clearly know1 or suppose we know1 to be really existing and operating1 but only causes of such kinds as we have already satisfied ourselves do exist in nature4 ,it may be urged that we are entitled to infer that the planets are governed in their motions by an attractive force1 because we find1 in the bodies immediately subject to observation and experiment1 that such motions are produced by attractive forces1 for example1 by that of the earth4 ,it may be said that we might on similar grounds infer forces which unite particles of chemical compounds1 or deflect particles of light1 because we see adhesion and deflection produced by forces4 ,but it is easy to show that the ,rule1 thus laxly understood1 loses all significance4 ,it prohibits no hypothesis2 for all hypotheses suppose causes such as1 in some case or other1 we have seen in action4 ,no one would think of explaining phenomena by referring them to forces and agencies altogether different from any which are known2 for on this supposition1 how could he pretend to reason about the effects of the assumed causes1 or undertake to prove that they would explain the facts8 ,some close similarity with some known kind of cause is requisite1 in order that the hypothesis may have the appearance of an explanation4 ,no forces1 or virtues1 or sympathies1 or fluids1 or ethers1 would be excluded by this interpretation of ver caus4 ,least of all1 would such an interpretation reject the ,cartesian hypothesis of vortices2 which undoubtedly1 as ,i conceive1 ,newton intended to condemn by his ,rule4 ,for that such a case as a whirling fluid1 carrying bodies round a centre in orbits1 does occur1 is too obvious to require proof4 ,every eddying stream1 or blast that twirls the dust in the road1 exhibits examples of such action1 and would justify the assumption of the vortices which carry the planets in their courses2 as indeed1 without doubt1 such facts suggested the ,cartesian explanation of the solar system4 ,the vortices1 in this mode of considering the subject1 are at the least as real a cause of motion as gravity itself4 #i4 ,thus the ,rule which enjoins true causes1 is nugatory1 if we take ver caus in the extended sense of any causes of a real kind1 and unphilosophical1 if we understand the term of those very causes which we familiarly suppose to exist4 ,but it may be said that we are to designate as true causes1 not those which are collected in a loose1 confused and precarious manner1 by undisciplined minds1 from obvious phenomena1 but those which are justly and rigorously inferred4 ,such a cause1 it may be added1 gravity is2 for the facts of the downward pressures and downward motions of bodies at the earth's surface lead us1 by the plainest and strictest induction1 to the assertion of such a force4 ,now to this interpretation of the ,rule there is no objection2 but then1 it must be observed1 that on this view1 terrestrial gravity is inferred by the same process as celestial gravitation2 and the cause is no more entitled to be called true1 because it is obtained from the former1 than because it is obtained from the latter class of facts4 ,we thus obtain an intelligible and tenable explanation of a vera causa2 but then1 by this explanation1 its verity ceases to be distinguishable from its other condition1 that it suffices for the explanation of the phenomena4 ,the assumption of universal gravitation accounts for the fall of a stone2 it also accounts for the revolutions of the ,moon or of ,saturn2 but since both these explanations are of the same kind1 we cannot with justice make the one a criterion or condition of the admissibility of the other4 #aj4 ,but still1 the ,rule1 so understood1 is so far from being unmeaning or frivolous1 that it expresses one of the most important tests which can be given of a sound physical theory4 ,it is true1 the explanation of one set of facts may be of the same nature as the explanation of the other class3 but then1 that the cause explains both classes1 gives it a very different claim upon our attention and assent from that which it would have if it explained one class only4 ,the very circumstance that the two explanations coincide1 is a most weighty presumption in their favour4 ,it is the testimony of two witnesses in behalf of the hypothesis2 and in proportion as these two witnesses are separate and independent1 the conviction produced by their agreement is more and more complete4 ,when the explanation of two kinds of phenomena1 distinct1 and not apparently connected1 leads us to the same cause1 such a coincidence does give a reality to the cause1 which it has not while it merely accounts for those appearances which suggested the supposition4 ,this coincidence of propositions inferred from separate classes of facts1 is exactly what we noticed in the ,novum ,organon ,renovatum 7b4 ii4 c4 #e1 sect4 #c71 as one of the most decisive characteristics of a true theory1 under the name of ,consilience of ,inductions4 ,that ,newton's ,first ,rule of ,philosophizing1 so understood1 authorizes the inferences which he himself made1 is really the ground on which they are so firmly believed by philosophers4 ,thus when the doctrine of a gravity varying inversely as the square of the distance from the body1 accounted at the same time for the relations of times and distances in the planetary orbits and for the amount of the moon's deflection from the tangent of her orbit1 such a doctrine became most convincing3 or again1 when the doctrine of the universal gravitation of all parts of matter1 which explained so admirably the inequalities of the moon's motions1 also gave a satisfactory account of a phenomenon utterly different1 the precession of the equinoxes4 ,and of the same kind is the evidence in favour of the undulatory theory of light1 when the assumption of the length of an undulation1 to which we are led by the colours of thin plates1 is found to be identical with that length which explains the phenomena of diffraction2 or when the hypothesis of transverse vibrations1 suggested by the facts of polarization1 explains also the laws of double refraction4 ,when such a convergence of two trains of induction points to the same spot1 we can no longer suspect that we are wrong4 ,such an accumulation of proof really persuades us that we have to do with a vera causa4 ,and if this kind of proof be multiplied2--if we again find other facts of a sort uncontemplated in framing our hypothesis1 but yet clearly accounted for when we have adopted the supposition2--we are still further confirmed in our belief2 and by such accumulation of proof we may be so far satisfied1 as to believe without conceiving it possible to doubt4 ,in this case1 when the validity of the opinion adopted by us has been repeatedly confirmed by its sufficiency in unforeseen cases1 so that all doubt is removed and forgotten1 the theoretical cause takes its place among the realities of the world1 and becomes a true cause4 #aa4 ,newton's ,rule then1 to avoid mistakes1 might be thus expressed3 ,that we may1 provisorily1 assume such hypothetical cause as will account for any given class of natural phenomena2 but that when two different classes of facts lead us to the same hypothesis1 we may hold it to be a true cause4 ,and this ,rule will rarely or never mislead us4 ,there are no instances1 in which a doctrine recommended in this manner has afterwards been discovered to be false4 ,there have been hypotheses which have explained many phenomena1 and kept their ground long1 and have afterwards been rejected4 ,but these have been hypotheses which explained only one class of phenomena2 and their fall took place when another kind of facts was examined and brought into conflict with the former4 ,thus the system of eccentrics and epicycles accounted for all the observed motions of the planets1 and was the means of expressing and transmitting all astronomical knowledge for two thousand years4 ,but then1 how was it overthrown8 ,by considering the distances as well as motions of the heavenly bodies4 ,here was a second class of facts2 and when the system was adjusted so as to agree with the one class1 it was at variance with the other4 ,these cycles and epicycles could not be true1 because they could not be made a just representation of the facts4 ,but if the measures of distance as well as of position had conspired in pointing out the cycles and epicycles1 as the paths of the planets1 the paths so determined could not have been otherwise than their real paths2 and the epicyclical theory would have been1 at least geometrically1 true4 #ab4 ,of the ,second ,rule4--,newton's ,second ,rule directs that natural events of the same kind are to be referred to the same causes1 so far as can be done4 ,such a precept at first appears to help us but little2 for all systems1 however little solid1 profess to conform to such a rule4 ,when any theorist undertakes to explain a class of facts1 he assigns causes which1 according to him1 will by their natural action1 as seen in other cases1 produce the effects in question4 ,the events which he accounts for by his hypothetical cause1 are1 he holds1 of the same kind as those which such a cause is known to produce4 ,kepler1 in ascribing the planetary motions to magnetism1 ,descartes1 in explaining them by means of vortices1 held that they were referring celestial motions to the causes which give rise to terrestrial motions of the same kind4 ,the question is1 ,are the effects of the same kind8 ,this once settled1 there will be no question about the propriety of assigning them to the same cause4 ,but the difficulty is1 to determine when events are of the same kind4 ,are the motions of the planets of the same kind with the motion of a body moving freely in a curvilinear path1 or do they not rather resemble the motion of a floating body swept round by a whirling current8 ,the ,newtonian and the ,cartesian answered this question differently4 ,how then can we apply this ,rule with any advantage8 #ac4 ,to this we reply1 that there is no way of escaping this uncertainty and ambiguity1 but by obtaining a clear possession of the ideas which our hypothesis involves1 and by reasoning rigorously from them4 ,newton asserts that the planets move in free paths1 acted on by certain forces4 ,the most exact calculation gives the closest agreement of the results of this hypothesis with the facts4 ,descartes asserts that the planets are carried round by a fluid4 ,the more rigorously the conceptions of force and the laws of motion are applied to this hypothesis1 the more signal is its failure in reconciling the facts to one another4 ,without such calculation1 we can come to no decision between the two hypotheses4 ,if the ,newtonian hold that the motions of the planets are evidently of the same kind as those of a body describing a curve in free space1 and therefore1 like that1 to be explained by a force acting upon the body2 the ,cartesian denies that the planets do move in free space4 ,they are1 he maintains1 immersed in a plenum4 ,it is only when it appears that comets pass through this plenum in all directions with no impediment1 and that no possible form and motion of its whirlpools can explain the forces and motions which are observed in the solar system1 that he is compelled to allow the ,newtonian's classification of events of the same kind4 ,thus it does not appear that this ,rule of ,newton can be interpreted in any distinct and positive manner1 otherwise than as enjoining that1 in the task of induction1 we employ clear ideas1 rigorous reasoning1 and close and fair comparison of the results of the hypothesis with the facts4 ,these are1 no doubt1 important and fundamental conditions of a just induction2 but in this injunction we find no peculiar or technical criterion by which we may satisfy ourselves that we are right1 or detect our errors4 ,still1 of such general prudential rules1 none can be more wise than one which thus1 in the task of connecting facts by means of ideas1 recommends that the ideas be clear1 the facts1 correct1 and the chain of reasoning which connects them1 without a flaw4 #ad4 ,of the ,third ,rule4--,the ,third ,rule1 that qualities which are observed without exception be held to be universal1 as ,i have already said1 seems to be intended to authorize the assertion of gravitation as a universal attribute of matter4 ,we formerly stated1 in treating of ,mechanical ,ideas#bba1 that this application of such a ,rule appears to be a mode of reasoning far from conclusive4 ,the assertion of the universality of any property of bodies must be grounded upon the reason of the case1 and not upon any arbitrary maxim4 ,is it intended by this ,rule to prohibit any further examination how far gravity is an original property of matter1 and how far it may be resolved into the result of other agencies8 ,we know perfectly well that this was not ,newton's intention2 since the cause of gravity was a point which he proposed to himself as a subject of inquiry4 ,it would certainly be very unphilosophical to pretend1 by this ,rule of ,philosophizing1 to prejudge the question of such hypotheses as that of ,mosotti1 ,that gravity is the excess of the electrical attraction over electrical repulsion1 and yet to adopt this hypothesis1 would be to suppose electrical forces more truly universal than gravity2 for according to the hypothesis1 gravity1 being the inequality of the attraction and repulsion1 is only an accidental and partial relation of these forces4 ,nor would it be allowable to urge this ,rule as a reason of assuming that double stars are attracted to each other by a force varying according to the inverse square of the distance2 without examining1 as ,herschel and others have done1 the orbits which they really describe4 ,but if the ,rule is not available in such cases1 what is its real value and authority8 and in what cases are they exemplified8 #ae4 ,in a former work#bbb1 it was shown that the fundamental laws of motion1 and the properties of matter which these involve1 are1 after a full consideration of the subject1 unavoidably assumed as universally true4 ,it was further shown1 that although our knowledge of these laws and properties be gathered from experience1 we are strongly impelled1 7some philosophers think1 authorized17 to look upon these as not only universally1 but necessarily true4 ,it was also stated1 that the law of gravitation1 though its universality may be deemed probable1 does not apparently involve the same necessity as the fundamental laws of motion4 ,but it was pointed out that these are some of the most abstruse and difficult questions of the whole of philosophy2 involving the profound1 perhaps insoluble1 problem of the identity or diversity of ,ideas and ,things4 ,it cannot1 therefore1 be deemed philosophical to cut these ,gordian knots by peremptory maxims1 which encourage us to decide without rendering a reason4 ,moreover1 it appears clear that the reason which is rendered for this ,rule by the ,newtonians is quite untenable2 namely1 that we know extension1 hardness1 and inertia1 to be universal qualities of bodies by experience alone1 and that we have the same evidence of experience for the universality of gravitation4 ,we have already observed that we cannot1 with any propriety1 say that we find by experience all bodies are extended4 ,this could not be a just assertion1 unless we conceive the possibility of our finding the contrary4 ,but who can conceive our finding by experience some bodies which are not extended8 ,it appears1 then1 that the reason given for the ,third ,rule of ,newton involves a mistake respecting the nature and authority of experience4 ,and the ,rule itself cannot be applied without attempting to decide1 by the casual limits of observation1 questions which necessarily depend upon the relations of ideas4 #af4 ,of the ,fourth ,rule4--,newton's ,fourth ,rule is1 that ,propositions collected from phenomena by induction1 shall be held to be true1 notwithstanding contrary hypotheses2 but shall be liable to be rendered more accurate1 or to have their exceptions pointed out1 by additional study of phenomena4 ,this ,rule contains little more than a general assertion of the authority of induction1 accompanied by ,newton's usual protest against hypotheses4 ,the really valuable part of the ,fourth ,rule is that which implies that a constant verification1 and1 if necessary1 rectification1 of truths discovered by induction1 should go on in the scientific world4 ,even when the law is1 or appears to be1 most certainly exact and universal1 it should be constantly exhibited to us afresh in the form of experience and observation4 ,this is necessary1 in order to discover exceptions and modifications if such exist3 and if the law be rigorously true1 the contemplation of it1 as exemplified in the world of phenomena1 will best give us that clear apprehension of its bearings which may lead us to see the ground of its truth4 ,the concluding clause of this ,fourth ,rule appears1 at first1 to imply that all inductive propositions are to be considered as merely provisional and limited1 and never secure from exception4 ,but to judge thus would be to underrate the stability and generality of scientific truths2 for what man of science can suppose that we shall hereafter discover exceptions to the universal gravitation of all parts of the solar system8 ,and it is plain that the author did not intend the restriction to be applied so rigorously2 for in the ,third ,rule1 as we have just seen1 he authorizes us to infer universal properties of matter from observation1 and carries the liberty of inductive inference to its full extent4 ,the ,third ,rule appears to encourage us to assert a law to be universal1 even in cases in which it has not been tried2 the ,fourth ,rule seems to warn us that the law may be inaccurate1 even in cases in which it has been tried4 ,nor is either of these suggestions erroneous2 but both the universality and the rigorous accuracy of our laws are proved by reference to ,ideas rather than to ,experience2 a truth1 which1 perhaps1 the philosophers of ,newton's time were somewhat disposed to overlook4 #ag4 ,the disposition to ascribe all our knowledge to ,experience1 appears in ,newton and the ,newtonians by other indications2 for instance1 it is seen in their extreme dislike to the ancient expressions by which the principles and causes of phenomena were described1 as the occult causes of the ,schoolmen1 and the forms of the ,aristotelians1 which had been adopted by ,bacon4 ,newton says#bbc1 that the particles of matter not only possess inertia1 but also active principles1 as gravity1 fermentation1 cohesion2 he adds1 ,these principles ,i consider not as ,occult ,qualities1 supposed to result from the ,specific ,forms of things1 but as ,general ,laws of ,nature1 by which the things themselves are formed3 their truth appearing to us by phenomena1 though their causes be not yet discovered4 ,for these are manifest qualities1 and their causes only are occult4 ,and the ,aristotelians gave the name of occult qualities1 not to manifest qualities1 but to such qualities only as they supposed to lie hid in bodies1 and to the unknown causes of manifest effects3 such as would be the causes of gravity1 and of magnetick and electrick attractions1 and of fermentations1 if we should suppose that these forces or actions arose from qualities unknown to us1 and incapable of being discovered and made manifest4 ,such occult qualities put a stop to the improvement of ,natural ,philosophy1 and therefore of late years have been rejected4 ,to tell us that every species of things is endowed with an occult specific quality by which it acts and produces manifest effects1 is to tell us nothing3 but to derive two or three general principles of motion from phenomena1 and afterwards to tell us how the properties and actions of all corporeal things follow from these manifest principles1 would be a great step in philosophy1 though the causes of those principles were not yet discovered3 and therefore ,i scruple not to propose the principles of motion above maintained1 they being of very general extent1 and leave their causes to be found out4 #ah4 ,all that is here said is highly philosophical and valuable2 but we may observe that the investigation of specific forms in the sense in which some writers had used the phrase1 was by no means a frivolous or unmeaning object of inquiry4 ,bacon and others had used form as equivalent to law#bbd4 ,if we could ascertain that arrangement of the particles of a crystal from which its external crystalline form and other properties arise1 this arrangement would be the internal form of the crystal4 ,if the undulatory theory be true1 the form of light is transverse vibrations3 if the emission theory be maintained1 the form of light is particles moving in straight lines1 and deflected by various forces4 ,both the terms1 form and law1 imply an ideal connexion of sensible phenomena2 form supposes matter which is moulded to the form2 law supposes objects which are governed by the law4 ,the former term refers more precisely to existences1 the latter to occurrences4 ,the latter term is now the more familiar1 and is1 perhaps1 the better metaphor3 but the former also contains the essential antithesis which belongs to the subject1 and might be used in expressing the same conclusions4 ,but occult causes1 employed in the way in which ,newton describes1 had certainly been very prejudicial to the progress of knowledge1 by stopping inquiry with a mere word4 ,the absurdity of such pretended explanations had not escaped ridicule4 ,the pretended physician in the comedy gives an example of an occult cause or virtue4 ,mihi demandatur ,a doctissimo ,doctore ,quare ,opium facit dormire3 ,et ego respondeo1 ,quia est in eo ,virtus dormitiva1 ,cujus natura est sensus assoupire4 #ai4 ,but the most valuable part of the view presented to us in the quotation just given from ,newton is the distinct separation1 already noticed as peculiarly brought into prominence by him1 of the determination of the laws of phenomena1 and the investigation of their causes4 ,the maxim1 that the former inquiry must precede the latter1 and that if the general laws of facts be discovered1 the result is highly valuable1 although the causes remain unknown1 is extremely important2 and had not1 ,i think1 ever been so strongly and clearly stated1 till ,newton both repeatedly promulgated the precept1 and added to it the weight of the most striking examples4 ,we have seen that ,newton1 along with views the most just and important concerning the nature and methods of science1 had something of the tendency1 prevalent in his time1 to suspect or reject1 at least speculatively1 all elements of knowledge except observation4 ,this tendency was1 however1 in him so corrected and restrained by his own wonderful sagacity and mathematical habits1 that it scarcely led to any opinion which we might not safely adopt4 ,but we must now consider the cases in which this tendency operated in a more unbalanced manner1 and led to the assertion of doctrines which1 if consistently followed1 would destroy the very foundations of all general and certain knowledge4 ,,footnotes3 ,footnote #bag3 ,optics1 qu4 #ca1 near the end4 ,footnote #bah3 ,qu4 #bh4 ,footnote #bai3 ,hist4 ,ind4 ,sc4 b4 v4 and b4 vii4 ,footnote #bbj3 ,optics1 qu4 #ca4 ,footnote #bba3 ,history of ,ideas1 b4 iii4 c4 x4 ,footnote #bbb3 ,ibid4 b4 iii4 c4 ix4 x4 xi4 ,footnote #bbc3 ,opticks1 qu4 #ca4 ,footnote #bbd3 ,nov4 ,org4 l4 ii4 ,aph4 #b4 ,licet enim in natura nihil existet prter corpora individua1 edentia actus puros individuos ex lege2 in doctrinis tamen illa ipsa lex1 ejusque inquisitio1 et inventio1 et explicatio1 pro fundamento est tam ad sciendum quam ad operandum4 ,eam autem legem1 ejusque paragraphos1 formarum nomine intelligimus2 prsertim cum hoc vocabulum invaluerit1 et familiariter occurrat4 ,aph4 #ag4 ,eadem res est forma calidi vel forma luminis1 et lex calidi aut lex luminis4 ,,chapter ,,xix4 ,,locke ,,and ,,his ,,french ,,followers4 #a4 ,in the constant opposition and struggle of the schools of philosophy1 which consider our ,senses and our ,ideas respectively1 as the principal sources of our knowledge1 we have seen that at the period of which we now treat1 the tendency was to exalt the external and disparage the internal element4 ,the disposition to ascribe our knowledge to observation alone1 had already1 in ,bacon's time1 led him to dwell to a disproportionate degree upon that half of his subject2 and had tinged ,newton's expressions1 though it had not biassed his practice4 ,but this partiality soon assumed a more prominent shape1 becoming extreme in ,locke1 and extravagant in those who professed to follow him4 ,indeed ,locke appears to owe his popularity and influence as a popular writer mainly to his being one of the first to express1 in a plain and unhesitating manner1 opinions which had for some time been ripening in the minds of a large portion of the cultivated public4 ,hobbes had already promulgated the main doctrines which ,locke afterwards urged1 on the subject of the origin and nature of our knowledge3 but in him these doctrines were combined with offensive opinions on points of morals1 government1 and religion1 so that their access to general favour was impeded3 and it was to ,locke that they were indebted for the extensive influence which they soon after obtained4 ,locke owed this authority mainly to the intellectual circumstances of the time4 ,although a writer of great merit1 he by no means possesses such metaphysical acuteness or such philosophical largeness of view1 or such a charm of writing1 as must necessarily give him the high place he has held in the literature of ,europe4 ,but he came at a period when the reign of ,ideas was tottering to its fall4 ,all the most active and ambitious spirits had gone over to the new opinions1 and were prepared to follow the fortunes of the ,philosophy of ,experiment1 then in the most prosperous and brilliant condition1 and full of still brighter promise4 ,there were1 indeed1 a few learned and thoughtful men who still remained faithful to the empire of ,ideas2 partly1 it may be1 from a too fond attachment to ancient systems2 but partly1 also1 because they knew that there were subjects of vast importance1 in which experience did not form the whole foundation of our knowledge4 ,they knew1 too1 that many of the plausible tenets of the new philosophy were revivals of fallacies which had been discussed and refuted in ancient times4 ,but the advocates of mere experience came on with a vast store of weighty truth among their artillery1 and with the energy which the advance usually bestows4 ,the ideal system of philosophy could1 for the present1 make no effectual resistance2 ,locke1 by putting himself at the head of the assault1 became the hero of his day3 and his name has been used as the watchword of those who adhere to the philosophy of the senses up to our own times4 #b4 ,locke himself did not assert the exclusive authority of the senses in the extreme unmitigated manner in which some who call themselves his disciples have done4 ,but this is the common lot of the leaders of revolutions1 for they are usually bound by some ties of affection and habit to the previous state of things1 and would not destroy all traces of that condition3 while their followers attend1 not to their inconsistent wishes1 but to the meaning of the revolution itself2 and carry out1 to their genuine and complete results1 the principles which won the victory1 and which have been brought out more sharp from the conflict4 ,thus ,locke himself does not assert that all our ideas are derived from ,sensation1 but from ,sensation and ,reflection4 ,but it was easily seen that1 in this assertion1 two very heterogeneous elements were conjoined3 that while to pronounce ,sensation the origin of ideas1 is a clear decided tenet1 the acceptance or rejection of which determines the general character of our philosophy2 to make the same declaration concerning ,reflection1 is in the highest degree vague and ambiguous2 since reflection may either be resolved into a mere modification of sensation1 as was done by one school1 or may mean all that the opposite school opposes to sensation1 under the name of ,ideas4 ,hence the clear and strong impression which fastened upon men's minds1 and which does in fact represent all the systematic and consistent part of ,locke's philosophy1 was1 that in it all our ideas are represented as derived from ,sensation4 #c4 ,we need not spend much time in pointing out the inconsistencies into which ,locke fell2 as all must fall into inconsistencies who recognize no source of knowledge except the senses4 ,thus he maintains that our ,idea of ,space is derived from the senses of sight and touch2 our ,idea of ,solidity from the touch alone4 ,our ,notion of ,substance is an unknown support of unknown qualities1 and is illustrated by the ,indian fable of the tortoise which supports the elephant1 which supports the world4 ,our ,notion of ,power or ,cause is in like manner got from the senses4 ,and yet1 though these ideas are thus mere fragments of our experience1 ,locke does not hesitate to ascribe to them necessity and universality when they occur in propositions4 ,thus he maintains the necessary truth of geometrical properties3 he asserts that the resistance arising from solidity is absolutely insurmountable#bbe2 he conceives that nothing short of ,omnipotence can annihilate a particle of matter#bbf2 and he has no misgivings in arguing upon the axiom that ,every thing must have a cause4 ,he does not perceive that1 upon his own account of the origin of our knowledge1 we can have no right to make any of these assertions4 ,if our knowledge of the truths which concern the external world were wholly derived from experience1 all that we could venture to say would be1--that geometrical properties of figures are true as far as we have tried them2--that we have seen no example of a solid body being reduced to occupy less space by pressure1 or of a material substance annihilated by natural means2--and that wherever we have examined1 we have found that every change has had a cause4 ,experience can never entitle us to declare that what she has not seen is impossible2 still less1 that things which she can not see are certain4 ,locke himself intended to throw no doubt upon the certainty of either human or divine knowledge2 but his principles1 when men discarded the temper in which he applied them1 and the checks to their misapplication which he conceived that he had provided1 easily led to a very comprehensive skepticism4 ,his doctrines tended to dislodge from their true bases the most indisputable parts of knowledge2 as1 for example1 pure and mixed mathematics4 ,it may well be supposed1 therefore1 that they shook the foundations of many other parts of knowledge in the minds of common thinkers4 ,it was not long before these consequences of the overthrow of ideas showed themselves in the speculative world4 ,i have already in a previous work#bbg mentioned ,hume's skeptical inferences from ,locke's maxim1 that we have no ideas except those which we acquire by experience2 and the doctrines set up in opposition to this by the metaphysicians of ,germany4 ,i might trace the progress of the sensational opinions in ,britain till the reaction took place here also3 but they were so much more clearly and decidedly followed out in ,france1 that ,i shall pursue their history in that country4 #d4 ,the ,french ,followers of ,locke1 ,condillac1 c4--,most of the ,french writers who adopted ,locke's leading doctrines1 rejected the ,reflection1 which formed an anomalous part of his philosophy1 and declared that ,sensation alone was the source of ideas4 ,among these writers1 ,condillac was the most distinguished4 ,he expressed the leading tenet of their school in a clear and pointed manner by saying that ,all ideas are transformed sensations4 ,we have already considered this phrase#bbh1 and need not here dwell upon it4 ,opinions such as these tend to annihilate1 as we have seen1 one of the two co-ordinate elements of our knowledge4 ,yet they were far from being so prejudicial to the progress of science1 or even of the philosophy of science1 as might have been anticipated4 ,one reason of this was1 that they were practically corrected1 especially among the cultivators of ,natural ,philosophy1 by the study of mathematics2 for that study did really supply all that was requisite on the ideal side of science1 so far as the ideas of space1 time1 and number1 were concerned1 and partly also with regard to the idea of cause and some others4 ,and the methods of discovery1 though the philosophy of them made no material advance1 were practically employed with so much activity1 and in so many various subjects1 that a certain kind of prudence and skill in this employment was very widely diffused4 #e4 ,importance of ,language4--,in one respect this school of metaphysicians rendered a very valuable service to the philosophy of science4 ,they brought into prominent notice the great importance of words and terms in the formation and progress of knowledge1 and pointed out that the office of language is not only to convey and preserve our thoughts1 but to perform the analysis in which reasoning consists4 ,they were led to this train of speculation1 in a great measure1 by taking pure mathematical science as their standard example of substantial knowledge4 ,condillac1 rejecting1 as we have said1 almost all those ideas on which universal and demonstrable truths must be based1 was still not at all disposed to question the reality of human knowledge2 but was1 on the contrary1 a zealous admirer of the evidence and connexion which appear in those sciences which have the ideas of space and number for their foundation1 especially the latter4 ,he looked for the grounds of the certainty and reality of the knowledge which these sciences contain2 and found them1 as he conceived1 in the nature of the language which they employ4 ,the ,signs which are used in arithmetic and algebra enable us to keep steadily in view the identity of the same quantity under all the forms which1 by composition and decomposition1 it may be made to assume2 and these ,signs also not only express the operations which are performed1 but suggest the extension of the operations according to analogy4 ,algebra1 according to him1 is only a very perfect language2 and language answers its purpose of leading us to truth1 by possessing the characteristics of algebra4 ,words are the symbols of certain groups of impressions or facts2 they are so selected and applied as to exhibit the analogies which prevail among these facts2 and these analogies are the truths of which our knowledge consists4 ,every language is an analytical method2 every analytical method is a language#bbi2 these were the truths alike new and simple1 as he held1 which he conceived that he had demonstrated4 ,the art of speaking1 the art of writing1 the art of reasoning1 the art of thinking1 are only1 at bottom1 one and the same art#bcj4 ,each of these operations consists in a succession of analytical operations2 and words are the marks by which we are able to fix our minds upon the steps of this analysis4 #f4 ,the analysis of our impressions and notions does in reality lead to truth1 not only in virtue of the identity of the whole with its parts1 as ,condillac held1 but also in virtue of certain ,ideas which govern the synthesis of our sensations1 and which contain the elements of universal truths1 as we have all along endeavoured to show4 ,but although ,condillac overlooked or rejected this doctrine1 the importance of words1 as marking the successive steps of this synthesis and analysis1 is not less than he represented it to be4 ,every truth1 once established by induction from facts1 when it is become familiar under a brief and precise form of expression1 becomes itself a fact2 and is capable of being employed1 along with other facts of a like kind1 as the materials of fresh inductions4 ,in this successive process1 the term1 like the cord of a fagot1 both binds together the facts which it includes1 and makes it possible to manage the assemblage as a single thing4 ,on occasion of most discoveries in science1 the selection of a technical term is an essential part of the proceeding4 ,in the ,history of ,science1 we have had numerous opportunities of remarking this2 and the ,list of technical terms given as an ,index to that work1 refers us1 by almost every word1 to one such occasion4 ,and these terms1 which thus have had so large a share in the formation of science1 and which constitute its language1 do also offer the means of analyzing its truths1 each into its constituent truths2 and these into facts more special1 till the original foundations of our most general propositions are clearly exhibited4 ,the relations of general and particular truths are most evidently represented by the ,inductive ,tables given in ,book ,,ii4 of the ,novum ,organon ,renovatum4 ,but each step in each of these ,tables has its proper form of expression1 familiar among the cultivators of science2 and the analysis which our ,tables display1 is commonly performed in men's minds1 when it becomes necessary1 by fixing the attention successively upon a series of words1 not upon the lines of a ,table4 ,language offers to the mind such a scale or ladder as the ,table offers to the eye2 and since such ,tables present to us1 as we have said1 the ,logic of ,induction1 that is1 the formal conditions of the soundness of our reasoning from facts1 we may with propriety say that a just analysis of the meaning of words is an essential portion of ,inductive ,logic4 ,in saying this1 we must not forget that a decomposition of general truths into ideas1 as well as into facts1 belongs to our philosophy2 but the point we have here to remark1 is the essential importance of words to the latter of these processes4 ,and this point had not ever had its due weight assigned to it till the time of ,condillac and other followers of ,locke1 who pursued their speculations in the spirit ,i have just described4 ,the doctrine of the importance of terms is the most considerable addition to the philosophy of science which has been made since the time of ,bacon#bca4 #g4 ,the ,french ,encyclopedists4--,the ,french ,encyclopdie1 published in #agea1 of which ,diderot and ,dalembert were the editors1 may be considered as representing the leading characters of ,european philosophy during the greater part of the eighteenth century4 ,the writers in this work belong for the most part to the school of ,locke and ,condillac2 and we may make a few remarks upon them1 in order to bring into view one or two points in addition to what we have already said of that school4 ,the ,discours ,prliminaire1 written by ,dalembert1 is celebrated as containing a view of the origin of our knowledge1 and the connexion and classification of the sciences4 ,a tendency of the speculations of the ,encyclopedists1 as of the ,school of ,locke in general1 is to reject all ideal principles of connexion among facts1 as something which experience1 the only source of true knowledge1 does not give4 ,hence all certain knowledge consists only in the recognition of the same thing under different aspects1 or different forms of expression4 ,axioms are not the result of an original relation of ideas1 but of the use1 or it may be the abuse#bcb1 of words4 ,in like manner1 the propositions of ,geometry are a series of modifications1--of distortions1 so to speak1--of one original truth2 much as if the proposition were stated in the successive forms of expression presented by a language which was constantly growing more and more artificial4 ,several of the sciences which rest upon physical principles1 that is1 7says the writer17 truths of experience or simple hypotheses1 have only an experimental or hypothetical certainty4 ,impenetrability added to the idea of extent is a mystery in addition3 the nature of motion is a riddle for philosophers3 the metaphysical principle of the laws of percussion is equally concealed from them4 ,the more profoundly they study the idea of matter and of the properties which represent it1 the more obscure this idea becomes2 the more completely does it escape them4 #h4 ,this is a very common style of reflection1 even down to our own times4 ,i have endeavoured to show that concerning the ,fundamental ,ideas of space1 of force and resistance1 of substance1 external quality1 and the like1 we know enough to make these ,ideas the grounds of certain and universal truths2--enough to supply us with axioms from which we can demonstratively reason4 ,if men wish for any other knowledge of the nature of matter than that which ideas1 and facts conformable to ideas1 give them1 undoubtedly their desire will be frustrated1 and they will be left in a mysterious vacancy2 for it does not appear how such knowledge as they ask for could be knowledge at all4 ,but in reality1 this complaint of our ignorance of the real nature of things proceeds from the rejection of ideas1 and the assumption of the senses alone as the ground of knowledge4 ,observation and calculation are the only sources of truth3 this is the motto of the school of which we now speak4 ,and its import amounts to this3--that they reject all ideas except the idea of number1 and recognize the modifications which parts undergo by addition and subtraction as the only modes in which true propositions are generated4 ,the laws of nature are assemblages of facts3 the truths of science are assertions of the identity of things which are the same4 ,by the avowal of almost all philosophers1 says a writer of this school#bcc1 the most sublime truths1 when once simplified and reduced to their lowest terms1 are converted into facts1 and thenceforth present to the mind only this proposition2 the white is white1 the black is black4 ,these statements are true in what they positively assert1 but they involve error in the denial which by implication they convey4 ,it is true that observation and demonstration are the only sources of scientific truth2 but then1 demonstration may be founded on other grounds besides the elementary properties of number4 ,it is true that the theory of gravitation is but the assertion of a general fact2 but this is so1 not because a sound theory does not involve ideas1 but because our apprehension of a fact does4 #i4 ,another characteristic indication of the temper of the ,encyclopedists and of the age to which they belong1 is the importance by them assigned to those practical ,arts which minister to man's comfort and convenience4 ,not only1 in the body of the ,encyclopedia1 are the ,mechanical ,arts placed side by side with the ,sciences1 and treated at great length2 but in the ,preliminary ,discourse1 the preference assigned to the liberal over the mechanical ,arts is treated as a prejudice#bcd1 and the value of science is spoken of as measured by its utility4 ,the discovery of the ,mariner's ,compass is not less advantageous to the human race than the explanation of its properties would be to physics4--,why should we not esteem those to whom we owe the fusee and the escapement of watches as much as the inventors of ,algebra8 ,and in the classification of sciences which accompanies the ,discourse1 the labours of artisans of all kinds have a place4 ,this classification of the various branches of science contained in the ,dissertation is often spoken of4 ,it has for its basis the classification proposed by ,bacon1 in which the parts of human knowledge are arranged according to the faculties of the mind in which they originate2 and these faculties are taken1 both by ,bacon and by ,dalembert1 as ,memory1 ,reason1 and ,imagination4 ,the insufficiency of ,bacon's arrangement as a scientific classification is so glaring1 that the adoption of it1 with only superficial modifications1 at the period of the ,encyclopedia1 is a remarkable proof of the want of original thought and real philosophy at the time of which we speak4 #aj4 ,we need not trace further the opinion which derives all our knowledge from the senses in its application to the philosophy of ,science4 ,its declared aim is to reduce all knowledge to the knowledge of ,facts2 and it rejects all inquiries which involve the ,idea of ,cause1 and similar ,ideas1 describing them as metaphysical1 or in some other damnatory way4 ,it professes1 indeed1 to discard all ,ideas2 but1 as we have long ago seen1 some ,ideas or other are inevitably included even in the simplest ,facts4 ,accordingly the speculations of this school are compelled to retain the relations of ,position1 ,succession1 ,number and ,resemblance1 which are rigorously ideal relations4 ,the philosophy of ,sensation1 in order to be consistent1 ought to reject these ,ideas along with the rest1 and to deny altogether the possibility of general knowledge4 ,when the opinions of the ,sensational ,school had gone to an extreme length1 a ,reaction naturally began to take place in men's minds4 ,such have been the alternations of opinion1 from the earliest ages of human speculation4 ,man may perhaps have existed in an original condition in which he was only aware of the impressions of ,sense2 but his first attempts to analyse his perceptions brought under his notice ,ideas as a separate element1 essential to the existence of knowledge4 ,ideas were thenceforth almost the sole subject of the study of philosophers2 of ,plato and his disciples1 professedly2 of ,aristotle1 and still more of the followers and commentators of ,aristotle1 practically4 ,and this continued till the time of ,galileo1 when the authority of the ,senses again began to be asserted2 for it was shown by the great discoveries which were then made1 that the ,senses had at least some share in the promotion of knowledge4 ,as discoveries more numerous and more striking were supplied by ,observation1 the world gradually passed over to the opinion that the share which had been ascribed to ,ideas in the formation of real knowledge was altogether a delusion1 and that ,sensation alone was true4 ,but when this was asserted as a general doctrine1 both its manifest falsity and its alarming consequences roused men's minds1 and made them recoil from the extreme point to which they were approaching4 ,philosophy again oscillated back towards ,ideas2 and over a great part of ,europe1 in the clearest and most comprehensive minds1 this regression from the dogmas of the ,sensational ,school is at present the prevailing movement4 ,we shall conclude our review by noticing a few indications of this state of things4 ,,footnotes3 ,footnote #bbe3 ,essay1 b4 xi4 c4 iv4 sect4 #c4 ,footnote #bbf3 ,ibid4 c4 xiii4 sect4 #bb4 ,footnote #bbg3 ,history of ,ideas1 b4 iii4 c4 iii4 ,modern ,opinions respecting the ,idea of ,cause4 ,footnote #bbh3 ,ibid4 b4 i4 c4 iv4 ,footnote #bbi3 ,langue des ,calculs1 p4 #a4 ,footnote #bcj3 ,grammaire1 p4 xxxvi4 ,footnote #bca3 ,since the selection and construction of terms is thus a matter of so much consequence in the formation of science1 it is proper that systematic rules1 founded upon sound principles1 should be laid down for the performance of this operation4 ,some such rules are accordingly suggested in b4 iv4 of the ,nov4 ,org4 ,ren4 ,footnote #bcb3 ,disc4 ,prlim4 p4 viii4 ,footnote #bcc3 ,helvetius ,sur l',homme1 c4 xxiii4 ,footnote #bcd3 ,p4 xiii4 ,,chapter ,,xx4 ,,the ,,reaction ,,against ,,the ,,sensational ,,school4 #a4 ,when ,locke's ,essay appeared1 it was easily seen that its tendency was to urge1 in a much more rigorous sense than had previously been usual1 the ancient maxim of ,aristotle1 adopted by the schoolmen of the middle ages1 that nothing exists in the intellect but what has entered by the senses4 ,leibnitz expressed in a pointed manner the limitation with which this doctrine had always been understood4 ,nihil est in intellectu quod non prius fuerit in sensu2--nempe1 he added1 nisi intellectus ipse4 ,to this it has been objected#bce1 that we cannot say that the intellect is in the intellect4 ,but this remark is obviously frivolous2 for the faculties of the understanding 7which are what the argument against the ,sensational ,school requires us to reserve7 may be said to be in the understanding1 with as much justice as we may assert there are in it the impressions derived from sense4 ,and when we take account of these faculties1 and of the ,ideas to which1 by their operation1 we necessarily subordinate our apprehension of phenomena1 we are led to a refutation of the philosophy which makes phenomena1 unconnected by ,ideas1 the source of all knowledge4 ,the succeeding opponents of the ,lockian school insisted upon and developed in various ways this remark of ,leibnitz1 or some equivalent view4 #b4 ,it was by inquiries into the foundations of ,morals that ,english philosophers were led to question the truth of ,locke's theory4 ,dr4 ,price1 in his ,review of the ,principal ,questions in ,morals1 first published in #ageg1 maintained that we cannot with propriety assert all our ideas to be derived from sensation and reflection4 ,he pointed out1 very steadily1 the other source4 ,the power1 ,i assert1 that understands1 or the faculty within us that discerns truth1 and that compares all the objects of thought and judges of them1 is a spring of new ideas#bcf4 ,and he exhibits the antithesis in various forms4 ,were not sense and knowledge entirely different1 we should rest satisfied with sensible impressions1 such as light1 colours and sounds1 and inquire no further about them1 at least when the impressions are strong and vigorous3 whereas1 on the contrary1 we necessarily desire some further acquaintance with them1 and can never be satisfied till we have subjected them to the survey of reason4 ,sense presents particular forms to the mind1 but cannot rise to any general ideas4 ,it is the intellect that examines and compares the presented forms1 that rises above individuals to universal and abstract ideas2 and thus looks downward upon objects1 takes in at one view an infinity of particulars1 and is capable of discovering general truths4 ,sense sees only the outside of things1 reason acquaints itself with their natures4 ,sensation is only a mode of feeling in the mind2 but knowledge implies an active and vital energy in the mind#bcg4 #c4 ,the necessity of refuting ,hume's inferences from the mere sensation system led other writers to limit1 in various ways1 their assent to ,locke4 ,especially was this the case with a number of intelligent metaphysicians in ,scotland1 as ,reid1 ,beattie1 ,dugald ,stewart1 and ,thomas ,brown4 ,thus ,reid asserts#bch1 that the account which ,mr4 ,locke himself gives of the ,idea of ,power cannot be reconciled to his favourite doctrine1 that all our simple ideas have their origin from sensation or reflection4 ,reid remarks1 that our memory and our reasoning power come in for a share in the origin of this idea3 and in speaking of reasoning1 he obviously assumes the axiom that every event must have a cause4 ,by succeeding writers of this school1 the assumption of the fundamental principles1 to which our nature in such cases irresistibly directs us1 is more clearly pointed out4 ,thus ,stewart defends the form of expression used by ,price#bci3 ,a variety of intuitive judgments might be mentioned1 involving simple ideas1 which it is impossible to trace to any origin but to the power which enables us to form these judgments4 ,thus it is surely an intuitive truth that the sensations of which ,i am conscious1 and all those ,i remember1 belong to one and the same being1 which ,i call myself4 ,here is an intuitive judgment involving the simple idea of ,identity4 ,in like manner1 the changes which ,i perceive in the universe impress me with a conviction that some cause must have operated to produce them4 ,here is an intuitive judgment involving the simple ,idea of ,causation4 ,when we consider the adjacent angles made by a straight line standing upon another1 and perceive that their sum is equal to two right angles1 the judgment we form involves a simple idea of ,equality4 ,to say1 therefore1 that the ,reason or the ,understanding is a source of new ideas1 is not so exceptionable a mode of speaking as has been sometimes supposed4 ,according to ,locke1 ,sense furnishes our ideas1 and ,reason perceives their agreements and disagreements4 ,but the truth is1 that these agreements and disagreements are in many instances1 simple ideas1 of which no analysis can be given2 and of which the origin must therefore be referred to ,reason1 according to ,locke's own doctrine4 ,this view1 according to which the ,reason or ,understanding is the source of certain simple ideas1 such as ,identity1 ,causation1 ,equality1 which ideas are necessarily involved in the intuitive judgments which we form1 when we recognize fundamental truths of science1 approaches very near in effect to the doctrine which in several works ,i have presented1 of ,fundamental ,ideas belonging to each science1 and manifesting themselves in the axioms of the science4 ,it may be observed1 however1 that by attempting to enumerate these ideas and axioms1 so as to lay the foundations of the whole body of physical science1 and by endeavouring1 as far as possible1 to simplify and connect each group of such ,ideas1 ,i have at least given a more systematic form to this doctrine4 ,i have1 moreover1 traced it into many consequences to which it necessarily leads1 but which do not appear to have been contemplated by the metaphysicians of the ,scotch school4 ,but ,i gladly acknowledge my obligations to the writers of that school2 and ,i trust that in the near agreement of my views on such points with theirs1 there is ground for believing the system of philosophy which ,i have presented1 to be that to which the minds of thoughtful men1 who have meditated on such subjects1 are generally tending4 #d4 ,as a further instance that such a tendency is at work1 ,i may make a quotation from an eminent ,english philosophical writer of another school4 ,if you will be at the pains1 says ,archbishop ,whately#bdj1 carefully to analyze the simplest description you hear of any transaction or state of things1 you will find that the process which almost invariably takes place is1 in logical language1 this3 that each individual has in his mind certain major premises or principles relative to the subject in question2--that observation of what actually presents itself to the senses1 supplies minor premises2 and that the statement given 7and which is reported as a thing experienced7 consists1 in fact1 of the conclusions drawn from the combinations of these premises4 ,the major premises here spoken of are the ,fundamental ,ideas1 and the ,axioms and ,propositions to which they lead2 and whatever is regarded as a fact of observation is necessarily a conclusion in which these propositions are assumed2 for these contain1 as we have said1 the conditions of our experience4 ,our experience conforms to these axioms and their consequences1 whether or not the connexion be stated in a logical manner1 by means of premises and a conclusion4 #e4 ,the same persuasion is also suggested by the course which the study of metaphysics has taken of late years in ,france4 ,in that country1 as we have seen1 the ,sensational ,system1 which was considered as the necessary consequence of the revolution begun by ,locke1 obtained a more complete ascendancy than it did in ,england2 and in that country too1 the reaction1 among metaphysical and moral writers1 when its time came1 was more decided and rapid than it was among ,locke's own countrymen4 ,it would appear that ,m4 ,laromiguire was one of the first to give expression to this feeling1 of the necessity of a modification of the sensational philosophy4 ,he began by professing himself the disciple of ,condillac1 even while he was almost unconsciously subverting the fundamental principles of that writer4 ,and thus1 as ,m4 ,cousin justly observes#bda1 his opinions had the more powerful effect from being presented1 not as thwarting and contradicting1 but as sharing and following out the spirit of his age4 ,m4 ,laromiguire's work1 entitled ,essai sur les ,facults de l',ame1 consists of lectures given to the ,faculty of ,letters of the ,academy of ,paris1 in the years #ahaa1 #ahab and #ahac4 ,in the views which these lectures present1 there is much which the author has in common with ,condillac4 ,but he is led by his investigation to assert#bdb1 that it is not true that sensation is the sole fundamental element of our thoughts and our understanding4 ,attention also is requisite3 and here we have an element of quite another kind4 ,for sensation is passive2 attention is active4 ,attention does not spring out of sensation2 the passive principle is not the reason of the active principle4 ,activity and passivity are two facts entirely different4 ,nor can this activity be defined or derived2 being1 as the author says1 a fundamental idea4 ,the distinction is manifest by its own nature2 and we may find evidence of it in the very forms of language4 ,to look is more than to see2 to hearken is more than to hear4 ,the ,french language marks this distinction with respect to other senses also4 ,on voit1 et l'on regarde2 on entend1 et l'on coute2 on sent1 et l'on flaire2 on gote1 et l'on savoure4 ,and thus the mere sensation1 or capacity of feeling1 is only the occasion on which the attention is exercised2 while the attention is the foundation of all the operations of the understanding4 ,the reader of my works will have seen how much ,i have insisted upon the activity of the mind1 as the necessary basis of all knowledge4 ,in all observation and experience1 the mind is active1 and by its activity apprehends all sensations in subordination to its own ideas2 and thus it becomes capable of collecting knowledge from phenomena1 since ideas involve general relations and connexions1 which sensations of themselves cannot involve4 ,and thus we see that1 in this respect also1 our philosophy stands at that point to which the speculations of the most reflecting men have of late constantly been verging4 #f4 ,m4 ,cousin himself1 from whom we have quoted the above account of ,laromiguire1 shares in this tendency1 and has argued very energetically and successfully against the doctrines of the ,sensational ,school4 ,he has made it his office once more to bring into notice among his countrymen1 the doctrine of ideas as the sources of knowledge2 and has revived the study of ,plato1 who may still be considered as one of the great leaders of the ideal school4 ,but the larger portion of ,m4 ,cousin's works refers to questions out of the reach of our present review1 and it would be unsuitable to dwell longer upon them in this place4 #g4 ,we turn to speculations more closely connected with our present subject4 ,m4 ,ampre1 a ,french man of science1 well entitled by his extensive knowledge1 and large and profound views1 to deal with the philosophy of the sciences1 published in #ahcd1 his ,essai sur la ,philosophie des ,sciences1 ou ,exposition analytique d'une ,classification ,naturelle de toutes les ,connaissances ,humaines4 ,in this remarkable work we see strong evidence of the progress of the reaction against the system which derives our knowledge from sensation only4 ,the author starts from a maxim1 that in classing the sciences1 we must not only regard the nature of the objects about which each science is concerned1 but also the point of view under which it considers them3 that is1 the ideas which each science involves4 ,m4 ,ampre also gives briefly his views of the intellectual constitution of man2 a subject on which he had long and sedulously employed his thoughts2 and these views are far from belonging to the ,sensational ,school4 ,human thought1 he says1 is composed of phenomena and of conceptions4 ,phenomena are external1 or sensitive2 and internal1 or active4 ,conceptions are of four kinds2 primitive1 as space and motion1 duration and cause2 objective1 as our idea of matter and substance2 onomatic1 or those which we associate with the general terms which language presents to us2 and explicative1 by which we ascend to causes after a comparative study of phenomena4 ,he teaches further1 that in deriving ideas from sensation1 the mind is not passive2 but exerts an action which1 when voluntary1 is called attention1 but when it is1 as it often is1 involuntary1 may be termed reaction4 ,i shall not dwell upon the examination of these opinions#bdc2 but ,i may remark1 that both in the recognition of conceptions as an original and essential element of the mind1 and in giving a prominent place to the active function of the mind1 in the origin of our knowledge1 this view approaches to that which ,i have presented in preceding works2 although undoubtedly with considerable differences4 #h4 ,the classification of the sciences which ,m4 ,ampre proposes1 is founded upon a consideration of the sciences themselves2 and is1 the author conceives1 in accordance with the conditions of natural classifications1 as exhibited in ,botany and other sciences4 ,it is of a more symmetrical kind1 and exhibits more steps of subordination1 than that to which ,i have been led2 it includes also practical ,art as well as theoretical ,science2 and it is extended to moral and political as well as physical ,sciences4 ,it will not be necessary for me here to examine it in detail3 but ,i may remark1 that it is throughout a dichotomous division1 each higher member being subdivided into two lower ones1 and so on4 ,in this way1 ,m4 ,ampre obtains sciences of the ,first ,order1 each of which is divided into two sciences of the ,second1 and four of the ,third ,order4 ,thus ,mechanics is divided into ,cinematics1 ,statics1 ,dynamics1 and ,molecular ,mechanics2 ,physics is divided into ,experimental ,physics1 ,chemistry1 ,stereometry1 and ,atomology2 ,geology is divided into ,physical ,geography1 ,mineralogy1 ,geonomy1 and ,theory of the ,earth4 ,without here criticizing these divisions or their principle1 ,i may observe that ,cinematics1 the doctrine of motion without reference to the force which produces it1 is a portion of knowledge which our investigation has led us also to see the necessity of erecting into a separate science2 and which we have termed ,pure ,mechanism4 ,of the divisions of ,geology1 ,physical ,geography1 especially as explained by ,m4 ,ampre1 is certainly a part of the subject1 both important and tolerably distinct from the rest4 ,geonomy contains what we have termed in the ,history1 ,descriptive ,geology2--the exhibition of the facts separate from the inquiry into their causes2 while our ,physical ,geology agrees with ,m4 ,ampre's ,theory of the ,earth4 ,mineralogy appears to be placed by him in a different place from that which it occupies in our scheme3 but in fact1 he uses the term for a different science2 he applies it to the classification not of simple minerals1 but of rocks1 which is a science auxiliary to geology1 and which has sometimes been called ,petralogy4 ,what we have termed ,mineralogy1 ,m4 ,ampre unites with ,chemistry4 ,it belongs1 he says#bdd1 to ,chemistry1 and not to ,mineralogy1 to inquire how many atoms of silicium and of oxygen compose silica2 to tell us that its primitive form is a rhombohedron of certain angles1 that it is called quartz1 c42 leaving1 on one hand1 to ,molecular ,geometry the task of explaining the different secondary forms which may result from the primitive form2 and on the other hand1 leaving to ,mineralogy the office of describing the different varieties of quartz1 and the rocks in which they occur1 according as the quartz is crystallized1 transparent1 coloured1 amorphous1 solid1 or in sand4 ,but we may remark1 that by adopting this arrangement1 we separate from ,mineralogy almost all the knowledge1 and absolutely all the general knowledge1 which books professing to treat of that science have usually contained4 ,the consideration of ,mineralogical ,classifications1 which1 as may be seen in the ,history of ,science1 is so curious and instructive1 is forced into the domain of ,chemistry1 although many of the persons who figure in it were not at all properly chemists4 ,and we lose1 in this way1 the advantage of that peculiar office which1 in our arrangement1 ,mineralogy fills2 of forming a rigorous transition from the sciences of classification to those which consider the mathematical properties of bodies2 and connecting the external characters and the internal constitution of bodies by means of a system of important general truths4 ,i conceive1 therefore1 that our disposition of this science1 and our mode of applying the name1 are far more convenient than those of ,m4 ,ampre4 #i4 ,we have seen the reaction against the pure sensational doctrines operating very powerfully in ,england and in ,france4 ,but it was in ,germany that these doctrines were most decidedly rejected2 and systems in extreme opposition to these put forth with confidence1 and received with applause4 ,of the authors who gave this impulse to opinions in that country1 ,kant was the first1 and by far the most important4 ,i have in the ,history of ,ideas 7b4 iii4 c4 #c71 endeavoured to explain how he was aroused1 by the skepticism of ,hume1 to examine wherein the fallacy lay which appeared to invalidate all reasonings from effect to cause2 and how this inquiry terminated in a conviction that the foundations of our reasonings on this and similar points were to be sought in the mind1 and not in the phenomena2--in the subject1 and not in the object4 ,the revolution in the customary mode of contemplating human knowledge which ,kant's opinions involved1 was most complete4 ,he himself1 with no small justice1 compares#bde it with the change produced by ,copernicus's theory of the solar system4 ,hitherto1 he says1 men have assumed that all our knowledge must be regulated by the objects of it2 yet all attempts to make out anything concerning objects priori by means of our conceptions1 7as for instance their geometrical properties7 must1 on this foundation1 be unavailing4 ,let us then try whether we cannot make out something more in the problems of metaphysics1 by assuming that objects must be regulated by our knowledge1 since this agrees better with that supposition1 which we are prompted to make1 that we can know something of them priori4 ,this thought is like that of ,copernicus1 who1 when he found that nothing was to be made of the phenomena of the heavens so long as everything was supposed to turn about the spectator1 tried whether the matter might not be better explained if he made the spectator turn1 and left the stars at rest4 ,we may make the same essay in metaphysics1 as to what concerns our intuitive knowledge respecting objects4 ,if our apprehension of objects must be regulated by the properties of the objects1 ,i cannot comprehend how we can possibly know anything about them priori4 ,but if the object1 as apprehended by us1 be regulated by the constitution of our faculties of apprehension1 ,i can readily conceive this possibility4 ,from this he infers that our experience must be regulated by our conceptions4 #aj4 ,this view of the nature of knowledge soon superseded entirely the doctrines of the ,sensational ,school among the metaphysicians of ,germany4 ,these philosophers did not gradually modify and reject the dogmas of ,locke and ,condillac1 as was done in ,england and ,france#bdf2 nor did they endeavour to ascertain the extent of the empire of ,ideas by a careful survey of its several provinces1 as we have been doing in this series of works4 ,the ,german metaphysicians saw at once that ,ideas and ,things1 the ,subjective and the ,objective elements of our knowledge1 were1 by ,kant's system1 brought into opposition and correlation1 as equally real and equally indispensable4 ,seeing this1 they rushed at once to the highest and most difficult problem of philosophy1--to determine what this correlation is2--to discover how ,ideas and ,things are at the same time opposite and identical2--how the world1 while it is distinct from and independent of us1 is yet1 as an object of our knowledge1 governed by the conditions of our thoughts4 ,the attempts to solve this problem1 taken in the widest sense1 including the forms which it assumes in ,morals1 ,politics1 the ,arts1 and ,religion1 as well as in the ,material ,sciences1 have1 since that time1 occupied the most profound speculators of ,germany2 and have given rise to a number of systems1 which1 rapidly succeeding each other1 have1 each in its day1 been looked upon as a complete solution of the problem4 ,to trace the characters of these various systems1 does not belong to the business of the present chapter3 my task is ended when ,i have shown1 as ,i have now done1 how the progress of thought in the philosophical world1 followed from the earliest up to the present time1 has led to that recognition of the co-existence and joint necessity of the two opposite elements of our knowledge2 and when ,i have pointed out processes adapted to the extension of our knowledge1 which a true view of its nature has suggested or may suggest4 ,the latter portion of this task occupies the ,third ,book of the ,novum ,organon ,renovatum4 ,with regard to the recent succession of ,german systems of philosophy1 ,i shall add something in a subsequent chapter3 and ,i shall also venture to trace further than ,i have yet done1 the bearing of the philosophy of science upon the theological view of the universe and the moral and religious condition of man4 ,,footnotes3 ,footnote #bce3 ,see ,mr4 ,sharpe's ,essays4 ,footnote #bcf3 ,price's ,essays1 p4 #af4 ,footnote #bcg3 ,p4 #ah4 ,footnote #bch3 ,reid1 ,essays on the ,powers of the ,human ,mind1 iii4 #ca4 ,footnote #bci3 ,stewart1 ,outlines of ,moral ,phil4 p4 #ach4 ,footnote #bdj3 ,whately1 ,polit4 ,econ4 p4 #gf4 ,footnote #bda3 ,cousin1 ,fragmens ,philosophiques1 i4 #ec4 ,footnote #bdb3 ,ibid4 i4 #fg4 ,footnote #bdc3 ,see also the vigorous critique of ,locke's ,essay1 by ,lemaistre1 ,soires de ,st4 ,petersbourg4 ,footnote #bdd3 ,ampre1 ,essai1 p4 #baj4 ,footnote #bde3 ,kritik der ,reinen ,vernunft1 ,pref4 p4 xv4 ,footnote #bdf3 ,the sensational system never acquired in ,germany the ascendancy which it obtained in ,england and ,france2 but ,i am compelled here to pass over the history of philosophy in ,germany1 except so far as it affects ourselves4 ,,chapter ,,xxi4 ,,further ,,advance ,,of ,,the ,,sensational ,,school4 ,m4 ,,auguste ,,comte4 ,i shall now take the liberty of noticing the views published by a contemporary writer2 not that it forms part of my design to offer any criticism upon the writings of all those who have treated of those subjects on which we are now employed2 but because we can more distinctly in this manner point out the contrasts and ultimate tendencies of the several systems of opinion which have come under our survey3 and since from among these systems we have endeavoured to extract and secure the portion of truth which remains in each1 and to reject the rest1 we are led to point out the errors on which our attention is thus fixed1 in recent as well as older writers4 ,m4 ,auguste ,comte published in #ahcj the first1 and in #ahce the second volume of his ,cours de ,philosophie ,positive2 of which the aim is not much different from that of the present work1 since as he states 7p4 viii47 such a title as the ,philosophy of the ,sciences would describe a part of his object1 and would be inappropriate only by excluding that portion 7not yet published7 which refers to speculations concerning social relations4 #a4 ,m4 ,comte on ,three ,states of ,science4--,by employing the term ,philosophie ,positive1 he wishes to distinguish the philosophy involved in the present state of our sciences from the previous forms of human knowledge4 ,for according to him1 each branch of knowledge passes1 in the course of man's history1 through three different states2 it is first theological1 then metaphysical1 then positive4 ,by the latter term he implies a state which includes nothing but general representations of facts2--phenomena arranged according to relations of succession and resemblance4 ,this positive philosophy rejects all inquiry after causes1 which inquiry he holds to be void of sense#bdg and inaccessible4 ,all such conceptions belong to the metaphysical state of science which deals with abstract forces1 real entities1 and the like4 ,still more completely does he reject1 as altogether antiquated and absurd1 the theological view of phenomena4 ,indeed he conceives#bdh that any one's own consciousness of what passes within himself is sufficient to convince him of the truth of the law of the three phases through which knowledge must pass4 ,does not each of us1 he says1 in contemplating his own history1 recollect that he has been successively a theologian in his infancy1 a metaphysician in his youth1 and a physicist in his ripe age8 ,this may easily be verified for all men who are up to the level of their time4 ,it is plain from such statements1 and from the whole course of his work1 that ,m4 ,comte holds1 in their most rigorous form1 the doctrines to which the speculations of ,locke and his successors led2 and which tended1 as we have seen1 to the exclusion of all ideas except those of number and resemblance4 ,as ,m4 ,comte refuses to admit into his philosophy the fundamental idea of ,cause1 he of course excludes most of the other ideas1 which are1 as we endeavoured to show1 the foundations of science2 such as the ideas of ,media by which secondary qualities are made known to us2 the ideas of ,chemical ,attraction1 of ,polar ,forces1 and the like4 ,he would reduce all science to the mere expression of laws of phenomena1 expressed in formul of space1 time1 and number2 and would condemn as unmeaning1 and as belonging to an obsolete state of science1 all endeavours to determine the causes of phenomena1 or even to refer them to any of the other ideas just mentioned4 #b4 ,m4 ,comte rejects the ,search of ,causes4--,in a previous work#bdi ,i have shown1 ,i trust decisively1 that it is the genuine office of science to inquire into the causes as well as the laws of phenomena2--that such an inquiry cannot be avoided2 and that it has been the source of almost all the science we possess4 ,i need not here repeat the arguments there urged2 but ,i may make a remark or two upon ,m4 ,comte's hypothesis1 that all science is first metaphysical and then positive2 since it is in virtue of this hypothesis that he rejects the investigation of causes1 as worthy only of the infancy of science4 ,all discussions concerning ideas1 ,m4 ,comte would condemn as metaphysical1 and would consider as mere preludes to positive philosophy4 ,now ,i venture to assert1 on the contrary1 that discussions concerning ideas1 and real discoveries1 have in every science gone hand in hand4 ,there is no science in which the pretended order of things can be pointed out4 ,there is no science in which the discoveries of the laws of phenomena1 when once begun1 have been carried on independently of discussions concerning ideas4 ,there is no science in which the expression of the laws of phenomena can at this time dispense with ideas which have acquired their place in science in virtue of metaphysical considerations4 ,there is no science in which the most active disquisitions concerning ideas did not come after1 not before1 the first discovery of laws of phenomena4 ,in ,astronomy1 the discovery of the phenomenal laws of the epicyclical motions of the heavens led to assumptions of the metaphysical principle of equable circular motions3 ,kepler's discoveries would never have been made but for his metaphysical notions4 ,these discoveries of the laws of phenomena did not lead immediately to ,newton's theory1 because a century of metaphysical discussions was requisite as a preparation4 ,newton then discovered1 not merely a law of phenomena1 but a cause2 and therefore he was the greatest of discoverers4 ,the same is the case in ,optics2 the ancients possessed some share of our knowledge of facts2 but meddled little with the metaphysical reasonings of the subject4 ,in modern times when men began to inquire into the nature of light1 they soon extended their knowledge of its laws4 ,when this series of discoveries had come to a pause1 a new series of brilliant discoveries of laws of phenomena went on1 inseparably connected with a new series of views of the nature and cause of light4 ,in like manner1 the most modern discoveries in chemistry involve indispensably the idea of polar forces4 ,the metaphysics 7in ,m4 ,comte's sense7 of each subject advances in a parallel line with the knowledge of physical laws4 ,the ,explication of ,conceptions must go on1 as we have already shown1 at the same rate as the ,colligation of ,facts4 ,m4 ,comte will say#bej that ,newton's discovery of gravitation only consists in exhibiting the astronomical phenomena of the universe as one single fact under different points of view4 ,but this fact involves the idea of force1 that is1 of cause4 ,and that this idea is not a mere modification of the ideas of time and space1 we have shown3 if it were so1 how could it lead to the axiom that attraction is mutual1 an indispensable part of the ,newtonian theory8 ,m4 ,comte says#bea that we do not know what attraction is1 since we can only define it by identical phrases3 but this is just as true of space1 or time1 or motion2 and is in fact exactly the characteristic of a fundamental idea4 ,we do not obtain such ideas from definitions1 but we possess them not the less truly because we cannot define them4 ,that ,m4 ,comte's hypothesis is historically false1 is obvious by such examples as ,i have mentioned4 ,metaphysical discussions have been essential steps in the progress of each science4 ,if we arbitrarily reject all these portions of scientific history as useless trifling1 belonging to the first rude attempts at knowledge1 we shall not only distort the progress of things1 but pervert the plainest facts4 ,of this we have an example in ,m4 ,comte's account of ,kepler's mechanical speculations4 ,we have seen1 in the ,history of ,physical ,astronomy1 that ,kepler's second law1 7that the planets describe areas about the sun proportional to the times17 was proved by him1 by means of calculations founded on the observations of ,tycho2 but that the mechanical reason of it was not assigned till a later period1 when it appeared as the first proposition of ,newton's ,principia4 ,it is plain from the writings of ,kepler1 that it was impossible for him to show how this law resulted from the forces which were in action2 since the forces which he considered were not those tending to the centre1 which really determine the property in question1 but forces exerted by the sun in the direction of the planet's motion1 without which forces ,kepler conceived that the motion could not go on4 ,in short1 the state of mechanical science in ,kepler's time was such that no demonstration of the law could be given4 ,the terms in which such a demonstration must be expressed had not at that time acquired a precise significance2 and it was in virtue of many subsequent metaphysical discussions 7as ,m4 ,comte would term them7 that these terms became capable of expressing sound mechanical reasoning4 ,kepler did indeed pretend to assign what he called a physical proof of his law1 depending upon this1 that the sun's force is less at greater distances2 a condition which does not at all influence the result4 ,thus ,kepler's reason for his law proves nothing but the confusion of thought in which he was involved on such subjects4 ,yet ,m4 ,comte assigns to ,kepler the credit of having proved this law by sound mechanical reasoning1 as well as established it as a matter of fact#beb4 ,this discovery by ,kepler1 he adds1 is the more remarkable1 inasmuch as it occurred before the science of dynamics had really been created by ,galileo4 ,we may remark that inasmuch as ,m4 ,comte perceived this incongruity in the facts as he stated them1 it is the more remarkable that he did not examine them more carefully4 #c4 ,causes in ,physics4--,the condemnation of the inquiry into causes which is conveyed in ,m4 ,comte's notion of the three stages of ,science1 he again expresses more in detail1 in stating#bec what he calls his ,fundamental theory of hypotheses4 ,this theory is1 that we may employ hypotheses in our natural philosophy1 but these hypotheses must always be such as admit of a positive verification4 ,we must have no suppositions concerning the agents by which effects are produced4 ,all such suppositions have an anti-scientific character1 and can only impede the real progress of physics4 ,there can be no use in the ethers and imaginary fluids to which some persons refer the phenomena of heat1 light1 electricity and magnetism4 ,and in agreement with this doctrine1 ,m4 ,comte in his account#bed of the ,science of ,optics1 condemns1 as utterly unphilosophical and absurd1 both the theory of emission and that of undulation4 ,to this we reply1 that theory of one kind or other is indispensable to the expression of the phenomena2 and that when the laws are expressed1 and apparently explained1 by means of a theory1 to forbid us to inquire whether it be really true or false1 is a pedantic and capricious limitation of our knowledge1 to which the intellect of man neither can nor should submit4 ,if any one holds the adoption of one or other of these theories to be indifferent1 let him express the laws of phenomena of diffraction in terms of the theory of emission#bee4 ,if any one rejects the doctrine of undulation1 let him point out some other way of connecting double refraction with polarization4 ,and surely no man of science will contend that the beautiful branch of science which refers to that connexion is not a portion of our positive knowledge4 ,m4 ,comte's contempt for the speculations of the undulationists seems to have prevented his acquainting himself with their reasonings1 and even with the laws of phenomena on which they have reasoned1 although these form by far the most striking and beautiful addition which ,science has received in modern times4 ,he adduces1 as an insuperable objection to the undulatory theory1 a difficulty which is fully removed by calculation in every work on the subject3--the existence of shadow#bef4 ,he barely mentions the subject of diffraction1 and ,young's law of interferences2--speaks of ,fresnel as having applied this principle to the phenomena of coloured rings1 on which the ingenious labours of ,newton left much to desire2 as if ,fresnel's labours on this subject had been the supplement of those of ,newton3 and after regretting that this principle of interferences has not yet been distinctly disentangled from chemical conceptions on the nature of light1 concludes his chapter4 ,he does not even mention the phenomena of dipolarization1 of circular and elliptical polarization1 or of the optical properties of crystals2 discoveries of laws of phenomena quite as remarkable as any which can be mentioned4 ,m4 ,comte's favourite example of physical research is ,thermotics1 and especially ,fourier's researches with regard to heat4 ,it is shown#beg in the ,history of ,thermotics1 that the general phenomena of radiation required the assumption of a fluid to express them2 as appears in the theory of exchanges#beh4 ,and the explanation of the principal laws of radiation1 which ,fourier gives1 depends upon the conception of material molecular radiation4 ,the flux of caloric1 of which ,fourier speaks1 cannot be conceived otherwise than as implying a material flow4 ,m4 ,comte apologizes#bei for this expression1 as too figurative1 and says that it merely indicates a fact4 ,but what is the flow of a current of fluid except a fact8 ,and is it not evident that without such expressions1 and the ideas corresponding to them1 ,fourier could neither have conveyed nor conceived his theory8 ,in concluding this discussion it must be recollected1 that though it is a most narrow and untenable rule to say that we will admit no agency of ethers and fluids into philosophy2 yet the reality of such agents is only to be held in the way1 and to the extent1 which the laws of phenomena indicate4 ,it is not only allowable1 but inevitable to assume1 as the vehicle of heat and light1 a medium possessing some of the properties of more familiar kinds of matter4 ,but the idea of such a medium1 which we possess1 and on which we cannot but reason1 can be fully developed only by an assiduous study of the cases in which it is applicable4 ,it may be1 that as science advances1 all our knowledge may converge to one general and single aspect of the universe4 ,we abandon and reject this hope1 if we refuse to admit those ideas which must be our stepping-stones in advancing to such a point3 and we no less frustrate such an expectation1 if we allow ourselves to imagine that from our present position we can stride at once to the summit4 #d4 ,causes in other ,sciences4--,but if it is1 in the sciences just mentioned1 impracticable to reduce our knowledge to laws of phenomena alone1 without referring to causes1 media1 and other agencies2 how much more plainly is it impossible to confine our thoughts to phenomena1 and to laws of succession and resemblance1 in other sciences1 as chemistry1 physiology1 and geology8 ,who shall forbid us1 or why should we be forbidden1 to inquire whether chemical and galvanic forces are identical2 whether irritability is a peculiar vital power2 whether geological causes have been uniform or paroxysmal8 ,to exclude such inquiries1 would be to secure ourselves from the poison of error by abstaining from the banquet of truth3--it would be to attempt to feed our minds with the meagre diet of space and number1 because we may find too delightful a relish in such matters as cause and end1 symmetry and affinity1 organization and development4 ,thus ,m4 ,comte's arrangement of the progress of science as successively metaphysical and positive1 is contrary to history in fact1 and contrary to sound philosophy in principle4 ,nor is there any better foundation for his statement that theological views are to be found only in the rude infantine condition of human knowledge1 and vanish as science advances4 ,even in material sciences this is not the case4 ,we have shown in the chapter on ,final ,causes1 that physiologists have been directed in their remarks by the conviction of a purpose in every part of the structure of animals2 and that this idea1 which had its rise after the first observations1 has gone on constantly gaining strength and clearness1 so that it is now the basis of a large portion of the science4 ,we have seen1 too1 in the ,book on the paltiological sciences1 that the researches of that class do by no means lead us to reject an origin of the series of events1 nor to suppose this origin to be included in the series of natural laws4 ,science has not at all shown any reason for denying either the creation or the purpose of the universe4 ,this is true of those aspects of the universe which have become the subjects of rigorous science3 but how small a portion of the whole do they form6 ,especially how minute a proportion does our knowledge bear to our ignorance1 if we admit into science1 as ,m4 ,comte advises1 only the laws of phenomena6 ,even in the best explored fields of science1 how few such laws do we know6 ,meteorology1 climate1 terrestrial magnetism1 the colours and other properties of bodies1 the conditions of musical and articulate sound1 and a thousand other facts of physics1 are not defined by any known laws4 ,in physiology we may readily convince ourselves how little we know of laws1 since we can hardly study one species without discovering some unguessed property1 or apply the microscope without seeing some new structure in the best known organs4 ,and when we go on to social and moral and political matters1 we may well doubt whether any one single rigorous rule of phenomena has ever been stated1 although on such subjects man's ideas have been busily and eagerly working ever since his origin4 ,what a wanton and baseless assumption it would be1 then1 to reject those suggestions of a ,governor of the universe which we derive from man's moral and spiritual nature1 and from the institutions of society1 because we fancy we see in the small field of our existing positive knowledge a tendency to exclude theological views6 ,because we can explain the motion of the stars by a general ,law which seems to imply no hyperphysical agency1 and can trace a few more limited laws in other properties of matter1 we are exhorted to reject convictions irresistibly suggested to us by our bodies and our souls1 by history and antiquities1 by conscience and human law4 #e4 ,m4 ,comte's practical philosophy4--,it is not merely as a speculative doctrine that ,m4 ,comte urges the necessity of our thus following the guidance of positive philosophy4 ,the fevered and revolutionary condition of human society at present arises1 according to him#bfj1 from the simultaneous employment of three kinds of philosophy radically incompatible2--theological1 metaphysical1 and positive philosophy4 ,the remedy for the evil is to reject the two former1 and to refer everything to that positive philosophy1 of which the destined triumph cannot be doubtful4 ,in like manner1 our ,european education#bfa1 still essentially theological1 metaphysical1 and literary1 must be replaced by a positive education1 suited to the spirit of our epoch4 ,with these practical consequences of ,m4 ,comte's philosophy we are not here concerned3 but the notice of them may serve to show how entirely the rejection of the theological view pervades his system2 and how closely this rejection is connected with the principles which lead him also to reject the fundamental ideas of the sciences as we have presented them4 #f4 ,m4 ,comte on ,hypotheses4--,in the detail of ,m4 ,comte's work1 ,i do not find any peculiar or novel remarks on the induction by which the sciences are formed2 except we may notice1 as such1 his permission of hypotheses to the inquirer1 already referred to4 ,there can only be1 he says#bfb1 two general modes fitted to reveal to us1 in a direct and entirely rational manner1 the true law of any phenomenon2--either the immediate analysis of this phenomenon1 or its exact and evident relation to some more extended law1 previously established2--in a word1 induction1 or deduction4 ,but both these ways would certainly be insufficient1 even with regard to the simplest phenomenon1 in the eyes of any one who fully comprehends the essential difficulties of the intimate study of nature1 if we did not often begin by anticipating the result1 and making a provisory supposition1 at first essentially conjectural1 even with respect to some of the notions which constitute the final object of inquiry4 ,hence the introduction1 which is strictly indispensable1 of hypotheses in natural philosophy4 ,we have already seen that the permissio intellectus had been noticed as a requisite step in discovery1 as long before as the time of ,bacon4 #g4 ,m4 ,comte's ,classification of ,sciences4--,i do not think it necessary to examine in detail ,m4 ,comte's views of the philosophy of the different sciences2 but it may illustrate the object of the present work1 to make a remark upon his attempt to establish a distinction between physical and chemical science4 ,this distinction he makes to consist in three points#bfc2--that ,physics considers general and ,chemistry special properties2--that ,physics considers masses and ,chemistry molecules2--that in ,physics the mode of arrangement of the molecules remains constant1 while in ,chemistry this arrangement is necessarily altered4 ,m4 ,comte however allows that these lines of distinction are vague and insecure2 for1 among many others1 magnetism1 a special property1 belongs to physics1 and breaks down his first criterion2 and molecular attractions are a constant subject of speculation in physics1 so that the second distinction cannot be insisted on4 ,to which we may add that the greater portion of chemistry does not attend at all to the arrangement of the molecules1 so that the third character is quite erroneous4 ,the real distinction of these branches of science is1 as we have seen1 the fundamental ideas which they employ4 ,physics deals with relations of space1 time1 and number1 media1 and scales of qualities1 according to intensity and other differences2 while chemistry has for its subject elements and attractions as shown in composition2 and polarity1 though in different senses1 belongs to both4 ,the failure of this attempt of ,m4 ,comte at distinguishing these provinces of science by their objects1 may be looked upon as an illustration of the impossibility of establishing a philosophy of the sciences on any other ground than the ideas which they involve4 ,we have thus traced to its extreme point1 so far as the nature of science is concerned1 one of those two antagonistic opinions1 of which the struggle began in the outset of philosophy1 and has continued during the whole of her progress2--namely1 the opinions which respectively make our sensations and our ideas the origin of our knowledge4 ,the former1 if it be consistent with itself1 must consider all knowledge of causes as impossible1 since no sensation can give us the idea of cause4 ,and when this opinion is applied to science1 it reduces it to the mere investigation of laws of phenomena1 according to relations of space1 time1 and number4 ,i purposely abstain1 as far as possible1 from the consideration of the other consequences1 not strictly belonging to the physical sciences1 which were drawn from the doctrine that all our ideas are only transformed sensations4 ,the materialism1 the atheism1 the sensualist morality1 the anarchical polity1 which some of the disciples of the ,sensational ,school erected upon the fundamental dogmas of their sect1 do not belong to our present subject1 and are matters too weighty to be treated of as mere accessories4 99 99 99 99 99 ,the above ,remarks were written before ,i had seen the third volume of ,m4 ,comte's work1 or the subsequent volumes4 ,but ,i do not find1 in anything which those volumes contain1 any ground for altering what ,i have written4 ,indeed they are occupied altogether with subjects which do not come within the field of my present speculations4 ,,footnotes3 ,footnote #bdg3 i4 p4 #ad4 ,footnote #bdh3 i4 p4 #g4 ,footnote #bdi3 ,hist4 ,ind4 ,sc4 b4 xi4 c4 vii4 ,footnote #bej3 ,p4 #ae4 ,footnote #bea3 ,p4 #af4 ,footnote #beb3 ,m4 ,comte's statement is so entirely at variance with the fact that ,i must quote it here4 7,phil4 ,pos4 vol4 i4 p4 #gje47 ,le second thorme gnral de dynamique consiste dans le clbre et important principe des aires1 dont le premire ide est due ,kepler1 qui dcouvrit et dmontra forte simplement cette proprit pour le cas du mouvement d'une molecule unique1 ou en d'autres terms1 d'un corps dont tous les points se meuvent identiquement4 ,kepler tablit1 par les considrations les plus lmentaires1 qui si la force acclratrice totale dont une molecule est anime tend constamment vers un point fix1 le rayon vecteur du mobile dcrit autour de ce point des aires gales en temps egaux1 de telle sorte que l'aire dcrite au bout d'un temps quelconque crot proportionellement ce temps4 ,il fit voir en outre que rciproquement1 si une semblable relation a t vrifie dans le mouvement d'un corps par rapport un certain point1 c'est une preuve suffisante de l'action sur le corps d'un force dirige sans cesse vers ce point4 ,there is not a trace of the above propositions in the work ,de ,stell ,martis1 which contains ,kepler's discovery of his law1 nor1 ,i am convinced1 in any other of ,kepler's works4 ,he is everywhere constant to his conceptions of the magnetic virtue residing in the sun1 by means of which the sun1 revolving on his axis1 carries the planets round with him4 ,m4 ,comte's statement so exactly expresses ,newton's propositions1 that one is led to suspect some extraordinary mistake1 by which what should have been said of the one was transferred to the other4 ,footnote #bec3 ,vol4 ii4 p4 #dcc4 ,footnote #bed3 ,vol4 ii4 #fdj4 ,footnote #bee3 ,i venture to offer this problem2--to express the laws of the phenomena of diffraction without the hypothesis of undulations2--as a challenge to any one who holds such hypothesis to be unphilosophical4 ,footnote #bef3 ii4 p4 #fda4 ,footnote #beg3 ii4 p4 #fgc4 ,footnote #beh3 ,hist4 ,ind4 ,sc4 ii4 #dhi1 b4 x4 c4 i4 ,footnote #bei3 ii4 p4 #efa4 ,footnote #bfj3 i4 #ej4 ,footnote #bfa3 i4 #da4 ,footnote #bfb3 ii4 #dcc4 ,footnote #bfc3 ,phil4 ,pos4 ii4 #cib-cih4 ,,chapter ,,xxii4 ,,mr4 ,,mill',s ,,logic#bfd4 ,the ,history of the ,inductive ,sciences was published in #ahcg1 and the ,philosophy of the ,inductive ,sciences in #ahdj4 ,in #ahdc ,mr4 ,mill published his ,system of ,logic1 in which he states that without the aid derived from the facts and ideas in my volumes1 the corresponding portion of his own would most probably not have been written1 and quotes parts of what ,i have said with commendation4 ,he also1 however1 dissents from me on several important and fundamental points1 and argues against what ,i have said thereon4 ,i conceive that it may tend to bring into a clearer light the doctrines which ,i have tried to establish1 and the truth of them1 if ,i discuss some of the differences between us1 which ,i shall proceed to do#bfe4 ,mr4 ,mill's work has had1 for a work of its abstruse character1 a circulation so extensive1 and admirers so numerous and so fervent1 that it needs no commendation of mine4 ,but if my main concern at present had not been with the points in which ,mr4 ,mill differs from me1 ,i should have had great pleasure in pointing out passages1 of which there are many1 in which ,mr4 ,mill appears to me to have been very happy in promoting or in expressing philosophical truth4 ,there is one portion of his work indeed which tends to give it an interest of a wider kind than belongs to that merely scientific truth to which ,i purposely and resolutely confined my speculations in the works to which ,i have referred4 ,mr4 ,mill has introduced into his work a direct and extensive consideration of the modes of dealing with moral and political as well as physical questions2 and ,i have no doubt that this part of his book has1 for many of his readers1 a more lively interest than any other4 ,such a comprehensive scheme seems to give to doctrines respecting science a value and a purpose which they cannot have1 so long as they are restricted to mere material sciences4 ,i still retain the opinion1 however1 upon which ,i formerly acted1 that the philosophy of science is to be extracted from the portions of science which are universally allowed to be most certainly established1 and that those are the physical sciences4 ,i am very far from saying1 or thinking1 that there is no such thing as ,moral and ,political ,science1 or that no method can be suggested for its promotion2 but ,i think that by attempting at present to include the ,moral ,sciences in the same formul with the ,physical1 we open far more controversies than we close2 and that in the moral as in the physical sciences1 the first step towards showing how truth is to be discovered1 is to study some portion of it which is assented to so as to be beyond controversy4 #a4 ,what is ,induction8--#a4 ,confining myself1 then1 to the material sciences1 ,i shall proceed to offer my remarks on ,induction with especial reference to ,mr4 ,mill's work4 ,and in order that we may1 as ,i have said1 proceed as intelligibly as possible1 let us begin by considering what we mean by ,induction1 as a mode of obtaining truth2 and let us note whether there is any difference between ,mr4 ,mill and me on this subject4 ,for the purposes of the present inquiry1 ,mr4 ,mill says 7i4 #cdgbff71 ,induction may be defined the operation of discovering and forming general propositions3 meaning1 as appears by the context1 the discovery of them from particular facts4 ,he elsewhere 7i4 #cgj7 terms it generalization from experience3 and again he speaks of it with greater precision as the inference of a more general proposition from less general ones4 #b4 ,now to these definitions and descriptions ,i assent as far as they go2 though1 as ,i shall have to remark1 they appear to me to leave unnoticed a feature which is very important1 and which occurs in all cases of ,induction1 so far as we are concerned with it4 ,science1 then1 consists of general propositions1 inferred from particular facts1 or from less general propositions1 by ,induction2 and it is our object to discern the nature and laws of ,induction in this sense4 ,that the propositions are general1 or are more general than the facts from which they are inferred1 is an indispensable part of the notion of ,induction1 and is essential to any discussion of the process1 as the mode of arriving at ,science1 that is1 at a body of general truths4 #c4 ,i am obliged therefore to dissent from ,mr4 ,mill when he includes1 in his notion of ,induction1 the process by which we arrive at individual facts from other facts of the same order of particularity4 ,such inference is1 at any rate1 not ,induction alone2 if it be ,induction at all1 it is ,induction applied to an example4 ,for instance1 it is a general law1 obtained by ,induction from particular facts1 that a body falling vertically downwards from rest1 describes spaces proportional to the squares of the times4 ,but that a particular body will fall through #af feet in one second and #fd feet in two seconds1 is not an induction simply1 it is a result obtained by applying the inductive law to a particular case4 ,but further1 such a process is often not induction at all4 ,that a ball striking another ball directly will communicate to it as much momentum as the striking ball itself loses1 is a law established by induction3 but if1 from habit or practical skill1 ,i make one billiard-ball strike another1 so as to produce the velocity which ,i wish1 without knowing or thinking of the general law1 the term ,induction cannot then be rightly applied4 ,if ,i know the law and act upon it1 ,i have in my mind both the general induction and its particular application4 ,but if ,i act by the ordinary billiard-player's skill1 without thinking of momentum or law1 there is no ,induction in the case4 #d4 ,this distinction becomes of importance1 in reference to ,mr4 ,mill's doctrine1 because he has extended his use of the term ,induction1 not only to the cases in which the general induction is consciously applied to a particular instance2 but to the cases in which the particular instance is dealt with by means of experience1 in that rude sense in which experience can be asserted of brutes2 and in which1 of course1 we can in no way imagine that the law is possessed or understood1 as a general proposition4 ,he has thus1 as ,i conceive1 overlooked the broad and essential difference between speculative knowledge and practical action2 and has introduced cases which are quite foreign to the idea of science1 alongside with cases from which we may hope to obtain some views of the nature of science and the processes by which it must be formed4 #e4 ,thus 7ii4 #bcb7 he says1 ,this inference of one particular fact from another is a case of induction4 ,it is of this sort of induction that brutes are capable4 ,and to the same purpose he had previously said 7i4 #bea71 ,he the burnt child who shuns the fire is not generalizing3 he is inferring a particular from particulars4 ,in the same way also1 brutes reason 444 not only the burnt child1 but the burnt dog1 dreads the fire4 #f4 ,this confusion1 7for such it seems to me17 of knowledge with practical tendencies1 is expressed more in detail in other places4 ,thus he says 7i4 #aah71 ,i cannot dig the ground unless ,i have an idea of the ground and of a spade1 and of all the other things ,i am operating upon4 #g4 ,this appears to me to be a use of words which can only tend to confuse our idea of knowledge by obliterating all that is distinctive in human knowledge4 ,it seems to me quite false to say that ,i cannot dig the ground1 unless ,i have an idea of the ground and of my spade4 ,are we to say that we cannot walk the ground1 unless we have an idea of the ground1 and of our feet1 and of our shoes1 and of the muscles of our legs8 ,are we to say that a mole cannot dig the ground1 unless he has an idea of the ground and of the snout and paws with which he digs it8 ,are we to say that a pholas cannot perforate a rock1 unless he have an idea of the rock1 and of the acid with which he corrodes it8 #h4 ,this appears to me1 as ,i have said1 to be a line of speculation which can lead to nothing but confusion4 ,the knowledge concerning which ,i wish to inquire is human knowledge4 ,and in order that ,i may have any chance of success in the inquiry1 ,i find it necessary to single out that kind of knowledge which is especially and distinctively human4 ,hence1 ,i pass by1 in this part of my investigation1 all the knowledge1 if it is to be so called1 which man has in no other way than brutes have it2--all that merely shows itself in action4 ,for though action may be modified by habit1 and habit by experience1 in animals as well as in men1 such experience1 so long as it retains that merely practical form1 is no part of the materials of science4 ,knowledge in a general form1 is alone knowledge for that purpose2 and to that1 therefore1 ,i must confine my attention2 at least till ,i have made some progress in ascertaining its nature and laws1 and am thus prepared to compare such knowledge1--human knowledge properly so called1--with mere animal tendencies to action2 or even with practical skill which does not include1 as for the most part practical skill does not include1 speculative knowledge4 #i4 ,and thus1 ,i accept ,mr4 ,mill's definition of ,induction only in its first and largest form2 and reject1 as useless and mischievous for our purposes1 his extension of the term to the practical influence which experience of one fact exercises upon a creature dealing with similar facts4 ,such influence cannot be resolved into ideas and induction1 without1 as ,i conceive1 making all our subsequent investigation vague and heterogeneous1 indefinite and inconclusive4 ,if we must speak of animals as learning from experience1 we may at least abstain from applying to them terms which imply that they learn1 in the same way in which men learn astronomy from the stars1 and chemistry from the effects of mixture and heat4 ,and the same may be said of the language which is to be used concerning what men learn1 when their learning merely shows itself in action1 and does not exist as a general thought4 ,induction must not be applied to such cases4 ,induction must be confined to cases where we have in our minds general propositions1 in order that the sciences1 which are our most instructive examples of the process we have to consider1 may be1 in any definite and proper sense1 ,inductive ,sciences4 #aj4 ,perhaps some persons may be inclined to say that this difference of opinion1 as to the extent of meaning which is to be given to the term ,induction1 is a question merely of words2 a matter of definition only4 ,this is a mode in which men in our time often seem inclined to dispose of philosophical questions2 thus evading the task of forming an opinion upon such questions1 while they retain the air of looking at the subject from a more comprehensive point of view4 ,but as ,i have elsewhere said1 such questions of definition are never questions of definition merely4 ,a proposition is always implied along with the definition2 and the truth of the proposition depends upon the settlement of the definition4 ,this is the case in the present instance4 ,we are speaking of ,induction1 and we mean that kind of ,induction by which the sciences now existing among men have been constructed4 ,on this account it is1 that we cannot include1 in the meaning of the term1 mere practical tendencies or practical habits2 for science is not constructed of these4 ,no accumulation of these would make up any of the acknowledged sciences4 ,the elements of such sciences are something of a kind different from practical habits4 ,the elements of such sciences are principles which we know2 truths which can be contemplated as being true4 ,practical habits1 practical skill1 instincts and the like1 appear in action1 and in action only4 ,such endowments or acquirements show themselves when the occasion for action arrives1 and then1 show themselves in the act2 without being put1 or being capable of being put1 in the form of truths contemplated by the intellect4 ,but the elements and materials of ,science are necessary truths contemplated by the intellect4 ,it is by consisting of such elements and such materials1 that ,science is ,science4 ,hence a use of the term ,induction which requires us to obliterate this distinction1 must make it impossible for us to arrive at any consistent and intelligible view of the nature of ,science1 and of the mental process by which ,sciences come into being4 ,we must1 for the purpose which ,mr4 ,mill and ,i have in common1 retain his larger and more philosophical definition of ,induction1--that it is the inference of a more general proposition from less general ones4 #aa4 ,perhaps1 again1 some persons may say1 that practical skill and practical experience lead to science1 and may therefore be included in the term ,induction1 which describes the formation of science4 ,but to this we reply1 that these things lead to science as occasions only1 and do not form part of science2 and that science begins then only when we look at the facts in a general point of view4 ,this distinction is essential to the philosophy of science4 ,the rope-dancer may1 by his performances1 suggest1 to himself or to others1 properties of the center of gravity2 but this is so1 because man has a tendency to speculate and to think of general truths1 as well as a tendency to dance on a rope on special occasions1 and to acquire skill in such dancing by practice4 ,the rope-dancer does not dance by ,induction1 any more than the dancing dog does4 ,to apply the terms ,science and ,induction to such cases1 carries us into the regions of metaphor2 as when we call birds of passage wise meteorologists1 or the bee a natural chemist1 who turns the flower-dust into honey4 ,this is very well in poetry3 but for our purposes we must avoid recognizing these cases as really belonging to the sciences of meteorology and chemistry1--as really cases of ,induction4 ,induction for us is general propositions1 contemplated as such1 derived from particulars4 ,science may result from experience and observation by ,induction2 but ,induction is not therefore the same thing as experience and observation4 ,induction is experience or observation consciously looked at in a general form4 ,this consciousness and generality are necessary parts of that knowledge which is science4 ,and accordingly1 on the other hand1 science cannot result from mere ,instinct1 as distinguished from ,reason2 because ,instinct by its nature is not conscious and general1 but operates blindly and unconsciously in particular cases1 the actor not seeing or thinking of the rule which he obeys4 #ab4 ,a little further on ,i shall endeavour to show that not only a general thought1 but a general word or phrase is a requisite element in ,induction4 ,this doctrine1 of course1 still more decidedly excludes the case of animals1 and of mere practical knowledge in man4 ,a burnt child dreads the fire2 but reason must be unfolded1 before the child learns to understand the words fire will hurt you4 ,the burnt dog never thus learns to understand words4 ,and this difference points to an entirely different state of thought in the two cases3 or rather1 to a difference between a state of rational thought on the one hand1 and of mere practical instinct on the other4 #ac4 ,besides this difference of speculative thought and practical instinct which thus are1 as appears to me1 confounded in ,mr4 ,mill's philosophy1 in such a way as tends to destroy all coherent views of human knowledge1 there is another set of cases to which ,mr4 ,mill applies the term ,induction1 and to which it appears to me to be altogether inapplicable4 ,he employs it to describe the mode in which superstitious men1 in ignorant ages1 were led to the opinion that striking natural events presaged or accompanied calamities4 ,thus he says 7i4 #chi71 ,the opinion so long prevalent that a comet or any other unusual appearance in the heavenly regions was the precursor of calamities to mankind1 or at least to those who witnessed it2 the belief in the oracles of ,delphi and ,dodona2 the reliance on astrology1 or on the weather-prophecies in almanacs2 were doubtless inductions supposed to be grounded on experience2 and he speaks of these insufficient inductions being extinguished by the stronger inductions subsequently obtained by scientific inquiry4 ,and in like manner1 he says in another place 7i4 #cfg71 ,let us now compare different predictions3 the first1 that eclipses will occur whenever one planet or satellite is so situated as to cast its shadow upon another3 the second1 that they will occur whenever some great calamity is impending over mankind4 #ad4 ,now ,i cannot see how anything but confusion can arise from applying the term ,induction to superstitious fancies like those here mentioned4 ,they are not imperfect truths1 but entire falsehoods4 ,of that1 ,mr4 ,mill and ,i are agreed3 how then can they exemplify the progress towards truth8 ,they were not collected from the facts by seeking a law of their occurrence2 but were suggested by an imagination of the anger of superior powers shown by such deviations from the ordinary course of nature4 ,if we are to speak of inductions to any purpose1 they must be such inductions as represent the facts1 in some degree at least4 ,it is not meant1 ,i presume1 that these opinions are in any degree true3 to what purpose then are they adduced8 ,if ,i were to hold that my dreams predict or conform to the motions of the stars or of the clouds1 would this be an induction8 ,it would be so1 as much one as those here so denominated3 yet what but confusion could arise from classing it among scientific truths8 ,mr4 ,mill himself has explained 7ii4 #chi7 the way in which such delusions as the prophecies of almanac-makers1 and the like1 obtain credence2 namely1 by the greater effect which the positive instances produce on ordinary minds in comparison with the negative1 when the rule has once taken possession of their thoughts4 ,and this being1 as he says1 the recognized explanation of such cases1 why should we not leave them to their due place1 and not confound and perplex the whole of our investigation by elevating them to the rank of inductions8 ,the very condemnation of such opinions is that they are not at all inductive4 ,when we have made any progress in our investigation of the nature of science1 to attempt to drive us back to the wearisome discussion of such elementary points as these1 is to make progress hopeless4 ,,ii4 ,induction or ,description8--#ae4 ,in the cases hitherto noticed1 ,mr4 ,mill extends the term ,induction1 as ,i think1 too widely1 and applies it to cases to which it is not rightly applicable4 ,i have now to notice a case of an opposite kind1 in which he does not apply it where ,i do1 and condemns me for using it in such a case4 ,i had spoken of ,kepler's discovery of the ,law1 that the planets move round the sun in ellipses1 as an example of ,induction4 ,the separate facts of any planet 7,mars1 for instance17 being in certain places at certain times1 are all included in the general proposition which ,kepler discovered1 that ,mars describes an ellipse of a certain form and position4 ,this appears to me a very simple but a very distinct example of the operation of discovering general propositions2 general1 that is1 with reference to particular facts2 which operation ,mr4 ,mill1 as well as myself1 says is ,induction4 ,but ,mr4 ,mill denies this operation in this case to be ,induction at all 7i4 #ceg74 ,i should not have been prepared for this denial by the previous parts of ,mr4 ,mill's book1 for he had said just before 7i4 #cej71 such facts as the magnitudes of the bodies of the solar system1 their distances from each other1 the figure of the earth and its rotation 444 are proved indirectly1 by the aid of inductions founded on other facts which we can more easily reach4 ,if the figure of the earth and its rotation are proved by ,induction1 it seems very strange1 and is to me quite incomprehensible1 how the figure of the earth's orbit and its revolution 7and of course1 of the figure of ,mars's orbit and his revolution in like manner17 are not also proved by ,induction4 ,no1 says ,mr4 ,mill1 ,kepler1 in putting together a number of places of the planet into one figure1 only performed an act of description4 ,this descriptive operation1 he adds 7i4 #cei71 ,mr4 ,whewell1 by an aptly chosen expression1 has termed ,colligation of ,facts4 ,he goes on to commend my observations concerning this process1 but says that1 according to the old and received meaning of the term1 it is not ,induction at all4 #af4 ,now ,i have already shown that ,mr4 ,mill himself1 a few pages earlier1 had applied the term ,induction to cases undistinguishable from this in any essential circumstance4 ,and even in this case1 he allows that ,kepler did really perform an act of ,induction 7i4 #ceh71 namely1 in concluding that1 because the observed places of ,mars were correctly represented by points in an imaginary ellipse1 therefore ,mars would continue to revolve in that same ellipse2 and even in concluding that the position of the planet during the time which had intervened between the two observations must have coincided with the intermediate points of the curve4 ,of course1 in ,kepler's ,induction1 of which ,i speak1 ,i include all this2 all this is included in speaking of the orbit of ,mars3 a continuous line1 a periodical motion1 are implied in the term orbit4 ,i am unable to see what would remain of ,kepler's discovery1 if we take from it these conditions4 ,it would not only not be an induction1 but it would not be a description1 for it would not recognize that ,mars moved in an orbit4 ,are particular positions to be conceived as points in a curve1 without thinking of the intermediate positions as belonging to the same curve8 ,if so1 there is no law at all1 and the facts are not bound together by any intelligible tie4 ,in another place 7ii4 #bji7 ,mr4 ,mill returns to his distinction of ,description and ,induction2 but without throwing any additional light upon it1 so far as ,i can see4 #ag4 ,the only meaning which ,i can discover in this attempted distinction of ,description and ,induction is1 that when particular facts are bound together by their relation in space1 ,mr4 ,mill calls the discovery of the connexion ,description1 but when they are connected by other general relations1 as time1 cause and the like1 ,mr4 ,mill terms the discovery of the connexion ,induction4 ,and this way of making a distinction1 would fall in with the doctrine of other parts of ,mr4 ,mill's book1 in which he ascribes very peculiar attributes to space and its relations1 in comparison with other ,ideas1 7as ,i should call them74 ,but ,i cannot see any ground for this distinction1 of connexion according to space and other connexions of facts4 ,to stand upon such a distinction1 appears to me to be the way to miss the general laws of the formation of science4 ,for example3 ,the ancients discovered that the planets revolved in recurring periods1 and thus connected the observations of their motions according to the ,idea of ,time4 ,kepler discovered that they revolved in ellipses1 and thus connected the observations according to the ,idea of ,space4 ,newton discovered that they revolved in virtue of the ,sun's attraction1 and thus connected the motions according to the ,idea of ,force4 ,the first and third of these discoveries are recognized on all hands as processes of ,induction4 ,why is the second to be called by a different name8 or what but confusion and perplexity can arise from refusing to class it with the other two8 ,it is1 you say1 ,description4 ,but such ,description is a kind of ,induction1 and must be spoken of as ,induction1 if we are to speak of ,induction as the process by which ,science is formed3 for the three steps are all1 the second in the same sense as the first and third1 in co-ordination with them1 steps in the formation of astronomical science4 #ah4 ,but1 says ,mr4 ,mill 7i4 #cfc71 it is a fact surely that the planet does describe an ellipse1 and a fact which we could see if we had adequate visual organs and a suitable position4 ,to this ,i should reply3 ,let it be so2 and it is a fact1 surely1 that the planet does move periodically3 it is a fact1 surely1 that the planet is attracted by the sun4 ,still1 therefore1 the asserted distinction fails to find a ground4 ,perhaps ,mr4 ,mill would remind us that the elliptical form of the orbit is a fact which we could see if we had adequate visual organs and a suitable position3 but that force is a thing which we cannot see4 ,but this distinction also will not bear handling4 ,can we not see a tree blown down by a storm1 or a rock blown up by gunpowder8 ,do we not here see force3--see it1 that is1 by its effects1 the only way in which we need to see it in the case of a planet1 for the purposes of our argument8 ,are not such operations of force1 ,facts which may be the objects of sense8 and is not the operation of the sun's ,force a ,fact of the same kind1 just as much as the elliptical form of orbit which results from the action8 ,if the latter be surely a ,fact1 the former is a ,fact no less surely4 #ai4 ,in truth1 as ,i have repeatedly had occasion to remark1 all attempts to frame an argument by the exclusive or emphatic appropriation of the term ,fact to particular cases1 are necessarily illusory and inconclusive4 ,there is no definite and stable distinction between ,facts and ,theories2 ,facts and ,laws2 ,facts and ,inductions4 ,inductions1 ,laws1 ,theories1 which are true1 are ,facts4 ,facts involve ,inductions4 ,it is a fact that the moon is attracted by the earth1 just as much as it is a ,fact that an apple falls from a tree4 ,that the former fact is collected by a more distinct and conscious ,induction1 does not make it the less a ,fact4 ,that the orbit of ,mars is a ,fact--a true ,description of the path--does not make it the less a case of ,induction4 #bj4 ,there is another argument which ,mr4 ,mill employs in order to show that there is a difference between mere colligation which is description1 and induction in the more proper sense of the term4 ,he notices with commendation a remark which ,i had made 7i4 #cfd71 that at different stages of the progress of science the facts had been successfully connected by means of very different conceptions1 while yet the later conceptions have not contradicted1 but included1 so far as they were true1 the earlier3 thus the ancient ,greek representation of the motions of the planets by means of epicycles and eccentrics1 was to a certain degree of accuracy true1 and is not negatived1 though superseded1 by the modern representation of the planets as describing ellipses round the sun4 ,and he then reasons that this1 which is thus true of ,descriptions1 cannot be true of ,inductions4 ,he says 7i4 #cfg71 ,different descriptions therefore may be all true3 but surely not different explanations4 ,he then notices the various explanations of the motions of the planets--the ancient doctrine that they are moved by an inherent virtue2 the ,cartesian doctrine that they are moved by impulse and by vortices2 the ,newtonian doctrine that they are governed by a central force2 and he adds1 ,can it be said of these1 as was said of the different descriptions1 that they are all true as far as they go8 ,is it not true that one only can be true in any degree1 and that the other two must be altogether false8 #ba4 ,and to this questioning1 the history of science compels me to reply very distinctly and positively1 in the way which ,mr4 ,mill appears to think extravagant and absurd4 ,i am obliged to say1 ,undoubtedly1 all these explanations may be true and consistent with each other1 and would be so if each had been followed out so as to show in what manner it could be made consistent with the facts4 ,and this was1 in reality1 in a great measure done#bfg4 ,the doctrine that the heavenly bodies were moved by vortices was successively modified1 so that it came to coincide in its results with the doctrine of an inverse-quadratic centripetal force1 as ,i have remarked in the ,history#bfh4 ,when this point was reached1 the vortex was merely a machinery1 well or ill devised1 for producing such a centripetal force1 and therefore did not contradict the doctrine of a centripetal force4 ,newton himself does not appear to have been averse to explaining gravity by impulse4 ,so little is it true that if the one theory be true the other must be false4 ,the attempt to explain gravity by the impulse of streams of particles flowing through the universe in all directions1 which ,i have mentioned in the ,philosophy#bfi so far from being inconsistent with the ,newtonian theory1 that it is founded entirely upon it4 ,and even with regard to the doctrine1 that the heavenly bodies move by an inherent virtue2 if this doctrine had been maintained in any such way that it was brought to agree with the facts1 the inherent virtue must have had its laws determined2 and then1 it would have been found that the virtue had a reference to the central body2 and so1 the inherent virtue must have coincided in its effect with the ,newtonian force2 and then1 the two explanations would agree1 except so far as the word inherent was concerned4 ,and if such a part of an earlier theory as this word inherent indicates1 is found to be untenable1 it is of course rejected in the transition to later and more exact theories1 in ,inductions of this kind1 as well as in what ,mr4 ,mill calls ,descriptions4 ,there is therefore still no validity discoverable in the distinction which ,mr4 ,mill attempts to draw between descriptions like ,kepler's law of elliptical orbits1 and other examples of induction4 #bb4 ,when ,mr4 ,mill goes on to compare what he calls different predictions--the first1 the true explanation of eclipses by the shadows which the planets and satellites cast upon one another1 and the other1 the belief that they will occur whenever some great calamity is impending over mankind1 ,i must reply1 as ,i have stated already1 7,art4 #ag71 that to class such superstitions as the last with cases of ,induction1 appears to me to confound all use of words1 and to prevent1 as far as it goes1 all profitable exercise of thought4 ,what possible advantage can result from comparing 7as if they were alike7 the relation of two descriptions of a phenomenon1 each to a certain extent true1 and therefore both consistent1 with the relation of a scientific truth to a false and baseless superstition8 #bc4 ,but ,i may make another remark on this example1 so strangely introduced4 ,if1 under the influence of fear and superstition1 men may make such mistakes with regard to laws of nature1 as to imagine that eclipses portend calamities1 are they quite secure from mistakes in description8 ,do not the very persons who tell us how eclipses predict disasters1 also describe to us fiery swords seen in the air1 and armies fighting in the sky8 ,so that even in this extreme case1 at the very limit of the rational exercise of human powers1 there is nothing to distinguish ,description from ,induction4 ,i shall now leave the reader to judge whether this feature in the history of science1--that several views which appear at first quite different are yet all true1--which ,mr4 ,mill calls a curious and interesting remark of mine1 and which he allows to be strikingly true of the ,inductions which he calls ,descriptions1 7i4 #cfd7 is1 as he says1 unequivocally false of other ,inductions4 ,and ,i shall confide in having general assent with me1 when ,i continue to speak of ,kepler's ,induction of the elliptical orbits4 ,i now proceed to another remark4 ,,iii4 ,in ,discovery a new ,conception is introduced4-- #bd4 ,there is a difference between ,mr4 ,mill and me in our view of the essential elements of this ,induction of ,kepler1 which affects all other cases of ,induction1 and which is1 ,i think1 the most extensive and important of the differences between us4 ,i must therefore venture to dwell upon it a little in detail4 ,i conceive that ,kepler1 in discovering the law of ,mars's motion1 and in asserting that the planet moved in an ellipse1 did this2--he bound together particular observations of separate places of ,mars by the notion1 or1 as ,i have called it1 the conception1 of an ellipse1 which was supplied by his own mind4 ,other persons1 and he too1 before he made this discovery1 had present to their minds the facts of such separate successive positions of the planet2 but could not bind them together rightly1 because they did not apply to them this conception of an ellipse4 ,to supply this conception1 required a special preparation1 and a special activity in the mind of the discoverer4 ,he1 and others before him1 tried other ways of connecting the special facts1 none of which fully succeeded4 ,to discover such a connexion1 the mind must be conversant with certain relations of space1 and with certain kinds of figures4 ,to discover the right figure was a matter requiring research1 invention1 resource4 ,to hit upon the right conception is a difficult step2 and when this step is once made1 the facts assume a different aspect from what they had before3 that done1 they are seen in a new point of view2 and the catching this point of view1 is a special mental operation1 requiring special endowments and habits of thought4 ,before this1 the facts are seen as detached1 separate1 lawless2 afterwards1 they are seen as connected1 simple1 regular2 as parts of one general fact1 and thereby possessing innumerable new relations before unseen4 ,kepler1 then1 ,i say1 bound together the facts by superinducing upon them the conception of an ellipse2 and this was an essential element in his ,induction4 #be4 ,and there is the same essential element in all ,inductive discoveries4 ,in all cases1 facts1 before detached and lawless1 are bound together by a new thought4 ,they are reduced to law1 by being seen in a new point of view4 ,to catch this new point of view1 is an act of the mind1 springing from its previous preparation and habits4 ,the facts1 in other discoveries1 are brought together according to other relations1 or1 as ,i have called them1 ,ideas2--the ,ideas of ,time1 of ,force1 of ,number1 of ,resemblance1 of ,elementary ,composition1 of ,polarity1 and the like4 ,but in all cases1 the mind performs the operation by an apprehension of some such relations2 by singling out the one true relation2 by combining the apprehension of the true relation with the facts2 by applying to them the ,conception of such a relation4 #bf4 ,in previous writings1 ,i have not only stated this view generally1 but ,i have followed it into detail1 exemplifying it in the greater part of the ,history of the principal ,inductive ,sciences in succession4 ,i have pointed out what are the ,conceptions which have been introduced in every prominent discovery in those sciences2 and have noted to which of the above ,ideas1 or of the like ,ideas1 each belongs4 ,the performance of this task is the office of the greater part of my ,philosophy of the ,inductive ,sciences4 ,for that work is1 in reality1 no less historical than the ,history which preceded it4 ,the ,history of the ,inductive ,sciences is the history of the discoveries1 mainly so far as concerns the ,facts which were brought together to form sciences4 ,the ,philosophy is1 in the first ten ,books1 the history of the ,ideas and ,conceptions1 by means of which the facts were connected1 so as to give rise to scientific truths4 ,it would be easy for me to give a long list of the ,ideas and ,conceptions thus brought into view1 but ,i may refer any reader who wishes to see such a list1 to the ,tables of ,contents of the ,history1 and of the first ten ,books of the ,philosophy4 #bg4 ,that these ,ideas and ,conceptions are really distinct elements of the scientific truths thus obtained1 ,i conceive to be proved beyond doubt1 not only by considering that the discoveries never were made1 nor could be made1 till the right ,conception was obtained1 and by seeing how difficult it often was to obtain this element2 but also1 by seeing that the ,idea and the ,conception itself1 as distinct from the ,facts1 was1 in almost every science1 the subject of long and obstinate controversies2--controversies which turned upon the possible relations of ,ideas1 much more than upon the actual relations of ,facts4 ,the first ten ,books of the ,philosophy to which ,i have referred1 contain the history of a great number of these controversies4 ,these controversies make up a large portion of the history of each science2 a portion quite as important as the study of the facts2 and a portion1 at every stage of the science1 quite as essential to the progress of truth4 ,men1 in seeking and obtaining scientific knowledge1 have always shown that they found the formation of right conceptions in their own minds to be an essential part of the process4 #bh4 ,moreover1 the presence of a ,conception of the mind as a special element of the inductive process1 and as the tie by which the particular facts are bound together1 is further indicated1 by there being some special new term or phrase introduced in every induction2 or at least some term or phrase thenceforth steadily applied to the facts1 which had not been applied to them before2 as when ,kepler asserted that ,mars moved round the sun in an elliptical orbit1 or when ,newton asserted that the planets gravitate towards the sun2 these new terms1 elliptical orbit1 and gravitate1 mark the new conceptions on which the inductions depend4 ,i have in the ,philosophy#bgj further illustrated this application of technical terms1 that is1 fixed and settled terms1 in every inductive discovery2 and have spoken of their use in enabling men to proceed from each such discovery to other discoveries more general4 ,but ,i notice these terms here1 for the purpose of showing the existence of a conception in the discoverer's mind1 corresponding to the term thus introduced2 which conception1 the term is intended to convey to the minds of those to whom the discovery is communicated4 #bi4 ,but this element of discovery1--right conceptions supplied by the mind in order to bind the facts together1--,mr4 ,mill denies to be an element at all4 ,he says1 of ,kepler's discovery of the elliptical orbit 7i4 #cfc71 ,it superadded nothing to the particular facts which it served to bind together2 yet he adds1 except indeed the knowledge that a resemblance existed between the planetary orbit and other ellipses2 that is1 except the knowledge that it was an ellipse2--precisely the circumstance in which the discovery consisted4 ,kepler1 he says1 asserted as a fact that the planet moved in an ellipse4 ,but this fact1 which ,kepler did not add to1 but found in the motion of the planet 444 was the very fact1 the separate parts of which had been separately observed2 it was the sum of the different observations4 #cj4 ,that the fact of the elliptical motion was not merely the sum of the different observations1 is plain from this1 that other persons1 and ,kepler himself before his discovery1 did not find it by adding together the observations4 ,the fact of the elliptical orbit was not the sum of the observations merely2 it was the sum of the observations1 seen under a new point of view1 which point of view ,kepler's mind supplied4 ,kepler found it in the facts1 because it was there1 no doubt1 for one reason2 but also1 for another1 because he had1 in his mind1 those relations of thought which enabled him to find it4 ,we may illustrate this by a familiar analogy4 ,we too find the law in ,kepler's book2 but if we did not understand ,latin1 we should not find it there4 ,we must learn ,latin in order to find the law in the book4 ,in like manner1 a discoverer must know the language of science1 as well as look at the book of nature1 in order to find scientific truth4 ,all the discussions and controversies respecting ,ideas and ,conceptions of which ,i have spoken1 may be looked upon as discussions and controversies respecting the grammar of the language in which nature speaks to the scientific mind4 ,man is the ,interpreter of ,nature2 not the ,spectator merely1 but the ,interpreter4 ,the study of the language1 as well as the mere sight of the characters1 is requisite in order that we may read the inscriptions which are written on the face of the world4 ,and this study of the language of nature1 that is1 of the necessary coherencies and derivations of the relations of phenomena1 is to be pursued by examining ,ideas1 as well as mere phenomena2--by tracing the formation of ,conceptions1 as well as the accumulation of ,facts4 ,and this is what ,i have tried to do in the books already referred to4 #ca4 ,mr4 ,mill has not noticed1 in any considerable degree1 what ,i have said of the formation of the ,conceptions which enter into the various sciences2 but he has1 in general terms1 denied that the ,conception is anything different from the facts themselves4 ,if1 he says 7i4 #cja71 the facts are rightly classed under the conceptions1 it is because there is in the facts themselves1 something of which the conception is a copy4 ,but it is a copy which cannot be made by a person without peculiar endowments2 just as a person cannot copy an ill-written inscription1 so as to make it convey sense1 unless he understand the language4 ,conceptions1 ,mr4 ,mill says 7ii4 #bag71 do not develope themselves from within1 but are impressed from without4 ,but what comes from without is not enough3 they must have both origins1 or they cannot make knowledge4 ,the conception1 he says again 7ii4 #bba71 is not furnished by the mind till it has been furnished to the mind4 ,but it is furnished to the mind by its own activity1 operating according to its own laws4 ,no doubt1 the conception may be formed1 and in cases of discovery1 must be formed1 by the suggestion and excitement which the facts themselves produce2 and must be so moulded as to agree with the facts4 ,but this does not make it superfluous to examine1 out of what materials such conceptions are formed1 and how they are capable of being moulded so as to express laws of nature2 especially1 when we see how large a share this part of discovery--the examination how our ideas can be modified so as to agree with nature1--holds1 in the history of science4 #cb4 ,i have already 7,art4 #bh7 given1 as evidence that the conception enters as an element in every induction1 the constant introduction in such cases1 of a new fixed term or phrase4 ,mr4 ,mill 7ii4 #bhb7 notices this introduction of a new phrase in such cases as important1 though he does not appear willing to allow that it is necessary4 ,yet the necessity of the conception at least1 appears to result from the considerations which he puts forward4 ,what darkness1 he says1 would have been spread over geometrical demonstration1 if wherever the word circle is used1 the definition of a circle was inserted instead of it4 ,if we want to make a particular combination of ideas permanent in the mind1 there is nothing which clenches it like a name specially devoted to express it4 ,in my view1 the new conception is the nail which connects the previous notions1 and the name1 as ,mr4 ,mill says1 clenches the junction4 #cc4 ,i have above 7,art4 #cj7 referred to the difficulty of getting hold of the right conception1 as a proof that induction is not a mere juxtaposition of facts4 ,mr4 ,mill does not dispute that it is often difficult to hit upon the right conception4 ,he says 7i4 #cfj71 that a conception of the mind is introduced1 is indeed most certain1 and ,mr4 ,whewell has rightly stated elsewhere1 that to hit upon the right conception is often a far more difficult1 and more meritorious achievement1 than to prove its applicability when obtained4 ,but1 he adds1 a conception implies and corresponds to something conceived2 and although the conception itself is not in the facts1 but in our mind1 it must be a conception of something which really is in the facts4 ,but to this ,i reply1 that its being really in the facts1 does not help us at all towards knowledge1 if we cannot see it there4 ,as the poet says1 ,it is the mind that sees3 the outward eyes ,present the object1 but the mind descries4 ,and this is true of the sight which produces knowledge1 as well as of the sight which produces pleasure and pain1 which is referred to in the ,tale4 #cd4 ,mr4 ,mill puts his view1 as opposed to mine1 in various ways1 but1 as will easily be understood1 the answers which ,i have to offer are in all cases nearly to the same effect4 ,thus1 he says 7ii4 #baf71 the tardy development of several of the physical sciences1 for example1 of ,optics1 ,electricity1 ,magnetism1 and the higher generalizations of ,chemistry1 ,mr4 ,whewell ascribes to the fact that mankind had not yet possessed themselves of the idea of ,polarity1 that is1 of opposite properties in opposite directions4 ,but what was there to suggest such an idea1 until by a separate examination of several of these different branches of knowledge it was shown that the facts of each of them did present1 in some instances at least1 the curious phenomena of opposite properties in opposite directions8 ,but on this ,i observe1 that these facts did not1 nor do yet1 present this conception to ordinary minds4 ,the opposition of properties1 and even the opposition of directions1 which are thus apprehended by profound cultivators of science1 are of an abstruse and recondite kind2 and to conceive any one kind of polarity in its proper generality1 is a process which few persons hitherto appear to have mastered2 still less1 have men in general come to conceive of them all as modifications of a general notion of ,polarity4 ,the description which ,i have given of ,polarity in general1 opposite properties in opposite directions1 is of itself a very imperfect account of the manner in which corresponding antitheses are involved in the portions of science into which ,polar relations enter4 ,in excuse of its imperfection1 ,i may say1 that ,i believe it is the first attempt to define ,polarity in general2 but yet1 the conception of ,polarity has certainly been strongly and effectively present in the minds of many of the sagacious men who have discovered and unravelled polar phenomena4 ,they attempted to convey this conception1 each in his own subject1 sometimes by various and peculiar expressions1 sometimes by imaginary mechanism by which the antithetical results were produced2 their mode of expressing themselves being often defective or imperfect1 often containing what was superfluous2 and their meaning was commonly very imperfectly apprehended by most of their hearers and readers4 ,but still1 the conception was there1 gradually working itself into clearness and distinctness1 and in the mean time1 directing their experiments1 and forming an essential element of their discoveries4 ,so far would it be from a sufficient statement of the case to say1 that they conceived polarity because they saw it2--that they saw it as soon as it came into view2--and that they described it as they saw it4 #ce4 ,the way in which such conceptions acquire clearness and distinctness is often by means of ,discussions of ,definitions4 ,to define well a thought which already enters into trains of discovery1 is often a difficult matter4 ,the business of such definition is a part of the business of discovery4 ,these1 and other remarks connected with these1 which ,i had made in the ,philosophy1 ,mr4 ,mill has quoted and adopted 7ii4 #bdb74 ,they appear to me to point very distinctly to the doctrine to which he refuses his assent1--that there is a special process in the mind1 in addition to the mere observation of facts1 which is necessary at every step in the progress of knowledge4 ,the ,conception must be formed before it can be defined4 ,the ,definition gives the last stamp of distinctness to the ,conception2 and enables us to express1 in a compact and lucid form1 the new scientific propositions into which the new ,conception enters4 #cf4 ,since ,mr4 ,mill assents to so much of what has been said in the ,philosophy1 with regard to the process of scientific discovery1 how1 it may be asked1 would he express these doctrines so as to exclude that which he thinks erroneous8 ,if he objects to our saying that when we obtain a new inductive truth1 we connect phenomena by applying to them a new ,conception which fits them1 in what terms would he describe the process8 ,if he will not agree to say1 that in order to discover the law of the facts1 we must find an appropriate ,conception1 what language would he use instead of this8 ,this is a natural question2 and the answer cannot fail to throw light on the relation in which his views and mine stand to each other4 ,mr4 ,mill would say1 ,i believe1 that when we obtain a new inductive law of facts1 we find something in which the facts resemble each other2 and that the business of making such discoveries is the business of discovering such resemblances4 ,thus1 he says 7of me17 7ii4 #baa71 his ,colligation of ,facts by means of appropriate ,conceptions1 is but the ordinary process of finding by a comparison of phenomena1 in what consists their agreement or resemblance4 ,and the ,methods of experimental ,inquiry which he gives 7i4 #dej1 c471 proceed upon the supposition that the business of discovery may be thus more properly described4 #cg4 ,there is no doubt that when we discover a law of nature by induction1 we find some point in which all the particular facts agree4 ,all the orbits of the planets agree in being ellipses1 as ,kepler discovered2 all falling bodies agree in being acted on by a uniform force1 as ,galileo discovered2 all refracted rays agree in having the sines of incidence and refraction in a constant ratio1 as ,snell discovered2 all the bodies in the universe agree in attracting each other1 as ,newton discovered2 all chemical compounds agree in being constituted of elements in definite proportions1 as ,dalton discovered4 ,but it appears to me a most scanty1 vague1 and incomplete account of these steps in science1 to say that the authors of them discovered something in which the facts in each case agreed4 ,the point in which the cases agree1 is of the most diverse kind in the different cases--in some1 a relation of space1 in others1 the action of a force1 in others1 the mode of composition of a substance2--and the point of agreement1 visible to the discoverer alone1 does not come even into his sight1 till after the facts have been connected by thoughts of his own1 and regarded in points of view in which he1 by his mental acts1 places them4 ,it would seem to me not much more inappropriate to say1 that an officer1 who disciplines his men till they move together at the word of command1 does so by finding something in which they agree4 ,if the power of consentaneous motion did not exist in the individuals1 he could not create it3 but that power being there1 he finds it and uses it4 ,of course ,i am aware that the parallel of the two cases is not exact2 but in the one case1 as in the other1 that in which the particular things are found to agree1 is something formed in the mind of him who brings the agreement into view4 ,,iv4 ,mr4 ,mill's ,four ,methods of ,inquiry4--#ch4 ,mr4 ,mill has not only thus described the business of scientific discovery2 he has also given rules for it1 founded on this description4 ,it may be expected that we should bestow some attention upon the methods of inquiry which he thus proposes4 ,i presume that they are regarded by his admirers as among the most valuable parts of his book2 as certainly they cannot fail to be1 if they describe methods of scientific inquiry in such a manner as to be of use to the inquirer4 ,mr4 ,mill enjoins four methods of experimental inquiry1 which he calls the ,method of ,agreement1 the ,method of ,difference1 the ,method of ,residues1 and the ,method of ,concomitant ,variations#bga4 ,they are all described by formul of this kind3--,let there be1 in the observed facts1 combinations of antecedents1 ,,abc1 ,,bc1 ,,ade1 c4 and combinations of corresponding consequents1 abc1 bc1 ade1 c42 and let the object of inquiry be1 the consequence of some cause ,a1 or the cause of some consequence a4 ,the ,method of ,agreement teaches us1 that when we find by experiment such facts as abc the consequent of ,,abc1 and ade the consequent of ,,ade1 then a is the consequent of ,a4 ,the ,method of ,difference teaches us that when we find such facts as abc the consequent of ,,abc1 and bc the consequent of ,,bc1 then a is the consequent of ,a4 ,the ,method of ,residues teaches us1 that if abc be the consequent of ,,abc1 and if we have already ascertained that the effect of ,a is a1 and the effect of ,b is b1 then we may infer that the effect of ,c is c4 ,the ,method of ,concomitant ,variations teaches us1 that if a phenomenon a varies according as another phenomenon ,a varies1 there is some connexion of causation direct or indirect1 between ,a and a4 #ci4 ,upon these methods1 the obvious thing to remark is1 that they take for granted the very thing which is most difficult to discover1 the reduction of the phenomena to formul such as are here presented to us4 ,when we have any set of complex facts offered to us2 for instance1 those which were offered in the cases of discovery which ,i have mentioned1--the facts of the planetary paths1 of falling bodies1 of refracted rays1 of cosmical motions1 of chemical analysis2 and when1 in any of these cases1 we would discover the law of nature which governs them1 or1 if any one chooses so to term it1 the feature in which all the cases agree1 where are we to look for our ,a1 ,b1 ,c and a1 b1 c8 ,nature does not present to us the cases in this form2 and how are we to reduce them to this form8 ,you say1 when we find the combination of ,,abc with abc and ,,abd with abd1 then we may draw our inference4 ,granted3 but when and where are we to find such combinations8 ,even now that the discoveries are made1 who will point out to us what are the ,a1 ,b1 ,c and a1 b1 c elements of the cases which have just been enumerated8 ,who will tell us which of the methods of inquiry those historically real and successful inquiries exemplify8 ,who will carry these formul through the history of the sciences1 as they have really grown up2 and show us that these four methods have been operative in their formation2 or that any light is thrown upon the steps of their progress by reference to these formul8 #dj4 ,mr4 ,mill's four methods have a great resemblance to ,bacon's ,prerogatives of ,instances2 for example1 the ,method of ,agreement to the ,instanti ,ostensiv2 the ,method of ,differences to the ,instanti ,absenti in ,proximo1 and the ,instanti ,crucis2 the ,method of ,concomitant ,variations to the ,instanti ,migrantes4 ,and with regard to the value of such methods1 ,i believe all study of science will convince us more and more of the wisdom of the remarks which ,sir ,john ,herschel has made upon them#bgb4 ,it has always appeared to us1 we must confess1 that the help which the classification of instances under their different titles of prerogative1 affords to inductions1 however just such classification may be in itself1 is yet more apparent than real4 ,the force of the instance must be felt in the mind before it can be referred to its place in the system2 and before it can be either referred or appreciated it must be known2 and when it is appreciated1 we are ready enough to weave our web of induction1 without greatly troubling ourselves whence it derives the weight we acknowledge it to have in our decisions4444 ,no doubt such instances as these are highly instructive2 but the difficulty in physics is to find such1 not to perceive their force when found4 ,v4 ,his ,examples4--#da4 ,if ,mr4 ,mill's four methods had been applied by him in his book to a large body of conspicuous and undoubted examples of discovery1 well selected and well analysed1 extending along the whole history of science1 we should have been better able to estimate the value of these methods4 ,mr4 ,mill has certainly offered a number of examples of his methods2 but ,i hope ,i may say1 without offence1 that they appear to me to be wanting in the conditions which ,i have mentioned4 ,as ,i have to justify myself for rejecting ,mr4 ,mill's criticism of doctrines which ,i have put forward1 and examples which ,i have adduced1 ,i may1 ,i trust1 be allowed to offer some critical remarks in return1 bearing upon the examples which he has given1 in order to illustrate his doctrines and precepts4 #db4 ,the first remark which ,i have to make is1 that a large proportion of his examples 7i4 #dhj1 c47 is taken from one favourite author2 who1 however great his merit may be1 is too recent a writer to have had his discoveries confirmed by the corresponding investigations and searching criticisms of other labourers in the same field1 and placed in their proper and permanent relation to established truths2 these alleged discoveries being1 at the same time1 principally such as deal with the most complex and slippery portions of science1 the laws of vital action4 ,thus ,mr4 ,mill has adduced1 as examples of discoveries1 ,prof4 ,liebig's doctrine--that death is produced by certain metallic poisons through their forming indecomposable compounds2 that the effect of respiration upon the blood consists in the conversion of peroxide of iron into protoxide--that the antiseptic power of salt arises from its attraction for moisture--that chemical action is contagious2 and others4 ,now supposing that we have no doubt of the truth of these discoveries1 we must still observe that they cannot wisely be cited1 in order to exemplify the nature of the progress of knowledge1 till they have been verified by other chemists1 and worked into their places in the general scheme of chemistry2 especially1 since it is tolerably certain that in the process of verification1 they will be modified and more precisely defined4 ,nor can ,i think it judicious to take so large a proportion of our examples from a region of science in which1 of all parts of our material knowledge1 the conceptions both of ordinary persons1 and even of men of science themselves1 are most loose and obscure1 and the genuine principles most contested2 which is the case in physiology4 ,it would be easy1 ,i think1 to point out the vague and indeterminate character of many of the expressions in which the above examples are propounded1 as well as their doubtful position in the scale of chemical generalization2 but ,i have said enough to show why ,i cannot give much weight to these1 as cardinal examples of the method of discovery2 and therefore ,i shall not examine in detail how far they support ,mr4 ,mill's methods of inquiry4 #dc4 ,mr4 ,liebig supplies the first and the majority of ,mr4 ,mill's examples in chapter ,,ix4 of his ,book on ,induction4 ,the second is an example for which ,mr4 ,mill states himself to be indebted to ,mr4 ,alexander ,bain2 the law established being this1 that 7i4 #dhg7 electricity cannot exist in one body without the simultaneous excitement of the opposite electricity in some neighbouring body1 which ,mr4 ,mill also confirms by reference to ,mr4 ,faraday's experiments on voltaic wires4 ,i confess ,i am quite at a loss to understand what there is in the doctrine here ascribed to ,mr4 ,bain which was not known to the electricians who1 from the time of ,franklin1 explained the phenomena of the ,leyden vial4 ,i may observe also that the mention of an electrified atmosphere implies a hypothesis long obsolete4 ,the essential point in all those explanations was1 that each electricity produced by induction the opposite electricity in neighbouring bodies1 as ,i have tried to make apparent in the ,history#bgc4 ,faraday has1 more recently1 illustrated this universal co-existence of opposite electricities with his usual felicity4 ,but the conjunction of this fact with voltaic phenomena1 implies a non-recognition of some of the simplest doctrines of the subject4 ,since1 it is said 7i4 #dhh71 common or machine electricity1 and voltaic electricity may be considered for the present purpose to be identical1 ,faraday wished to know1 c4 ,i think ,mr4 ,faraday would be much astonished to learn that he considered electricity in equilibrium1 and electricity in the form of a voltaic current1 to be1 for any purpose1 identical4 ,nor do ,i conceive that he would assent to the expression in the next page1 that from the nature of a voltaic charge1 the two opposite currents necessary to the existence of each other are both accommodated in one wire4 ,mr4 ,faraday has1 as it appears to me1 studiously avoided assenting to this hypothesis4 #dd4 ,the next example is the one already so copiously dwelt upon by ,sir ,john ,herschel1 ,dr4 ,wells's researches on the production of ,dew4 ,i have already said#bgd that this investigation1 although it has sometimes been praised as an original discovery1 was in fact only resolving the phenomenon into principles already discovered namely1 the doctrine of a constituent temperature of vapour1 the different conducting power of different bodies1 and the like4 ,and this agrees in substance with what ,mr4 ,mill says 7i4 #dig72 that the discovery1 when made1 was corroborated by deduction from the known laws of aqueous vapour1 of conduction1 and the like4 ,dr4 ,wells's researches on ,dew tended much in this country to draw attention to the general principles of ,atmology2 and we may see1 in this and in other examples which ,mr4 ,mill adduces1 that the explanation of special phenomena by means of general principles1 already established1 has1 for common minds1 a greater charm1 and is more complacently dwelt on1 than the discovery of the general principles themselves4 #de4 ,the next example1 7i4 #ejb7 is given in order to illustrate the ,method of ,residues1 and is the discovery by ,m4 ,arago that a disk of copper affects the vibrations of the magnetic needle4 ,but this apparently detached fact affords little instruction compared with the singularly sagacious researches by which ,mr4 ,faraday discovered the cause of this effect to reside in the voltaic currents which the motion of the magnetic needle developed in the copper4 ,i have spoken of this discovery in the ,history#bge4 ,mr4 ,mill however is quoting ,sir ,john ,herschel in thus illustrating the ,method of ,residues4 ,he rightly gives the ,perturbations of the ,planets and ,satellites as better examples of the method#bgf4 #df4 ,in the next chapter 7c4 x47 ,mr4 ,mill speaks of ,plurality of causes and of the ,intermixture of effects1 and gives examples of such cases4 ,he here teaches 7i4 #eag7 that chemical synthesis and analysis1 7as when oxygen and hydrogen compose water1 and when water is resolved into oxygen and hydrogen17 is properly transformation1 but that because we find that the weight of the compound is equal to the sum of the weights of the elements1 we take up the notion of chemical composition4 ,i have endeavoured to show#bgg that the maxim1 that the sum of the weights of the elements is equal to the weight of the compound1 was1 historically1 not proved from experiment1 but assumed in the reasonings upon experiments4 #dg4 ,i have now made my remarks upon nearly all the examples which ,mr4 ,mill gives of scientific inquiry1 so far as they consist of knowledge which has really been obtained4 ,i may mention1 as points which appear to me to interfere with the value of ,mr4 ,mill's references to examples1 expressions which ,i cannot reconcile with just conceptions of scientific truth2 as when he says 7i4 #ebc71 some other force which impinges on the first force2 and very frequently indeed1 of the tangential force1 as co-ordinate with the centripetal force4 ,when he speaks 7ii4 #bj1 ,note7 of the doctrine now universally received that the earth is a great natural magnet with two poles1 he does not recognize the recent theory of ,gauss1 so remarkably coincident with a vast body of facts#bgh4 ,indeed in his statement1 he rejects no less the earlier views proposed by ,halley1 theorized by ,euler1 and confirmed by ,hansteen1 which show that we are compelled to assume at least four poles of terrestrial magnetism2 which ,i had given an account of in the first edition of the ,history4 ,there are several other cases which he puts1 in which1 the knowledge spoken of not having been yet acquired1 he tells us how he would set about acquiring it2 for instance1 if the question were 7i4 #ebf7 whether mercury be a cure for a given disease2 or whether the brain be a voltaic pile 7ii4 #ba72 or whether the moon be inhabited 7ii4 #ajj72 or whether all crows are black 7ii4 #abd72 ,i confess that ,i have no expectation of any advantage to philosophy from discussions of this kind4 #dh4 ,i will add also1 that ,i do not think any light can be thrown upon scientific methods1 at present1 by grouping along with such physical inquiries as ,i have been speaking of1 speculations concerning the human mind1 its qualities and operations4 ,thus he speaks 7i4 #ejh7 of human characters1 as exemplifying the effect of plurality of causes2 of 7i4 #eah7 the phenomena of our mental nature1 which are analogous to chemical rather than to dynamical phenomena2 of 7i4 #eah7 the reason why susceptible persons are imaginative2 to which ,i may add1 the passage where he says 7i4 #ddd71 let us take as an example of a phenomenon which we have no means of fabricating artificially1 a human mind4 ,these1 and other like examples1 occur in the part of his work in which he is speaking of scientific inquiry in general1 not in the ,book on the ,logic of the ,moral ,sciences2 and are1 ,i think1 examples more likely to lead us astray than to help our progress1 in discovering the laws of ,scientific ,inquiry1 in the ordinary sense of the term4 ,,vi4 ,mr4 ,mill against ,hypothesis4--#di4 ,i will now pass from ,mr4 ,mill's methods1 illustrated by such examples as those which ,i have been considering1 to the views respecting the conditions of ,scientific ,induction to which ,i have been led1 by such a survey as ,i could make1 of the whole history of the principal ,inductive ,sciences2 and especially1 to those views to which ,mr4 ,mill offers his objections#bgi4 ,mr4 ,mill thinks that ,i have been too favourable to the employment of hypotheses1 as means of discovering scientific truth2 and that ,i have countenanced a laxness of method1 in allowing hypotheses to be established1 merely in virtue of the accordance of their results with the phenomena4 ,i believe ,i should be as cautious as ,mr4 ,mill1 in accepting mere hypothetical explanations of phenomena1 in any case in which we had the phenomena1 and their relations1 placed before both of us in an equally clear light4 ,i have not accepted the ,undulatory theory of ,heat1 though recommended by so many coincidences and analogies#bhj4 ,but ,i see some grave reasons for not giving any great weight to ,mr4 ,mill's admonitions2--reasons drawn from the language which he uses on the subject1 and which appears to me inconsistent with the conditions of the cases to which he applies it4 ,thus1 when he says 7ii4 #bb7 that the condition of a hypothesis accounting for all the known phenomena is often fulfilled equally well by two conflicting hypotheses1 ,i can only say that ,i know of no such case in the history of ,science1 where the phenomena are at all numerous and complicated2 and that if such a case were to occur1 one of the hypotheses might always be resolved into the other4 ,when he says1 that this evidence 7the agreement of the results of the hypothesis with the phenomena7 cannot be of the smallest value1 because we cannot have in the case of such an hypothesis the assurance that if the hypothesis be false it must lead to results at variance with the true facts1 we must reply1 with due submission1 that we have1 in the case spoken of1 the most complete evidence of this2 for any change in the hypothesis would make it incapable of accounting for the facts4 ,when he says that if we give ourselves the license of inventing the causes as well as their laws1 a person of fertile imagination might devise a hundred modes of accounting for any given fact2 ,i reply1 that the question is about accounting for a large and complex series of facts1 of which the laws have been ascertained3 and as a test of ,mr4 ,mill's assertion1 ,i would propose as a challenge to any person of fertile imagination to devise any one other hypothesis to account for the perturbations of the moon1 or the coloured fringes of shadows1 besides the hypothesis by which they have actually been explained with such curious completeness4 ,this challenge has been repeatedly offered1 but never in any degree accepted2 and ,i entertain no apprehension that ,mr4 ,mill's supposition will ever be verified by such a performance4 #ej4 ,i see additional reason for mistrusting the precision of ,mr4 ,mill's views of that accordance of phenomena with the results of a hypothesis1 in several others of the expressions which he uses 7ii4 #bc74 ,he speaks of a hypothesis being a plausible explanation of all or most of the phenomena2 but the case which we have to consider is where it gives an exact representation of all the phenomena in which its results can be traced4 ,he speaks of its being certain that the laws of the phenomena are in some measure analogous to those given by the hypothesis2 the case to be dealt with being1 that they are in every way identical4 ,he speaks of this analogy being certain1 from the fact that the hypothesis can be for a moment tenable2 as if any one had recommended a hypothesis which is tenable only while a small part of the facts are considered1 when it is inconsistent with others which a fuller examination of the case discloses4 ,i have nothing to say1 and have said nothing1 in favour of hypotheses which are not tenable4 ,he says there are many such harmonies running through the laws of phenomena in other respects radically distinct2 and he gives as an instance1 the laws of light and heat4 ,i have never alleged such harmonies as grounds of theory1 unless they should amount to identities2 and if they should do this1 ,i have no doubt that the most sober thinkers will suppose the causes to be of the same kind in the two harmonizing instances4 ,if chlorine1 iodine and brome1 or sulphur and phosphorus1 have1 as ,mr4 ,mill says1 analogous properties1 ,i should call these substances analogous3 but ,i can see no temptation to frame an hypothesis that they are identical 7which he seems to fear71 so long as ,chemistry proves them distinct4 ,but any hypothesis of an analogy in the constitution of these elements 7suppose1 for instance1 a resemblance in their atomic form or composition7 would seem to me to have a fair claim to trial2 and to be capable of being elevated from one degree of probability to another by the number1 variety1 and exactitude of the explanations of phenomena which it should furnish4 ,,vii4 ,against prediction of ,facts4--#ea4 ,these expressions of ,mr4 ,mill have reference to a way in which hypotheses may be corroborated1 in estimating the value of which1 it appears that he and ,i differ4 ,it seems to be thought1 he says 7ii4 #bc71 that an hypothesis of the sort in question is entitled to a more favourable reception1 if1 besides accounting for the facts previously known1 it has led to the anticipation and prediction of others which experience afterwards verified4 ,and he adds1 ,such predictions and their fulfilment are indeed well calculated to strike the ignorant vulgar2 but it is strange1 he says1 that any considerable stress should be laid upon such a coincidence by scientific thinkers4 ,however strange it may seem to him1 there is no doubt that the most scientific thinkers1 far more than the ignorant vulgar1 have allowed the coincidence of results predicted by theory with fact afterwards observed1 to produce the strongest effects upon their conviction2 and that all the best-established theories have obtained their permanent place in general acceptance in virtue of such coincidences1 more than of any other evidence4 ,it was not the ignorant vulgar alone1 who were struck by the return of ,halley's comet1 as an evidence of the ,newtonian theory4 ,nor was it the ignorant vulgar1 who were struck with those facts which did so much strike men of science1 as curiously felicitous proofs of the undulatory theory of light1--the production of darkness by two luminous rays interfering in a special manner2 the refraction of a single ray of light into a conical pencil2 and other complex yet precise results1 predicted by the theory and verified by experiment4 ,it must1 one would think1 strike all persons in proportion to their thoughtfulness1 that when ,nature thus does our bidding1 she acknowledges that we have learnt her true language4 ,if we can predict new facts which we have not seen1 as well as explain those which we have seen1 it must be because our explanation is not a mere formula of observed facts1 but a truth of a deeper kind4 ,mr4 ,mill says1 ,if the laws of the propagation of light agree with those of the vibrations of an elastic fluid in so many respects as is necessary to make the hypothesis a plausible explanation of all or most of the phenomena known at the time1 it is nothing strange that they should accord with each other in one respect more4 ,nothing strange1 if the theory be true2 but quite unaccountable1 if it be not4 ,if ,i copy a long series of letters of which the last half-dozen are concealed1 and if ,i guess those aright1 as is found to be the case when they are afterwards uncovered1 this must be because ,i have made out the import of the inscription4 ,to say1 that because ,i have copied all that ,i could see1 it is nothing strange that ,i should guess those which ,i cannot see1 would be absurd1 without supposing such a ground for guessing4 ,the notion that the discovery of the laws and causes of phenomena is a loose haphazard sort of guessing1 which gives plausible explanations1 accidental coincidences1 casual harmonies1 laws1 in some measure analogous to the true ones1 suppositions tenable for a time1 appears to me to be a misapprehension of the whole nature of science2 as it certainly is inapplicable to the case to which it is principally applied by ,mr4 ,mill4 #eb4 ,there is another kind of evidence of theories1 very closely approaching to the verification of untried predictions1 and to which1 apparently1 ,mr4 ,mill does not attach much importance1 since he has borrowed the term by which ,i have described it1 ,consilience1 but has applied it in a different manner 7ii4 #ecj1 #efc1 #eij74 ,i have spoken1 in the ,philosophy#bha1 of the ,consilience of ,inductions1 as one of the ,tests of ,hypotheses1 and have exemplified it by many instances2 for example1 the theory of universal gravitation1 obtained by induction from the motions of the planets1 was found to explain also that peculiar motion of the spheroidal earth which produces the ,precession of the ,equinoxes4 ,this1 ,i have said1 was a striking and surprising coincidence which gave the theory a stamp of truth beyond the power of ingenuity to counterfeit4 ,i may compare such occurrences to a case of interpreting an unknown character1 in which two different inscriptions1 deciphered by different persons1 had given the same alphabet4 ,we should1 in such a case1 believe with great confidence that the alphabet was the true one2 and ,i will add1 that ,i believe the history of science offers no example in which a theory supported by such consiliences1 had been afterwards proved to be false4 #ec4 ,mr4 ,mill accepts 7ii4 #ba7 a rule of ,m4 ,comte's1 that we may apply hypotheses1 provided they are capable of being afterwards verified as facts4 ,i have a much higher respect for ,mr4 ,mill's opinion than for ,m4 ,comte's#bhb2 but ,i do not think that this rule will be found of any value4 ,it appears to me to be tainted with the vice which ,i have already noted1 of throwing the whole burthen of explanation upon the unexplained word fact--unexplained in any permanent and definite opposition to theory4 ,as ,i have said1 the ,newtonian theory is a fact4 ,every true theory is a fact4 ,nor does the distinction become more clear by ,mr4 ,mill's examples4 ,the vortices of ,descartes would have been1 he says1 a perfectly legitimate hypothesis1 if it had been possible by any mode of explanation which we could entertain the hope of possessing1 to bring the question whether such vortices exist or not1 within the reach of our observing faculties4 ,but this was possible1 and was done4 ,the free passage of comets through the spaces in which these vortices should have been1 convinced men that these vortices did not exist4 ,in like manner ,mr4 ,mill rejects the hypothesis of a luminiferous ether1 because it can neither be seen1 heard1 smelt1 tasted1 or touched4 ,it is a strange complaint to make of the vehicle of light1 that it cannot be heard1 smelt1 or tasted4 ,its vibrations can be seen4 ,the fringes of shadows for instance1 show its vibrations1 just as the visible lines of waves near the shore show the undulations of the sea4 ,whether this can be touched1 that is1 whether it resists motion1 is hardly yet clear4 ,i am far from saying there are not difficulties on this point1 with regard to all theories which suppose a medium4 ,but there are no more difficulties of this kind in the undulatory theory of light1 than there are in ,fourier's theory of heat1 which ,m4 ,comte adopts as a model of scientific investigation2 or in the theory of voltaic currents1 about which ,mr4 ,mill appears to have no doubt2 or of electric atmospheres1 which1 though generally obsolete1 ,mr4 ,mill appears to favour2 for though it had been said that we feel such atmospheres1 no one had said that they have the other attributes of matter4 ,,viii4 ,newton's ,vera ,causa4--#ed4 ,mr4 ,mill conceives 7ii4 #ag7 that his own rule concerning hypotheses coincides with ,newton's ,rule1 that the cause assumed must be a vera causa4 ,but he allows that ,mr4 ,whewell 444 has had little difficulty in showing that his 7,newton's7 conception was neither precise nor consistent with itself4 ,he also allows that ,mr4 ,whewell is clearly right in denying it to be necessary that the cause assigned should be a cause already known2 else how could we ever become acquainted with new causes8 ,these points being agreed upon1 ,i think that a little further consideration will lead to the conviction that ,newton's ,rule of philosophizing will best become a valuable guide1 if we understand it as asserting that when the explanation of two or more different kinds of phenomena 7as the revolutions of the planets1 the fall of a stone1 and the precession of the equinoxes17 lead us to the same cause1 such a coincidence gives a reality to the cause4 ,we have1 in fact1 in such a case1 a ,consilience of ,inductions4 #ee4 ,when ,mr4 ,mill condemns me 7ii4 #bd7 7using1 however1 expressions of civility which ,i gladly acknowledge17 for having recognized no mode of ,induction except that of trying hypothesis after hypothesis until one is found which fits the phenomena1 ,i must beg to remind the readers of our works1 that ,mr4 ,mill himself allows 7i4 #cfc7 that the process of finding a conception which binds together observed facts is tentative1 that it consists of a succession of guesses1 many being rejected until one at last occurs fit to be chosen4 ,i must remind them also that ,i have given a ,section upon the ,tests of ,hypotheses1 to which ,i have just referred1--that ,i have given various methods of ,induction1 as the ,method of ,gradation1 the ,method of ,natural ,classification1 the ,method of ,curves1 the ,method of ,means1 the ,method of ,least ,squares1 the ,method of ,residues3 all which ,i have illustrated by conspicuous examples from the ,history of ,science2 besides which1 ,i conceive that what ,i have said of the ,ideas belonging to each science1 and of the construction and explication of conceptions1 will point out in each case1 in what region we are to look for the ,inductive ,element in order to make new discoveries4 ,i have already ventured to say1 elsewhere1 that the methods which ,i have given1 are as definite and practical as any others which have been proposed1 with the great additional advantage of being the methods by which all great discoveries in science have really been made4 ,,ix4 ,successive ,generalizations4--#ef4 ,there is one feature in the construction of science which ,mr4 ,mill notices1 but to which he does not ascribe1 as ,i conceive1 its due importance3 ,i mean1 that process by which we not only ascend from particular facts to a general law1 but when this is done1 ascend from the first general law to others more general2 and so on1 proceeding to the highest point of generalization4 ,this character of the scientific process was first clearly pointed out by ,bacon1 and is one of the most noticeable instances of his philosophical sagacity4 ,there are1 he says1 two ways1 and can be only two1 of seeking and finding truth4 ,the one from sense and particulars1 takes a flight to the most general axioms1 and from these principles and their truth1 settled once for all1 invents and judges of intermediate axioms4 ,the other method collects axioms from sense and particulars1 ascending continuously and by degrees1 so that in the end it arrives at the most general axioms3 meaning by axioms1 laws or principles4 ,the structure of the most complete sciences consists of several such steps1--floors1 as ,bacon calls them1 of successive generalization2 and thus this structure may be exhibited as a kind of scientific pyramid4 ,i have constructed this pyramid in the case of the science of ,astronomy#bhc3 and ,i am gratified to find that the illustrious ,humboldt approves of the design1 and speaks of it as executed with complete success#bhd4 ,the capability of being exhibited in this form of successive generalizations1 arising from particulars upward to some very general law1 is the condition of all tolerably perfect sciences2 and the steps of the successive generalizations are commonly the most important events in the history of the science4 #eg4 ,mr4 ,mill does not reject this process of generalization2 but he gives it no conspicuous place1 making it only one of three modes of reducing a law of causation into other laws4 ,there is1 he says 7i4 #eee71 the subsumption of one law under another2 444 the gathering up of several laws into one more general law which includes them all4 ,he adds afterwards1 that the general law is the sum of the partial ones 7i4 #eeg71 an expression which appears to me inadequate1 for reasons which ,i have already stated4 ,the general law is not the mere sum of the particular laws4 ,it is1 as ,i have already said1 their amount in a new point of view4 ,a new conception is introduced2 thus1 ,newton did not merely add together the laws of the motions of the moon and of the planets1 and of the satellites1 and of the earth2 he looked at them altogether as the result of a universal force of mutual gravitation2 and therein consisted his generalization4 ,and the like might be pointed out in other cases4 #eh4 ,i am the more led to speak of ,mr4 ,mill as not having given due importance to this process of successive generalization1 by the way in which he speaks in another place 7ii4 #ebe7 of this doctrine of ,bacon4 ,he conceives ,bacon to have been radically wrong when he enunciates1 as a universal rule1 that induction should proceed from the lowest to the middle principles1 and from those to the highest1 never reversing that order1 and consequently1 leaving no room for the discovery of new principles by way of deduction#bhe at all4 #ei4 ,i conceive that the ,inductive ,table of ,astronomy1 to which ,i have already referred1 shows that in that science1--the most complete which has yet existed1--the history of the science has gone on1 as to its general movement1 in accordance with the view which ,bacon's sagacity enjoined4 ,the successive generalizations1 so far as they were true1 were made by successive generations4 ,i conceive also that the ,inductive ,table of ,optics shows the same thing2 and this1 without taking for granted the truth of the ,undulatory ,theory2 for with regard to all the steps of the progress of the science1 lower than that highest one1 there is1 ,i conceive1 no controversy4 #fj4 ,also1 the ,science of ,mechanics1 although ,mr4 ,mill more especially refers to it1 as a case in which the highest generalizations 7for example the ,laws of ,motion7 were those earliest ascertained with any scientific exactness1 will1 ,i think1 on a more careful examination of its history1 be found remarkably to confirm ,bacon's view4 ,for1 in that science1 we have1 in the first place1 very conspicuous examples of the vice of the method pursued by the ancients in flying to the highest generalizations first2 as when they made their false distinctions of the laws of natural and violent motions1 and of terrestrial and celestial motions4 ,many erroneous laws of motion were asserted through neglect of facts or want of experiments4 ,and when ,galileo and his school had in some measure succeeded in discovering some of the true laws of the motions of terrestrial bodies1 they did not at once assert them as general3 for they did not at all apply those laws to the celestial motions4 ,as ,i have remarked1 all ,kepler's speculations respecting the causes of the motions of the planets1 went upon the supposition that the ,first ,law of terrestrial ,motion did not apply to celestial bodies2 but that1 on the contrary1 some continual force was requisite to keep up1 as well as to originate1 the planetary motions4 ,nor did ,descartes1 though he enunciated the ,laws of ,motion with more generality than his predecessors1 7but not with exactness17 venture to trust the planets to those laws2 on the contrary1 he invented his machinery of ,vortices in order to keep up the motions of the heavenly bodies4 ,newton was the first who extended the laws of terrestrial motion to the celestial spaces2 and in doing so1 he used all the laws of the celestial motions which had previously been discovered by more limited inductions4 ,to these instances1 ,i may add the gradual generalization of the ,third ,law of motion by ,huyghens1 the ,bernoullis1 and ,herman1 which ,i have described in the ,history#bhf as preceding that ,period of ,deduction1 to which the succeeding narrative#bhg is appropriated4 ,in ,mechanics1 then1 we have a cardinal example of the historically gradual and successive ascent of science from particulars to the most general laws4 #fa4 ,the ,science of ,hydrostatics may appear to offer a more favourable example of the ascent to the most general laws1 without going through the intermediate particular laws2 and it is true1 with reference to this science1 as ,i have observed#bhh1 that it does exhibit the peculiarity of our possessing the most general principles on which the phenomena depend1 and from which many cases of special facts are explained by deduction2 while other cases cannot be so explained1 from the want of principles intermediate between the highest and the lowest4 ,and ,i have assigned1 as the reason of this peculiarity1 that the general principles of the ,mechanics of ,fluids were not obtained with reference to the science itself1 but by extension from the sister science of the ,mechanics of ,solids4 ,the two sciences are parts of the same ,inductive ,pyramid2 and having reached the summit of this ,pyramid on one side1 we are tempted to descend on the other from the highest generality to more narrow laws4 ,yet even in this science1 the best part of our knowledge is mainly composed of inductive laws1 obtained by inductive examination of particular classes of facts4 ,the mere mathematical investigations of the laws of waves1 for instance1 have not led to any results so valuable as the experimental researches of ,bremontier1 ,emy1 the ,webers1 and ,mr4 ,scott ,russell4 ,and in like manner in ,acoustics1 the ,mechanics of ,elastic ,fluids#bhi1 the deductions of mathematicians made on general principles have not done so much for our knowledge1 as the cases of vibrations of plates and pipes examined experimentally by ,chladni1 ,savart1 ,mr4 ,wheatstone and ,mr4 ,willis4 ,we see therefore1 even in these sciences1 no reason to slight the wisdom which exhorts us to ascend from particulars to intermediate laws1 rather than to hope to deduce these latter better from the more general laws obtained once for all4 #fb4 ,mr4 ,mill himself indeed1 notwithstanding that he slights ,bacon's injunction to seek knowledge by proceeding from less general to more general laws1 has given a very good reason why this is commonly necessary and wise4 ,he says 7ii4 #ebf71 ,before we attempt to explain deductively1 from more general laws1 any new class of phenomena1 it is desirable to have gone as far as is practicable in ascertaining the empirical laws of these phenomena2 so as to compare the results of deduction1 not with one individual instance after another1 but with general propositions expressive of the points of agreement which have been found among many instances4 ,for1 he adds with great justice1 if ,newton had been obliged to verify the theory of gravitation1 not by deducing from it ,kepler's laws1 but by deducing all the observed planetary positions which had served ,kepler to establish those laws1 the ,newtonian theory would probably never have emerged from the state of an hypothesis4 ,to which we may add1 that it is certain1 from the history of the subject1 that in that case the hypothesis would never have been framed at all4 ,x4 ,mr4 ,mill's ,hope from ,deduction4--#fc4 ,mr4 ,mill expresses a hope of the efficacy of ,deduction1 rather than ,induction1 in promoting the future progress of ,science2 which hope1 so far as the physical sciences are concerned1 appears to me at variance with all the lessons of the history of those sciences4 ,he says 7i4 #egi71 that the advances henceforth to be expected even in physical1 and still more in mental and social science1 will be chiefly the result of deduction1 is evident from the general considerations already adduced3 these considerations being1 that the phenomena to be considered are very complex1 and are the result of many known causes1 of which we have to disentangle the results4 #fd4 ,i cannot but take a very different view from this4 ,i think that any one1 looking at the state of physical science1 will see that there are still a vast mass of cases1 in which we do not at all know the causes1 at least1 in their full generality2 and that the knowledge of new causes1 and the generalization of the laws of those already known1 can only be obtained by new inductive discoveries4 ,except by new ,inductions1 equal1 in their efficacy for grouping together phenomena in new points of view1 to any which have yet been performed in the history of science1 how are we to solve such questions as those which1 in the survey of what we already know1 force themselves upon our minds8 ,such as1 to take only a few of the most obvious examples--,what is the nature of the connexion of heat and light8 ,how does heat produce the expansion1 liquefaction and vaporization of bodies8 ,what is the nature of the connexion between the optical and the chemical properties of light8 ,what is the relation between optical1 crystalline and chemical polarity8 ,what is the connexion between the atomic constitution and the physical qualities of bodies8 ,what is the tenable definition of a mineral species8 ,what is the true relation of the apparently different types of vegetable life 7monocotyledons1 dicotyledons1 and cryptogamous plants78 ,what is the relation of the various types of animal life 7vertebrates1 articulates1 radiates1 c478 ,what is the number1 and what are the distinctions of the ,vital ,powers8 ,what is the internal constitution of the earth8 ,these1 and many other questions of equal interest1 no one1 ,i suppose1 expects to see solved by deduction from principles already known4 ,but we can1 in many of them1 see good hope of progress by a large use of induction2 including1 of course1 copious and careful experiments and observations4 #fe4 ,with such questions before us1 as have now been suggested1 ,i can see nothing but a most mischievous narrowing of the field and enfeebling of the spirit of scientific exertion1 in the doctrine that ,deduction is the great scientific work of the present and of future ages2 and that ,a revolution is peaceably and progressively effecting itself in philosophy the reverse of that to which ,bacon has attached his name4 ,i trust1 on the contrary1 that we have many new laws of nature still to discover2 and that our race is destined to obtain a sight of wider truths than any we yet discern1 including1 as cases1 the general laws we now know1 and obtained from these known laws as they must be1 by ,induction4 #ff4 ,i can see1 however1 reasons for the comparatively greater favour with which ,mr4 ,mill looks upon ,deduction1 in the views to which he has mainly directed his attention4 ,the explanation of remarkable phenomena by known laws of ,nature1 has1 as ,i have already said1 a greater charm for many minds than the discovery of the laws themselves4 ,in the case of such explanations1 the problem proposed is more definite1 and the solution more obviously complete4 ,for the process of induction includes a mysterious step1 by which we pass from particulars to generals1 of which step the reason always seems to be inadequately rendered by any words which we can use2 and this step to most minds is not demonstrative1 as to few is it given to perform it on a great scale4 ,but the process of explanation of facts by known laws is deductive1 and has at every step a force like that of demonstration1 producing a feeling peculiarly gratifying to the clear intellects which are most capable of following the process4 ,we may often see instances in which this admiration for deductive skill appears in an extravagant measure2 as when men compare ,laplace with ,newton4 ,nor should ,i think it my business to argue against such a preference1 unless it were likely to leave us too well satisfied with what we know already1 to chill our hope of scientific progress1 and to prevent our making any further strenuous efforts to ascend1 higher than we have yet done1 the mountain-chain which limits human knowledge4 #fg4 ,but there is another reason which1 ,i conceive1 operates in leading ,mr4 ,mill to look to ,deduction as the principal means of future progress in knowledge1 and which is a reason of considerable weight in the subjects of research which1 as ,i conceive1 he mainly has in view4 ,in the study of our own minds and of the laws which govern the history of society1 ,i do not think that it is very likely that we shall hereafter arrive at any wider principles than those of which we already possess some considerable knowledge2 and this1 for a special reason2 namely1 that our knowledge in such cases is not gathered by mere external observation of a collection of external facts2 but acquired by attention to internal facts1 our own emotions1 thoughts1 and springs of action2 facts are connected by ties existing in our own consciousness1 and not in mere observed juxtaposition1 succession1 or similitude4 ,how the character1 for instance1 is influenced by various causes1 7an example to which ,mr4 ,mill repeatedly refers1 ii4 #eah1 c471 is an inquiry which may perhaps be best conducted by considering what we know of the influence of education and habit1 government and occupation1 hope and fear1 vanity and pride1 and the like1 upon men's characters1 and by tracing the various effects of the intermixture of such influences4 ,yet even here1 there seems to be room for the discovery of laws in the way of experimental inquiry3 for instance1 what share race or family has in the formation of character2 a question which can hardly be solved to any purpose in any other way than by collecting and classing instances4 ,and in the same way1 many of the principles which regulate the material wealth of states1 are obtained1 if not exclusively1 at least most clearly and securely1 by induction from large surveys of facts4 ,still1 however1 ,i am quite ready to admit that in ,mental and ,social ,science1 we are much less likely than in ,physical ,science1 to obtain new truths by any process which can be distinctively termed ,induction2 and that in those sciences1 what may be called ,deductions from principles of thought and action of which we are already conscious1 or to which we assent when they are felicitously picked out of our thoughts and put into words1 must have a large share2 and ,i may add1 that this observation of ,mr4 ,mill appears to me to be important1 and1 in its present connexion1 new4 ,,xi4 ,fundamental opposition of our doctrines4--#fh4 ,i have made nearly all the remarks which ,i now think it of any consequence to make upon ,mr4 ,mill's ,logic1 so far as it bears upon the doctrines contained in my ,history and ,philosophy4 ,and yet there remains still untouched one great question1 involving probably the widest of all the differences between him and me4 ,i mean the question whether geometrical axioms1 7and1 as similar in their evidence to these1 all axioms17 be truths derived from experience1 or be necessary truths in some deeper sense4 ,this is one of the fundamental questions of philosophy2 and all persons who take an interest in metaphysical discussions1 know that the two opposite opinions have been maintained with great zeal in all ages of speculation4 ,to me it appears that there are two distinct elements in our knowledge1 ,experience1 without1 and the ,mind1 within4 ,mr4 ,mill derives all our knowledge from ,experience alone4 ,in a question thus going to the root of all knowledge1 the opposite arguments must needs cut deep on both sides4 ,mr4 ,mill cannot deny that our knowledge of geometrical axioms and the like1 seems to be necessary4 ,i cannot deny that our knowledge1 axiomatic as well as other1 never is acquired without experience4 #fi4 ,perhaps ordinary readers may despair of following our reasonings1 when they find that they can only be made intelligible by supposing1 on the one hand1 a person who thinks distinctly and yet has never seen or felt any external object2 and on the other hand1 a person who is transferred1 as ,mr4 ,mill supposes 7ii4 #aag71 to distant parts of the stellar regions where the phenomena may be entirely unlike those with which we are acquainted1 and where even the axiom1 that every effect must have a cause1 does not hold good4 ,nor1 in truth1 do ,i think it necessary here to spend many words on this subject4 ,probably1 for those who take an interest in this discussion1 most of the arguments on each side have already been put forwards with sufficient repetition4 ,i have1 in an ,essay on the ,fundamental ,antithesis of ,philosophy1 and in some accompanying ,remarks1 printed#bij at the end of the second edition of my ,philosophy1 given my reply to what has been said on this subject1 both by ,mr4 ,mill1 and by the author of a very able critique on my ,history and ,philosophy which appeared in the ,quarterly ,review in #ahda3 and ,i will not here attempt to revive the general discussion4 #gj4 ,perhaps ,i may be allowed to notice1 that in one part of ,mr4 ,mill's work where this subject is treated1 there is the appearance of one of the parties to the controversy pronouncing judgment in his own cause4 ,this indeed is a temptation which it is especially difficult for an author to resist1 who writes a treatise upon ,fallacies1 the subject of ,mr4 ,mill's fifth ,book4 ,in such a treatise1 the writer has an easy way of disposing of adverse opinions by classing them as ,fallacies1 and putting them side by side with opinions universally acknowledged to be false4 ,in this way1 ,mr4 ,mill has dealt with several points which are still1 as ,i conceive1 matters of controversy 7ii4 #ceg1 c474 #ga4 ,but undoubtedly1 ,mr4 ,mill has given his argument against my opinions with great distinctness in another place 7i4 #cai74 ,in order to show that it is merely habitual association which gives to an experimental truth the character of a necessary truth1 he quotes the case of the laws of motion1 which were really discovered from experiment1 but are now looked upon as the only conceivable laws2 and especially1 what he conceives as the reductio ad absurdum of the theory of inconceivableness1 an opinion which ,i had ventured to throw out1 that if we could conceive the ,composition of bodies distinctly1 we might be able to see that it is necessary that the modes of their composition should be definite4 ,i do not think that readers in general will see anything absurd in the opinion1 that the laws of ,mechanics1 and even the laws of the ,chemical ,composition of bodies1 may depend upon principles as necessary as the properties of space and number2 and that this necessity1 though not at all perceived by persons who have only the ordinary obscure and confused notions on such subjects1 may be evident to a mind which has1 by effort and discipline1 rendered its ideas of ,mechanical ,causation1 ,elementary ,composition and ,difference of ,kind1 clear and precise4 ,it may easily be1 ,i conceive1 that while such necessary principles are perceived to be necessary only by a few minds of highly cultivated insight1 such principles as the axioms of ,geometry and ,arithmetic may be perceived to be necessary by all minds which have any habit of abstract thought at all3 and ,i conceive also1 that though these axioms are brought into distinct view by a certain degree of intellectual cultivation1 they may still be much better described as conditions of experience1 than as results of experience3--as laws of the mind and of its activity1 rather than as facts impressed upon a mind merely passive4 ,,xii4 ,absurdities in ,mr4 ,mill's ,logic4--#gb4 ,i will not pursue the subject further3 only1 as the question has arisen respecting the absurdities to which each of the opposite doctrines leads1 ,i will point out opinions connected with this subject1 which ,mr4 ,mill has stated in various parts of his book4 ,he holds 7i4 #cag7 that it is merely from habit that we are unable to conceive the last point of space or the last instant of time4 ,he holds 7ii4 #cfj7 that it is strange that any one should rely upon the priori evidence that space or extension is infinite1 or that nothing can be made of nothing4 ,he holds 7i4 #cjd7 that the first law of motion is rigorously true1 but that the axioms respecting the lever are only approximately true4 ,he holds 7ii4 #aaj7 that there may be sidereal firmaments in which events succeed each other at random1 without obeying any laws of causation2 although one might suppose that even if space and cause are both to have their limits1 still they might terminate together3 and then1 even on this bold supposition1 we should no where have a world in which events were casual4 ,he holds 7ii4 #aaa7 that the axiom1 that every event must have a cause1 is established by means of an induction by simple enumeration3 and in like manner1 that the principles of number and of geometry are proved by this method of simple enumeration alone4 ,he ascribes the proof 7i4 #afb7 of the axiom1 things which are equal to the same are equal to each other1 to the fact that this proposition has been perpetually found true and never false4 ,he holds 7i4 #cch7 that ,in all propositions concerning numbers1 a condition is implied1 without which none of them would be true2 and that condition is an assumption which may be false4 ,the condition is that #a #a4 #gc4 ,mr4 ,mill further holds 7i4 #cji71 that it is a characteristic property of geometrical forms1 that they are capable of being painted in the imagination with a distinctness equal to reality3--that our ideas of forms exactly resemble our sensations3 which1 it is implied1 is not the case with regard to any other class of our ideas2--that we thus may have mental pictures of all possible combinations of lines and angles1 which are as fit subjects of geometrical experimentation as the realities themselves4 ,he says1 that we know that the imaginary lines exactly resemble real ones2 and that we obtain this knowledge respecting the characteristic property of the idea of space by experience2 though it does not appear how we can compare our ideas with the realities1 since we know the realities only by our ideas2 or why this property of their resemblance should be confined to one class of ideas alone4 #gd4 ,i have now made such remarks as appear to me to be necessary1 on the most important parts of ,mr4 ,mill's criticism of my ,philosophy4 ,i hope ,i have avoided urging any thing in a contentious manner2 as ,i have certainly written with no desire of controversy1 but only with a view to offer to those who may be willing to receive it1 some explanation of portions of my previous writings4 ,i have already said1 that if this had not have been my especial object1 ,i could with pleasure have noted the passages of ,mr4 ,mill's ,logic which ,i admire1 rather than the points in which we differ4 ,i will in a very few words refer to some of these points1 as the most agreeable way of taking leave of the dispute4 ,i say then that ,mr4 ,mill appears to me especially instructive in his discussion of the nature of the proof which is conveyed by the syllogism2 and that his doctrine1 that the force of the syllogism consists in an inductive assertion1 with an interpretation added to it1 solves very happily the difficulties which baffle the other theories of this subject4 ,i think that this doctrine of his is made still more instructive1 by his excepting from it the cases of ,scriptural ,theology and of ,positive ,law 7i4 #bfj71 as cases in which general propositions1 not particular facts1 are our original data4 ,i consider also that the recognition of ,kinds 7i4 #aff7 as classes in which we have1 not a finite but an inexhaustible body of resemblances among individuals1 and as groups made by nature1 not by mere definition1 is very valuable1 as stopping the inroad to an endless train of false philosophy4 ,i conceive that he takes the right ground in his answer to ,hume's argument against miracles 7ii4 #ahc73 and ,i admire the acuteness with which he has criticized ,laplace's tenets on the ,doctrine of ,chances1 and the candour with which he has1 in the second edition1 acknowledged oversights on this subject made in the first4 ,i think that much1 ,i may almost say all1 which he says on the subject of ,language1 is very philosophical2 for instance1 what he says 7ii4 #bch7 of the way in which words acquire their meaning in common use4 ,i especially admire the acuteness and force with which he has shown 7ii4 #bee7 how moral principles expressed in words degenerate into formulas1 and yet how the formula cannot be rejected without a moral loss4 ,this perpetual oscillation in spiritual truths1 as he happily terms it1 has never1 ,i think1 been noted in the same broad manner1 and is a subject of most instructive contemplation4 ,and though ,i have myself refrained from associating moral and political with physical science in my study of the subject1 ,i see a great deal which is full of promise for the future progress of moral and political knowledge in ,mr4 ,mill's sixth ,book1 ,on the ,logic of the ,moral and ,political ,sciences4 ,even his arrangement of the various methods which have been or may be followed in the ,social ,science1--the ,chemical or ,experimental ,method1 the ,geometrical or ,abstract ,method1 the ,physical or ,concrete ,deductive ,method1 the ,inverse ,deductive or ,historical ,method1 though in some degree fanciful and forced1 abounds with valuable suggestions2 and his estimate of the interesting philosophy of the ,bentham school1 the main example of the geometrical method1 is interesting and philosophical4 ,on some future occasion1 ,i may1 perhaps1 venture into the region of which ,mr4 ,mill has thus essayed to map the highways3 for it is from no despair either of the great progress to be made in such truth as that here referred to1 or of the effect of philosophical method in arriving at such truth1 that ,i have1 in what ,i have now written1 confined myself to the less captivating but more definite part of the subject4 ,,footnotes3 ,footnote #bfd3 ,a ,system of ,logic1 ,ratiocinative and ,inductive1 being a connected view of the ,principles of ,evidence1 and of the ,methods of ,scientific ,investigation4 ,by ,john ,stuart ,mill4 ,footnote #bfe3 ,these ,remarks were published in #ahdi1 under the title ,of ,induction1 with especial reference to ,mr4 ,j4 ,s4 ,mill's ,system of ,logic4 ,footnote #bff3 ,my references are throughout 7except when otherwise expressed7 to the volume and the page of ,mr4 ,mill's first edition of his ,logic4 ,footnote #bfg3 ,on this subject see an ,essay ,on the ,transformation of ,hypotheses1 given in the ,appendix4 ,footnote #bfh3 ,b4 vii4 c4 iii4 sect4 #c4 ,footnote #bfi3 ,b4 iii4 c4 ix4 art4 #g4 ,footnote #bgj3 ,b4 i4 c4 iii4 ,footnote #bga3 ,b4 iii4 c4 viii4 ,footnote #bgb3 ,discourse1 ,art4 #aib4 ,footnote #bgc3 ,b4 xi4 c4 xi4 ,footnote #bgd3 ,phil4 b4 xiii4 c4 ix4 art4 #g4 ,footnote #bge3 ,b4 xiii4 c4 viii4 ,footnote #bgf3 ,given also in the ,phil4 ,ind4 ,sc4 b4 xiii4 c4 vii4 sect4 #ag4 ,footnote #bgg3 ,ibid4 b4 vi4 c4 iv4 ,footnote #bgh3 ,see ,hist4 ,ind4 ,sc4 b4 xii4 note ,d1 in the second edition4 ,footnote #bgi3 ,there are some points in my doctrines on the subject of the ,classificatory ,sciences to which ,mr4 ,mill objects1 7ii4 #cad1 c471 but there is nothing which ,i think it necessary to remark here1 except one point4 ,after speaking of ,classification of organized beings in general1 ,mr4 ,mill notices 7ii4 #cba7 as an additional subject1 the arrangement of natural groups into a ,natural ,series2 and he says1 that all who have attempted a theory of natural arrangement1 including among the rest ,mr4 ,whewell1 have stopped short of this3 all except ,m4 ,comte4 ,on this ,i have to observe1 that ,i stopped short of1 or rather passed by1 the doctrine of a ,series of organized beings1 because ,i thought it bad and narrow philosophy3 and that ,i sufficiently indicated that ,i did this4 ,in the ,history 7b4 xvi4 c4 vi47 ,i have spoken of the doctrine of ,circular ,progression propounded by ,mr4 ,macleay1 and have said1 so far as this view negatives a mere linear progression in nature1 which would place each genus in contact with the preceding and succeeding ones1 and so far as it requires us to attend to the more varied and ramified resemblances1 there can be no doubt that it is supported by the result of all the attempts to form natural systems4 ,and with regard to the difference between ,cuvier and ,m4 de ,blainville1 to which ,mr4 ,mill refers 7ii4 #cba71 ,i certainly cannot think that ,m4 ,comte's suffrage can add any weight to the opinion of either of those great naturalists4 ,footnote #bhj3 ,hist4 ,ind4 ,sc4 b4 x4 note 7,,va7 in the second edition4 ,footnote #bha3 ,b4 xi4 c4 v4 art4 #aa4 ,footnote #bhb3 ,i have given elsewhere 7see last chapter7 reasons why ,i cannot assign to ,m4 ,comte's ,philosophie ,positive any great value as a contribution to the philosophy of science4 ,in this judgment ,i conceive that ,i am supported by the best philosophers of our time4 ,m4 ,comte owes1 ,i think1 much of the notice which has been given to him to his including1 as ,mr4 ,mill does1 the science of society and of human nature in his scheme1 and to his boldness in dealing with these4 ,he appears to have been received with deference as a mathematician3 but ,sir ,john ,herschel has shown that a supposed astronomical discovery of his is a mere assumption4 ,i conceive that ,i have shown that his representation of the history of science is erroneous1 both in its details and in its generalities4 ,his distinction of the three stages of sciences1 the theological1 metaphysical1 and positive1 is not at all supported by the facts of scientific history4 ,real discoveries always involve what he calls metaphysics2 and the doctrine of final causes in physiology1 the main element of science which can properly be called theological1 is retained at the end1 as well as the beginning of the science1 by all except a peculiar school4 ,footnote #bhc3 ,i have also1 in the same place1 given the ,inductive ,pyramid for the science of ,optics4 ,these ,pyramids are necessarily inverted in their form1 in order that1 in reading in the ordinary way1 we may proceed to the vertex4 ,phil4 ,ind4 ,sc4 b4 xi4 c4 vi4 ,footnote #bhd3 ,cosmos1 vol4 ii4 note #ce4 ,footnote #bhe3 ,the reader will probably recollect that as ,induction means the inference of general propositions from particular cases1 ,deduction means the inference by the application of general propositions to particular cases1 and by combining such applications2 as when from the most general principles of ,geometry or of ,mechanics1 we prove some less general theorem2 for instance1 the number of the possible regular solids1 or the principle of vis viva4 ,footnote #bhf3 ,b4 vi4 c4 v4 ,footnote #bhg3 c4 vi4 ,footnote #bhh3 ,hist4 b4 vi4 c4 vi4 sect4 #ac4 ,footnote #bhi3 ,hist4 ,ind4 ,sc4 b4 viii4 ,footnote #bij3 ,reprinted in the ,appendix to this volume4 ,,chapter ,,xxiii4 ,,political ,,economy ,,as ,,an ,,inductive ,,science4 7,moral ,sciences47--#a4 ,both ,m4 ,comte and ,mr4 ,mill1 in speaking of the methods of advancing science1 aim1 as ,i have said1 at the extension of their methods to moral subjects1 and aspire to suggest means for the augmentation of our knowledge of ethical1 political1 and social truths4 ,i have not here ventured upon a like extension of my conclusions1 because ,i wished to confine my views of the philosophy of discovery to the cases in which all allow that solid and permanent discoveries have been made4 ,moreover in the case of moral speculations1 we have to consider not only observed external facts and the ideas by which they are colligated1 but also internal facts1 in which the instrument of observation is consciousness1 and in which observations and ideas are mingled together1 and act and react in a peculiar manner4 ,it may therefore be doubted whether the methods which have been effectual in the discovery of physical theories will not require to be greatly modified1 or replaced by processes altogether different1 when we would make advances in ethical1 political1 or social knowledge4 ,in ethics1 at least1 it seems plain that we must take our starting-point not without but within us4 ,our mental powers1 our affections1 our reason1 and any other faculties which we have1 must be the basis of our convictions4 ,and in this field of knowledge1 the very form of our highest propositions is different from what it is in the physical sciences4 ,in ,physics we examine what is1 in a form more or less general3 in ,ethics we seek to determine what ,,ought to be1 as the highest rule1 which is supreme over all others4 ,in this case we cannot expect the methods of physical discovery to aid us4 ,but others of the subjects which ,i have mentioned1 though strongly marked and influenced by this ethical element1 are still of a mixed character1 and require also observation of external facts of human1 individual1 and social conduct1 and generalizations derived from such observations4 ,the facts of political constitutions and social relations in communities of men1 and the histories of such communities1 afford large bodies of materials for political and social science2 and it seems not at all unlikely that such science may be governed1 in its formation and progress1 by laws like those which govern the physical sciences1 and may be steered clear of errors and directed towards truths by an attention to the forms which error and truth have assumed in the most stable and certain sciences4 ,the different forms of society1 and the principal motives which operate upon men regarded in masses1 may be classified as facts2 and though our consciousness of what we ourselves are and the affections which we ourselves feel are always at work in our interpretations of such facts1 yet the knowledge which we thus obtain may lead us to bodies of knowledge which we may call ,sciences1 and compare with the other sciences as to their form and maxims4 7,political ,economy47--#b4 ,among such bodies of knowledge1 ,i may notice as a specimen1 the science of ,political ,economy1 and may compare it with other sciences in the respects which have been referred to4 ,m4 ,comte has given a few pages to the discussion of this science of ,political ,economy#bia2 but what he has said amounts only to a few vague remarks on ,adam ,smith and ,destutt de ,tracy2 his main object being1 it would seem1 to introduce his usual formula1 and to condemn all that has hitherto been done 7with which there is no evidence that he is adequately acquainted7 as worthless1 because it is theological1 metaphysical1 literary1 and not positive4 ,mr4 ,mill has much more distinctly characterized the plan and form of ,political ,economy in his system#bib4 ,he regards this science as that which deals with the results which take place in human society in consequence of the desire of wealth4 ,he explains1 however1 that it is only for the sake of convenience that one of the motives which operate upon man is thus insulated and treated as if it were the only one3--that there are other principles1 for instance1 the principles on which the progress of population depends1 which co-operate with the main principle1 and materially modify its results3 and he gives reasons why this mode of simplifying the study of social phenomena tends to promote the progress of systematic knowledge4 ,instead of discussing these reasons1 ,i will notice the way in which the speculations of political economists have exemplified tendencies to error1 and corrections of those tendencies1 of the same nature as those which we have already noticed in speaking of other sciences4 7,wages1 ,profits1 and ,rent47--#c4 ,we may regard as one of the first important steps in this science1 ,adam ,smith's remark1 that the value or price of any article bought and sold consists of three elements1 ,wages1 ,profits1 and ,rent4 ,some of the most important of subsequent speculations were attempts to determine the laws of each of these three elements4 ,at first it might be supposed that there ought to be added to them a fourth element1 ,materials4 ,but upon consideration it will be seen that materials1 as an element of price1 resolves itself into wages and rent2 for all materials derive their value from the labour which is bestowed upon them4 ,the iron of the ploughshare costs just what it costs to sink the mine1 dig up and smelt the iron4 ,the wood of the frame costs what it costs to cut down the tree1 together with the rent of the ground on which it grows4 7,premature ,generalizations47--#d4 ,but what determines ,wages8--,the amount of persons seeking work1 that is1 speaking loosely1 the population2 and the amount of money which is devoted to the payment of wages4 ,and what determines the population8 ,it was replied1--the means of subsistence4 ,and how does the population tend to increase8--,in a geometrical ratio4 ,and how does the subsistence tend to increase8--,at most in an arithmetical ratio4 ,and hence it was inferred that the population tends constantly to run beyond the means of subsistence1 and will be limited by a threatened deficiency of these means4 ,and the wages paid must be such as to form this limit4 ,and therefore the wages paid will always be such as just to keep up the population in its ordinary state of progress4 ,here was one general proposition which was gathered from summary observations of society4 ,again3 as to ,rent3 ,adam ,smith had treated ,rent as if it were a monopoly price--the result of a monopoly of the land by the landowners4 ,but subsequent writers acutely remarked that land is of various degrees of fertility1 and there is some land which barely pays the cultivator1 if cultivating it he pay no rent4 ,and rent can be afforded for other land only in so far as it is better than this bad land4 ,and thus1 there was obtained another general proposition2 that the ,rent of good land was just equal to the excess of its produce over the worst cultivable land4 ,now these two propositions are examples of a hasty and premature generalization1 like that from which the sweeping physical systems of antiquity were derived4 ,they were examples of that process which ,francis ,bacon calls anticipation2 in which we leap at once from a few facts to propositions of the highest generality2 and supposing these to be securely established1 proceed to draw a body of conclusions from them1 and thus frame a system4 ,and what is the sounder and wiser mode of proceeding in order to obtain a science of such things8 ,we must classify the facts which we observe1 and take care that we do not ascribe to the facts in our immediate neighbourhood or specially under our notice1 a generality of prevalence which does not belong to them4 ,we must proceed by the ladder of ,induction1 and be sure we have obtained the narrower generalizations1 before we aspire to the widest4 7,correction of them by ,induction4 ,rent47--#e4 ,for instance2 in the case of the latter of the above two propositions--that ,rent is the excess of the produce of good soils over the worst--that is the case in ,england and ,scotland2 but is it the case in other countries8 ,let us see4 ,why is it the case in ,england8 ,because if the rent demanded for good land were more than the excess of the produce over bad land1 the farmer would prefer the bad land as more gainful4 ,if the rent demanded for good land were less than the excess1 the bad land would be abandoned by the farmer4 ,but all this goes upon the supposition that the farmer can remove from good land to bad1 or from bad to good1 or apply his capital in some other way than farming1 according as it is more gainful4 ,this is true in ,england2 but is it true all over the world8 ,by no means4 ,it is true in scarcely any other part of the world4 ,in almost every other part of the world the cultivator is bound to the land1 so that he cannot remove himself and his capital from it2 and cannot1 because he is not satisfied with his position upon it1 seek and find a position and a subsistence elsewhere4 ,on the contrary1 he is bound by the laws and customs of the country1 by constitution1 history and character1 so that he cannot1 or can only with great difficulty1 change his plan and mode of life4 ,and thus over great part of the world the fundamental supposition on which rests the above generalization respecting ,rent is altogether false4 ,an able political economist#bic has taken the step1 which as we have said1 sound philosophy would have prescribed3 he has classified the states of society which exist or have existed on the earth1 as they bear on this point1 the amount of ,rent4 ,he has classified the modes in which the produce is1 in different countries and different stages of society1 divided between the cultivator and the proprietor3 and he finds that the natural divisions are these3--,serf ,rents1 that is1 labour rents paid by the ,cultivator to the ,landowner1 as in ,russia3 ,mtayer ,rents1 where the produce is divided between the ,cultivator and the ,landowner1 as in ,central ,europe3 ,ryot ,rents1 where a portion of the produce is paid to the ,sovereign as ,landlord1 as in ,india3 ,cottier ,rents1 where a money-rent is paid by a ,cultivator who raises his own subsistence from the soil2 and ,farmers' ,rents1 where a covenanted ,rent is paid by a person employing labourers4 ,in this last case alone is it true that the ,rent is equal to the excess of good over bad soils4 ,the error of the conclusion1 in this case1 arises from assuming the mobility of capital and labour in cases in which it is not moveable3 which is much as if mechanicians had reasoned respecting rigid bodies1 supposing them to be fluid bodies4 ,but the error of method was in not classifying the facts of societies before jumping to a conclusion which was to be applicable to all societies4 7,wages47--#f4 ,and in like manner there is an error of the same kind in the assertion of the other general principles3--that wages are determined by the capital which is forthcoming for the payment of wages2 and that population is determined in its progress by wages4 ,for there is a vast mass of population on the surface of the earth which does not live upon wages3 and though in ,england the greater part of the people lives upon wages1 in the rest of the world the part that does so is small4 ,and in this case1 as in the other1 we must class these facts as they exist in different nations1 before we can make assertions of any wide generality4 ,mr4 ,jones#bid classed the condition of labourers in different countries in the same inductive manner in which he classed the tenure of land4 ,he pointed out that there are three broad distinct classes of them3 ,unhired ,labourers1 who cultivate the ground which they occupy1 and live on self-produced wages2 ,paid ,dependants1 who are paid out of the revenue or income of their employers1 as the military retainers and domestic artizans of feudal times in ,europe1 and the greater part of the people of ,asia at the present day2 and ,hired ,labourers1 who are paid wages from capital4 ,this last class1 though taken as belonging to the normal condition of society by many political economists1 is really the exceptional case1 taking the world at large2 and no propositions concerning the structure and relations of ranks in society can have any wide generality which are founded on a consideration of this case alone4 7,population47--#g4 ,and again3 with regard to the proposition that the progress of population depends merely on the rate of wages1 a very little observation of different communities1 and of the same communities at different times1 will show that this is a very rash and hasty generalization4 ,when wages rise1 whether or not population shall undergo a corresponding increase depends upon many other circumstances besides this single fact of the increase of wages4 ,the effect of a rise of wages upon population is affected by the form of the wages1 the time occupied by the change1 the institutions of the society under consideration1 and other causes3 and a due classification of the conditions of the society according to these circumstances1 is requisite in order to obtain any general proposition concerning the effect of a rise or fall of wages upon the progress of the population4 ,and thus those precepts of the philosophy of discovery which we have repeated so often1 which are so simple1 and which seem so obvious1 have been neglected or violated in the outset of ,political ,economy as in so many other sciences3--namely1 the precepts that we must classify our facts before we generalize1 and seek for narrower generalizations and inductions before we aim at the widest4 ,if these maxims had been obeyed1 they would have saved the earlier speculators on this subject from some splendid errors2 but1 on the other hand1 it may be said1 that if these earlier speculators had not been thus bold1 the science could not so soon have assumed that large and striking form which made it so attractive1 and to which it probably owes a large part of its progress4 ,,footnotes3 ,footnote #bia3 ,phil4 ,pos4 t4 iv4 p4 #bfd4 ,footnote #bib3 ,logic1 b4 vi4 c4 #c4 ,footnote #bic3 ,jones1 ,on ,rent1 #ahcc4 ,footnote #bid3 ,literary ,remains1 #ahei4 ,,chapter ,,xxiv4 ,,modern ,,german ,,philosophy#bie4 ,i4 ,science is the ,idealization of ,facts4 #a4 ,i have spoken1 a few chapters back1 of the ,reaction against the doctrines of the ,sensational ,school in ,england and ,france4 ,in ,germany also there was a ,reaction against these doctrines2--but there1 this movement took a direction different from its direction in other countries4 ,omitting many other names1 ,kant1 ,fichte1 ,schelling and ,hegel may be regarded as the writers who mark1 in a prominent manner1 this ,germanic line of speculation4 ,the problem of philosophy1 in the way in which they conceived it1 may best be explained by reference to that ,fundamental ,antithesis of which ,i had occasion to speak in the ,history of ,scientific ,ideas#bif4 ,and in order to characterize the steps taken by these modern ,german philosophers1 ,i must return to what ,i have said concerning the ,fundamental ,antithesis4 ,this ,antithesis1 as ,i have there remarked1 is stated in various ways3--as the ,antithesis of ,thoughts and ,things2 of ,ideas and ,sensations2 of ,theory and ,facts2 of ,necessary ,truth and ,experience2 of the ,subjective and ,objective elements of our knowledge2 and in other phrases4 ,i have further remarked that the elements thus spoken of1 though opposed1 are inseparable4 ,we cannot have the one without the other4 ,we cannot have thoughts without thinking of ,things3 we cannot have things before us without thinking of them4 ,further1 it has been shown1 ,i conceive1 that our knowledge derives from the former of these two elements1 namely our ,ideas1 its form and character of knowledge2 our ideas being the necessary ,forms of knowledge1 while the ,matter of our knowledge in each case is supplied by the appropriate perception or outward experience4 ,thus our ,ideas of ,space and ,time are the necessary ,forms of our geometrical and arithmetical knowledge2 and no sensations or experience are needed as the matter of such knowledge1 except in so far as sensation and experience are needed to evoke our ,ideas in any degree4 ,and hence these sciences are sometimes called ,formal sciences4 ,all other ,sciences involve1 along with the experience and observation appropriate to each1 a development of the ideal conditions of knowledge existing in our minds2 and ,i have given the history1 both of this development of ideas and of the matter derived from experience1 in two former works1 the ,history of ,scientific ,ideas1 and the ,history of the ,inductive ,sciences4 ,i have there traced this history through the whole body of the physical sciences4 ,but though ,ideas and ,perceptions are thus separate elements in our philosophy1 they cannot in fact be distinguished and separated1 but are different aspects of the same thing4 ,and the only way in which we can approach to truth is by gradually and successively1 in one instance after another1 advancing from the perception to the idea2 from the fact to the theory4 #b4 ,i would now further observe1 that in this progression from fact to theory1 we advance 7when the theory is complete and completely possessed by the mind7 from the apprehension of truths as actual to the apprehension of them as necessary2 and thus ,facts which were originally observed merely as ,facts become the consequences of theory1 and are thus brought within the domain of ,ideas4 ,that which was a part of the objective world becomes also a part of the subjective world2 a necessary part of the thoughts of the theorist4 ,and in this way the progress of true theory is the ,idealization of ,facts4 ,thus the ,progress of ,science consists in a perpetual reduction of ,facts to ,ideas4 ,portions are perpetually transferred from one side to another of the ,fundamental ,antithesis3 namely1 from the ,objective to the ,subjective side4 ,the ,centre or ,fulcrum of the ,antithesis is shifted by every movement which is made in the advance of science1 and is shifted so that the ideal side gains something from the real side4 #c4 ,i will proceed to illustrate this ,proposition a little further4 ,necessary ,truths belong to the ,subjective1 ,observed ,facts to the ,objective side of our knowledge4 ,now in the progress of that exact speculative knowledge which we call ,science1 ,facts which were at a previous period merely ,observed ,facts1 come to be known as ,necessary ,truths2 and the attempts at new advances in science generally introduce the representation of known truths of fact1 as included in higher and wider truths1 and therefore1 so far1 necessary4 ,we may exemplify this progress in the history of the science of ,mechanics4 ,thus the property of the lever1 the inverse proportion of the weights and arms1 was known as a fact before the time of ,aristotle1 and known as no more2 for he gives many fantastical and inapplicable reasons for the fact4 ,but in the writings of ,archimedes we find this fact brought within the domain of necessary truth4 ,it was there transferred from the empirical to the ideal side of the ,fundamental ,antithesis2 and thus a progressive step was made in science4 ,in like manner1 it was at first taken by ,galileo as a mere fact of experience1 that in a falling body1 the velocity increases in proportion to the time2 but his followers have seen in this the necessary effect of the uniform force of gravity4 ,in like manner1 ,kepler's empirical ,laws were shown by ,newton to be necessary results of a central force attracting inversely as the square of the distance4 ,and if it be still1 even at present1 doubtful whether this is the necessary law of a central force1 as some philosophers have maintained that it is1 we cannot doubt that if now or hereafter1 those philosophers could establish their doctrine as certain1 they would make an important step in science1 in addition to those already made4 ,and thus1 such steps in science are made1 whenever empirical facts are discerned to be necessary laws2 or1 if ,i may be allowed to use a briefer expression1 whenever facts are idealized4 #d4 ,in order to show how widely this statement is applicable1 ,i will exemplify it in some of the other sciences4 ,in ,chemistry1 not to speak of earlier steps in the science1 which might be presented as instances of the same general process1 we may remark that the analyses of various compounds into their elements1 according to the quantity of the elements1 form a vast multitude of facts1 which were previously empirical only1 but which are reduced to a law1 and therefore to a certain kind of ideal necessity1 by the discovery of their being compounded according to definite and multiple proportions4 ,and again1 this very law of definite proportions1 which may at first be taken as a law given by experience only1 it has been attempted to make into a necessary truth1 by asserting that bodies must necessarily consist of atoms1 and atoms must necessarily combine in definite small numbers4 ,and however doubtful this ,atomic ,theory may at present be1 it will not be questioned that any chemical philosopher who could establish it1 or any other ,theory which would produce an equivalent change in the aspect of the science1 would make a great scientific advance4 ,and thus1 in this ,science also1 the ,progress of ,science consists in the transfer of facts from the empirical to the necessary side of the antithesis2 or1 as it was before expressed1 in the idealization of facts4 #e4 ,we may illustrate the same process in the ,natural ,history ,sciences4 ,the discovery of the principle of ,morphology in plants was the reduction of a vast mass of ,facts to an ,idea2 as ,schiller said to ,gthe when he explained the discovery2 although the latter1 cherishing a horror of the term ,idea1 which perhaps is quite as common in ,england as in ,germany1 was extremely vexed at being told that he possessed such furniture in his mind4 ,the applications of this ,principle to special cases1 for instance1 to ,euphorbia by ,brown1 to ,reseda by ,lindley1 have been attempts to idealize the facts of these special cases4 #f4 ,we may apply the same view to steps in ,science which are still under discussion2--the question being1 whether an advance has really been made in science or not4 ,for instance1 in ,astronomy1 the ,nebular ,hypothesis has been propounded1 as an explanation of many of the observed phenomena of the ,universe4 ,if this ,hypothesis could be conceived ever to be established as a true ,theory1 this must be done by its taking into itself1 as necessary parts of the whole ,idea1 many ,facts which have already been observed2 such as the various form of nebul2--many ,facts which it must require a long course of years to observe1 such as the changes of nebul from one form to another2--and many facts which1 so far as we can at present judge1 are utterly at variance with the ,idea1 such as the motions of satellites1 the relations of the material elements of planets1 the existence of vegetable and animal life upon their surfaces4 ,but if all these ,facts1 when fully studied1 should appear to be included in the general ,idea of ,nebular ,condensation according to the ,laws of ,nature1 the ,facts so idealized would undoubtedly constitute a very remarkable advance in science4 ,but then1 we are to recollect that we are not to suppose that the ,facts will agree with the ,idea1 merely because the ,idea1 considered by itself1 and without carefully attending to the ,facts1 is a large and striking ,idea4 ,and we are also to recollect that the ,facts may be compared with another ,idea1 no less large and striking2 and that if we take into our account1 7as1 in forming an ,idea of the ,course of the ,universe1 we must do17 not only vegetable and animal1 but also human life1 this other ,idea appears likely to take into it a far larger portion of the known ,facts1 than the ,idea of the ,nebular ,hypothesis4 ,the other ,idea which ,i speak of is the ,idea of ,man as the principal ,object in the ,creation2 to whose sustenance and development the other parts of the ,universe are subservient as means to an end2 and although1 in our attempts to include all known ,facts in this ,idea1 we again meet with many difficulties1 and find many trains of ,facts which have no apparent congruity with the ,idea2 yet we may say that1 taking into account the ,facts of man's intellectual and moral condition1 and his history1 as well as the mere ,facts of the material world1 the difficulties and apparent incongruities are far less when we attempt to idealize the ,facts by reference to this ,idea1 of ,man as the ,end of ,creation1 than according to the other ,idea1 of the ,world as the result of ,nebular ,condensation1 without any conceivable ,end or ,purpose4 ,i am now1 of course1 merely comparing these two views of the ,universe1 as supposed steps in science1 according to the general notion which ,i have just been endeavouring to explain1 that a step in science is some ,idealization of ,facts4 #g4 ,perhaps it will be objected1 that what ,i have said of the ,idealization of ,facts1 as the manner in which the progress of science goes on1 amounts to no more than the usual expressions1 that the progress of science consists in reducing ,facts to ,theories4 ,and to this ,i reply1 that the advantage at which ,i aim1 by the expression which ,i have used1 is this1 to remind the reader1 that ,fact and ,theory1 in every subject1 are not marked by separate and prominent features of difference1 but only by their present opposition1 which is a transient relation4 ,they are related to each other no otherwise than as the poles of the fundamental antithesis3 the point which separates those poles shifts with every advance of science2 and then1 what was ,theory becomes ,fact4 ,as ,i have already said elsewhere1 a true ,theory is a ,fact2 a ,fact is a familiar ,theory4 ,if we bear this in mind1 we express the view on which ,i am now insisting when we say that the progress of science consists in reducing ,facts to ,theories4 ,but ,i think that speaking of ,ideas as opposed to ,facts1 we express more pointedly the original ,antithesis1 and the subsequent identification of the ,facts with the ,idea4 ,the expression appears to be simple and apt1 when we say1 for instance1 that the ,facts of ,geography are identified with the ,idea of globular ,earth2 the ,facts of ,planetary ,astronomy with the ,idea of the ,heliocentric system2 and ultimately1 with the ,idea of ,universal ,gravitation4 #h4 ,we may further remark1 that though by successive steps in science1 successive ,facts are reduced to ,ideas1 this process can never be complete4 ,however the point may shift which separates the two poles1 the two poles will always remain4 ,however1 far the ideal element may extend1 there will always be something beyond it4 ,however far the phenomena may be idealized1 there will always remain some which are not idealized1 and which are mere phenomena4 ,this also is implied by making our expressions refer to the fundamental antithesis3 for because the antithesis is fundamental1 its two elements will always be present2 the objective as well as the subjective4 ,and thus1 in the contemplation of the universe1 however much we understand1 there must always be something which we do not understand2 however far we may trace necessary truths1 there must always be things which are to our apprehension arbitrary3 however far we may extend the sphere of our internal world1 in which we feel power and see light1 it must always be surrounded by our external world1 in which we see no light1 and only feel resistance4 ,our subjective being is inclosed in an objective shell1 which1 though it seems to yield to our efforts1 continues entire and impenetrable beyond our reach1 and even enlarges in its extent while it appears to give up to us a portion of its substance4 ,,ii4 ,successive ,german ,philosophies4 #i4 ,the doctrine of the ,fundamental ,antithesis of two elements of which the union is involved in all knowledge1 and of which the separation is the task of all philosophy1 affords us a special and distinct mode of criticizing the philosophies which have succeeded each other in the world2 and we may apply it to the ,german ,philosophies of which we have spoken4 ,the doctrine of the ,fundamental ,antithesis is briefly this3 ,that in every act of knowledge 7#a7 there are two opposite elements which we may call ,ideas and ,perceptions2 but of which the opposition appears in various other antitheses2 as ,thoughts and ,things1 ,theories and ,facts1 ,necessary ,truths and ,experiential ,truths2 and the like3 7#b7 that our knowledge derives from the former of these elements1 namely our ,ideas1 its form and character as knowledge1 our ,ideas of space and time being the necessary forms1 for instance1 of our geometrical and arithmetical knowledge2 7#c7 and in like manner1 all our other knowledge involving a development of the ideal conditions of knowledge existing in our minds3 7#d7 but that though ideas and perceptions are thus separate elements in our philosophy1 they cannot1 in fact1 be distinguished and separated1 but are different aspects of the same thing2 7#e7 that the only way in which we can approach to truth is by gradually and successively1 in one instance after another1 advancing from the perception to the idea2 from the fact to the theory2 from the apprehension of truths as actual to the apprehension of them as necessary4 7#f7 ,this successive and various progress from fact to theory constitutes the history of science2 7#g7 and this progress1 though always leading us nearer to that central unity of which both the idea and the fact are emanations1 can never lead us to that point1 nor to any measurable proximity to it1 or definite comprehension of its place and nature4 #aj4 ,now the doctrine being thus stated1 successive sentences of the statement contain successive steps of ,german philosophy1 as it has appeared in the series of celebrated authors whom ,i have named4 ,ideas1 and ,perceptions or ,sensations1 being regarded as the two elements of our knowledge1 ,locke1 or at least the successors of ,locke1 had rejected the former element1 ,ideas1 and professed to resolve all our knowledge into ,sensation4 ,after this philosophy had prevailed for a time1 ,kant exposed1 to the entire conviction of the great body of ,german speculators1 the untenable nature of this account of our knowledge4 ,he taught 7one of the first sentences of the above statement7 that 7#b7 ,our knowledge derives from our ,ideas its form and character as knowledge2 our ,ideas of space and time being1 for instance1 the necessary forms of our geometrical and arithmetical knowledge4 ,fichte carried still further this view of our knowledge1 as derived from our ,ideas1 or from its nature as knowledge2 and held that 7#c7 all our knowledge is a development of the ideal conditions of knowledge existing in our minds 7one of our next following sentences74 ,but when the ideal element of our knowledge was thus exclusively dwelt upon1 it was soon seen that this ideal system no more gave a complete explanation of the real nature of knowledge1 than the old sensational doctrine had done4 ,both elements1 ,ideas and ,sensations1 must be taken into account4 ,and this was attempted by ,schelling1 who1 in his earlier works1 taught 7as we have also stated above7 that 7#d7 ,ideas and ,facts are different aspects of the same thing3--this thing1 the central basis of truth in which both elements are involved and identified1 being1 in ,schelling's language1 the ,absolute1 while each of the separate elements is subjected to conditions arising from their union4 ,but this ,absolute1 being a point inaccessible to us1 and inconceivable by us1 as our philosophy teaches 7as above71 cannot to any purpose be made the basis of our philosophy3 and accordingly this ,philosophy of the ,absolute has not been more permanent than its predecessors4 ,yet the philosophy of ,hegel1 which still has a wide and powerful sway in ,germany1 is1 in the main1 a development of the same principle as that of ,schelling2--the identity of the idea and the fact2 and ,hegel's ,identity-,system1 is rather a more methodical and technical exposition of ,schelling's ,philosophy of the ,absolute than a new system4 ,but ,hegel traces the manifestation of the identity of the idea and fact in the progress of human knowledge2 and thus in some measure approaches to our doctrine 7above stated71 that 7#e7 the way in which we approach to truth is by gradually and successively1 in one instance after another1 that is1 historically1 advancing from the perception to the idea1 from the fact to the theory3 while at the same time ,hegel has not carried out this view in any comprehensive or complete manner1 so as to show that 7#f7 this process constitutes the history of science3 and as with ,schelling1 his system shows an entire want of the conviction 7above expressed as part of our doctrine71 7#g7 that we can never1 in our speculations reach or approach to the central unity of which both idea and fact are emanations4 #aa4 ,this view of the relation of the ,sensational ,school1 of the ,schools of ,kant1 ,fichte1 ,schelling1 and ,hegel1 and of the fundamental defects of all1 may be further illustrated4 ,it will1 of course1 be understood that our illustration is given only as a slight and imperfect sketch of these philosophies2 but their relation may perhaps become more apparent by the very brevity with which it is stated2 and the object of the present chapter is not the detailed criticism of systems1 but this very relation of systems to each other4 ,the actual and the ideal1 the external and the internal elements of knowledge1 were called by the ,germans the objective and the subjective elements respectively4 ,the forms of knowledge and especially space and time1 were pronounced by ,kant to be essentially subjective2 and this view of the nature of knowledge1 more fully unfolded and extended to all knowledge1 became the subjective ideality of ,fichte4 ,but the subjective and the objective are1 as we have said1 in their ultimate and supreme form1 one2 and hence we are told of the subjective-objective1 a phrase which has also been employed by ,mr4 ,coleridge4 ,fichte had spoken of the subjective element as the ,me1 7das ,ich72 and of the objective element as the ,not-me1 7das ,nicht-,ich72 and has deduced the ,not-me from the ,me4 ,schelling1 on the contrary1 laboured with great subtlety to deduce the ,me from the ,absolute which includes both4 ,and this ,absolute1 or ,subjective-objective1 is spoken of by ,schelling as unfolding itself into endless other antitheses4 ,it was held that from the assumption of such a principle might be deduced and explained the oppositions which1 in the contemplation of nature1 present themselves at every step1 as leading points of general philosophy3--for example1 the opposition of matter as passive and active1 as dead and organized1 as unconscious or conscious2 the opposition of individual and species1 of will and moral rule4 ,and this antithetical development was carried further by ,hegel1 who taught that the ,absolute ,idea developes itself so as to assume qualities1 limitations1 and seeming oppositions1 and then completes the cycle of its development by returning into unity4 #ab4 ,that there is1 in the history of ,science1 much which easily lends itself to such a formula1 the views which ,i have endeavoured to expound1 show and exemplify in detail4 ,but yet the attempts to carry this view into detail by conjecture--by a sort of divination--with little or no attention to the historical progress and actual condition of knowledge1 7and such are those which have been made by the philosophers whom ,i have mentioned17 have led to arbitrary and baseless views of almost every branch of knowledge4 ,such oppositions and differences as are found to exist in nature1 are assumed as the representatives of the elements of necessary antitheses1 in a manner in which scientific truth and inductive reasoning are altogether slighted4 ,thus1 this peculiar and necessary antithetical character is assumed to be displayed in attraction and repulsion1 in centripetal and centrifugal forces1 in a supposed positive and negative electricity1 in a supposed positive and negative magnetism2 in still more doubtful positive and negative elements of light and heat2 in the different elements of the atmosphere1 which are1 quite groundlessly1 assumed to have a peculiar antithetical character3 in animal and vegetable life3 in the two sexes2 in gravity and light4 ,these and many others1 are given by ,schelling1 as instances of the radical opposition of forces and elements which necessarily pervades all nature4 ,i conceive that the heterogeneous and erroneous principles involved in these views of the material world show us how unsafe and misleading is the philosophical assumption on which they rest4 ,and the ,triads of ,hegel1 consisting of ,thesis1 ,antithesis1 and ,union1 are still more at variance with all sound science4 ,thus we are told that matter and motion are determined as inertia1 impulsion1 fall2 that ,absolute ,mechanics determines itself as centripetal force1 centrifugal force1 universal gravitation4 ,light1 it is taught1 is a secondary determination of matter4 ,light is the most intimate element of nature1 and might be called the ,me of nature3 it is limited by what we may call negative light1 which is darkness4 #ac4 ,in these rash and blind attempts to construct physical science priori1 we may see how imperfect the ,hegelian doctrines are as a complete philosophy4 ,in the views of moral and political subjects the results of such a scheme are naturally less obviously absurd1 and may often be for a moment striking and attractive1 as is usually the case with attempts to reduce history to a formula4 ,thus we are told that the ,state appears under the following determinations3--first as one1 substantial1 self-included3 next1 varied1 individual1 active1 disengaging itself from the substantial and motionless unity3 next1 as two principles1 altogether distinct1 and placed front to front in a marked and active opposition3 then1 arising out of the ruins of the preceding1 the idea appears afresh1 one1 identical1 harmonious4 ,and the ,east1 ,greece1 ,rome1 ,germany1 are declared to be the historical forms of these successive determinations4 ,whatever amount of real historical colour there may be for this representation1 it will hardly1 ,i think1 be accepted as evidence of a profound political philosophy2 but on such parts of the subject ,i shall not here dwell4 #ad4 ,i may observe that in the series of philosophical systems now described1 the two elements of the ,fundamental ,antithesis are alternately dwelt upon in an exaggerated degree1 and then confounded4 ,the ,sensational ,school could see in human knowledge nothing but facts3 ,kant and ,fichte fixed their attention almost entirely upon ideas3 ,schelling and ,hegel assume the identity of the two1 7a point we never can reach17 as the origin of their philosophy4 ,the external world in ,locke's school was all in all4 ,in the speculations of ,kant this external world became a dim and unknown region4 ,things were acknowledged to be something in themselves1 but what1 the philosopher could not tell4 ,besides the phnomenon which we see1 ,kant acknowledged a noumenon which we think of2 but this assumption1 for such it is1 exercises no influence upon his philosophy4 #ae4 ,we may for the sake of illustration imagine to ourselves each system of philosophy as a ,drama in which ,things are the ,dramatis ,person and the ,idea which governs the system is the ,plot of the drama4 ,in ,kant's ,drama1 ,things in themselves are merely a kind of ',mute ,personages1' 1 which stand on the stage to be pointed at and talked about1 but which do not tell us anything1 or enter into the action of the piece4 ,fichte carries this further1 and if we go on with the same illustration1 we may say that he makes the whole drama into a kind of ,monologue2 in which the author tells the story1 and merely names the persons who appear4 ,if we would still carry on the image1 we may say that ,schelling1 going upon the principle that the whole of the drama is merely a progress to the ,denouement1 which denouement contains the result of all the preceding scenes and events1 starts with the last scene of the piece2 and bringing all the characters on the stage in their final attitudes1 would elicit the story from this4 ,while the true mode of proceeding is1 to follow the drama ,scene by ,scene1 learning as much as we can of the ,action and the ,characters1 but knowing that we shall not be allowed to see the ,denouement1 and that to do so is probably not the lot of our species on earth4 ,so far as any philosopher has thus followed the historical progress of the grand spectacle offered to the eyes of speculative man1 in which the ,phenomena of ,nature are the ,scenes1 and the ,theory of them the ,plot1 he has taken the course by which knowledge really has made its advances4 ,but those who have partially done this1 have often1 like ,hegel1 assumed that they had divined the whole course and end of the story1 and have thus criticised the scenes and the characters in a spirit quite at variance with that by which any real insight into the import of the representation can be obtained4 ,if it be asked which position we can assign1 in this dramatic illustration1 to those who hold that all our knowledge is derived from facts only1 and who reject the supposition of ideas2 we may say that they look on with a belief that the drama has no plot1 and that these scenes are improvised without connexion or purpose4 #af4 ,i will only offer one more illustration of the relative position of these successive philosophies4 ,kant compares the change which he introduced into philosophy to the change which ,copernicus introduced into astronomical theory4 ,when ,copernicus found that nothing could be made of the phenomena of the heavens so long as everything was made to turn round the spectator1 he tried whether the matter might not be better explained if he made the spectator turn1 and left the stars at rest4 ,so ,kant conceives that our experience is regulated by our own faculties1 as the phenomena of the heavens are regulated by our own motions4 ,but accepting and carrying out this illustration1 we may say that ,kant1 in explaining the phenomena of the heavens by means of the motions of the earth1 has almost forgotten that the planets have their own proper motions1 and has given us a system which hardly explains anything besides broadest appearances1 such as the annual and daily motions of the sun2 and that ,fichte appears as if he wished to deduce all the motions of the planets1 as well as of the sun1 from the conditions of the spectator2--while ,schelling goes to the origin of the system1 like ,descartes1 and is not content to show how the bodies move1 without also proving that from some assumed original condition1 all the movements and relations of the system must necessarily be what they are4 ,it may be that a theory which explains how the planets1 with their orbits and accompaniments1 have come into being1 may offer itself to bold speculators1 like those who have framed and produced the nebular hypothesis4 ,but ,i need not remind my readers either how precarious such a hypothesis is2 or1 that if it be capable of being considered probable1 its proofs must gradually dawn upon us1 step by step1 age after age3 and that a system of doctrine which assumes such a scheme as a certain and fundamental truth1 and deduces the whole of astronomy from it1 must needs be arbitrary1 and liable to the gravest error at every step4 ,such a precarious and premature philosophy1 at best1 is that of ,schelling and ,hegel2 especially as applied to those sciences in which1 by the past progress of all sure knowledge1 we are taught what the real cause and progress of knowledge is3 while at the same time we may allow that all these forms of philosophy1 since they do recognize the condition and motion of the spectator1 as a necessary element in the explanation of the phenomena1 are a large advance upon the ,ptolemaic scheme--the view of those who appeal to phenomena alone as the source of our knowledge1 and say that the sun1 the moon1 and the planets move as we see them move1 and that all further theory is imaginary and fantastical4 ,,footnotes3 ,footnote #bie3 ,the substance of this and the next chapter was printed as a communication to the ,cambridge ,phil4 ,soc4 in #ahdj4 ,footnote #bif3 ,or in the earlier editions1 in the ,philosophy of the ,inductive ,sciences4 ,,chapter ,,xxv4 ,,the ,,fundamental ,,antithesis ,,as ,,it ,,exists ,,in ,,the ,,moral ,,world4 #a4 ,we have hitherto spoken of the ,fundamental ,antithesis as the ground of our speculations concerning the material world1 at least mainly4 ,we have indeed been led by the physical sciences1 and especially by ,biology1 to the borders of ,psychology4 ,we have had to consider not only the mechanical effects of muscular contraction1 but the sensations which the nerves receive and convey3--the way in which sensations become perceptions2 the way in which perceptions determine actions4 ,in this manner we have been led to the subject of volition or will#big1 and this brings us to a new field of speculation1 the moral nature of man2 and this moral nature is a matter not only of speculative but of practical interest4 ,on this subject ,i shall make only a few brief remarks4 #b4 ,even in the most purely speculative view1 the moral aspect of man's nature differs from the aspect of the material universe1 in this respect1 that in the moral world1 external events are governed in some measure by the human will4 ,when we speculate concerning the laws of material nature1 we suppose that the phenomena of nature follow a course and order which we may perhaps1 in some measure1 discover and understand1 but which we cannot change or control4 ,but when we consider man as an agent1 we suppose him able to determine some at least of the events of the external world2 and thus1 able to determine the actions of other men1 and to lay down laws for them4 ,he cannot alter the properties of fire and metals1 stones and fluids1 air and light2 but he can use fire and steel so as to compel other men's actions2 stone-walls and ocean-shores so as to control other men's motions2 gold and gems so as to have a hold on other men's desires2 articulate sounds and intelligible symbols so as to direct other men's thoughts and move their will4 ,there is an external world of ,facts2 and in this1 the ,facts are such as he makes them by his ,acts4 #c4 ,but besides this1 there is also1 standing over against this external world of ,facts1 an internal world of ,ideas4 ,the ,moral ,acts without are the results of ,moral ,ideas within4 ,men have an ,idea of ,justice1 for instance1 according to which they are led to external acts1 as to use force1 to make a promise1 to perform a contract1 as individuals2 or to make war and peace1 to enact laws and to execute them1 as a nation4 #d4 ,some such internal moral ,idea necessarily exists1 along with all properly human actions4 ,man feels not only pain and anger1 but indignation and the sentiment of wrong1 which feelings imply a moral idea of right and wrong4 ,again1 what he thinks of as wrong1 he tries to prevent2 what he deems right1 he attempts to realize4 ,the ,idea gives a character to the ,act2 the ,act embodies the ,idea4 ,in the moral world as in the natural world1 the ,antithesis is universal and inseparable4 ,it is an ,antithesis of inseparable elements4 ,in human action1 there is ever involved the ,idea of what is right1 and the external ,act in which this idea is in some measure embodied4 #e4 ,but the moral ,ideas1 such as that of ,justice1 of ,rightness1 and the like1 are always embodied incompletely in the world of external action4 ,although men's actions are to a great extent governed by the ,ideas of ,justice1 ,rightness and the like2 7for it must be recollected that we include in their actions1 laws1 and the enforcement of laws27 yet there is a large portion of human actions which is not governed by such ideas3 7actions which result from mere desire1 and violations of law74 ,there is a perpetual ,antithesis of ,ideas and ,facts1 which is the fundamental basis of moral as of natural philosophy4 ,in the former as in the latter subject1 besides what is ideal1 there is an ,actual which the ideal does not include4 ,this ,actual is the region in which the results of mere desire1 of caprice1 of apparent accident1 are found4 ,it is the region of history1 as opposed to justice2 it is the region of what is1 as distinct from what ought to be4 #f4 ,now what ,i especially wish here to remark1 is this2--that the progress of man as a moral being consists in a constant extension of the ,idea into the region of ,facts4 ,this progress consists in making human actions conform more and more to the moral ,ideas of ,justice1 ,rightness1 and the like2 including in human actions1 as we have said1 ,laws1 the enforcement of ,laws1 and other collective acts of bodies of men4 ,the ,history of ,man as ,man consists in this extension of moral ,ideas into the region of ,facts4 ,it is not that the actual history of what men do has always consisted in such an extension of moral ,ideas2 for there has ever been1 in the actual doings of men1 a large portion of facts which had no moral character2 acts of desire1 deeds of violence1 transgressions of acknowledged law1 and the like4 ,but such events are not a part of the genuine progress of humanity4 ,they do not belong to the history of man as man1 but to the history of man as brute4 ,on the other hand1 there are events which belong to the history of man as man1 events which belong to the genuine progress of humanity2 such as the establishment of just laws2 their enforcement2 their improvement by introducing into them a fuller measure of moral ,ideas4 ,by such means there is a constant progress of man as a moral being4 ,by this realization of moral ,ideas there is a constant progress of ,humanity4 #g4 ,i have made this reflection1 because it appears to me to bring into view an analogy between the ,progress of ,science and the ,progress of ,man1 or of ,humanity1 in the sense in which ,i have used the term4 ,in both these lines of ,progress1 ,facts are more and more identified with ,ideas4 ,in both1 there is a fundamental ,antithesis of ,ideas and ,facts1 and progress consists in a constant advance of the point which separates the two elements of this ,antithesis4 ,in both1 ,facts are constantly won over to the domain of ,ideas4 ,but still1 there is a difference in the two cases2 for in the one case the ,facts are beyond our control4 ,we cannot make them other than they are2 and all that we can do1 if we can do that1 is to shape our ,ideas so that they shall coincide with the ,facts1 and still have the manifest connexion which belongs to them as ,ideas4 ,in the other case1 the ,facts are1 to a certain extent1 in our power4 ,they are what we make them1 for they are what we do4 ,in this case1 the ,facts ought to come towards the ,ideas1 rather than the ,ideas towards the ,facts4 ,as we called the former process the ,idealization of ,facts1 we may call this the ,realization of ,ideas2 and the analogy which ,i have here wished to bring into view may be expressed by saying1 that the ,progress of ,physical ,science consists in a constant successive ,idealization of ,physical ,facts2 and the ,progress of man's ,moral ,being is a constant successive ,realization of ,moral ,ideas4 #h4 ,thus the necessary co-existence of an objective and a subjective element belongs not only to human knowledge1 as was before explained1 but also to human action4 ,the objective and the subjective element are inseparable in this case as in the other4 ,we have always the ,fact of ,positive ,law1 along with the ,idea of ,absolute ,justice2 the ,facts of ,gain or ,loss1 along with the ,idea of ,rights4 ,the ,idea of ,justice is inseparable from historical facts1 for justice gives to each his own1 and history determines what that is4 ,we cannot even conceive justice without society1 or society without law1 and thus in the moral and in the natural world the fundamental antithesis is inseparable1 even in thought4 ,the two elements must always subsist2 for however far the moral ideas be realized in the world1 there will always remain much in the world which is not conformable to moral ideas1 even if it were only through its necessary dependence on an unmoral and immoral past4 ,as in the physical world so in the moral1 however much the ideal sphere expands1 it is surrounded by a region which is not conformable to the idea1 although in one case the expansion takes place by educing ideas out of facts1 in the other1 by producing facts from ideas4 ,i shall hereafter venture to pursue further this train of speculation1 but at present ,i shall make some remarks on writers who may be regarded as the successors amongst ourselves of these ,german schools of ,philosophy4 ,,footnotes3 ,footnote #big3 ,phil4 of ,biol4 c4 v4 ,,chapter ,,xxvi4 ,,of ,,the ,,philosophy ,,of ,,the ,,infinite4 ,in the last ,chapter but one ,i stated that ,schelling propounded a ,philosophy of the ,absolute1 the ,absolute being the original basis of truth in which the two opposite elements1 ,ideas and ,facts1 are identified1 and that ,hegel also founded his philosophy on the ,identity of these two elements4 ,these ,german philosophies appear to me1 as ,i have ventured to intimate1 of small or no value in their bearing on the history of actual science4 ,i have in the history of the sciences noted instances in which these writers seem to me to misconceive altogether the nature and meaning of the facts of scientific history2 as where#bih ,schelling condemns ,newton's ,opticks as a fabric of fallacies3 and where#bii ,hegel says that the glory due to ,kepler has been unjustly transferred to ,newton4 ,as it appears to me important that ,english philosophers should form a just estimate of ,hegel's capacity of judging and pronouncing on this subject1 ,i will print in the ,appendix a special discussion of what he has said respecting ,newton's discovery of the law of gravitation4 ,recently attempts have been made to explain to ,english readers these systems of ,german philosophy1 and in these attempts there are some points which may deserve our notice as to their bearing on the philosophy of science4 ,i find some difficulty in discussing these attempts1 for they deal much with phrases which appear to me to offer no grasp to man's power of reason4 ,what1 for instance1 is the ,absolute1 which occupies a prominent place in these expositions8 ,it is1 as ,i have stated1 in ,schelling1 the central basis of truth in which things and thoughts are united and identified4 ,to attempt to reason about such an ,absolute appears to me to be an entire misapprehension of the power of reason4 ,again2 one of the most eminent of the expositors has spoken of each system of this kind as a ,philosophy of the ,unconditioned#cjj4 ,but what1 we must ask1 is the ,unconditioned8 ,that which is subject to no conditions1 is subject to no conditions which distinguish it from any thing else1 and so1 cannot be a matter of thought4 ,but again2 this ,absolute or ,unconditioned is 7if ,i rightly understand7 said to be described also by various other names2 unity1 identity1 substance1 absolute cause1 the infinite1 pure thought1 c4 ,as each of these terms expresses some condition on which the name fixes our thoughts1 ,i cannot understand why they should any of them be called the ,unconditioned2 and as they express very different thoughts1 ,i cannot understand why they should be called by the same name4 ,from speculations starting from such a point1 ,i can expect nothing but confusion and perplexity2 nor can ,i find that anything else has come of them4 ,they appear to me more barren1 and more certain to be barren1 of any results which have any place in our real knowledge1 than the most barren speculations of the schoolmen of the middle ages3 which indeed they much resemble in all their features--their acuteness1 their learning1 their ambitious aim1 and their actual failure4 #b4 ,but leaving the ,absolute and the ,unconditioned1 as notions which cannot be dealt with by our reason without being something entirely different from their definitions1 we may turn for a moment to another notion which is combined with them by the expositors of whom ,i speak1 and which has some bearing upon our positive science1 because it enters into the reasonings of mathematics3 ,i mean the notion of ,infinite4 ,some of those who hold that we can know nothing concerning the ,absolute and the ,unconditioned1 7which they pretend to prove1 though concerning such words ,i do not conceive that anything can be true or false17 hold also that the ,infinite is in the same condition2--that we can know nothing concerning what is ,infinite2--therefore1 ,i presume1 nothing concerning infinite space1 infinite time1 infinite number1 or infinite degrees4 ,to disprove this doctrine1 it might be sufficient to point out that there is a vast mass of mathematical science which includes the notion of infinites1 and leads to a great body of propositions concerning ,infinites4 ,the whole of the infinitesimal calculus depends upon conceiving finite magnitudes divided into an infinite number of parts3 these parts are infinitely small1 and of these parts there are other infinitesimal parts infinitely smaller still1 and so on1 as far as we please to go4 ,and even those methods which shun the term infinite1 as ,newton's method of ,ultimate ,ratios1 the method of ,indivisibles1 and the method of ,exhaustions of the ancient geometers1 do really involve the notion of infinite2 for they imply a process continued without limit4 #c4 ,but perhaps it will be more useful to point out the fallacies of the pretended proofs that we can know nothing concerning ,infinity and infinite things4 ,the argument offered is1 that of infinity we have no notion but the negation of a limit1 and that from this negative notion no positive result can be deduced4 ,but to this ,i reply3 ,it is not at all true that our notion of what is infinite is merely that it is that which has no limit4 ,we must ask further that what8 that space8 that time8 that number8--,and if that space1 that what kind of space8 ,that line8 that surface8 that solid space8--,and if that line1 that line bounded at one end1 or not8 ,if that surface1 that surface bounded on one1 or on two1 or on three sides8 or on none8 ,however any of these questions are answered1 we may still have an infinite space4 ,till they are answered1 we can assert nothing about the space2 not because we can assert nothing about infinites2 but because we are not told what kind of infinite we are talking of4 ,in reality the definition of an ,infinite ,quantity is not negative merely1 but contains a positive part as well4 ,we assume a quantity of a certain kind which may be augmented by carrying onward its limits in one or more directions3 this is a finite quantity of a given kind4 ,we then--when we have thus positively determined the kind of the quantity--suppose the limit in one or more directions to be annihilated1 and thus we have an infinite quantity4 ,but in this infinite quantity there remain the positive properties from which we began1 as well as the negative property1 the negation of a limit2 and the positive properties joined with the negative property may and do supply grounds of reasoning respecting the infinite quantity4 #d4 ,this is lore so elementary to mathematicians that it appears almost puerile to dwell upon it2 but this seems to have been overlooked1 in the proof that we can have no knowledge concerning infinites4 ,in such proof it is assumed as quite evident1 that all infinites are equal4 ,yet1 as we have seen1 infinites may differ infinitely among themselves1 both in quantity and in kind4 ,a ,german writer is quoted#cja for an ingenious proof of this kind4 ,in his writings1 the opponent is supposed to urge that a line ,,bac may be made infinite by carrying the extremity ,c infinitely to the right1 and again infinite by carrying the extremity ,b infinitely to the left2 and thus the line infinitely extended both ways would be double of the line infinite on one side only4 ,the supposed reply to this is1 that it cannot be so1 because one infinite is equal to another3 and moreover that what is bounded at one end ,a1 cannot be infinite3 both which assumptions are without the smallest ground4 ,that one infinite quantity may be double of another1 is just as clear and certain as that one finite quantity may4 ,for instance1 if one leaf of the book which the reader has before him were produced infinitely upwards it would be an infinite space1 though bounded at the bottom and at both sides4 ,if the other leaf were in like manner produced infinitely upwards it would in like manner be infinite2 and the two together1 though each infinite1 would be double of either of them4 #e4 ,as ,i have said1 infinite quantities are conceived by conceiving finite quantities increased by the transfer of a certain limit1 and then by negativing this limit altogether4 ,and thus an infinite number is conceived by assuming the series #a1 #b1 #c1 #d1 and so on1 up to a limit1 and then removing this limit altogether4 ,and this shows the baselessness of another argument quoted from ,werenfels4 ,the opponent asks1 ,are there in the infinite line an infinite number of feet8 ,then in the double line there must be twice as many2 and thus the former infinite number did not contain all the 7possible7 unities2 7numerus infinitus non omnes habet unitates1 sed prter eum concipi possunt totidem unitates1 quibus ille careat1 eique possunt addi74 ,to which ,i reply1 that the definition of an infinite number is not that it contains all possible unities3 but this--that the progress of numeration being begun according to a certain law1 goes on without limit4 ,and accordingly it is easy to conceive how one infinite number may be larger than another infinite number1 in any proportion4 ,if1 for instance1 we take1 instead of the progression of the natural numbers #a1 #b1 #c1 #d1 c4 and the progression of the square numbers #a1 #d1 #i1 #af1 c4 any term of the latter series will be greater than the corresponding term of the other series in a ratio constantly increasing1 and the infinite term of the one1 infinitely greater than the corresponding infinite term of the other4 #f4 ,in the same manner we form a conception of infinite time1 by supposing time to begin now1 and to go on1 after the nature of time1 without limit2 or by going back in thought from the present to a past time1 and by continuing this retrogression without limit4 ,and thus we have time infinite a parte ante and a parte post1 as the phrase used to run2 and time infinite both ways includes both1 and is the most complete notion of eternity4 #g4 ,perhaps those who thus maintain that we cannot conceive anything infinite1 mean that we cannot form to ourselves a definite image of anything infinite4 ,and this of course is true4 ,we cannot form to ourselves an image of anything of which one of the characteristics is that it is1 in a certain way1 unlimited4 ,but this impossibility does not prevent our reasoning about infinite quantities2 combining as elements of our reasoning1 the absence of a limit with other positive characters4 #h4 ,one of the consequences which is drawn by the assertors of the doctrine that we cannot know anything about ,infinity1 is that we cannot obtain from science any knowledge concerning ,god3 ,and ,i have been the more desirous to show the absence of proof of this doctrine1 because ,i conceive that science does give us some knowledge1 though it be very little1 of the nature of ,god3 as ,i shall endeavour to show hereafter4 ,for instance1 ,i conceive that when we say that ,god is an eternal ,being1 this phraseology is not empty and unmeaning4 ,it has been used by the wisest and most thoughtful men in all ages1 and1 as ,i conceive1 may be used with undiminished1 or with increased propriety1 after all the light which science and philosophy have thrown upon such declarations4 ,the reader of ,newton will recollect how emphatically he uses this expression along with others of a cognate character#cjb3 ,god is eternal and infinite1 444 that is1 ,he endures from eternity to eternity1 and is present from infinity to infinity4444 ,he is not eternity and infinity1 but eternal and infinite4 ,he is not duration and space1 but ,he endures and is present4 ,he endures always1 and is present everywhere1 and by existing always and everywhere ,he constitutes duration and space4 ,we shall see shortly that the view to which we are led may be very fitly expressed by this language4 ,but ,i will first notice some other aspects of this philosophy4 ,,footnotes3 ,footnote #bih3 ,hist4 ,ind4 ,sc4 b4 ix4 c4 iii4 ,footnote #bii3 ,ibid4 b4 vii4 c4 ii4 ,footnote #cjj3 ,sir ,w4 ,hamilton's ,note on the ,philosophy of the ,unconditioned4 ,footnote #cja3 ,werenfels in ,mr4 ,mansel's ,bampton ,lectures1 lect4 ii4 ,note #ae4 ,footnote #cjb3 ,scholium ,generale at the end of the ,principia4 ,,chapter ,,xxvii4 ,,sir ,,william ,,hamilton ,,on ,,inertia ,,and ,,weight4 ,in a preceding chapter ,i have spoken of ,sir ,william ,hamilton as the expositor1 to ,english readers1 of modern ,german systems1 and especially of the so-called ,philosophy of the ,unconditioned4 ,but the same writer is also noticeable as a continuator of the speculations of ,english and ,scottish philosophers concerning primary and secondary qualities2 and these speculations bear so far upon the philosophy of science that it is proper to notice them here4 #a4 ,in our survey of the sciences1 we have spoken of a class which we have termed the ,secondary ,mechanical ,sciences2 these being the sciences which explain certain sensible phenomena1 as sound1 light1 and heat1 by means of a medium interposed between external bodies and our organs of sense4 ,in these cases1 we ascribe to bodies certain qualities3 we call them resonant1 bright1 red or green1 hot or cold4 ,but in the sciences which relate to these subjects1 we explain these qualities by the figure1 size and motions of the parts of the medium which intervenes between the object and the ear1 eye1 or other sensible organ4 ,and those former qualities1 sound1 warmth and colour1 are called secondary qualities of the bodies2 while the latter1 figure1 size and motion1 are called the primary qualities of body4 #b4 ,this distinction1 in its substance1 is of great antiquity4 ,the atomic theory which was set up at an early period of ,greek philosophy was an attempt to account for the secondary qualities of bodies by means of their primary qualities4 ,and this is really the scientific ground of the distinction4 ,those are primary qualities or attributes of body by means of which we1 in a scientific view1 explain and derive their other qualities4 ,but the explanation of the sensible qualities of bodies by means of their operation through a medium has till now been very defective1 and is so still4 ,we have to a certain extent theories of ,sound1 ,light and ,heat1 which reduce these qualities to scales and standards1 and in some measure account mechanically for their differences and gradations4 ,but we have as yet no similar theory of ,smells and ,tastes4 ,still1 we do not doubt that fragrance and flavour are perceived by means of an aerial medium in which odours float1 and a fluid medium in which sapid matters are dissolved4 ,and the special odour and flavour which are thus perceived must depend upon the size1 figure1 motion1 number1 c4 of the particles thus conveyed to the organs of taste and smell3 that is1 those secondary qualities1 as well as the others1 must depend upon the primary qualities of the parts of the medium4 #c4 ,in this way the distinction of primary and secondary qualities is definite and precise4 ,but when men attempt to draw the distinction by guess1 without any scientific principle1 the separation of the two classes is vague and various4 ,i have1 in the ,history of ,scientific ,ideas#cjc1 pointed out some of the variations which are to be found on this subject in the writings of philosophers4 ,sir ,william ,hamilton#cjd has given an account of many more which he has compared and analysed with great acuteness4 ,he has shown how this distinction is treated1 among others1 by the ancient atomists1 ,leucippus and ,democritus1 by ,aristotle1 ,galen1 ,galileo1 ,descartes1 ,boyle1 ,malebranche1 ,locke1 ,reid1 ,stewart1 ,royer-,collard4 ,he then proceeds to give his own view2 which is1 that we may most properly divide the qualities of bodies into three classes1 which he calls ,primary1 ,secundo-primary1 and ,secondary4 ,the former he enumerates as #a1 ,extension2 #b1 ,divisibility2 #c1 ,size2 #d1 ,density or ,rarity2 #e1 ,figure2 #f1 ,incompressibility absolute2 #g1 ,mobility2 #h1 ,situation4 ,the ,secundo-primary are ,gravity1 ,cohesion1 ,inertia1 ,repulsion4 ,the ,secondary are those commonly so called1 ,colour1 ,sound1 ,flavour1 ,savour1 and ,tactical ,sensation2 to which he says may be added the muscular and cutaneous sensation which accompany the perception of the ,secundo-primary qualities4 ,such1 though less directly the result of foreign causes1 are ,titillation1 ,sneezing1 ,horripilation1 ,shuddering1 the feeling of what is called ,setting-the-teeth-on-edge1 c4 ,the ,secundo-primary qualities ,sir ,william ,hamilton traces in further detail4 ,he explains that with reference to ,gravity1 bodies are heavy or light4 ,with reference to ,cohesion1 there are many coordinate pairs1 of which he enumerates these3--hard and soft2 firm and fluid1--the fluid being subdivided into thick and thin2 viscid and friable2 tough and brittle2 rigid and flexible2 fissile and infissile2 ductile and inductile2 retractile and irretractile2 rough and smooth2 slippery and tenacious4 ,with reference to ,repulsion he gives these qualities3--compressible and incompressible2 elastic and inelastic4 ,and with reference to ,inertia he mentions only moveable and immoveable4 ,i do not see what advantage is gained to philosophy by such an enumeration of qualities as this1 which1 after all1 does not pretend to completeness2 nor do ,i see anything either precise or fundamental in such distinctions as that of elasticity1 a mode of cohesion1 and elasticity1 a mode of repulsion4 ,but a question in which our philosophy is really concerned is how far any of these qualities are universal qualities of matter4 ,sir ,w4 ,hamilton holds that they are none of them necessary qualities of matter1 and therefore of course not universal1 and argues this point at some length4 ,with regard to one of his ,secundo-primary qualities1 ,i will make some remarks4 #d4 ,inertia4--,in discussing the ,ideas which enter into the ,mechanical ,sciences#cje1 ,i have stated that the ,idea of ,force and ,resistance to ,force1 that is1 of ,force and ,matter1 are the necessary foundations of those sciences4 ,force cannot act without matter to act on2 ,matter cannot exist without ,force to keep its parts together and to keep it in its place4 ,but ,force acting upon matter may either be ,force producing rest1 or ,force producing motion4 ,if we consider ,force producing motion1 the motion produced1 that is1 the velocity produced1 must depend upon the quantity of matter moved4 ,it cannot be that the same power1 acting in the same way1 shall produce the same velocity by pushing a small pebble and a large rock4 ,if this were so1 we could have no science on such matters4 ,it must needs be that the same force produces a smaller velocity in the larger body2 and this according to some measure of its largeness4 ,the measure of the degree in which the body thus resists this communication of motion is inertia4 ,and the inertia is necessarily supposed to be proportional to the quantity of matter1 because it is by this inertia that this existence and quantity of the matter is measured4 ,if therefore any ,science concerning ,force and ,matter is to exist1 matter must have inertia1 and the inertia must be proportional to the quantity of matter4 #e4 ,sir ,w4 ,hamilton1 in opposition to this1 says1 that we can conceive a body occupying space1 and yet without attraction or repulsion for another body1 and wholly indifferent to this or that position1 in space1 to motion and to rest4 ,he infers thence that inertia is not a necessary quality of bodies4 ,to this ,i reply1 that even if we can conceive such bodies1 7which in fact man1 living in a world of matter cannot conceive17 at any rate we cannot conceive any science about such bodies4 ,if bodies were indifferent to motion and rest1 ,forces could not be measured by their effects2 nor could be measured or known in any way4 ,such bodies might float about like clouds1 visible to the eye1 but intangible1 and governed by no laws of motion4 ,but if we have any science about bodies1 they must be tangible1 and governed by laws of motion4 ,not1 then1 from any observed properties of bodies1 but from the possibility of any science about bodies1 does it follow that all bodies have inertia4 #f4 ,gravity4--,reasoning of the same kind may be employed about weight4 ,we can conceive1 it is urged1 matter without weight4 ,but ,i reply1 we cannot conceive a science which deals with matter that has no weight3--a science1 ,i mean1 which deals with the quantity of matter of bodies1 as arising from the sum of their elements4 ,for the quantity of matter of bodies is and must be measured by those sensible properties of matter which undergo quantitative addition1 subtraction and division1 as the matter is added1 subtracted1 and divided4 ,the quantity of matter cannot be known in any other way4 ,but this mode of measuring the quantity of matter1 in order to be true at all1 must be universally true4 ,if it were only partially true--if some kinds of matter had weight and others had not--the limits of the mode of measuring matter by weight would be arbitrary3 and therefore the whole procedure would be arbitrary1 and as a mode of obtaining philosophical truth1 altogether futile4 ,but we suppose truth respecting the composition of bodies to be attainable2 therefore we must suppose the rule1 which is the necessary basis of such truth1 to be itself true4 ,sir ,w4 ,hamilton has replied to these arguments1 but1 as ,i conceive1 without affecting the force of them4 ,i will repeat here the answer which ,i have already given#cjf1 and will reprint in the ,appendix the ,memoir by which his objections were occasioned4 ,he says1 7#a71 that our reasoning assumes that we must necessarily have it in our power to ascertain the ,quantity of ,matter2 whereas this may be a problem out of the reach of human determination4 ,to this ,i reply1 that my reasoning does assume that there is a science1 or sciences1 which make assertions concerning the ,quantity of ,matter3 ,mechanics and ,chemistry are such sciences4 ,my assertion is1 that to make such sciences possible1 ,quantity of ,matter must be proportional to ,weight4 ,if my opponent deny that ,mechanics and ,chemistry can exist as science1 he may invalidate my proof2 but not otherwise4 7#b7 ,he says that there are two conceivable ways of estimating the ,quantity of ,matter3 by the ,space occupied1 and by the ,weight or ,inertia2 and that ,i assume the second measure gratuitously4 ,to which ,i reply1 that the most elementary steps in ,mechanics and in ,chemistry contradict the notion that the ,quantity of ,matter is proportionate to the ,space4 ,they proceed necessarily on a distinction between ,space and ,matter3--between mere ,extension and material ,substance4 7#c7 ,he allows that we cannot make the ,extension of a body the measure of the ,quantity of ,matter1 because1 he says1 we do not know if the compressing force is such as to produce the closest compression4 ,that is1 he assumes a compressing force1 assumes a closest compression1 assumes a peculiar 7and very improbable7 atomic hypothesis2 and all this1 to supply a reason why we are not to believe the first simple principle of ,mechanics and ,chemistry4 7#d7 ,he speaks of a series of apparent fluids 7as ,light or its vehicle1 the ,calorific1 the ,electro-galvanic1 and ,magnetic agents7 which we can neither denude of their character of substance1 nor clothe with the attribute of weight4 ,to which my reply is1 that precisely because ,i cannot clothe these agents with the attribute of ,weight1 ,i do denude them of the character of ,substance4 ,they are not substances1 but agencies4 ,these ,imponderable ,agents are not properly called ,imponderable ,fluids4 ,this ,i conceive that ,i have proved2 and the proof is not shaken by denying the conclusion without showing any defect in the reasoning4 7#e7 ,finally1 my critic speaks about a logical canon1 and about a criterion of truth1 subjectively necessary and objectively certain2 which matters ,i shall not waste the reader's time by discussing4 ,,footnotes3 ,footnote #cjc3 ,b4 iv4 c4 i4 ,footnote #cjd3 ,reid's ,works1 ,supplementary ,dissertation ,d4 ,footnote #cje3 ,hist4 ,sc4 ,id4 b4 iii4 ,footnote #cjf3 ,hist4 ,sc4 ,id4 b4 vi4 c4 iii4 ,,chapter ,,xxviii4 ,,influence ,,of ,,german ,,systems ,,of ,,philosophy ,,in ,,britain4 ,the philosophy of ,kant1 as ,i have already said1 involved a definite doctrine on the subject of the ,fundamental ,antithesis1 and a correction of some of the errors of ,locke and his successors4 ,it was not however at first favourably received among ,british philosophers1 and those who accepted it were judged somewhat capriciously and captiously4 ,i will say a word on these points#cjg4 #a4 7,stewart7--,dugald ,stewart1 in his ,dissertation on the ,progress of the ,moral ,sciences1 repeatedly mentions ,kant's speculations1 and always unfavourably4 ,in ,note ,i to ,part ,i4 of the ,dissertation he says1 ,in our own times1 ,kant and his followers seem to have thought that they had thrown a strong light on the nature of space and also of time1 when they introduced the word form 7form of the intellect7 as a common term applicable to both4 ,is not this to revert to the scholastic folly of verbal generalization8 ,and in ,part ,,ii4 he gives a long and laborious criticism of a portion of ,kant's speculations2 of which the spirit may be collected from his describing them as resulting in the metaphysical conundrum1 that the human mind 7considered as a noumenon and not as a phenomenon7 neither exists in space nor time4 ,and after mentioning ,meiners and ,herder along with ,kant1 he adds1 ,i am ashamed to say that in ,great ,britain the only one of these names which has been much talked of is ,kant4 ,and again in ,note ,,ee1 he translates some portion of the ,german philosopher1 adding1 that to the expressions so employed he can attach no meaning4 ,stewart1 in his criticism of ,kant's doctrines1 remarks that1 in asserting that the human mind possesses1 in its own ideas1 an element of necessary and universal truth1 not derived from experience1 ,kant had been anticipated by ,price1 by ,cudworth1 and even by ,plato2 to whose ,thetetus both ,price and ,cudworth refer1 as containing views similar to their own4 ,and undoubtedly this doctrine of ideas1 as indispensable sources of necessary truths1 was promulgated and supported by weighty arguments in the ,thetetus2 and has ever since been held by many philosophers1 in opposition to the contrary doctrine1 also extensively held1 that all truth is derived from experience4 ,but1 in pointing out this circumstance as diminishing the importance of ,kant's speculations1 ,stewart did not sufficiently consider that doctrines1 fundamentally the same1 may discharge a very different office at different periods of the history of philosophy4 ,plato's ,dialogues did not destroy1 nor even diminish1 the value of ,cudworth's ,immutable ,morality4 ,notwithstanding ,cudworth's publications1 ,price's doctrines came out a little afterwards with the air and with the effect of novelties4 ,cudworth's assertion of ideas did not prevent the rise of ,hume's skepticism2 and it was ,hume's skepticism which gave occasion to ,kant's new assertion of necessary and universal truth1 and to his examination into the grounds of the possibility and reality of such truth4 ,to maintain such doctrine after the appearance of intermediate speculations1 and with reference to them1 was very different from maintaining it before2 and this is the merit which ,kant's admirers claim for him4 ,nor can it be denied that his writings produced an immense effect upon the mode of treating such questions in ,germany2 and have had1 even in this country1 an influence far beyond what ,mr4 ,stewart would have deemed their due4 #b4 7,mr4 ,g4 ,h4 ,lewes47--,but as injustice has thus been done to ,kant by confounding his case with that of his predecessors of like opinions1 so on the other hand1 injustice has also been done1 both to him and those who have followed him in the assertion of ideas1 by confounding their case with his4 ,this injustice seems to me to be committed by a writer on the ,history of ,philosophy1 who has given an account of the successive schools of philosophy up to our own time2--has assigned to ,kant an important and prominent place in the recent history of metaphysics2--but has still maintained that ,kant's philosophy1 and indeed every philosophy1 is and must be a failure4 ,in order to prove this thesis1 the author naturally has to examine ,kant's doctrines and the reasons assigned for them1 and to point out what he conceives to be the fallacy of these arguments4 ,this accordingly he professes to do2 but as soon as he has entered upon the argument1 he substitutes1 as his opponent1 for the philosopher of ,knigsberg1 a writer of our own time and country1 who does not profess himself a ,kantian1 who has been repeatedly accused1 with whatever justice1 of misrepresenting what he has borrowed from ,kant1 and whose main views are1 in the opinion of the writer himself1 very different from ,kant's4 ,mr4 ,lewes#cjh1 in the chapter entitled ,examination of ,kant's ,fundamental ,principles1 after a preliminary statement of the points he intends to consider1 says ,now to the question4 ,as ,kant confessedly was led to his own system by the speculations of ,hume1 and so on2 and forthwith he introduces the name of ,dr4 ,whewell as the writer whose views he has to criticize1 without stating how he connects him with ,kant1 and goes on arguing against him for a dozen pages to the end of the ,chapter4 #c4 ,it is true1 however1 that ,i had adopted some of ,kant's views1 or at least some of his arguments4 ,the chapters#cji on the ,ideas of ,space and ,time in the ,philosophy of the ,inductive ,sciences1 were almost literal translations of chapters in the ,kritik der ,reinen ,vernunft4 ,yet the author was charged by a reviewer at the time1 with explaining these doctrines in a manner incompatible with the clear views of ,emanuel ,kant4 ,it appeared to be assumed by the ,english admirers of the ,kantian philosophy1 that ,kant's views were true and clear in ,germany1 but became untenable when adopted in ,england4 #d4 7,mr4 ,mansel7--,but the most important of my critics on this ground is ,mr4 ,mansel1 who has revived the censure of my speculations as not doing justice to the ,kantian philosophy4 ,it is much to be regretted1 he says#caj1 that ,dr4 ,whewell1 who has made good use of ,kantian principles in many parts of his ,philosophy of the ,inductive ,sciences1 has not more accurately observed ,kant's distinction between the necessary laws under which all men think1 and the contingent laws under which certain men think of certain things4 ,and further on ,mr4 ,mansel1 after giving great praise to the general spirit of the ,philosophy of the ,inductive ,sciences1 says1 ,it is to be regretted that the accuracy of his theory has been in so many instances vitiated by a stumble at the threshold of the ,critical ,philosophy4 ,mr4 ,mansel is1 indeed1 by much the most zealous ,english ,kantian whose writings ,i have seen2--among those1 ,i mean1 who have brought original powers of philosophical thought to bear upon such subjects2 and have not been1 as some have been1 enslaved by an admiration of ,german systems1 just as bigotted as the contempt of them which others feel4 ,and as ,mr4 ,mansel has stated distinctly some of the points in which he conceives that ,i have erred in deviating from the doctrines of ,kant1 ,i should wish to make a few remarks on those points4 #e4 ,kant considers that ,space and ,time are conditions of perception1 and hence sources of necessary and universal truth4 ,dr4 ,whewell agrees with ,kant in placing in the mind certain sources of necessary truth2 he calls these ,fundamental ,ideas1 and reckons1 besides ,space and ,time1 others1 as ,cause1 ,likeness1 ,substance1 and several more4 ,mr4 ,mill1 the most recent and able expounder of the opposite doctrine1 derives all truths from ,observation1 and denies that there is such a separate source of truth as ,ideas4 ,mr4 ,mansel does not agree either with ,mr4 ,mill or ,dr4 ,whewell2 he adheres to the original ,kantian thesis1 that ,space and ,time are sources of necessary truths1 but denies the office to the other ,fundamental ,ideas of ,dr4 ,whewell4 ,in reading what has been said by ,mr4 ,mill1 ,mr4 ,mansel1 and other critics1 on the subject of what ,i have called ,fundamental ,ideas1 ,i am led to perceive that ,i have expressed myself incautiously1 with regard to the identity of character between the first two of these ,fundamental ,ideas1 namely1 ,space and ,time1 and the others1 as ,force1 ,composition1 and the like4 ,and ,i am desirous of explaining1 to those who take an interest in these speculations1 how far ,i claim for the other ,fundamental ,ideas the same character and attributes as for ,space and ,time4 #f4 ,the special and characteristic property of all the ,fundamental ,ideas is what ,i have already mentioned1 that they are the mental sources of necessary and universal scientific truths4 ,i call them ,ideas1 as being something not derived from sensation1 but governing sensation1 and consequently giving form to our experience2--,fundamental1 as being the foundation of knowledge1 or at least of ,science4 ,and the way in which those ,ideas become the foundations of ,science is1 that when they are clearly and distinctly entertained in the mind1 they give rise to inevitable convictions or intuitions1 which may be expressed as ,axioms2 and these ,axioms are the foundations of ,sciences respective of each ,idea4 ,the ,idea of ,space1 when clearly possessed1 gives rise to geometrical ,axioms1 and is thus the foundation of the ,science of ,geometry4 ,the ,idea of ,mechanical ,force1 7a modification of the ,idea of ,cause17 when clearly developed in the mind1 gives birth to ,axioms which are the foundation of the ,science of ,mechanics4 ,the ,idea of ,substance gives rise to the ,axiom which is universally accepted1--that we cannot1 by any process1 7for instance1 by chemical processes17 create or destroy matter1 but can only combine and separate elements2--and thus gives rise to the ,science of ,chemistry4 #g4 ,now it may be observed1 that in giving this account of the foundation of ,science1 ,i lay stress on the condition that the ,ideas must be clearly and distinctly possessed4 ,the ,idea of ,space must be quite clear in the mind1 or else the ,axioms of ,geometry will not be seen to be true3 there will be no intuition of their truth2 and for a mind in such a state1 there can be no ,science of ,geometry4 ,a man may have a confused and perplexed1 or a vacant and inert state of mind1 in which it is not clearly apparent to him1 that two straight lines cannot inclose a space4 ,but this is not a frequent case4 ,the ,idea of ,space is much more commonly clear in the minds of men than the other ,ideas on which science depends1 as ,force1 or ,substance4 ,it is much more common to find minds in which these latter ,ideas are not so clear and distinct as to make the ,axioms of ,mechanics or of ,chemistry self-evident4 ,indeed the examples of a state of mind in which the ,ideas of ,force or of ,substance are so clear as to be made the basis of science1 are comparatively few4 ,they are the examples of minds scientifically cultivated1 at least to some extent4 ,hence1 though the ,axioms of ,mechanics or of ,chemistry may be1 in their own nature1 as evident as those of ,geometry1 they are not evident to so many persons1 nor at so early a period of intellectual or scientific culture4 ,and this being the case1 it is not surprising that some persons should doubt whether these ,axioms are evident at all2--should think that it is an error to assert that there exist1 in such sciences as ,mechanics or ,chemistry1 ,fundamental ,ideas1 fit to be classed with ,space1 as being1 like it1 the origin of ,axioms4 ,in speaking of all the ,fundamental ,ideas as being alike the source of ,axioms when clearly possessed1 without dwelling sufficiently upon the amount of mental discipline which is requisite to give the mind this clear possession of most of them2 and in not keeping before the reader the different degrees of evidence which1 in most minds1 the ,axioms of different sciences naturally have1 ,i have1 as ,i have said1 given occasion to my readers to misunderstand me4 ,i will point out one or two passages which show that this misunderstanding has occurred1 and will try to remove it4 #h4 ,the character of axiomatic truths seen by intuition is1 that they are not only seen to be true1 but to be necessary2--that the contrary of them is not only false1 but inconceivable4 ,but this inconceivableness depends entirely upon the clearness of the ,ideas which the axioms involve4 ,so long as those ,ideas are vague and indistinct1 the contrary of an ,axiom may be assented to1 though it cannot be distinctly conceived4 ,it may be assented to1 not because it is possible1 but because we do not see clearly what is possible4 ,to a person who is only beginning to think geometrically1 there may appear nothing absurd in the assertion1 that two straight lines may inclose a space4 ,and in the same manner1 to a person who is only beginning to think of mechanical truths1 it may not appear to be absurd1 that in mechanical processes1 ,reaction should be greater or less than ,action2 and so1 again1 to a person who has not thought steadily about ,substance1 it may not appear inconceivable1 that by chemical operations1 we should generate new matter1 or destroy matter which already exists4 ,here then we have a difficulty3--the test of ,axioms is that the contrary of them is inconceivable2 and yet persons1 till they have in some measure studied the subject1 do not see this inconceivableness4 ,hence our ,axioms must be evident only to a small number of thinkers2 and seem not to deserve the name of self-evident or necessary truths4 ,this difficulty has been strongly urged by ,mr4 ,mill1 as supporting his view1 that all knowledge of truth is derived from experience4 ,and in order that the opposite doctrine1 which ,i have advocated1 may not labour under any disadvantages which really do not belong to it1 ,i must explain1 that ,i do not by any means assert that those truths which ,i regard as necessary1 are all equally evident to common thinkers1 or evident to persons in all stages of intellectual development4 ,i may even say1 that some of those truths which ,i regard as necessary1 and the necessity of which ,i believe the human mind to be capable of seeing1 by due preparation and thought1 are still such1 that this amount of preparation and thought is rare and peculiar2 and ,i will willingly grant1 that to attain to and preserve such a clearness and subtlety of mind as this intuition requires1 is a task of no ordinary difficulty and labour4 #i4 ,this doctrine1--that some truths may be seen by intuition1 but yet that the intuition of them may be a rare and difficult attainment1--,i have not1 it would seem1 conveyed with sufficient clearness to obviate misapprehension4 ,mr4 ,mill has noticed a passage of my ,philosophy on this subject1 which he has understood in a sense different from that which ,i intended4 ,speaking of the two ,principles of ,chemical ,science1--that combinations are definite in kind1 and in quantity1--,i had tried to elevate myself to the point of view in which these ,principles are seen1 not only to be true1 but to be necessary4 ,i was aware that even the profoundest chemists had not ventured to do this2 yet it appeared to me that there were considerations which seemed to show that any other rule would imply that the world was a world on which the human mind could not employ itself in scientific speculation at all4 ,these considerations ,i ventured to put forwards1 not as views which could at present be generally accepted1 but as views to which chemical philosophy appeared to me to tend4 ,mr4 ,mill1 not unnaturally1 ,i must admit1 supposed me to mean that the two ,principles of ,chemistry just stated1 are self-evident1 in the same way and in the same degree as the ,axioms of ,geometry are so4 ,i afterwards explained that what ,i meant to do was1 to throw out an opinion1 that if we could conceive the composition of bodies distinctly1 we might be able to see that it is necessary that the modes of this composition should be definite4 ,this ,mr4 ,mill does not object to#caa3 but he calls it a great attenuation of my former opinion2 which he understood to be that we1 7that is1 men in general17 already see1 or may see1 or ought to see1 this necessity4 ,such a general apprehension of the necessity of definite chemical composition ,i certainly never reckoned upon2 and even in my own mind1 the thought of such a necessity was rather an anticipation of what the intuitions of philosophical chemists in another generation would be1 than an assertion of what they now are or ought to be2 much less did ,i expect that persons1 neither chemists nor philosophers1 would already1 or perhaps ever1 see that a proposition1 so recently discovered to be true1 is not only true1 but necessary4 #aj4 ,of the bearing of this view on the question at issue between ,mr4 ,mill and me1 ,i may hereafter speak2 but ,i will now notice other persons who have misunderstood me in the same way4 ,an able writer in the ,edinburgh ,review#cab has1 in like manner1 said1 ,dr4 ,whewell seems to us to have gone much too far in reducing to necessary truths what assuredly the generality of mankind will not feel to be so4 ,it is a fact which ,i do not at all contest1 that the generality of mankind will not feel the ,axioms of ,chemistry1 or even of ,mechanics1 to be necessary truths4 ,but ,i had said1 not that the generality of mankind would feel this necessity1 but 7in a passage just before quoted by the ,reviewer7 that the mind under certain circumstances attains a point of view from which it can pronounce mechanical 7and other7 fundamental truths to be necessary in their nature1 though disclosed to us by experience and observation4 ,both the ,edinburgh ,reviewer and ,mr4 ,mansel appear to hold a distinction between the fundamental truths of ,geometry1 and those of the other subjects which ,i have classed with them4 ,the latter says1 that perhaps metaphysicians may hereafter establish the existence of other subjective conditions of intuitions 7or1 as ,i should call them1 ,fundamental ,ideas17 besides ,space and ,time1 but that in asserting such to exist in the science of ,mechanics1 ,i certainly go too far3 and he gives as an instance my ,essay1--,demonstration that all matter is heavy4 ,i certainly did not expect that the ,principles asserted in that ,essay would be assented to as readily or as generally as the ,axioms of ,geometry2 but ,i conceive that ,i have there proved that ,chemical ,science1 using the balance as one of its implements1 cannot admit imponderable bodies among its elements4 ,this impossibility will1 ,i think1 not only be found to exist in fact1 but seen to exist necessarily1 by chemists1 in proportion as they advance towards general propositions of ,chemical ,science in which the so-called imponderable fluids enter4 ,but even if ,i be right in this opinion1 to how few will this necessity be made apparent1 and how slowly will the intuition spread6 ,i am as well aware as my critics1 that the necessity will probably never be apparent to ordinary thinkers4 #aa4 ,though ,mr4 ,mansel does not acknowledge any subjective conditions of intuition besides ,space and ,time1 he does recognize other kinds of necessity1 which ,i should equally refer to ,fundamental ,ideas2 because they are1 no less than ,space and ,time1 the foundations of universal and necessary truths in science4 ,such are#cac the ,principle of ,substance2--,all ,qualities exist in some subject3 and the ,principle of ,causality2-- ,every ,event has its ,cause4 ,to these ,principles he ascribes a metaphysical necessity1 the nature and grounds of which he analyses with great acuteness4 ,but what ,i have to observe is1 that whatever differences may be pointed out between the grounds of the necessity1 in this case of metaphysical necessity1 and in that which ,mr4 ,mansel calls mathematical necessity which belongs to the ,conditions or ,ideas of ,space and of ,time2 still1 it is not the less true that the ,ideas of ,substance and of ,cause1 do afford a foundation for necessary truths1 and that on these truths are built ,sciences4 ,that every ,change must have a ,cause1 with the corresponding ,axioms1--that the ,cause is known by the ,effect1 and ,measured by it1--is the basis of the ,science of ,mechanics4 ,that there is a ,substance to which qualities belong1 with the corresponding ,axiom1--that we cannot create or destroy ,substance1 though we may alter ,qualities by combining and separating ,substances1--is the basis of the ,science of ,chemistry4 ,and that this doctrine of the ,indestructibility of ,substance is a primary axiomatic truth1 is certain2 both because it has been universally taken for granted by men seeking for general truths2 and because it is not and cannot be proved by experience#cad4 ,so that ,i have here1 even according to ,mr4 ,mansel's own statement1 other grounds besides ,space and ,time1 for necessary truths in ,science4 #ab4 ,besides mathematical and metaphysical necessity1 ,mr4 ,mansel recognizes also a logical necessity4 ,i will not pretend to say that this kind of necessity is exactly represented by any of those ,fundamental ,ideas which are the basis of ,science2 but yet ,i think it will be found that this logical necessity mainly operates through the attribution of ,names to things2 and that a large portion of its cogency arises from these maxims1--that names must be so imposed that ,general ,propositions shall be possible1--and so that ,reasoning shall be possible4 ,now these maxims are really the basis of ,natural ,history1 and are so stated in the ,philosophy of the ,inductive ,sciences4 ,the former maxim is the principle of all ,classification2 and though we have no syllogisms in ,natural ,history1 the apparatus of genus1 species1 differentia1 and the like1 which was introduced in the analysis of syllogistic reasoning1 is really more constantly applied in ,natural ,history than in any other science4 #ac4 ,besides the different kinds of necessity which ,mr4 ,mansel thus acknowledges1 ,i do not see why he should not1 on his own principles1 recognize others2 as indeed he appears to me to do4 ,he acknowledges1 ,i think1 the distinction of ,primary and ,secondary qualities2 and this must involve him in the doctrine that ,secondary ,qualities are necessarily perceived by means of a ,medium4 ,again3 he would1 ,i think1 acknowledge that in organized bodies1 the parts exist for a ,purpose2 and ,purpose is an ,idea which cannot be inferred by reasoning from facts1 without being possessed and applied as an ,idea4 ,so that there would1 ,i conceive1 exist1 in his philosophy1 all the grounds of necessary truth which ,i have termed ,fundamental ,ideas2 only that he would further subdivide1 classify1 and analyse1 the kinds and grounds of this necessity4 ,in this he would do well2 and some of his distinctions and analyses of this kind are1 in my judgment1 very instructive4 ,but ,i do not see what objection there can be to my putting together all these kinds of necessity1 when my purpose requires it2 and1 inasmuch as they all are the bases of ,science1 ,i may call them by a general name2 for instance1 ,grounds of ,scientific ,necessity2 and these are precisely what ,i mean by ,fundamental ,ideas4 ,that some steady thought1 and even some progress in the construction of ,science1 is needed in order to see the necessity of the ,axioms thus introduced1 is true1 and is repeatedly asserted and illustrated in the ,history of the ,sciences4 ,the necessity of such ,axioms is seen1 but it is not seen at first4 ,it becomes clearer and clearer to each person1 and clear to one person after another1 as the human mind dwells more and more steadily on the several subjects of speculation4 ,there are scientific truths which are seen by intuition1 but this intuition is progressive4 ,this is the remark which ,i wish to make in answer to those of my critics who have objected that truths which ,i have propounded as ,axioms1 are not evident to all4 #ad4 ,that the ,axioms of ,science are not evident to all1 is true enough1 and too true4 ,take the ,axiom of ,substance3--that we may change the condition of a substance in various ways1 but cannot destroy it4 ,this has been assumed as evident by philosophers in all ages2 but if we ask an ordinary person whether a body can be destroyed by fire1 or diminished1 will he unhesitatingly reply1 that it cannot8 ,it requires some thought to say#cae1 as the philosopher said1 that the weight of the smoke is to be found by subtracting the weight of the ashes from that of the fuel2 nay1 even when this is said1 it appears1 at first1 rather an epigram than a scientific truth4 ,yet it is by thinking only1 not by an experiment1 that1 from a happy guess it becomes a scientific truth4 ,and the thought is the basis1 not the result1 of experimental truths2 for which reason ,i ascribe it to a ,fundamental ,idea4 ,and so1 such truths are the genuine growth of the human mind2 not innate1 as if they needed not to grow2 still less1 dead twigs plucked from experience and stuck in from without2 not universal1 as if they grew up everywhere2 but not the less1 under favourable circumstances1 the genuine growth of the scientific intellect4 #ae4 ,not only do ,i hold that the ,axioms1 on which the truths of science rest1 grow from guesses into ,axioms in various ways1 and often gradually1 and at different periods in different minds1 and partially1 even in the end2 but ,i conceive that this may be shown by the history of science1 as having really happened1 with regard to all the most conspicuous of such principles4 ,the scientific insight which enabled discoverers to achieve their exploits1 implied that they were among the first to acquire an intuitive conviction of the ,axioms of their ,science3 the controversies which form so large a portion of the history of science1 arise from the struggles between the clear-sighted and the dimsighted1 between those who were forwards and those who were backwards in the progress of ideas2 and these controversies have very often ended in diffusing generally a clearness of thought1 on the controverted subject1 which at first1 the few only1 or perhaps not even they1 possessed4 ,the ,history of ,science consists of the ,history of ,ideas1 as well as of the ,history of ,experience and ,observation4 ,the latter portion of the subject formed the principal matter of my ,history of the ,inductive ,sciences2 the former occupied a large portion of the ,philosophy of the ,inductive ,sciences#caf2 which1 ,i may perhaps be allowed to explain1 is1 for the most part1 a ,historical ,work no less than the other2 and was written in a great measure1 at the same time1 and from the same survey of the works of scientific writers4 #af4 ,i am aware that the explanation which ,i have given1 may naturally provoke the opponents of the doctrine of scientific necessity to repeat their ordinary fundamental objections1 in a form adapted to the expressions which ,i have used4 ,they may say1 the fact that these so-called ,axioms thus become evident only during the progress of experience1 proves that they are derived from experience3 they may1 in reply to our image1 say1 that truths are stuck into the mind by experience1 as seeds are stuck into the ground2 and that to maintain that they can grow under any other conditions1 is to hold the doctrine of spontaneous generation1 which is equally untenable in the intellectual and in the physical world4 ,i shall not however here resume the general discussion2 but shall only say briefly in reply1 that ,axioms1--for instance1 this ,axiom1 that material substances cannot be created or annihilated by any process which we can apply1--though it becomes evident in the progress of experience1 cannot be derived from experience2 for it is a proposition which never has nor can be proved by experience2 but which1 nevertheless1 has been always assumed by men1 seeking for general truths1 as necessarily true1 and as controlling and correcting all possible experience4 ,and with regard to the image of vegetable development1 ,i may say1 that as such development implies both inherent forms in the living seed1 and nutritive powers in earth and air2 so the development of our scientific ideas implies both a formative power1 and materials acted on2 and that1 though the analogy must be very defective1 we conceive that we best follow it by placing the formative power in the living mind1 and in the external world the materials acted on3 while the doctrine that all truth is derived from experience only1 appears to reject altogether one of these elements1 or to assert the two to be one4 ,,footnotes3 ,footnote #cjg3 ,the remarks contained in this chapter have for the most part been already printed and circulated in a ,letter to the ,author of ,prolegomena ,logica1 #aheb4 ,footnote #cjh3 ,biographical ,history of ,philosophy1 #ahdf4 ,in a more recent edition the author of this work has modified his expressions1 but still employs himself in arguing against ,dr4 ,whewell1 in order to overthrow ,kant4 ,so far as his arguments affect my philosophy1 they are1 as ,i conceive1 answered in the various expositions which ,i have given of that philosophy4 ,footnote #cji3 ,b4 ii4 ,the ,philosophy of the ,pure ,sciences4 ,chap4 ii4 ,of the ,idea of ,space4 ,chap4 iii4 ,of some peculiarities of the ,idea of ,space4 ,chap4 vii4 ,of the ,idea of ,time4 ,chap4 viii4 ,of some peculiarities of the ,idea of ,time4 ,footnote #caj3 ,prolegomena ,logica1 by ,h4 ,l4 ,mansel1 ,m4,a4 #ahea4 ,footnote #caa3 ,logic1 i4 p4 #bgc1 #crd edit4 ,footnote #cab3 ,no4 #aic1 p4 #bi4 ,footnote #cac3 ,prol4 ,log4 p4 #abc4 ,footnote #cad3 ,see ,phil4 ,ind4 ,sc4 b4 vi4 c4 iii4 ,footnote #cae3 ,kant4 ,footnote #caf3 ,republished as ,the ,history of ,scientific ,ideas4 ,,chapter ,,xxix4 ,,necessary ,,truth ,,is ,,progressive4 ,,objections ,,considered4 ,the doctrine that necessary truth is progressive is a doctrine very important in its bearing upon the nature of the human mind2 and1 as ,i conceive1 in its theological bearing also4 ,but it is a doctrine to which objections are likely to be made from various quarters1 and ,i will consider some of these objections4 #a4 ,necessary truths1 it will be said1 cannot increase in number4 ,new ones cannot be added to the old ones4 ,for necessary truths are those of which the necessity is plain and evident to all mankind--to the common sense of man2 such as the axioms of geometry4 ,but that which is evident to all mankind must be evident from the first3 that which is plain to the common sense of man cannot require scientific discovery3 that which is necessarily true cannot require accumulated proof4 ,to this ,i reply1 that necessary truths require for their apprehension a certain growth and development of the human mind4 ,though it is seen that they are necessarily true1 this is seen only by those who think steadily and clearly1 and to think steadily and clearly on any kind of subject1 requires time and attention2--requires mental culture4 ,this may be seen even in the case of the axioms of geometry4 ,these axioms are self-evident3 but to whom are they self-evident8 ,not to uncultured savages1 or young children2 or persons of loose vague habits of thought4 ,to see the truth and necessity of geometrical axioms1 we need geometrical culture4 ,therefore that any axioms are not evident without patient thought and continued study of the subject1 does not disprove their necessity4 ,principles may be axiomatic and necessary1 although they require time1 and the progress of thought and of knowledge1 to bring them to light4 ,and axioms may be thus gradually brought to light by the progress of knowledge4 ,nor is it difficult to give examples of such axioms1 other than geometrical4 ,there is an axiom which has obtained currency among thoughtful men from the time that man began to speculate about himself and the universe3--,e nihilo nil fit3 ,nothing can be made of nothing4 ,no material substance can be produced or destroyed by natural causes1 though its form and consistence may be changed indefinitely4 ,is not this an axiom8 a necessary truth8 ,yet it is not evident to all men at first1 and without mental culture4 ,at first and before habits of steady and consistent thought are formed1 men think familiarly of the creation and destruction of matter4 ,only when the mind has received some philosophical culture does it see the truth and necessity of the axiom of substance1 and then it does see it4 ,and the axioms on which the science of mechanics rests1 that the cause is measured by the effects1 that reaction is equal and opposite to action1 and the like1--are not these evident to a mind cultivated by steady thought on such subjects8 and do they not require such culture of the mind in order to see them8 ,are they not obscure or uncertain to those who are not so cultured1 that is to common thinkers3 to the general bulk of mankind8 ,thus then it requires the discipline of the science of mechanics to enable the mind to see the axioms of that science4 ,and does not this go further1 as science and the careful study of the grounds of science go further8 ,to a person well disciplined in mechanical reasoning it has become1 not a conclusion1 but a principle1 that in mechanical action what is gained in power is lost in time3 or that in any change1 the force gained is equal to the force lost1 so that new force cannot be generated1 any more than new matter1 by natural changes4 ,is this an axiom8 a necessary fundamental truth8 ,it appears so to at least one great thinker and discoverer now alive among us4 ,if it do not appear so to us1 or not in the same sense1 may not this be because we have not yet reached his point of view8 ,may not the conviction which is now his alone become hereafter the conviction of the philosophical world8 ,and whatever the case may be in this instance1 have there not been examples of this progress8 ,did not ,galileo and the disciples of ,galileo reduce several mechanical principles to the character of necessary truths1 after they had by experiment and reasoning discovered them to be actually true8 ,and have we not in these cases so many proofs that necessary truth is progressive1 along with the progress of knowledge8 #b4 ,but1 it will be said1 the necessary character claimed for such truths is an illusion4 ,the propositions so brought into view are really established by observation3 by the study of external facts3 and it is only the effect of habit and familiarity which makes men of science1 when they well know them to be true1 think them to be necessarily true4 ,they are really the results of experience1 as their history shows2 and therefore cannot be necessary and priori truths4 ,to which ,i reply3 ,such principles as ,i have mentioned1--that material substance cannot be produced or destroyed--that the cause is measured by the effect--that reaction is equal and opposite to action3 are not the results of experience1 nor can be4 ,no experience can prove them2 they are necessarily assumed as the interpretation of experience4 ,they were not proved in the course of scientific investigations1 but brought to light as such investigations showed their necessity4 ,they are not the results1 but the conditions of experimental sciences4 ,if the ,axiom of ,substance were not true1 and were not assumed1 we could not have such a science as ,chemistry1 that is1 we could have no knowledge at all respecting the changes of form of substances4 ,if the ,axioms of ,mechanics were not true and were not assumed1 we could have no science of ,mechanics1 that is1 no knowledge of the laws of force acting on matter4 ,it is not any special results of the science in such cases2 but the existence1 the possibility1 of any science1 which establishes the necessity of these axioms4 ,they are not the consequences of knowledge1 acquired from without1 but the internal condition of our being able to know4 ,and when we are to know concerning any new subject contained in the universe1 it is not inconceivable nor strange that there should be new conditions of our knowledge4 ,it is not inconceivable or strange1 therefore1 that as new sciences are formed1 new axioms1 the foundations of such sciences1 should come into view4 ,as the light of clear and definite knowledge is kindled in successive chambers of the universe1 it may disclose1 not only the aspect of those new apartments1 but also the form and structure of the lamp which man is thus allowed to carry from point to point1 and to transmit from hand to hand4 ,and though the space illumined to man's vision may always be small in comparison with the immeasurable abyss of darkness by which it is surrounded1 and though the light may be dim and feeble1 as well as partial2 this need not make us doubt that1 so far as we can by the aid of this lamp1 we see truly3 so far as we discern the necessary laws of the universe1 the laws are true1 and their truth is rooted in that in which the being of the universe is rooted4 ,and1 to dwell for a moment longer on this image1 we may also conceive that all that this lamp--the intellect of man cultivated by science1--does1 by the light which it gives1 is this--that it dispels a darkness which is dark for man alone1 and discloses to him some things in some measure as all things lie in clear and perfect light before the eye of ,god4 ,to the ,divine ,mind all the laws of the universe are plain and clear in all their multiplicity1 extent and depth4 ,the human mind is capable of seeing some of these laws1 though only a few2 to some extent1 though but a little way2 to some depth1 though never to the bottom4 ,but the ,human ,mind1 can1 in the course of ages and generations1 by the long exercise of thought1 successfully employed in augmenting knowledge1 improve its powers of vision2 and may thus come to see more laws than at first1 to trace their extent more largely1 to understand them more thoroughly2 and thus the inward intellectual light of man may become broader and broader from age to age1 though ever narrow when compared with completeness4 #c4 ,is it strange to any one that inward light1 as well as outward knowledge1 should thus increase in the course of man's earthly career8 that as knowledge extends1 the foundations of knowledge should expand8 that as man goes on discovering new truths1 he should also discover something concerning the conditions of truth8 ,is it wonderful that as science is progressive the philosophy of science also should be progressive8 that as we know more of everything else1 we should also come to know more of our powers of knowing8 ,this does not seem to have been supposed by philosophers in general2 or rather1 they have assumed that they could come to know more about the powers of knowing by thinking about them1 even without taking into account the light thrown upon the nature of knowledge by the progress of knowledge4 ,from ,plato downwards1 through ,aristotle1 through the ,schoolmen1 to ,descartes1 to ,locke1 to ,kant1 ,schelling and ,hegel1 philosophers have been perpetually endeavouring to explore the nature1 the foundations1 the consequences of our knowledge4 ,but since ,plato1 scarcely one of them has ever proceeded as if new light were thrown upon knowledge by new knowledge4 ,they have1 many or all of them1 attempted to establish fundamental truths1 some of them new fundamental truths1 about the human mind and the nature and conditions of its knowledge4 ,these attempts show that they do not deny or doubt that there may be such new fundamental truths4 ,such new fundamental truths respecting the human mind and respecting knowledge must be1 in many cases at least1 7as it will be seen that they are1 on examining the systems proposed by the philosophers just mentioned17 seen by their own light to be true4 ,they are new axioms in philosophy4 ,these philosophers therefore1 or their disciples1 cannot consistently blame us for holding the possibility of new axioms being introduced into philosophy from age to age1 as there arise philosophers more and more clear-sighted4 #d4 ,but though they have no ground for rejecting our new axioms merely because they are new1 we may have good ground for doubting the value of their new axioms1 that is1 of the foundations of their systems2 because they are new truths about knowledge gathered by merely exploring the old fields of knowledge4 ,we found our hopes of obtaining a larger view of the constitution of the human mind than the early philosophers had1 on this3--that we obtain our view by studying the operation of the human mind since their time2 its progress in acquiring a large stock of uncontested truths and in obtaining a wide and real knowledge of the universe4 ,here are new materials which the ancients had not2 and which may therefore justify the hope that we may build our philosophy higher than the ancients did4 ,but modern philosophers who use only the same materials as the ancient philosophers used1 have not the same grounds for hope which we have4 ,if they borrow all their examples and illustrations of man's knowledge of the universe1 from the condition of the universe as existing in ,space and ,time1 that is1 from the geometrical condition of the universe1 they may fail to obtain the light which might be obtained if they considered that the universe is also subject to conditions of ,substance1 of ,cause and ,effect1 of ,force and ,matter3 is filled with ,kinds of things1 in whose structure we assume ,design and ,ends2 and so on2 and if they reflected that these conditions or ,ideas are not mere vague notions1 but the bases of sciences which all thoughtful persons allow to be certain and real4 ,it is then1 as ,i have said1 from taking advantage of the progressive character which physical science1 in the history of man1 has been found to possess1 that ,i hope to learn more of the nature and prospects of the human mind and soul1 than those can learn who still take their stand on the old limited ground of man's knowledge4 ,the knowledge of ,geometry by the ,greeks was the starting-point of their sound philosophy4 ,it showed that something might be certainly known1 and it showed1 in some degree1 how it was known4 ,it thus refuted the skepticism which was destroying philosophy1 and offered specimens of solid truth for the philosopher to analyse4 ,but the ,greeks tried to go beyond geometry in their knowledge of the universe4 ,they tried to construct a science of ,astronomy--of ,harmonics--of ,optics--of ,mechanics4 ,in the two former subjects1 they succeeded to a very considerable extent4 ,the question then arose1 ,what was the philosophical import of these new sciences8 ,what light did they throw on the nature of the universe1 on the nature of knowledge1 on the nature of the human mind8 ,these questions ,plato attempted to answer4 ,he said that the lesson of these new sciences is this3--that the universe is framed upon the ,divine ,ideas2 that man can to a certain extent obtain sight of these ,ideas2 and that when he does this1 he knows concerning the universe4 ,and again1 he also put the matter otherwise3 there is an ,intelligible ,world1 of which the ,visible and ,sensible world is only a dim image4 ,science consists in understanding the ,intelligible ,world1 which man is to a certain extent able to do1 by the nature of his understanding4 ,this was ,plato's philosophy1 founded upon the progress which human knowledge had made up to his time4 ,since his time1 knowledge1 that is science1 has made a large additional progress4 ,what is the philosophical lesson to be derived from this progress1 and from the new provinces thus added to human knowledge8 ,this is a question which ,i have tried to answer4 ,i am not aware that any one since ,plato has taken this line of speculation2--,i mean1 has tried to spell out the lesson of philosophy which is taught us1 not by one specimen1 or a few only1 of the knowledge respecting the universe which man has acquired2 but by including in his survey all the provinces of human knowledge1 and the whole history of each4 ,at any rate1 whatever any one else may have done in this way1 it seems to me that new inferences remain to be drawn1 of the nature of those which ,plato drew3 and those ,i here attempt to deduce and to illustrate4 ,,chapter ,,xxx4 ,,the ,,theological ,,bearing ,,of ,,the ,,philosophy ,,of ,,discovery4 ,that necessary truth is progressive2--that science is the idealization of facts1 and that this process goes on from age to age1 and advances with the advance of scientific discovery2--these are doctrines which ,i have endeavoured to establish and to elucidate4 ,if these doctrines are true1 they are so important that ,i may be excused should ,i return to them again and again1 and trace their consequences in various directions4 ,especially ,i would examine the bearing of these doctrines upon our religious philosophy4 ,i have hitherto abstained in a great measure from discussing religious doctrines2 but such a reserve carried too far must deprive our philosophy of all completeness4 ,no philosophy of science can be complete which is not also a philosophy of the universe2 and no philosophy of the universe can satisfy thoughtful men1 which does not include a reference to the power by which the universe came to be what it is4 ,supposing1 then1 such a reference to be admitted1 let us see what aspect our doctrines give to it4 #a4 7,how can there be necessary truths concerning the actual universe87--,in looking at the bearing of our doctrine on the philosophy of the universe1 we are met by a difficulty1 which is indeed1 only a former difficulty under a new aspect4 ,when we are come to the conclusion that science consists of facts idealized1 we are led to ask1 ,how this can be8 ,how can facts be idealized8 ,how can that which is a fact of external observation become a result of internal thought8 ,how can that which was known posteriori become known priori8 ,how can the world of things be identified with the world of thoughts8 ,how can we discover a necessary connexion among mere phenomena8 ,or to put the matter otherwise3 ,how is it that the deductions of the intellect are verified in the world of sense8 ,how is it that the truths of science obtained priori are exemplified in the general rules of facts observed posteriori8 ,how is it that facts1 in science1 always do correspond to our ideas8 ,i have propounded this paradox in various forms1 because ,i wish it to be seen that it is1 at first sight1 a real1 not merely a verbal contradiction1 or at least a difficulty4 ,if we can discover the solution of this difficulty in any one form1 probably we can transpose the answer so as to suit the other forms of the question4 #b4 ,suppose the case to be as ,i have stated it2 that in some sciences at least1 laws which were at first facts of observation come to be seen as necessary truths2 and let us see to what this amounts in the several sciences4 ,it amounts to this3 the truths of ,geometry1 such as we discern them by the exercise of our own thoughts1 are always verified in the world of observation4 ,the laws of space1 derived from our ,ideas1 are universally true in the external world4 ,in the same way1 as to number3 the laws or truths respecting number1 which are deduced from our ,idea of ,number1 are universally true in the external world4 ,in the same way1 as to the science which deals with matter and force3 the truths of which ,i have spoken as derived from ,ideas3--that action is equal to reaction2 and that causes are measured by their effects2--are universally verified in all the laws of phenomena of the external world1 which are disclosed by the science of ,mechanics4 ,in the same way with regard to the composition and resolution of bodies into their elements2 the truths derived from our ,idea of ,matter3--that no composition or resolution can increase or diminish the quantity of matter in the world1 and that the properties of compounds are determined by their composition2--are truths derived from ,ideas of quantity of matter1 and of composition and resolution2 but these truths are universally verified when we come to the facts of ,chemistry4 ,in the same way it is a truth flowing from the ,ideas of the ,kinds of things1 7as the possible subject of general propositions expressed in language17 that the kinds of things must be definite2 and this law is verified whenever we express general propositions in general terms3 for instance1 when we distinguish species in ,mineralogy4 #c4 ,this last example may appear to most readers doubtful4 ,i have purposely pursued the enumeration till ,i came to a doubtful example1 because it is1 and ,i conceive always will be1 impossible to extend this general view to all the ,sciences4 ,on the contrary1 this doctrine applies at present to only a very few of the sciences1 even in the eyes of those who hold the existence of ideal truths4 ,the doctrine extends at present to a few only of the sciences1 even if it extend to one or two besides those which have been mentioned--,geometry1 ,mechanics1 ,chemistry1 ,mineralogy3 and though it may hereafter appear that ,ideal ,truths are possible and attainable for a few other sciences1 yet the laws disclosed by sciences which cannot be reduced to ideal elements will1 ,i conceive1 always very far outnumber those which can be so reduced4 ,the great body of our scientific knowledge will always be knowledge obtained by mere observation1 not knowledge obtained by the use of theories alone4 #d4 ,the survey of the history and philosophy of the ,sciences which we have attempted in previous works enables us to offer a sort of estimate of the relative portions of science which have and which have not thus been idealized4 ,for the ,aphorisms#cag which we have collected from that survey1 contain ,axioms which may be regarded as the ,ideal portions of the various sciences2 and the inspection of that series of aphorisms will show us to how such a portion of science1 anything of this axiomatic or ideal character can he applied4 ,these ,axioms are the ,axioms of ,geometry 7,aphorism ,,xxvi72 of ,arithmetic 7,,xxxvi72 of ,causation 7,,xlvii72 of a medium for the sensation of secondary qualities 7,,lviii71 and their measure 7,,lxix72 of ,polarity 7,,lxxii72 of ,chemical ,affinity 7,,lxxvi72 of ,substance 7,,lxxvii72 of ,atoms 7,,lxxix74 ,have we any axioms in the sciences which succeed these in our survey1 as ,botany1 ,zoology1 ,biology1 ,palontology8 ,there is the ,axiom of ,symmetry 7,,lxxx72 of ,kind1 7already in some measure spoken of1 7,,lxxxiii772 of ,final ,cause 7,,cv72 of ,first ,cause 7,,cxvi74 #e4 7,small extent of necessary truth47--,it is easily seen how small a portion of each of these latter sciences is included in these axioms3 while1 with regard to the sciences first mentioned1 the ,axioms include1 in a manner1 the whole of the science4 ,the science is only the consequence of the ,axioms4 ,the whole science of ,mechanics is only the development of the ,axioms concerning action and reaction1 and concerning cause and its measures1 which ,i have mentioned as a part of our ,ideal knowledge4 ,in fact1 beginning from ,geometry and ,arithmetic1 and going through the sciences of ,mechanics1 of ,secondary ,qualities1 and of ,chemistry1 onwards to the sciences which deal with ,organized ,beings1 we find that our ideal truths occupy a smaller and smaller share of the sciences in succession1 and that the vast variety of facts and phenomena which nature offers to us1 is less and less subject to any rules or principles which we can perceive to be necessary4 ,but still1 that there are principles1--necessary principles1 which prevail universally even in these higher parts of the natural sciences1--appears on a careful consideration of the axioms which ,i have mentioned3--that in symmetrical natural bodies the similar parts are similarly affected2--that every event must have a cause2--that there must be a ,first ,cause1 and the like4 #f4 ,it being established1 then1 that in the progress of science1 facts are idealized--that posteriori truths become priori truths2--that the world of things is identified with the world of thoughts to a certain extent2--to an extent which grows larger as we see into the world of things more clearly2 the question recurs which ,i have already asked3 ,how can this be8 ,how can it be that the world without us is thus in some respects identical with the world within us8--that is our question4 #g4 7,how did things come to be as they are87--,it would seem that we may make a step in the solution of this question1 if we can answer this other3 ,how did the world without us and the world within us come to be what they are8 ,to this question1 two very different answers are returned by those who do and those who do not believe in a ,supreme ,mind or ,intelligence1 as the cause and foundation of the world4 ,those who do not believe that the world has for its cause and foundation a ,supreme ,intelligence1 or who do not connect their philosophy with this belief1 would reply to our inquiry1 that the reason why man's thoughts and ideas agree with the world is1 that they are borrowed from the world2 and that the persuasion that these ,ideas and truths derived from them have any origin except the world without us1 is an illusion4 ,on this view ,i shall not now dwell2 for ,i wish to trace out the consequences of the opposite view1 that there exists a ,supreme ,mind1 which is the cause and foundation of the universe4 ,those who hold this1 and who also hold that the human mind can become possessed of necessary truths1 if they are asked how it is that these necessary truths are universally verified in the material world1 will reply1 that it is so because the ,supreme ,creative-,mind has made it so to be3--that the truths which exist or can be generated in man's mind agree with the laws of the universe1 because ,he who has made and sustains man and the universe has caused them to agree3--that our ,ideas correspond to the ,facts of the world1 and the ,facts to our ,ideas1 because our ,ideas are given us by the same power which made the world1 and given so that these can and must agree with the world so made4 #h4 7,view of the ,theist74--,this1 in its general form1 would be the answer of the theist1 7so we may call him who believes in a ,supreme ,intelligent ,cause of the world and of man17 to the questions which we have propounded--the perplexity or paradox which we have tried to bring into view4 ,but we must endeavour to trace this view--this answer--more into detail4 ,if a ,supreme ,intelligence be the cause of the world and of the ,laws which prevail among its phenomena1 these ,laws must exist as ,acts of that ,intelligence--as ,laws caused by the thoughts of the ,supreme ,mind--as ,ideas in the ,mind of ,god4 ,and then the question would be1 ,how we are to conceive these thoughts1 these ,ideas1 to be at the same time ,divine and human3--to be at the same time ,ideas in the ,divine ,mind1 and necessary truths in the human mind2 and this is the question which ,i would now inquire into4 #i4 7,is this ,platonism87--,to the terms in which the inquiry is now propounded it may be objected that ,i am taking for granted the ,platonic doctrine1 that the world is constituted according to the ,ideas of the ,divine ,mind4 ,it may be said that this doctrine is connected with gross extravagancies of speculation and fiction1 and has long been obsolete among sound philosophers4 ,to which ,i reply1 that if such doctrines have been pushed into extravagancies1 with them ,i have nothing to do1 nor have ,i any disposition or wish to revive them4 ,but ,i do not conceive the doctrine1 to the extent to which ,i have stated it1 to be at all obsolete3--that the ,cause and ,foundation of the ,universe is a ,divine ,mind3 and from that doctrine it necessarily follows1 that the laws of the ,universe are in the ,ideas of the ,divine ,mind4 ,i would then1 as ,i have said1 examine the consequences of this doctrine1 in reference to the question of which ,i have spoken4 ,and in order to do this1 it may help us1 if we consider separately the bearing of this doctrine upon separate portions of our knowledge of the universe2--separately its bearing upon the laws which form the subject-matter of different sciences3--if we take particular human ,ideas1 and consider what the ,divine ,ideas must be with regard to each of them4 #aj4 7,idea of ,space47--,let us take1 in the first place1 the ,idea of ,space4 ,concerning this ,idea we possess necessary truths2 namely1 the ,axioms of ,geometry2 and1 as necessarily resulting from them1 the whole body of ,geometry4 ,and our former inquiry1 as narrowed within the limits of this ,idea1 will be1 ,how is it that the truths of ,geometry-- priori truths--are universally verified in the observed phenomena of the universe8 ,and the theist's answer which we have given will now assume this form3--,this is so because the ,supreme ,mind has constituted and constitutes the universe according to the ,idea of ,space4 ,the universe conforms to the ,idea of ,space1 and the ,idea of ,space exists in the human mind2--is necessarily evoked and awakened in the human mind existing in the universe4 ,and since the ,idea of ,space1 which is a constituent of the universe1 is also a constituent of the human mind1 the consequences of this ,idea in the universe and in the human mind necessarily coincide2 that is1 the spacial ,laws of the universe necessarily coincide with the spacial ,science which man elaborates out of his mind4 #aa4 ,to this it may be objected1 that we suppose the ,idea of ,space in the ,divine ,mind 7according to which ,idea1 among others1 the universe is constituted17 to be identical with the ,idea of ,space in the human mind2 and this1 it may be urged1 is too limited and material a notion of the ,divine ,mind to be accepted by a reverent philosophy4 ,i reply1 that ,i suppose the ,divine ,idea of ,space and the human ,idea of ,space to coincide1 only so far as the human ,idea goes2 and that the ,divine ,idea may easily have so much more luminousness and comprehensiveness as ,divine ,ideas may be supposed to have compared with human4 ,further1 that this ,idea of ,space1 the first of the ,ideas on which human science is founded1 is the most luminous and comprehensive of such ,ideas2 and there are innumerable other ,ideas1 the foundations of sciences more or less complete1 which are extremely obscure and limited in the human mind1 but which must be conceived to be perfectly clear and unlimitedly comprehensive in the ,divine ,mind4 ,and thus1 the distance between the human and the ,divine ,mind1 even as to the views which constitute the most complete of the human sciences1 is as great in our view as in any other4 #ab4 ,that the ,idea of ,space in the human mind1 though sufficiently clear and comprehensive to be the source of necessary truths1 is far too obscure and limited to be regarded as identical with the ,divine ,idea1 will be plain to us1 if we call to mind the perplexities which the human mind falls into when it speculates concerning space infinite4 ,an ,intelligence in which all these perplexities should vanish by the light of the ,idea itself1 would be infinitely elevated in clearness and comprehensiveness of intellectual vision above human intelligence1 even though its ,idea of ,space should coincide with the human ,idea as far as the human ,idea goes4 ,i do not shrink from saying1 therefore1 that the ,idea of ,space which is a constituent of the human mind existing in the universe is1 as far as it goes1 identical with the ,idea of ,space which is a constituent of the universe4 ,and this ,i give as the answer to the question1 ,how it is that the necessary truths of ,geometry universally coincide with the relations of the phenomena of the universe8 ,and this doctrine1 it is to be remembered1 carries us to the further doctrine1 that the ,idea of ,space in the human mind is1 so far as it goes1 coincident with the ,idea of ,space in the ,divine ,mind4 #ac4 7,idea of ,time47--,what ,i have said of the ,idea of ,space1 may be repeated1 for the most part1 with regard to the ,idea of ,time2 except that the ,idea of ,time1 as such1 does not give rise to a large collection of necessary truths1 such as the propositions of ,geometry4 ,some philosophers regard ,number as a modification or derivative of the ,idea of ,time4 ,if we accept this view1 we have1 in the ,science of ,arithmetic1 a body of necessary truths which flow from the ,idea of ,time4 ,but this doctrine1 whichever way held1 does not bear much on the question with which we are now concerned4 ,that which we do hold is1 that the ,idea of ,time in the human mind is1 so far as it goes1 coincident with the ,idea of ,time in the ,divine ,mind3 and that this is the reason why the events of the universe1 as contemplated by us1 conform to necessary laws of succession3 while at the same time we must suppose that all the perplexities in the ,idea of ,time which embarrass the human mind--the perplexities1 for instance1 which arise from contemplating a past and a future eternity1 are1 in the ,divine ,mind1 extinguished in the ,light of the ,idea itself4 ,space and ,time have1 and have generally been regarded as having1 peculiar prerogatives in our speculations concerning the constitution of the universe4 ,we see and perceive all things as subject to the laws of ,space and ,time2 or rather 7for the term ,law does not here satisfy us71 as being and happening in space and in time3 and probably most persons will have no repugnance to the doctrine that the ,divine ,mind1 as well as the human1 so regards them1 and has so constituted them and us that they must be so regarded4 ,space and ,time are human ,ideas which include all objects and events1 and are the foundation of all human ,science4 ,and we can conceive that ,space and ,time are also ,divine ,ideas which the ,divine ,mind causes to include all objects and events1 and makes to be the foundation of all existence4 ,so far as these ,ideas go1 our doctrine is not difficult or new4 #ad4 7,ideas of ,force and ,matter47--,but what are we to say of the ,ideas which come next in the survey of the sciences1 ,force and ,matter8 ,these are human ,ideas--the foundations of several sciences--of the mechanical sciences in particular4 ,but are they the foundations of necessary truths8 ,have we necessary truths respecting ,force and ,matter8 ,we have endeavoured to prove that we have3--that certain fundamental propositions in the ,science of ,mechanics1 although1 historically speaking1 they were discovered by observation and experience1 are yet1 philosophically speaking1 necessary propositions4 ,and being such1 the facts of the universe must needs conform to these propositions2 and the reason why they do so1 we hold1 in this as in the former case1 to be1 that these ,ideas1 ,force and ,matter1 are ,ideas in the ,divine ,mind3--,ideas according to which the universe is1 by the ,divine ,cause1 constituted and established4 #ae4 ,that ,force and ,matter are ,ideas existing in the ,divine ,mind1 and coincident with the ,idea of ,force and ,matter in the human mind1 as far as these go1 is a doctrine which is important in our view of the universe in relation to its ,cause and ,foundation4 ,these are very comprehensive and fundamental ,ideas1 and there are certain universal relations among external things which rest upon these ,ideas4 ,the two1 ,force and ,matter1 are1 in a certain way1 the necessary antithesis and opposite condition each of the other4 ,force 7that is ,mechanical ,force1 ,pressure or ,impulse7 cannot act without matter to act upon4 ,matter 7that is ,body7 cannot exist without ,force by which it is kept in its place1 by which its parts are held together1 and by which it excludes every other body from the place which it occupies4 ,we cannot conceive ,force without ,matter1 or ,matter without ,force2 the two are1 as ,action and ,reaction1 necessarily co-ordinate and coexistent4 ,in every part of the universe they must be so4 ,in every part of the universe1 if there be material objects1 there must be ,force2 if there be ,force1 there must be material objects4 ,our apprehension of this universal necessity arises from our having the ,ideas of ,force and ,matter which are human ,ideas4 ,the actuality of this universal antithesis arises from the ,ideas of ,force and ,matter being ,ideas in the ,divine ,mind2--,ideas realized as a part of the fundamental constitution of the universe4 ,that ,force and ,matter are thus among the ,ideas in the ,divine ,mind1 and that1 with them1 the ,ideas of ,force and ,matter in the human mind1 regarded in their most general form1 agree so far as they go1 is another step in the doctrine which ,i am trying to unfold4 ,that the ,ideas of ,force and ,matter in the ,divine ,mind are such as to banish by their own light1 innumerable contradictions and perplexities which darken these ,ideas in the human mind1 is to be supposed3 and thus the ,divine ,mind is infinitely luminous and comprehensive compared with the human mind4 #af4 7,creation of ,matter47--,it may perhaps be urged1 as an objection to this doctrine1 that it asserts ,matter to be a necessary constituent of the universe1 and thus involves the assertion of the eternity of ,matter4 ,but in reality the doctrine asserts ,matter to be eternal1 only in the way in which time and space are eternal4 ,whether we hold that there was a creation before which time and space did not exist1--with the poet who says ,ere ,time and ,space were ,time and ,space were not1-- is not essential to our present inquiry4 ,certainly we cannot conceive such a state1 and therefore cannot reason about it4 ,we have no occasion here to speak of ,creation1 nor have spoken of it4 ,what ,i have said is1 that ,space and ,time1 ,force and ,matter are universal elements1 principles1 constituents1 of the universe as it is--and necessary ,ideas of the human mind existing in that universe4 ,if there ever was a ,creation before which ,matter did not exist1 it was a ,creation before which ,force did not exist4 ,and in the universe as it is1 the two are necessarily co-existent in the human thought because they are co-existent in the ,divine ,thought which makes the world4 ,we apply then to ,force and ,matter the doctrine--the ,platonic doctrine1 if any one please so to call it1--that the world is constituted according to the ,ideas of the ,divine ,mind1 and that the human mind apprehends the inward and most fundamental relations of the universe by sharing in some measure of those same ,ideas4 #ag4 7,platonic ,ideas47--,but do we go on with ,plato to extend this doctrine of ,ideas to all the objects and all the aspects of objects which constitute the material universe8 ,do we say with ,plato that there is not only an ,idea of a ,triangle by conformity to which a figure is a triangle1 but an ,idea of ,gold1 by conformity to which a thing is gold1 and ,idea of a ,table1 by conformity to which a thing is a table8 ,we say none of these things4 ,we say nothing which at all approaches to them4 ,we do not say that there is an ,idea of a ,triangle1 the archetype of all triangles2 we only say that man has an ,idea of ,space1 which is an ,idea of a fundamental reality2 and that therefore from this ,idea flow real and universal truths--about triangles and other figures4 ,still less do we say that we have an archetypal ,idea of ,gold1 or of a ,metal in general1 or of any of the kinds of objects which exist in the world4 ,here we part company with ,plato altogether4 ,but have we any ,ideas at all with regard to objects which we thus speak of as separable into ,kinds8 ,we can have knowledge1--even exact and general knowledge1 that is1 science--with regard to such things--with regard to plants and metals--gold and iron4 ,do we possess in our minds1 with regard to those objects1 any ,ideas1 any universal principles1 such as we possess with regard to geometrical figures or mechanical actions8 ,and if so1 are those human ,ideas verified in the universe1 as the ,ideas hitherto considered are8 and do they thus afford us further examples of ,ideas in the human mind which are also ,ideas in the ,divine ,mind1 manifested in the constitution of the universe8 #ah4 7,idea of ,kinds47--,we answer ,yes to these questions1 on this ground3--the objects that exist in the world1 plants and metals1 gold and iron1 for example1 in order that they may be objects with regard to which we can have any knowledge1 must be objects of distinct and definite thought4 ,plant must differ from metal1 gold from iron1 in order that we may know anything at all about any of these objects4 ,the differences by which such objects differ need not necessarily be expressed by definitions1 as the difference of a triangle and a square are expressed2 but there must manifestly be fixed and definite differences1 in order that we may have any knowledge about them4 ,these ,kinds of things must be so far distinct and definite1 as to be objects of distinct and definite thought4 ,the ,kinds of natural objects must differ1 and we must think of things as of different ,kinds1 in order that we may know anything about natural objects4 ,living in a world in which we exercise our ,intellect upon the natural objects which surround us1 we must regard them as distinct from each other in ,kind4 ,we must have an ,idea of ,kinds of natural objects4 #ai4 ,the ,idea of a ,kind involves this principle3 ,that where the ,kind differs the ,properties may differ1 but so far as the ,kind is the same the ,properties contemplated in framing the notion of each ,kind are the same4 ,gold cannot have the distinctive properties of ,iron without being ,iron4 ,in the case of human knowledge1 each ,kind is marked by a word--a name2 and the doctrine that the notion of the ,kind must be so applied that this same ,kind of object shall have the same properties1 has been otherwise expressed by saying that ,names must be so applied that general propositions may be possible4 ,we must so apply the name of ,gold that we may be able to say1 gold has a specific gravity of a certain amount and is ductile in a certain degree4 #bj4 ,but this condition of the names of ,kinds1--that they must be such that general propositions about these ,kinds of objects shall be possible2--is it a necessary result of the ,idea of ,kind8 ,and if so1 can the ,idea of ,kind1 thus implying the use of language1 and a condition depending on the use of language1 be an ,idea in the ,divine as well as in the human mind8 ,can it be1 in this respect1 like the ,ideas which we have already considered1 ,space and ,time1 ,force and ,matter8 ,we cannot suppose that the ,ideas which exist in the ,divine ,mind imply1 in the ,supreme ,intelligence1 the need of language1 like human language4 ,but there is no incongruity in supposing that they imply that which we take as the condition of such language as we speak of1 namely1 distinct thought4 ,there is nothing incongruous in supposing that the ,supreme ,intelligence regards the objects which exist in the universe as distinct in ,kind3 and that the ,idea of ,kind in the human mind agrees with the ,idea of ,kind in the ,divine ,mind1 as far as it goes4 ,and as we have seen1 the ,idea of ,properties is correlative and coexistent with the ,idea of ,kind1 so that the one changing1 the other changes also4 ,there is nothing incongruous in supposing that the ,divine ,mind manifests in the universe of which it is the ,cause and ,foundation1 these two1 its co-ordinate ,ideas3 and that the human mind sees that these two ,ideas are co-ordinate and coexistent1 in virtue of its participating in these ,ideas of the ,divine ,mind4 ,the universe is full of things which man perceives do and must differ correspondingly in kind and in properties2 and this is so1 because the ,ideas of various ,kinds and various ,properties are part of the scheme of the universe in the ,divine ,mind4 #ba4 ,that the ,ideas of ,kinds and ,properties as coordinate and interdependent1 though common1 to a certain extent1 to the human and the ,divine ,mind1 are immeasurably more luminous1 penetrating and comprehensive in the ,divine than in the human mind1 is abundantly evident4 ,in fact1 though man assents to such axioms as these1--that the ,properties of ,things depend upon their ,kinds1 and that the ,kinds of ,things are determined by their ,properties1--yet the nature of connexion of ,kinds and ,properties is a matter in which man's mind is all but wholly dark1 and on which the ,divine ,mind must be perfectly clear4 ,for in how few cases--if indeed in any one--can we know what is the essence of any ,kind2--what is the real nature of the connexion between the character of the ,kind and its ,properties6 ,yet on this point we must suppose that the ,divine ,intellect1 which is the foundation of the world1 is perfectly clear4 ,every ,kind of thing1 every genus and species of object1 appears to ,him in its essential character1 and its properties follow as necessary consequences4 ,he sees the essences of things through all time and through all space2 while we1 slowly and painfully1 by observation and experiment1 which we cannot idealize or can idealize only in the most fragmentary manner1 make out a few of the properties of each ,kind of thing4 ,our ,science here is but a drop in the ocean of that truth1 which is known to the ,divine ,mind but kept back from us2 but still1 that we can know and do know anything1 arises from our taking hold of that principle1 human as well as ,divine1 that there are differences of ,kinds of things1 and corresponding differences of their properties4 #bb4 7,idea of ,substance47--,i shall not attempt to enumerate all the ,ideas which1 being thus a part of the foundation of ,science in the human mind and of ,existence in the universe1 are shown to be at the same time ,ideas in the ,divine and in the human mind4 ,but there is one other of which the necessary and universal application is so uncontested1 that it may well serve further to exemplify our doctrine4 ,in all reasonings concerning the composition and resolution of the elements of bodies1 it is assumed that the quantity of matter cannot be increased or diminished by anything which we can do to them4 ,we have an ,idea of ,substance1 as something which may have its qualities altered by our operations upon it1 but cannot have its quantity changed4 ,and this ,idea of ,substance is universally verified in the facts of observation and experiment4 ,indeed it cannot fail to be so2 for it regulates and determines the way in which we interpret the facts of observation and experiment4 ,it authorized the philosopher who was asked the weight of a column of smoke to reply1 ,subtract the weight of the ashes from that of the fuel1 and you have the weight of the smoke3 for in virtue of that idea we assume that1 in combustion1 or in any other operation1 all the substance which is subjected to the operation must exist in the result in some form or other4 ,now why may we reasonably make this assumption1 and thus1 as it were1 prescribe laws to the universe8 ,our reply is1 ,because ,substance is one of the ,ideas according to which the universe is constituted4 ,the material things which make up the universe are substance according to this ,idea4 ,they are substance according to this ,idea in the ,divine ,mind1 and they are substance according to this ,idea in the human mind1 because the human mind has this ,idea1 to a certain extent1 in common with the ,divine ,mind4 ,in this1 as in the other cases1 the ,idea must be immeasurably more clear and comprehensive in the ,divine ,mind than in the human4 ,the human ,idea of substance is full of difficulty and perplexity3 as for instance2 how a substance can assume successively a solid1 fluid and airy form2 how two substances can be combined so as entirely to penetrate one another and have new qualities3 and the like4 ,all these perplexities and difficulties we must suppose to vanish in the ,divine ,idea of ,substance4 ,but still there remains in the human1 as in the ,divine ,idea1 the source and root of the universal truth1 that though substances may be combined or separated or changed in form in the processes of nature or of art1 no portion of substance can come into being or cease to be4 #bc4 7,idea of ,final ,cause47--,there is yet one other ,idea which ,i shall mention1 though it is one about which difficulties have been raised1 since the consideration of such difficulties may be instructive3 the ,idea of a purpose1 or as it is often termed1 a ,final ,cause1 in organized bodies4 ,it has been held1 and rightly#cah1 that the assumption of a ,final ,cause of each part of animals and plants is as inevitable as the assumption of an efficient cause of every event4 ,the maxim1 that in organized bodies nothing is in vain1 is as necessarily true as the maxim that nothing happens by chance4 ,i have elsewhere#cai shown fully that this ,idea is not deduced from any special facts1 but is assumed as a law governing all facts in organic nature1 directing the researches and interpreting the observations of physiologists4 ,i have also remarked that it is not at variance with that other law1 that plants and that animals are constructed upon general plans1 of which plans1 it may be1 we do not see the necessity1 though we see how wide is their generality4 ,this ,idea of a purpose1--of a ,final ,cause1--then1 thus supplied by our minds1 is found to be applicable throughout the organic world4 ,it is in virtue of this ,idea that we conceive animals and plants as subject to disease2 for disease takes place when the parts do not fully answer their purpose2 when they do not do what they ought to do4 ,how is it then that we thus find an ,idea which is supplied by our own minds1 but which is exemplified in every part of the organic world8 ,here perhaps the answer will be readily allowed4 ,it is because this ,idea is an ,idea of the ,divine ,mind4 ,there is a ,final ,cause in the constitution of these parts of the universe1 and therefore we can interpret them by means of the ,idea of ,final ,cause4 ,we can see a purpose1 because there is a purpose4 ,is it too presumptuous to suppose that we can thus enter into the ,ends and ,purposes of the ,divine ,mind8 ,we willingly grant and declare that it would be presumptuous to suppose that we can enter into them to any but a very small degree4 ,they doubtless go immeasurably beyond our mode of understanding or conceiving them4 ,but to a certain extent we can go4 ,we can go so far as to see that they are ,ends and ,purposes4 ,it is not a vain presumption in us to suppose that we know that the eye was made for seeing and the ear for hearing4 ,in this the most pious of men see nothing impious3 the most cautious philosophers see nothing rash4 ,and that we can see thus far into the designs of the ,divine ,mind1 arises1 we hold1 from this3--that we have an ,idea of ,design and of ,purpose which1 so far as it is merely that1 is true2 and so far1 is ,design and ,purpose in the same sense in the one case and in the other4 ,i am very far from having exhausted the list of ,fundamental ,ideas which the human mind possesses and which have been made the foundations of ,sciences4 ,of all such ,ideas1 ,i might go on to remark1 that they are of universal validity and application in the region of external ,facts4 ,in all the cases ,i might go on to inquire1 ,how is it that man's ,ideas1 developed in his internal world1 are found to coincide universally with the laws of the external world8 ,by what necessity1 on what ground does this happen8 ,and in all cases ,i should have had to reply1 that this happens1 and must happen1 because these ,ideas of the human mind are also ,ideas of the ,divine ,mind according to which the universe is constituted4 ,man has these thoughts1 and sees them verified in the universe1 because ,god had these thoughts and exemplifies them in the universe4 #bd4 7,human immeasurably inferior to ,divine74--,but of all these ,ideas1 ,i should also have to remark1 that the way in which man possesses them is immeasurably obscure and limited in comparison with the way in which ,god must be supposed to possess them4 ,these human ,ideas1 though clear and real as far as they go1 in every case run into obscurity and perplexity1 from which the ,ideas of the ,divine ,mind must be supposed to be free4 ,in every case1 man1 by following the train of thought involved in each ,idea1 runs into confusion and seeming contradictions4 ,it may be that by thinking more and more1 and by more and more studying the universe1 he may remove some of this confusion and solve some of these contradictions4 ,but when he has done in this way all that he can1 an immeasurable region of confusion and contradiction will still remain2 nor can he ever hope to advance very far1 in dispelling the darkness which hangs over the greater part of the universe4 ,his knowledge1 his science1 his ,ideas1 extend only so far as he can keep his footing in the shallow waters which lie on the shore of the vast ocean of unfathomable truth4 #be4 ,but further1 we have not1 even so1 exhausted our estimate of the immeasurable distance between the human mind and the ,divine ,mind3--very far from it3 we have only spoken of the smallest portion of the region of truth1--that about which we have ,sciences and ,scientific ,ideas4 ,in that region alone do we claim for man the possession of ,ideas the clearness of which has in it something divine4 ,but how narrow is the province of ,science compared with the whole domain of human thought6 ,we may enumerate the sciences of which we have been speaking1 and which involve such ,ideas as ,i have mentioned4 ,how many are they8 ,geometry1 ,arithmetic1 ,chemistry1 ,classification1 ,physiology4 ,to these we might have added a few others2 as the sciences which deal with ,light1 ,heat1 ,polarities2 ,geology and the other ,paltiological ,sciences2 and there our enumeration at present must stop4 ,for we can hardly as yet claim to have ,sciences1 in the rigorous sense in which we use the term1 about the ,vital ,powers of man1 his ,mental ,powers1 his historical attributes1 as ,language1 ,society1 ,arts1 ,law1 and the like4 ,on these subjects few philosophers will pretend to exhibit to us ,ideas of universal validity1 prevailing through all the range of observation4 ,yet all these things proceed according to ,ideas in the ,divine ,mind by which the universe1 and by which man1 is constituted4 ,in such provinces of knowledge1 at least1 we have no difficulty in seeing or allowing how blind man is with regard to their fundamental and constituent principles2 how weak his reason2 how limited his view4 ,if on some of the plainest portions of possible knowledge1 man have ,ideas which may be regarded as coincident to a certain extent with those by which the universe is really constituted2 still on by far the largest portion of the things which most concern him1 he has no knowledge but that which he derives from experience1 and which he cannot put in so general a form as to have any pretensions to rest it upon a foundation of connate ,ideas4 #bf4 7,science advances towards the ,divine ,ideas47--,but there is yet one remark tending somewhat in the opposite direction1 which ,i must make1 as a part of the view which ,i wish to present4 ,science1 in the rigorous sense of the term1 involves1 we have said1 ,ideas which to a certain extent agree with the ,ideas of the ,divine ,mind4 ,but science in that sense is progressive2 new sciences are formed and old sciences extended4 ,hence it follows that the ,ideas which man has1 and which agree with the ,ideas of the ,divine ,mind1 may receive additions to their number from time to time4 ,this may seem a bold assertion2 yet this is what1 with due restriction1 we conceive to be true4 ,such ,ideas as we have spoken of receive additions1 in respect of their manifestation and development4 ,the ,ideas1 the germ of them at least1 were in the human mind before2 but by the progress of scientific thought they are unfolded into clearness and distinctness4 ,that this takes place with regard to scientific ,ideas1 the history of science abundantly shows4 ,the ,ideas of ,space and ,time indeed1 were clear and distinct from the first1 and accordingly the ,sciences of ,geometry and ,arithmetic have existed from the earliest times of man's intellectual history4 ,but the ,ideas upon which the ,science of ,mechanics depends1 having been obscure in the ancient world1 are become clear in modern times4 ,the ,ideas of ,composition and ,resolution have only in recent centuries become so clear as to be the basis of a definite science4 ,the ,idea of ,substance indeed was always assumed1 though vaguely applied by the ancients2 and the ,idea of a ,design or ,end in vital structures is at least as old as ,socrates4 ,but the ,idea of ,polarities was never put forth in a distinct form till quite recently2 and the ,idea of ,successive ,causation1 as applied in ,geology and in the other ,paltiological ,sciences1 was never scientifically applied till modern times3 and without attempting to prove the point by enumeration1 it will hardly be doubted that many ,scientific ,ideas are clear and distinct among modern men of science which were not so in the ancient days4 ,now all such scientific ,ideas are1 as ,i have been urging1 points on which the human mind is a reflex of the ,divine ,mind4 ,and therefore in the progress of science1 we obtain1 not indeed new points where the human mind reflects the ,divine1 but new points where this reflection is clear and luminous4 ,we do not assert that the progress of science can bring into existence new elements of truth in the human mind1 but it may bring them into view4 ,it cannot add to the characters of ,divine origin in the human mind1 but it may add to or unfold the proofs of such an origin4 ,and this is what we conceive it does4 ,and though we do not conceive that the ,ideas which science thus brings into view are the most important of man's thoughts in other respects1 yet they may1 and we conceive do1 supply a proof of the ,divine nature of the human mind1 which proof is of peculiar cogency4 ,what other proofs may be collected from other trains of human thought1 we shall hereafter consider4 #bg4 7,recapitulation47--,this1 then1 is the argument to which we have been led by the survey of the sciences in which we have been engaged3--,that the human mind can and does put forth1 out of its natural stores1 duly unfolded1 certain ,ideas as the bases of scientific truths3 ,these ,ideas are universally and constantly verified in the universe3 ,and the reason of this is1 that they agree with the ,ideas of the ,divine ,mind according to which the universe is constituted and sustained3 ,the human mind has thus in it an element of resemblance to the ,divine ,mind3 ,to a certain extent it looks upon the universe as the ,divine ,mind does2 and therefore it is that it can see a portion of the truth3 ,and not only can the human mind thus see a portion of the truth1 as the ,divine ,mind sees it3 but this portion1 though at present immeasurably small1 and certain to be always immeasurably small compared with the whole extent of truth which with greater intellectual powers1 he might discern1 nevertheless may increase from age to age4 ,this is then1 ,i conceive1 one of the results of the progress of scientific discovery--the ,theological ,result of the ,philosophy of ,discovery1 as it may1 ,i think1 not unfitly be called3--,that by every step in such discovery by which external facts assume the aspect of necessary consequences of our ,ideas1 we obtain a fresh proof of the ,divine nature of the human mind3 ,and though these steps1 however far we may go in this path1 can carry us only a very little way in the knowledge of the universe1 yet that such knowledge1 so far as we do obtain it1 is ,divine in its kind1 and shows that the human mind has something ,divine in its nature4 ,the progress by which external facts assume the aspect of necessary consequences of our ,ideas1 we have termed the idealization of facts2 and in this sense we have said1 that the progress of science consists in the ,idealization of ,facts4 ,but there is another way in which the operation of man's mind may be considered--an opposite view of the identification of ,ideas with ,facts2 which we must consider1 in order to complete our view of the bearing of the progress of human thought upon the nature of man4 ,,footnotes3 ,footnote #cag3 ,given in the ,novum ,organon ,renovatum4 ,footnote #cah3 ,nov4 ,org4 ,ren4 ,aph4 cv4 ,footnote #cai3 ,hist4 ,sc4 ,id4 b4 ix4 c4 vi4 ,,chapter ,,xxxi4 ,,man',s ,,knowledge ,,of ,,god4 #a4 ,man's powers and means of knowledge are so limited and imperfect that he can know little concerning ,god4 ,it is well that men in their theological speculations should recollect that it is so1 and should pursue all such speculations in a modest and humble spirit4 ,but this humility and modesty defeat their own ends1 when they lead us to think that we can know nothing concerning ,god3 for to be modest and humble in dealing with this subject1 implies that we know this1 at least1 that ,god is a proper object of modest and humble thought4 #b4 ,some philosophers have been led1 however1 by an examination of man's faculties and of the nature of being1 to the conclusion that man can know nothing concerning ,god4 ,but we may very reasonably doubt the truth of this conclusion4 ,we may ask1 ,how can we know that we can know nothing8 ,if we can know nothing1 we cannot even know that4 ,it is much more reasonable to begin with things that we really do know1 and to examine how far such knowledge can carry us1 respecting ,god1 as well as anything else4 ,this is the course which we have been following1 and its results are very far from being trifling or unimportant4 ,in thus beginning from what we know1 we start from two points1 on each of which we have1 we conceive1 some real and sure knowledge3--namely1 mathematical and physical knowledge of the universe without us2 and a knowledge of our own moral and personal nature within us4 #c4 7,from ,nature we learn something of ,god47--,in pursuing the first line of thought1 we are led to reason thus4 ,the universe is governed by certain ,ideas3 for instance1 everything which exists and happens in the universe1 exists and happens ,,in ,space and ,time4 ,why is this8 ,it is1 we conceive1 because ,god has constituted and constitutes the universe so that it may be so2 that is1 because the ,ideas of ,space and of ,time are ,ideas according to which ,god has established and upholds the universe4 ,but we may proceed further in this way1 as we have already said4 ,the universe not only exists in space and time1 but it has in it substances--material substances3 or taking it collectively1 ,material ,substance4 ,can we know anything concerning this substance8 ,yes3 something we can know2 for we know that material substance cannot be brought into being or annihilated by any natural process4 ,we have then an ,idea of ,substance which is a ,law of the universe4 ,how is this8--,we reply1 that it is because our ,idea of ,substance is an ,idea on which ,god has established and upholds the universe4 ,can we proceed further still8 ,can we discern any other ,ideas according to which the universe is constituted8 ,yes3 as we have already remarked1 we can discern several1 though as we go on from one to another they become gradually fainter in their light1 less cogent in their necessity4 ,we can see that ,force as well as ,material ,substance is an ,idea on which the universe is constituted1 and that ,force and ,matter are a necessary and universal antithesis3 we can see that the ,things which occupy the universe must be of definite ,kinds1 in order that an intelligent mind may occupy itself about them1 and thus that the ,idea of ,kind is a constitutive ,idea of the universe4 ,we can see that some kinds of things have life1 and our ,idea of ,life is1 that every part of a living thing is a means to an ,end2 and thus we recognize ,end1 or ,final ,cause1 as an ,idea which prevails throughout the universe1 and we recognize this ,idea as an ,idea according to which ,god constitutes and upholds the universe4 ,since we know so much concerning the universe1 and since every ,law of the universe which is a necessary form of thought about the universe must exist in the ,divine ,mind1 in order that it may find a place in our minds1 how can we say that we can know nothing concerning the ,divine ,mind8 #d4 7,though but ,little47--,but on the other hand1 we easily see how little our knowledge is1 compared with what we do not know4 ,even the parts of our knowledge which are the clearest are full of perplexities2 and of the ,laws of the universe1 including living as well as lifeless things1 how small a portion do we know at all6 ,even the parts of our knowledge which are the clearest1 ,i say1 are full of perplexities4 ,infinite ,space and an infinite ,past1 an infinite ,future1--how helplessly our reason struggles with these aspects of our ,ideas6 ,and with regard to ,substance1 how did ingenerable and indestructible substance come into being8 ,and with regard to ,matter1 how can passive ,matter be endued with living force8 ,and with regard to ,kinds1 how immeasurably beyond our power of knowing are their numbers and their outward differences3 still more their internal differences and central essence6 ,and with regard to the ,design which we see in the organs of living things1 though we can confidently say we see it1 how obscurely is it shown1 and how much is our view of it disturbed by other ,laws and ,analogies6 ,and the ,life of things1 the end to which such ,design tends1 how full of impenetrable mysteries is it6 or rather how entirely a mass of mystery into which our powers of knowledge strive in vain to penetrate6 ,there is therefore no danger that by following this train of thought we should elevate our view of man too high1 or bring down ,god in our thoughts to the likeness of man4 ,even if we were to suppose the ,idea of the ,divine ,mind to be of the same kind as the ,ideas of the human mind1 the very few ,ideas of this kind1 which man possesses1 compared with the whole range of the universe1 and the scanty length to which he can follow each1 make his knowledge so small and imperfect1 that he has abundant reason to be modest and humble in his contemplations concerning the ,intelligence that knows all and constitutes all4 ,he can1 as ,i have already said1 wade but a few steps into the margin of the boundless and unfathomable ocean of truth4 #e4 ,but the ,ideas of the ,divine ,mind must necessarily be different in kind1 as well as in number and extent1 from the ,ideas of the human mind1 on this very account1 that they are complete and perfect4 ,the ,mind which can conceive all the parts and laws of the universe in all their mutual bearings1 fundamental reasons1 and remote consequences1 must be different in kind1 as well as in extent1 from the mind which can only trace a few of these parts1 and see these laws in a few of their aspects1 and cannot sound the whole depth of any of them4 ,the ,divine ,mind differs from the human1 in the way in which we must needs suppose what is ,divine to differ from what is human4 #f4 ,it has sometimes been said that the ,divine ,mind differs from the human as the ,infinite from the finite4 ,and this has been given as a reason why we cannot know anything concerning ,god2 for we cannot1 it is said1 know anything concerning the ,infinite4 ,our conception of the ,infinite being merely negative1 7the negation of a limit17 makes all knowledge about it impossible4 ,but this is not truly said4 ,our conception of the ,infinite is not merely negative4 ,as ,i have elsewhere remarked1 our conception of the ,infinite is positive in this way3--that in order to form this conception1 we begin to follow a given ,idea in a given direction2 and then1 having thus begun1 we suppose that the progress of thought goes on in that direction without limit4 ,to arrive at our ,idea of infinite space1 for example1 we must determine what kind of space we mean1--line1 area or solid2 and from what origin we begin3 and infinite space has different attributes as we take different beginnings in this way4 ,and so with regard to the kinds of infinity 7for there are many7 which belong to the ,divine ,mind4 ,we have a few ,ideas which represent the ,laws of the universe3--as ,space1 ,time1 ,substance1 ,force1 ,matter1 ,kind1 ,end2 of such ,ideas the ,divine ,mind may have an infinite number4 ,these ,ideas in the human mind are limited in depth and clearness3 in the ,divine ,mind they must be infinitely clearer than the clearest human ,intuition2 infinitely more profound than the profoundest human thought4 ,and in this way1 and1 as we shall see1 in other ways also1 the ,divine ,mind infinitely transcends the human mind when most fully instructed and unfolded4 ,in this way and in other ways also1 ,i say4 ,for we have hitherto spoken of the human mind only as contemplating the external world2--as discerning1 to a certain small extent1 the laws of the universe4 ,we have spoken of the world of things without3 we must now speak of the world within us2--of the world of our thoughts1 our being1 our moral and personal being4 #g4 7,from ourselves we learn something concerning ,god47--,we must speak of this3 for this is1 as ,i have said1 another starting point and another line in which we may proceed from what we know1 and see how far our knowledge carries us1 and how far it teaches us anything concerning ,god4 ,looking at ourselves1 we perceive that we have to act1 as well as to contemplate3 we are practical as well as speculative beings4 ,and tracing the nature and conditions of our actions1 in the depths of our thought we find that there is in the aspect of actions a supreme and inevitable distinction of right and wrong4 ,we cannot help judging of our actions as right and wrong4 ,we acknowledge that there must be such a judgment appropriate to them4 ,we have these ,ideas of right and wrong as attributes of actions2 and thus we are moral beings4 #h4 ,and again3 the actions are our actions4 ,we act in this way or that4 ,and we are not mere things1 which move and change as they are acted on1 but which do not themselves act1 as man acts4 ,i am not a ,thing but a ,person2 and the men with whom ,i act1 who act with me--act in various ways towards me1 well or ill--are also persons4 ,man is a personal being4 ,the ,ideas of right and wrong--the moral ,ideas of man--are then a part of the scheme of the universe to which man belongs4 ,could they be this1 if they were not also a part of the nature of that ,divine ,mind which constitutes the universe8--,it would seem not3 the ,moral ,law of the universe must be a ,law of the ,divine ,mind1 in order that it may be a ,law felt and discerned by man4 #i4 7,objection answered47--,but1 it may be objected1 the ,moral ,law of the universe is a ,law in a different sense from the ,laws of the universe of which we spoke before--the mathematical and physical laws of the universe4 ,those were laws according to which things are1 and events occur3 but ,moral ,laws are ,laws according to which men ought to act1 and according to which actions ought to be4 ,there is a difference1 so that we cannot reason from the human to the ,divine ,mind in the same manner in this case as in the other4 ,true3 we cannot reason in the same manner4 ,but we can reason still more confidently4 ,for the ,law directing what ought to be is the ,supreme ,law1 and the mind which constitutes the ,supreme ,law is the ,supreme ,mind1 that is1 the ,divine ,mind4 #aj4 ,that the ,moral ,law is not verified among men in fact1 is not a ground for doubting that it is a ,law of the ,divine ,mind2 but it is a ground for inquiring what consequences the ,divine ,mind has annexed to the violation of the ,law2 and in what manner the supremacy of the ,law will be established in the total course of the history of the universe1 including1 it may be1 the history of other worlds than that in which we now live4 ,considering how dimly and imperfectly we see what consequences the ,divine ,governor has annexed to the violation of the ,moral ,law1 ,he who sees all these consequences and has provided for the establishment of ,his ,law in the whole history of the human race1 must be supposed to be infinitely elevated above man in wisdom2--more even in virtue of this aspect of ,his nature1 than in virtue of that which is derived from the contemplation of the universe4 #aa4 ,man is a person2 and his personality is his highest attribute1 or at least1 that which makes all his highest attributes possible4 ,and the highest attribute which belongs to the finite minds which exist in the universe must exist also in the ,infinite ,mind which constitutes the universe as it is4 ,the ,divine ,mind must reside in a ,divine ,person4 ,and as man1 by his personality1 acts in obedience to or in transgression of a moral law1 so ,god1 by ,his ,personality1 acts in establishing the ,law and in securing its supremacy in the whole history of the world4 #ab4 7,creation47--,acknowledging a ,divine ,mind which is the foundation and support of the world as it is1 constituting and upholding its laws1 it may be asked1 ,does this view point to a beginning of the world8 ,was there a time when the ,divine ,mind called into being the world1 before non-existent8 ,was there a ,creation of the world8 ,i do not think that an answer to this question1 given either way1 affects the argument which ,i have been urging4 ,the ,laws of the ,universe discoverable by the human mind1 are the ,laws of the ,divine ,mind1 whether or not there was a time when these ,laws first came into operation1 or first produced the world which we see4 ,the argument respecting the nature of the ,divine ,mind is the same1 whether or not we suppose a ,creation4 ,but1 in point of fact1 every part of our knowledge of the ,universe does seem to point to a beginning4 ,every part of the world has been1 so far as we can see1 formed by natural causes out of something different from what it now is4 ,the ,earth1 with its lands and seas1 teeming with innumerable forms of living things1 has been produced from an earth formed of other lands and seas1 occupied with quite different forms of life3 and if we go far enough back1 from an earth in which there was no life4 ,the stars which we call fixed move and change2 the nebul in their shape show that they too are moving and changing4 ,the ,earth was1 some at least hold1 produced by the condensation of a nebula4 ,the history of man1 as well as of others of its inhabitants1 points to a beginning4 ,languages1 ,arts1 ,governments1 ,histories1 all seem to have begun from a starting-point1 however remote4 ,indeed not only a beginning1 but a beginning at no remote period1 appears to be indicated by most of the sciences which carry us backwards in the world's history4 ,but we must allow1 on the other hand1 that though all such lines of research point towards a beginning1 none of them can be followed up to a beginning4 ,all the lines converge1 but all melt away before they reach the point of convergence4 ,as ,i have elsewhere said#cbj1 in no science has man been able to arrive at a beginning which is homogeneous with the known course of events1 though we can often go very far back1 and limit the hypotheses respecting the origin4 ,we have1 in the impossibility of thus coming to any conclusion by natural reason on the subject of creation1 another evidence of the infinitely limited nature of the human mind1 when compared with the ,creative or ,constitutive ,divine ,mind4 #ac4 7,end of the ,world47--,but if our natural reason1 aided by all that science can teach1 can tell us nothing respecting the origin and beginning of this world1 still less can reason tell us anything with regard to the ,end of this world4 ,on this subject1 the natural sciences are even more barren of instruction than on the subject of ,creation4 ,yet we may say that as the ,constitution of the ,universe1 and its conformity to a ,collection of eternal and immutable ,ideas as its elements1 are not inconsistent with the supposition of a ,beginning of the present course of the world1 so neither are they inconsistent with the supposition of an ,end4 ,indeed it would not be at all impossible that physical inquiries should present the prospect of an ,end1 even more clearly than they afford the retrospect of a ,beginning4 ,if1 for instance1 it should be found that the planets move in a resisting medium which constantly retards their velocity1 and must finally make them fall in upon the central sun1 there would be an end of the earth as to its present state4 ,we cannot therefore1 on the grounds of ,science1 deny either a ,beginning or an ,end of the present world4 #ad4 ,but here another order of considerations comes into play1 namely1 those derived from moral and theological views of the world4 ,on these we must1 in conclusion1 say a few words4 ,it is very plain that these considerations may lead us to believe in a view of the ,beginning1 ,middle1 and ,end of the history of the world1 very different from anything which the mere physical and natural sciences can disclose to us4 ,and these expressions to which ,i have been led1 the ,beginning1 the ,middle1 and the ,end of the world's history according to theological views1 are full of suggestions of the highest interest4 ,but the interest which belongs to these suggestions is of a solemn and peculiar kind2 and the considerations to which such suggestions point are better1 ,i think1 kept apart from such speculations as those with which ,i have been concerned in the present volume4 ,,footnotes3 ,footnote #cbj3 ,hist4 ,ind4 ,sc4 b4 xviii4 c4 vi4 sect4 #e ,,chapter ,,xxxii4 ,,analogies ,,of ,,physical ,,and ,,religious ,,philosophy4 #a4 ,any assertion of analogy between physical and religious philosophy will very properly be looked upon with great jealousy as likely to be forced and delusive2 and it is only in its most general aspects that a sound philosophy on the two subjects can offer any points of resemblance4 ,but in some of its general conditions the discovery of truth in the one field of knowledge and in the other may offer certain analogies1 as well as differences1 which it may be instructive to notice2 and to some such aspects of our philosophy ,i shall venture to refer4 ,for the physical sciences--the sciences of observation and speculation--the progress of our exact and scientific knowledge1 as ,i have repeatedly said1 consists in reducing the objects and events of the universe to a conformity with ,ideas which we have in our own minds3--the ,ideas1 for instance1 of ,space1 ,force1 ,substance1 and the like4 ,in this sense1 the intellectual progress of men consists in the ,idealization of ,facts4 #b4 ,in moral subjects1 on the other hand1 where man has not merely to observe and speculate1 but also to act2--where he does not passively leave the facts and events of the world such as they are1 but tries actively to alter them and to improve the existing state of things1 his progress consists in doing this4 ,he makes a moral advance when he succeeds in doing what he thus attempts3--when he really improves the state of things with which he has to do by removing evil and producing good3--when he makes the state of things1 namely1 the relations between him and other persons1 his acts and their acts1 conform more and more to ,ideas which he has in his own mind3--namely1 to the ,ideas of ,justice1 ,benevolence1 and the like4 ,his moral progress thus consists in the realization of ,ideas4 ,and thus we are led to the ,aphorism1 as we may call it1 that ,man's ,intellectual ,progress consists in the ,idealization of ,facts1 and his ,moral ,progress consists in the ,realization of ,ideas4 #c4 ,but further1 though that progress of science which consists in the idealization of facts may be carried through several stages1 and indeed1 in the history of science1 has been carried through many stages1 yet it is1 and always must be1 a progress exceedingly imperfect and incomplete1 when compared with the completeness to which its nature points4 ,only a few sciences have made much progress2 none are complete2 most have advanced only a step or two4 ,in none have we reduced all the ,facts to ,ideas4 ,in all or almost all the unreduced ,facts are far more numerous and extensive than those which have been reduced4 ,the general mass of the facts of the universe are mere facts1 unsubdued to the rule of science4 ,the ,facts are not ,idealized4 ,the intellectual progress is miserably scanty and imperfect1 and would be so1 even if it were carried much further than it is carried4 ,how can we hope that it will ever approach to completeness8 #d4 ,and in like manner1 the moral progress of man is still more miserably scanty and incomplete4 ,in how small a degree has he in this sense realized his ,ideas6 ,in how small a degree has he carried into real effect1 and embodied in the relations of society1 in his own acts and in those of others with whom he is concerned1 the ,ideas of ,justice and ,benevolence and the like6 ,how far from a complete realization of such moral ,ideas are the acts of the best men1 and the relations of the best forms of society6 ,how far from perfection in these respects is man6 and how certain it is that he will always be very far from perfection6 ,far below even such perfection as he can conceive1 he will always be in his acts and feelings4 ,the moral progress of man1 of each man1 and of each society1 is1 as ,i have said1 miserably scanty and incomplete2 and when regarded as the realization of his moral ,ideas1 its scantiness and incompleteness become still more manifest than before4 ,hence we are led to another ,aphorism3--that man's progress in the realization of ,moral ,ideas1 and his progress in the ,scientific idealization of ,facts1 are1 and always will be1 exceedingly scanty and incomplete4 #e4 ,but there is another aspect of ,ideas1 both physical and moral1 in which this scantiness and incompleteness vanish4 ,in the ,divine ,mind1 all the physical ,ideas are entertained with complete fulness and luminousness2 and it is because they are so entertained in the ,divine ,mind1 and it is because the universe is constituted and framed upon them1 that we find them verified in every part of the universe1 whenever we make our observation of facts and deduce their laws4 ,in like manner the ,moral ,ideas exist in the ,divine ,mind in complete fulness and luminousness2 and we are naturally led to believe and expect that they must be exemplified in the moral universe1 as completely and universally as the physical laws are exemplified in the physical universe4 ,is this so8 or under what conditions can we conceive this to be8 #f4 ,in answering this question1 we must consider how far the moral1 still more even than the physical ,ideas of the ,divine ,mind1 are elevated above our human ,ideas2 but yet not so far as to have no resemblance to our corresponding human ,ideas2 for if this were so1 we could not reason about them at all4 ,in speaking of man's moral ,ideas1 ,benevolence1 ,justice1 and the like1 we speak of them as belonging to man's ,soul1 rather than to his ,mind1 which we have commonly spoken of as the seat of his physical ,ideas4 ,a distinction is thus often made between the intellectual and the moral faculties of man2 but on this distinction we here lay no stress4 ,we may speak of man's ,mind and ,soul1 meaning that part of his being in which are all his ,ideas1 intellectual and moral4 ,and now let us consider the question which has just been asked3--how we can conceive the ,divine ,benevolence and ,justice to be completely and universally realized in the moral world1 as the ,ideas of ,space1 ,time1 c4 are in the physical world8 #g4 ,our ,ideas of ,benevolence1 ,justice1 and of other ,virtues1 may be elevated above their original narrowness1 and purified from their original coarseness1 by moral culture2 as our ,ideas of ,force and ,matter1 of ,substance and ,elements1 and the like1 may be made clear and convincing by philosophical and scientific culture4 ,this appears1 in some degree1 in the history of moral terms1 as the progress of clearness and efficacy in the ,idea of the material sciences appears in the history of the terms belonging to such sciences4 ,thus among the ,romans1 while they confined their kindly affections within their own class1 a stranger was universally an enemy2 peregrinus was synonymous with hostis4 ,but at a later period1 they regarded all men as having a claim on their kindness2 and he who felt and acted on this claim was called humane4 ,this meaning of the word humanity shows the progress 7in their ,ideas at least7 of the virtue which the word humanity designates4 #h4 ,and as man can thus rise to a point of view where he sees that man is to be loved as man1 so the humane and loving man inevitably assumes that ,god loves all men2 and thus assumes that there is1 or may be1 a love of man in man's heart1 which represents and resembles in kind1 however remote in degree1 the love of ,god to man4 ,but as in man's love of man there are very widely different stages1 rising from the narrow love of a savage to his family or his tribe1 to the widest and warmest feelings of the most enlightened and loving universal philanthropist2--so must we suppose that there are stages immeasurably wider by which ,god's love of man is more comprehensive and more tender than any love of man for man4 ,the religious philosopher will fully assent to the expressions of this conviction delivered by pious men in all ages4 ,the eternal ,god is thy refuge1 and beneath thee are the everlasting arms4 ,when my father and my mother forsake me the ,lord taketh me up1 is the expression of ,divine ,love1 consistent with philosophy as well as with revelation4 ,but as the ,divine ,love is more comprehensive and enduring than any human love1 so is it in an immeasurably greater degree1 more enlightened4 ,it is not a love that seeks merely the pleasure and gratification of its object2 that even an enlightened human love does not do4 ,it seeks the good of its objects2 and such a good as is the greatest good1 to an ,intelligence which can embrace all cases1 causes1 and contingencies4 ,to our limited understanding1 evil seems often to be inflicted1 and the good of a part seems inconsistent with the good of another part4 ,our attempts to conceive a ,supreme and complete ,good provided for all the creatures which exist in the universe1 baffle and perplex us1 even more than our attempts to conceive infinite space1 infinite time1 and an infinite chain of causation4 ,but as the most careful attention which we can give to the ,ideas of ,space1 ,time1 and ,causation convinces us that these ,ideas are perfectly clear and complete in the ,divine ,mind1 and that our perplexity and confusion on these subjects arise only from the vast distance between the ,divine ,mind and our human mind1 so is it reasonable to suppose the same to be the source of the confusion which we experience when we attempt to determine what most conduces to the good of our fellow-creatures2 and when1 urged by love to them1 we endeavour to promote this good4 ,we can do little of what ,infinite ,love would do1 yet are we not thereby dispensed from seeking in some degree to imitate the working of ,divine ,love4 ,we can see but little of what ,infinite ,intelligence sees1 and this should be one source of confidence and comfort1 when we stumble upon perplexities produced by the seeming mixture of good and evil in the world4 #i4 ,but when we ask the questions which have already been stated3 ,whether this ,infinite ,divine ,love is realized in the world1 and if so1 ,how3 ,i conceive that we are irresistibly impelled to reply to the former question1 that it is3 and we then turn to the latter4 ,we are led to assume that there is in ,god an ,infinite ,love of man1 a creature in a certain degree of a ,divine nature4 ,we must1 as a consequence of this1 assume that the ,love of ,god to man1 necessarily is1 in the end1 and on the whole1 completely and fully realized in the history of the world4 ,but what is the complete history of the world6 ,is it that which consists in the lives of men such as we see them between their birth and their death8 ,if the minds or souls of men are alive after the death of the body1 that future life1 as well as this present life1 belongs to the history of the world2--to that providential history1 of which the totality1 as we have said1 must be governed by ,infinite ,divine ,love4 ,and in addition to all other reasons for believing that the minds and souls of men do thus survive their present life1 is this3--that we thus can conceive1 what otherwise it is difficult or impossible to conceive1 the operation of ,infinite ,love in the whole of the history of mankind4 ,if there be a ,future ,state in which men's souls are still under the authority and direction of the ,divine ,governor of the world1 all that is here wanting to complete the scheme of a perfect government of ,intelligent ,love may thus be applied3 all seeming and partial evil may be absorbed and extinguished in an ultimate and universal good4 #aj4 ,the ,idea of ,justice as belonging to ,god suggests to us some of the same kind of reflexions as those which we have made respecting the ,divine ,love4 ,we believe ,god to be just3 otherwise1 as has been said1 ,he would not be ,god4 ,and as we thus1 from the nature of our minds and souls1 believe ,god to be just1 we must1 in this belief1 understand ,justice according to the ,idea which we have of ,justice2 that is1 in some measure1 according to the ,idea of ,justice1 as exemplified in human actions and feelings4 ,it would be absurd to combine the two propositions1 that we necessarily believe that ,god is just1 and that by just1 we mean something entirely different from the common meaning of the word4 ,but though the ,divine ,idea of ,justice must necessarily1 in some measure1 coincide with our ,idea of ,justice1 we must believe in this1 as in other cases1 that the ,divine ,idea is immeasurably more profound1 comprehensive1 and clear1 than the human ,idea4 ,even the human ,idea of ,justice is susceptible of many and large progressive steps1 in the way of clearness1 consistency1 and comprehensiveness4 ,in the moral history of man this ,idea advances from the hard rigour of inflexible written ,law to the equitable estimation of the real circumstances of each case2 it advances also from the narrow ,law of a single community to a larger ,law1 which includes and solves the conflicts of all such ,laws4 ,further1 the administration of human ,law is always imperfect1 often erroneous1 in consequence of man's imperfect knowledge of the facts of each case1 and still more1 from his ignorance of the designs and feelings of the actors4 ,if the ,judge could see into the heart of the person accused1 and could himself rise higher and higher in judicial wisdom1 he might exemplify the ,idea of ,justice in a far higher degree than has ever yet been done4 #aa4 ,but all such advance in the improvement of human ,justice must still be supposed to stop immeasurably short of the ,divine ,justice1 which must include a perfect knowledge of all men's actions1 and all men's hearts and thoughts2 and a universal application of the wisest and most comprehensive ,laws4 ,and the difference of the ,divine and of the human ,idea of ,justice may1 like the differences of other ,divine and human ,ideas1 include the solution of all the perplexities in which we find ourselves involved when we would trace the ,idea to all its consequences4 ,the ,divine ,idea is immeasurably elevated above the human ,idea2 in the ,divine ,idea all inconsistency1 defect1 and incompleteness vanish1 and ,justice includes in its administration every man1 without any admixture of injustice4 ,this is what we must conceive of the ,divine administration1 since ,god is perfectly just4 #ab4 ,but here1 as before1 we have another conclusion suggested to us4 ,we are1 by the considerations just now spoken of1 led to believe that1 in the ,divine administration of the world is an administration of perfect ,justice2--that is1 such is the ,divine ,administration in the end and on the whole1 taking into account the whole of the providential history of the world4 ,but the course of the world1 taking into account only what happens to man in this present life1 is not1 we may venture to say1 a complete and entire administration of justice4 ,it often happens that injustice is successful and triumphant1 even in the end1 so far as the end is seen here4 ,it happens that wrong is done1 and is not remedied or punished4 ,it happens that blameless and virtuous men are subjected to pain1 grief1 violence1 and oppression1 and are not protected1 extricated1 or avenged4 ,in the affairs of this world1 the prevalence of injustice and wrong-doing is so apparent1 as to be a common subject of complaint3 and though the complaint may be exaggerated1 and though a calm and comprehensive view may often discern compensating and remedial influences which are not visible at first sight1 still we cannot regard the lot of happiness or misery which falls to each man in this world and this life as apportioned according to a scheme of perfect and universal justice1 such as in our thoughts we cannot but require the ,divine administration to be4 #ac4 ,here then we are again led to the same conviction by regarding the ,divine administration of the world as the realization of the ,divine ,justice1 to which we were before led by regarding it as the realization of the ,divine ,love4 ,since the ,idea is not fully or completely realized in man's life in this present world1 this present world cannot be the whole of the ,divine ,administration4 ,to complete the realization of the ,idea of ,justice1 as an element of the ,divine ,administration1 there must be a life of man after his life in this present world4 ,if man's mind and soul1 the part of him which is susceptible of happiness and misery1 survive this present life1 and be still subject to the ,divine ,administration1 the ,idea of ,divine ,justice may still be completely realized1 notwithstanding all that here looks like injustice or defective justice2 and it belongs to the ,idea of ,justice to remedy and compensate1 not to prevent wrong4 ,and thus by this supposition of a ,future ,state of man's existence1 we are enabled to conceive that1 in the whole of the ,divine ,government of the universe1 all seeming injustice and wrong may be finally corrected and rectified1 in an ultimate and universal establishment of a reign of perfect ,righteousness4 #ad4 ,admitting the view thus presented1 we may again discern a remarkable analogy between what we have called our physical ,ideas 7those of ,space1 ,time1 ,cause1 ,substance1 and the like71 and our moral ,ideas1 7those of ,benevolence1 ,justice1 c474 ,in both classes we must suppose that our human ,ideas represent1 though very incompletely and at an immeasurable distance1 the ,divine ,ideas4 ,even our physical ,ideas1 when pursued to their consequences1 are involved in a perplexity and confusion from which the ,divine ,ideas are free4 ,our ,ideas of ,benevolence and ,justice are still more full of imperfections and inconsistency1 when we would frame them into a complete scheme1 and yet from such imperfections and inconsistency we must suppose that the ,divine ,benevolence and ,justice are exempt4 ,our physical ,ideas we find in every case exactly exemplified and realized in the universe1 and we account for this by considering that they are the ,divine ,ideas1 on which the universe is constituted4 ,our moral ,ideas1 the ,ideas of ,benevolence and ,justice in particular1 must also be realized in the universe1 as a scheme of ,divine ,government4 ,but they are not realized in the world as constituted of man living this present life4 ,the ,divine ,scheme of the world1 therefore1 extends beyond this present life of man4 ,if we could include in our survey the future life as well as the present life of man1 and the future course of the ,divine ,government1 we should have a scheme of the ,moral ,government of the universe1 in which the ,ideas of ,perfect ,benevolence and ,perfect ,justice are as completely and universally exemplified and realized1 as the ,ideas of ,space1 ,time1 ,cause1 ,substance1 and the like1 are in the physical universe4 #ae4 ,there is one other remark bearing upon this analogy1 which seems to deserve our attention4 ,as ,i have said in the last chapter1 the scheme of the world1 as governed by our physical ,ideas1 seems to point to a ,beginning of the world1 or at least of the present course of the world3 and if we suppose a ,beginning1 our thoughts naturally turn to an ,end4 ,but if our physical ,ideas point to a ,beginning and suggest an ,end1 do our ,ideas of ,divine ,benevolence and ,justice in any way lend themselves to this suggestion8--,perhaps we might venture to say that in some degree they do1 even to the eye of a mere philosophical reason4 ,perhaps our reason alone might suggest that there is a progression in the human race1 in various moral attributes--in art1 in civilization1 and even in humanity and in justice1 which implies a beginning4 ,and that at any rate there is nothing inconsistent with our ,idea of the ,divine ,government in the supposition that the history of this world has a ,beginning1 a ,middle and an ,end4 #af4 ,if therefore there should be conveyed to us by some channel especially appropriated to the communication and development of moral and religious ,ideas1 the knowledge that the world1 as a scheme of ,divine ,government1 has a ,beginning1 a ,middle1 and an ,end1 of a ,kind1 or at least1 invested with circumstances quite different from any which our physical ,ideas can disclose to us1 there would be1 in such a belief1 nothing at all inconsistent with the analogies which our philosophy--the philosophy of our ,ideas illustrated by the whole progress of science--has impressed upon us4 ,on the grounds of this philosophy1 we need find no difficulty in believing that as the visible universe exhibits the operation of the ,divine ,ideas of ,space1 ,time1 ,cause1 ,substance1 and the like1 and discloses to us traces of a ,beginning of the present mode of operation1 so the moral universe exhibits to us the operation of the ,divine ,benevolence and ,justice2 and that these ,divine attributes wrought in a special and peculiar manner in the ,beginning2 interposed in a peculiar and special manner in the ,middle2 and will again act in a peculiar and special manner in the ,end of the world4 ,and thus the conditions of the physical universe1 and the ,government of the ,moral world1 are both1 though in different ways1 a part of the work which ,god is carrying on from the ,beginning of things to the ,end--opus quod ,deus operator a principio usque ad finem4 #ag4 ,we are led by such analogies as ,i have been adducing to believe that the whole course of events in which the minds and souls of men survive the present life1 and are hereafter subjected to the ,divine government in such a way as to complete all that is here deficient in the world's history1 is a scheme of perfect ,benevolence and ,justice4 ,now1 can we discern in man's mind or soul itself any indication of a destiny like this8 ,are there in us any powers and faculties which seem as if they were destined to immortality8 ,if there be1 we have in such faculties a strong confirmation of that belief in the future life of man which has already been suggested to us as necessary to render the ,divine government conceivable4 #ah4 ,according to our philosophy there are powers and faculties which do thus seem fitted to endure1 and not fitted to terminate and be extinguished4 ,the ,ideas which we have in our minds--the physical ,ideas1 as we have called them1 according to which the universe is constituted1--agree1 as far as they go1 with the ,ideas of the ,divine ,mind1 seen in the constitution of the universe4 ,but these ,divine ,ideas are eternal and imperishable3 we therefore naturally conclude that the human mind which includes such elements1 is also eternal and imperishable4 ,since the mind can take hold of eternal truths1 it must be itself eternal4 ,since it is1 to a certain extent1 the image of ,god in its faculties1 it cannot ever cease to be the image of ,god4 ,when it has arrived at a stage in which it sees several aspects of the universe in the same form in which they present themselves to the ,divine ,mind1 we cannot suppose that the ,author of the human mind will allow it and all its intellectual light to be extinguished4 #ai4 ,and our conviction that this extinction of the human mind cannot take place becomes stronger still1 when we consider that the mind1 however imperfect and scanty its discernment of truth may be1 is still capable of a vast1 and even of an unlimited progress in the pursuit and apprehension of truth4 ,the mind is capable of accepting and appropriating1 through the action of its own ,ideas1 every step in science which has ever been made--every step which shall hereafter be made4 ,can we suppose that this vast and boundless capacity exists for a few years only1 is unfolded only into a few of its simplest consequences1 and is then consigned to annihilation8 ,can we suppose that the wonderful powers which carry man on1 generation by generation1 from the contemplation of one great and striking truth to another1 are buried with each generation8 ,may we not rather suppose that that mind1 which is capable of indefinite progression1 is allowed to exist in an infinite duration1 during which such progression may take place8 #bj4 ,i propose this argument as a ground of hope and satisfactory reflexion to those who love to dwell on the natural arguments for the ,immortality of the ,soul4 ,i do not attempt to follow it into detail4 ,i know too well how little such a cause can gain by obstinate and complicated argumentation1 to attempt to urge the argument in that manner3 and probably different persons1 among those who accept the argument as valid1 would give different answers to many questions of detail1 which naturally arise out of the acceptance of this argument4 ,i will not here attempt to solve1 or even to propound these questions4 ,my main purpose in offering these views and this argument at all1 is to give some satisfaction to those who would think it a sad and blank result of this long survey of the nature and progress of science in which we have been so long engaged 7through this series of works71 that it should in no way lead to a recognition of the ,author of that world about which our ,science is1 and to the high and consolatory hopes which lift man beyond this world4 ,no survey of the universe can be at all satisfactory to thoughtful men1 which has not a theological bearing2 nor can any view of man's powers and means of knowing be congenial to such men1 which does not recognize an infinite destination for the mind which has an infinite capacity2 an eternal being of the ,faculty which can take a steady hold of eternal being4 #ba4 ,and as we may derive such a conviction from our physical ,ideas1 so too may we no less from our moral ,ideas4 ,our minds apprehend ,space and ,time and ,force and the like1 as ,ideas which are not dependent on the body2 and hence we believe that our minds shall not perish with our bodies4 ,and in the same manner our souls conceive pure ,benevolence and perfect ,justice1 which go beyond the conditions of this mortal life2 and hence we believe that our souls have to do with a life beyond this mortal life4 ,it is more difficult to speak of man's indefinite moral progression even than of his indefinite intellectual progression4 ,yet in every path of moral speculation we have such a progression suggested to us4 ,we may begin1 for instance1 with the ordinary feelings and affections of our daily nature3--,love1 ,hate1 ,scorn4 ,but when we would elevate the ,soul in our imagination1 we ascend above these ordinary affections1 and take the repulsive and hostile ones as fitted only to balance their own influences4 ,and thus the poet1 speaking of a morally poetical nature1 describes it3 ,the ,poet in a golden clime was born1 ,with golden stars above4 ,he felt the hate of hate1 the scorn of scorn1 ,the love of love4 ,but the loftier moralist can rise higher than this1 and can1 and will1 reject altogether ,hate and ,scorn from his view of man's better nature4 ,his description would rather be-- ,the good man in a loving clime was born1 ,with loving stars above4 ,he felt sorrow for hate1 pity for scorn1 ,and love of love4 ,he would1 in his conception of such a character1 ascribe to it all the virtues which result from the control and extinction of these repulsive and hostile affections3--the virtues of magnanimity1 forgivingness1 unselfishness1 self-devotion1 tenderness1 sweetness4 ,and these we can conceive in a higher and higher degree1 in proportion as our own hearts become tender1 forgiving1 pure and unselfish4 ,and though in every human stage of such a moral proficiency1 we must suppose that there is still some struggle with the remaining vestiges of our unkind1 unjust1 angry and selfish affections1 we can see no limit to the extent to which this struggle may be successful2 no limit to the degree in which these traces of the evil of our nature may be worn out by an enduring practice and habit of our better nature4 ,and when we contemplate a human character which has1 through a long course of years1 and through many trials and conflicts1 made a large progress in this career of melioration1 and is still capable1 if time be given1 of further progress towards moral perfection1 is it not reasonable to suppose that ,he who formed man capable of such progress1 and who1 as we must needs believe1 looks with approval on such progress where made1 will not allow the progress to stop when it has gone on to the end of man's short earthly life8 ,is it not rather reasonable to suppose that the pure and elevated and all-embracing affection1 extinguishing all vices and including all virtues1 to which the good man thus tends1 shall continue to prevail in him as a permanent and ever-during condition1 in a life after this8 ,but can man raise himself to such a stage of moral progress1 by his own efforts8 ,such a progress is an approximation towards the perfection of moral ,ideas1 and therefore an approximation towards the image of ,god1 in whom that perfection resides3 is it not then reasonable to suppose that man needs a ,divine ,influence to enable him to reach this kind of moral completeness8 ,and is it not also reasonable to suppose that1 as he needs such aid1 in order that the ,idea of his moral progress may be realized1 so he will receive such aid from the ,divine ,power which realizes the ,idea of ,divine ,love in the world2 and to do so1 must realize it in those human souls which are most fitted for such a purpose8 ,but these questions remind me how difficult1 and indeed1 how impossible it is to follow such trains of reflexion by the light of philosophy alone4 ,to answer such questions1 we need1 not ,religious ,philosophy only1 but ,religion3 and as ,i do not here venture beyond the domain of philosophy1 ,i must1 however abruptly1 conclude4 ,,the ,,end4 ,,appendix4 ,,appendix ,a4 ,,of ,,the ,,platonic ,,theory ,,of ,,ideas4 7,cam4 ,phil4 ,soc4 ,nov4 #aj1 #ahef47 ,though ,plato has1 in recent times1 had many readers and admirers among our ,english scholars1 there has been an air of unreality and inconsistency about the commendation which most of these professed adherents have given to his doctrines4 ,this appears to be no captious criticism1 for instance1 when those who speak of him as immeasurably superior in argument to his opponents1 do not venture to produce his arguments in a definite form as able to bear the tug of modern controversy2--when they use his own ,greek phrases as essential to the exposition of his doctrines1 and speak as if these phrases could not be adequately rendered in ,english2--and when they assent to those among the systems of philosophy of modern times which are the most clearly opposed to the system of ,plato4 ,it seems not unreasonable to require1 on the contrary1 that if ,plato is to supply a philosophy for us1 it must be a philosophy which can be expressed in our own language2--that his system1 if we hold it to be well founded1 shall compel us to deny the opposite systems1 modern as well as ancient2--and that1 so far as we hold ,plato's doctrines to be satisfactorily established1 we should be able to produce the arguments for them1 and to refute the arguments against them4 ,these seem reasonable requirements of the adherents of any philosophy1 and therefore1 of ,plato's4 ,i regard it as a fortunate circumstance1 that we have recently had presented to us an exposition of ,plato's philosophy which does conform to those reasonable conditions2 and we may discuss this exposition with the less reserve1 since its accomplished author1 though belonging to this generation1 is no longer alive4 ,i refer to the ,lectures on the ,history of ,ancient ,philosophy1 by the late ,professor ,butler of ,dublin4 ,in these ,lectures1 we find an account of the ,platonic ,philosophy which shows that the writer had considered it as1 what it is1 an attempt to solve large problems1 which in all ages force themselves upon the notice of thoughtful men4 ,in ,lectures ,,viii4 and ,x41 of the ,second ,series1 especially1 we have a statement of the ,platonic ,theory of ,ideas1 which may be made a convenient starting point for such remarks as ,i wish at present to make4 ,i will transcribe this account2 omitting1 as ,i do so1 the expressions which ,professor ,butler uses1 in order to present the theory1 not as a dogmatical assertion1 but as a view1 at least not extravagant4 ,for this purpose1 he says1 of the successive portions of the theory1 that one is not too absurd to be maintained2 that another is not very extravagant either2 that a third is surely allowable2 that a fourth presents no incredible account of the subject2 that a fifth is no preposterous notion in substance1 and no unwarrantable form of phrase4 ,divested of these modest formul1 his account is as follows3 ,vol4 ,,ii4 p4 #aag4 ,man's soul is made to contain not merely a consistent scheme of its own notions1 but a direct apprehension of real and eternal laws beyond it4 ,these real and eternal laws are things intelligible1 and not things sensible4 ,these laws impressed upon creation by its ,creator1 and apprehended by man1 are something distinct equally from the ,creator and from man1 and the whole mass of them may fairly be termed the ,world of ,things ,intelligible4 ,further1 there are qualities in the supreme and ultimate ,cause of all1 which are manifested in ,his creation1 and not merely manifested1 but1 in a manner--after being brought out of his super-essential nature into the stage of being which is below him1 but next to him--are then by the causative act of creation deposited in things1 differencing them one from the other1 so that the things partake of them 771 communicate with them 774 ,the intelligence of man1 excited to reflection by the impressions of these objects thus 7though themselves transitory7 participant of a divine quality1 may rise to higher conceptions of the perfections thus faintly exhibited2 and inasmuch as these perfections are unquestionably real existences1 and known to be such in the very act of contemplation1--this may be regarded as a direct intellectual apperception of them1--a ,union of the ,reason with the ,ideas in that sphere of being which is common to both4 ,finally1 the ,reason1 in proportion as it learns to contemplate the ,perfect and ,eternal1 desires the enjoyment of such contemplations in a more consummate degree1 and cannot be fully satisfied1 except in the actual fruition of the ,perfect itself4 ,these suppositions1 taken together1 constitute the ,theory of ,ideas4 ,in remarking upon the theory thus presented1 ,i shall abstain from any discussion of the theological part of it1 as a subject which would probably be considered as unsuited to the meetings of this ,society1 even in its most purely philosophical form4 ,but ,i conceive that it will not be inconvenient1 if it be not wearisome1 to discuss the ,theory of ,ideas as an attempt to explain the existence of real knowledge2 which ,prof4 ,butler very rightly considers as the necessary aim of this and cognate systems of philosophy#cba4 ,i conceive1 then1 that one of the primary objects of ,plato's ,theory of ,ideas is1 to explain the existence of real knowledge1 that is1 of demonstrated knowledge1 such as the propositions of geometry offer to us4 ,in this view1 the ,theory of ,ideas is one attempt to solve a problem1 much discussed in our times1 ,what is the ground of geometrical truth8 ,i do not mean that this is the whole object of the ,theory1 or the highest of its claims4 ,as ,i have said1 ,i omit its theological bearings2 and ,i am aware that there are passages in the ,platonic ,dialogues1 in which the ,ideas which enter into the apprehension and demonstration of geometrical truths are spoken of as subordinate to ,ideas which have a theological aspect4 ,but ,i have no doubt that one of the main motives to the construction of the ,theory of ,ideas was1 the desire of solving the ,problem1 ,how is it possible that man should apprehend necessary and eternal truths8 ,that the truths are necessary1 makes them eternal1 for they do not depend on time2 and that they are eternal1 gives them at once a theological bearing4 ,that ,plato1 in attempting to explain the nature and possibility of real knowledge1 had in his mind geometrical truths1 as examples of such knowledge is1 ,i think1 evident from the general purport of his discourses on such subjects4 ,the advance of ,greek geometry into a conspicuous position1 at the time when the ,heraclitean sect were proving that nothing could be proved and nothing could be known1 naturally suggested mathematical truth as the refutation of the skepticism of mere sensation4 ,on the one side it was said1 we can know nothing except by our sensations2 and that which we observe with our senses is constantly changing2 or at any rate1 may change at any moment4 ,on the other hand it was said1 we do know geometrical truths1 and as truly as we know them1 that they cannot change4 ,plato was quite alive to the lesson1 and to the importance of this kind of truths4 ,in the ,meno and in the ,phdo he refers to them1 as illustrating the nature of the human mind3 in the ,republic and the ,timus he again speaks of truths which far transcend anything which the senses can teach1 or even adequately exemplify4 ,the senses1 he argues in the ,thetetus1 cannot give us the knowledge which we have2 the source of it must therefore be in the mind itself2 in the ,ideas which it possesses4 ,the impressions of sense are constantly varying1 and incapable of giving any certainty3 but the ,ideas on which real truth depends are constant and invariable1 and the certainty which arises from these is firm and indestructible4 ,ideas are the permanent1 perfect objects1 with which the mind deals when it contemplates necessary and eternal truths4 ,they belong to a region superior to the material world1 the world of sense4 ,they are the objects which make up the furniture of the ,intelligible ,world2 with which the ,reason deals1 as the ,senses deal each with its appropriate ,sensation4 ,but1 it will naturally be asked1 what is the ,relation of ,ideas to the ,objects of ,sense8 ,some connexion1 or relation1 it is plain1 there must be4 ,the objects of sense can suggest1 and can illustrate real truths4 ,though these truths of geometry cannot be proved1 cannot even be exactly exemplified1 by drawing diagrams1 yet diagrams are of use in helping ordinary minds to see the proof2 and to all minds1 may represent and illustrate it4 ,and though our conclusions with regard to objects of sense may be insecure and imperfect1 they have some show of truth1 and therefore some resemblance to truth4 ,what does this arise from8 ,how is it explained1 if there is no truth except concerning ,ideas8 ,to this the ,platonist replied1 that the phenomena which present themselves to the senses partake1 in a certain manner1 of ,ideas1 and thus include so much of the nature of ,ideas1 that they include also an element of ,truth4 ,the geometrical diagram of ,triangles and ,squares which is drawn in the sand of the floor of the ,gymnasium1 partakes of the nature of the true ,ideal ,triangles and ,squares1 so that it presents an imitation and suggestion of the truths which are true of them4 ,the real triangles and squares are in the mind3 they are1 as we have said1 objects1 not in the ,visible1 but in the ,intelligible ,world4 ,but the ,visible ,triangles and ,squares make us call to mind the ,intelligible2 and thus the objects of sense suggest1 and1 in a way1 exemplify the eternal truths4 ,this ,i conceive to be the simplest and directest ground of two primary parts of the ,theory of ,ideas2--,the ,eternal ,ideas constituting an ,intelligible ,world2 and the ,participation in these ,ideas ascribed to the objects of the world of sense4 ,and it is plain that so far1 the ,theory meets what1 ,i conceive1 was its primary purpose2 it answers the questions1 ,how can we have certain knowledge1 though we cannot get it from ,sense8 and1 ,how can we have knowledge1 at least apparent1 though imperfect1 about the world of sense8 ,but is this the ground on which ,plato himself rests the truth of his ,theory of ,ideas8 ,as ,i have said1 ,i have no doubt that these were the questions which suggested the ,theory2 and it is perpetually applied in such a manner as to show that it was held by ,plato in this sense4 ,but his applications of the ,theory refer very often to another part of it2--to the ,ideas1 not of ,triangles and ,squares1 of space and its affections2 but to the ,ideas of ,relations--as the ,relations of ,like and ,unlike1 ,greater and ,less2 or to things quite different from the things of which geometry treats1 for instance1 to ,tables and ,chairs1 and other matters1 with regard to which no demonstration is possible1 and no general truth 7still less necessary an eternal truth7 capable of being asserted4 ,i conceive that the ,theory of ,ideas1 thus asserted and thus supported1 stands upon very much weaker ground than it does1 when it is asserted concerning the objects of thought about which necessary and demonstrable truths are attainable4 ,and in order to devise arguments against this part of the ,theory1 and to trace the contradictions to which it leads1 we have no occasion to task our own ingenuity4 ,we find it done to our hands1 not only in ,aristotle1 the open opponent of the ,theory of ,ideas1 but in works which stand among the ,platonic ,dialogues themselves4 ,and ,i wish especially to point out some of the arguments against the ,ideal ,theory1 which are given in one of the most noted of the ,platonic ,dialogues1 the ,parmenides4 ,the ,parmenides contains a narrative of a ,dialogue held between ,parmenides and ,zeno1 the ,eleatic ,philosophers1 on the one side1 and ,socrates1 along with several other persons1 on the other4 ,it may be regarded as divided into two main portions2 the first1 in which the ,theory of ,ideas is attacked by ,parmenides1 and defended by ,socrates2 the second1 in which ,parmenides discusses1 at length1 the ,eleatic doctrine that ,all things are ,one4 ,it is the former part1 the discussion of the ,theory of ,ideas1 to which ,i especially wish to direct attention at present3 and in the first place1 to that extension of the ,theory of ,ideas1 to things of which no general truth is possible2 such as ,i have mentioned1 tables and chairs4 ,plato often speaks of a ,table1 by way of example1 as a thing of which there must be an ,idea1 not taken from any special ,table or assemblage of ,tables2 but an ,ideal ,table1 such that all ,tables are ,tables by participating in the nature of this ,idea4 ,now the question is1 whether there is any force1 or indeed any sense1 in this assumption2 and this question is discussed in the ,parmenides4 ,socrates is there represented as very confident in the existence of ,ideas of the highest and largest kind1 the ,just1 the ,fair1 the ,good1 and the like4 ,parmenides asks him how far he follows his theory4 ,is there1 he asks1 an ,idea of ,man1 which is distinct from us men8 an ,idea of ,fire8 of ,water8 ,in truth1 replies ,socrates1 ,i have often hesitated1 ,parmenides1 about these1 whether we are to allow such ,ideas4 ,when ,plato had proceeded to teach that there is an ,idea of a ,table1 of course he could not reject such ,ideas as ,man1 and ,fire1 and ,water4 ,parmenides1 proceeding in the same line1 pushes him further still4 ,do you doubt1 says he1 whether there are ,ideas of things apparently worthless and vile8 ,is there an ,idea of a ,hair8 of ,mud8 of ,filth8 ,socrates has not the courage to accept such an extension of the theory4 ,he says1 ,by no means4 ,these are not ,ideas4 ,these are nothing more than just what we see them4 ,i have often been perplexed what to think on this subject4 ,but after standing to this a while1 ,i have fled the thought1 for fear of falling into an unfathomable abyss of absurdities4 ,on this1 ,parmenides rebukes him for his want of consistency4 ,ah ,socrates1 he says1 you are yet young2 and philosophy has not yet taken possession of you as ,i think she will one day do--when you will have learned to find nothing despicable in any of these things4 ,but now your youth inclines you to regard the opinions of men4 ,it is indeed plain1 that if we are to assume an ,idea of a ,chair or a ,table1 we can find no boundary line which will exclude ,ideas of everything for which we have a name1 however worthless or offensive4 ,and this is an argument against the assumption of such ,ideas1 which will convince most persons of the groundlessness of the assumption3--the more so1 as for the assumption of such ,ideas1 it does not appear that ,plato offers any argument whatever2 nor does this assumption solve any problem1 or remove any difficulty#cbb4 ,parmenides1 then1 had reason to say that consistency required ,socrates1 if he assumed any such ,ideas1 to assume all4 ,and ,i conceive his reply to be to this effect2 and to be thus a reductio ad absurdum of the ,theory of ,ideas in this sense4 ,according to the opinions of those who see in the ,parmenides an exposition of ,platonic doctrines1 ,i believe that ,parmenides is conceived in this passage1 to suggest to ,socrates what is necessary for the completion of the ,theory of ,ideas4 ,but upon either supposition1 ,i wish especially to draw the attention of my readers to the position of superiority in the ,dialogue in which ,parmenides is here placed with regard to ,socrates4 ,parmenides then proceeds to propound to ,socrates difficulties with regard to the ,ideal ,theory1 in another of its aspects2--namely1 when it assumes ,ideas of ,relations of things2 and here also1 ,i wish especially to have it considered how far the answers of ,socrates to these objections are really satisfactory and conclusive4 ,tell me1 says he 7 #aj1 ,bekker71 ,you conceive that there are certain ,ideas1 and that things partaking of these ,ideas1 are called by the corresponding names2--an ,idea of ,likeness1 things partaking of which are called ,like2--of ,greatness1 whence they are ,great3 of ,beauty1 whence they are ,beautiful8 ,socrates assents1 naturally3 this being the simple and universal statement of the ,theory1 in this case4 ,but then comes one of the real difficulties of the ,theory4 ,since the special things participate of the ,general ,idea1 has each got the whole of the ,idea1 which is1 of course1 ,one2 or has each a part of the ,idea8 ,for1 says ,parmenides1 can there be any other way of participation than these two8 ,socrates replies by a similitude3 ,the ,idea1 though ,one1 may be wholly in each object1 as the ,day1 one and the same1 is wholly in each place4 ,the physical illustration1 ,parmenides damages by making it more physical still4 ,you are ingenious1 ,socrates1 he says1 7 #aa7 in making the same thing be in many places at the same time4 ,if you had a number of persons wrapped up in a sail or web1 would you say that each of them had the whole of it8 ,is not the case similar8 ,socrates cannot deny that it is4 ,but in this case1 each person has only a part of the whole2 and thus your ,ideas are partible4 ,to this1 ,socrates is represented as assenting in the briefest possible phrase2 and thus1 here again1 as ,i conceive1 ,parmenides retains his superiority over ,socrates in the ,dialogue4 ,there are many other arguments urged against the ,ideal ,theory by ,parmenides4 ,the next is a consequence of this partibility of ,ideas1 thus supposed to be proved1 and is ingenious enough4 ,it is this3 ,if the ,idea of ,greatness be distributed among things that are ,great1 so that each has a part of it1 each separate thing will be ,great in virtue of a part of ,greatness which is less than ,greatness itself4 ,is not this absurd8 ,socrates submissively allows that it is4 ,and the same argument is applied in the case of the ,idea of ,equality4 ,if each of several things have a part of the ,idea of ,equality1 it will be ,equal to something1 in virtue of something which is less than ,equality4 ,and in the same way with regard to the ,idea of ,smallness4 ,if each thing be small by having a part of the ,idea of ,smallness1 ,smallness itself will be greater than the small thing1 since that is a part of itself4 ,these ingenious results of the partibility of ,ideas remind us of the ingenuity shown in the ,greek geometry1 especially the ,fifth ,book of ,euclid4 ,they are represented as not resisted by ,socrates 7 #ab73 ,in what way1 ,socrates1 can things participate in ,ideas1 if they cannot do so either integrally or partibly8 ,by my troth1 says ,socrates1 it does not seem easy to tell4 ,parmenides1 who completely takes the conduct of the ,dialogue1 then turns to another part of the subject and propounds other arguments4 ,what do you say to this8 he asks4 ,there is an ,ideal ,greatness1 and there are many things1 separate from it1 and ,great by virtue of it4 ,but now if you look at ,greatness and the ,great things together1 since they are all ,great1 they must be ,great in virtue of some higher ,idea of ,greatness which includes both4 ,and thus you have a ,second ,idea of ,greatness2 and in like manner you will have a third1 and so on indefinitely4 ,this also1 as an argument against the separate existence of ,ideas1 ,socrates is represented as unable to answer4 ,he replies interrogatively3 ,why1 ,parmenides1 is not each of these ,ideas a ,thought1 which1 by its nature1 cannot exist in anything except in the ,mind8 ,in that case your consequences would not follow4 ,this is an answer which changes the course of the reasoning3 but still1 not much to the advantage of the ,ideal ,theory4 ,parmenides is still ready with very perplexing arguments4 7 #ac47 ,the ,ideas1 then1 he says1 are ,thoughts4 ,they must be ,thoughts of something4 ,they are ,thoughts of something1 then1 which exists in all the special things2 some one thing which the ,thought perceives in all the special things2 and this one ,thought thus involved in all1 is the ,idea4 ,but then1 if the special things1 as you say1 participate in the ,idea1 they participate in the ,thought2 and thus1 all objects are made up of ,thoughts1 and all things think2 or else1 there are thoughts in things which do not think4 ,this argument drives ,socrates from the position that ,ideas are ,thoughts1 and he moves to another1 that they are ,paradigms1 ,exemplars of the qualities of things1 to which the things themselves are like1 and their being thus like1 is their participating in the ,idea4 ,but here too1 he has no better success4 ,parmenides argues thus3 ,if the ,object be like the ,idea1 the ,idea must be like the ,object4 ,and since the ,object and the ,idea are like1 they must1 according to your doctrine1 participate in the ,idea of ,likeness4 ,and thus you have one ,idea participating in another ,idea1 and so on in infinitum4 ,socrates is obliged to allow that this demolishes the notion of objects partaking in their ,ideas by likeness3 and that he must seek some other way4 ,you see then1 ,o ,socrates1 says ,parmenides1 what difficulties follow1 if any one asserts the independent existence of ,ideas6 ,socrates allows that this is true4 ,and yet1 says ,parmenides1 you do not half perceive the difficulties which follow from this doctrine of ,ideas4 ,socrates expresses a wish to know to what ,parmenides refers2 and the aged sage replies by explaining that if ,ideas exist independently of us1 we can never know anything about them3 and that even the ,gods could not know anything about man4 ,this argument1 though somewhat obscure1 is evidently stated with perfect earnestness1 and ,socrates is represented as giving his assent to it4 ,and yet1 says ,parmenides 7end of #ah71 if any one gives up entirely the doctrine of ,ideas1 how is any reasoning possible8 ,all the way through this discussion1 ,parmenides appears as vastly superior to ,socrates2 as seeing completely the tendency of every line of reasoning1 while ,socrates is driven blindly from one position to another2 and as kindly and graciously advising a young man respecting the proper aims of his philosophical career2 as well as clearly pointing out the consequences of his assumptions4 ,nothing can be more complete than the higher position assigned to ,parmenides in the ,dialogue4 ,this has not been overlooked by the ,editors and ,commentators of ,plato4 ,to take for example one of the latest2 in ,steinhart's ,introduction to ,hieronymus ,mller's translation of ,parmenides 7,leipzig1 #aheb71 p4 #bfa1 he says3 ,it strikes us1 at first1 as strange1 that ,plato here seems to come forward as the assailant of his own doctrine of ,ideas4 ,for the difficulties which he makes ,parmenides propound against that doctrine are by no means sophistical or superficial1 but substantial and to the point4 ,moreover there is among all these objections1 which are partly derived from the ,megarics1 scarce one which does not appear again in the penetrating and comprehensive argumentations of ,aristotle against the ,platonic ,doctrine of ,ideas4 ,of course1 both this writer and other commentators on ,plato offer something as a solution of this difficulty4 ,but though these explanations are subtle and ingenious1 they appear to leave no satisfactory or permanent impression on the mind4 ,i must avow that1 to me1 they appear insufficient and empty2 and ,i cannot help believing that the solution is of a more simple and direct kind4 ,it may seem bold to maintain an opinion different from that of so many eminent scholars2 but ,i think that the solution which ,i offer1 will derive confirmation from a consideration of the whole ,dialogue2 and therefore ,i shall venture to propound it in a distinct and positive form4 ,it is this3 ,i conceive that the ,parmenides is not a ,platonic ,dialogue at all2 but ,antiplatonic1 or more properly1 ,eleatic3 written1 not by ,plato1 in order to explain and prove his ,theory of ,ideas1 but by some one1 probably an admirer of ,parmenides and ,zeno1 in order to show how strong were his master's arguments against the ,platonists and how weak their objections to the ,eleatic doctrine4 ,i conceive that this view throws an especial light on every part of the ,dialogue1 as a brief survey of it will show4 ,parmenides and ,zeno come to ,athens to the ,panathenaic festival3 ,parmenides already an old man1 with a silver head1 dignified and benevolent in his appearance1 looking five and sixty years old3 ,zeno about forty1 tall and handsome4 ,they are the guests of ,pythodorus1 outside the ,wall1 in the ,ceramicus2 and there they are visited by ,socrates then young1 and others who wish to hear the written discourses of ,zeno4 ,these discourses are explanations of the philosophy of ,parmenides1 which he had delivered in verse4 ,socrates is represented as showing1 from the first1 a disposition to criticize ,zeno's dissertation very closely2 and without any prelude or preparation1 he applies the ,doctrine of ,ideas to refute the ,eleatic ,doctrine that ,all ,things are ,one4 7 #c47 ,when he had heard to the end1 he begged to have the first ,proposition of the ,first ,book read again4 ,and then1 ,how is it1 ,o ,zeno1 that you say1 ,that if the ,things which exist are ,many1 and not ,one1 they must be at the same time like and unlike8 ,is this your argument8 ,or do ,i misunderstand you8 ,no1 says ,zeno1 you understand quite rightly4 ,socrates then turns to ,parmenides1 and says1 somewhat rudely1 as it seems1 ,zeno is a great friend of yours1 ,parmenides3 he shows his friendship not only in other ways1 but also in what he writes4 ,for he says the same things which you say1 though he pretends that he does not4 ,you say1 in your poems1 that ,all ,things are ,one1 and give striking proofs3 he says that existences are not many1 and he gives many and good proofs4 ,you seem to soar above us1 but you do not really differ4 ,zeno takes this sally good-humouredly1 and tells him that he pursues the scent with the keenness of a ,laconian hound4 ,but1 says he 7 #f71 there really is less of ostentation in my writing than you think4 ,my ,essay was merely written as a defence of ,parmenides long ago1 when ,i was young2 and is not a piece of display composed now that ,i am older4 ,and it was stolen from me by some one2 so that ,i had no choice about publishing it4 ,here we have1 as ,i conceive1 ,socrates already represented as placed in a disadvantageous position1 by his abruptness1 rude allusions1 and readiness to put bad interpretations on what is done4 ,for this1 ,zeno's gentle pleasantry is a rebuke4 ,socrates1 however1 forthwith rushes into the argument2 arguing1 as ,i have said1 for his own ,theory4 ,tell me1 he says1 do you not think there is an ,idea of ,likeness1 and an ,idea of ,unlikeness8 ,and that everything partakes of these ,ideas8 ,the things which partake of ,unlikeness are unlike4 ,if all things partake of both ,ideas1 they are both like and unlike2 and where is the wonder8 7 #g47 ,if you could show that ,likeness itself was ,unlikeness1 it would be a prodigy2 but if things which partake of these opposites1 have both the opposite qualities1 it appears to me1 ,zeno1 to involve no absurdity4 ,so if ,oneness itself were to be shown to be ,maniness 7,i hope ,i may use this word1 rather than multiplicity7 ,i should be surprised2 but if any one say that ,i am at the same time one and many1 where is the wonder8 ,for ,i partake of maniness3 my right side is different from my left side1 my upper from my under parts4 ,but ,i also partake of ,oneness1 for ,i am here ,one of us seven4 ,so that both are true4 ,and so if any one say that stocks and stones1 and the like1 are both one and many1--not saying that ,oneness is ,maniness1 nor ,maniness ,oneness1 he says nothing wonderful3 he says what all will allow4 7 #h47 ,if then1 as ,i said before1 any one should take separately the ,ideas or ,essence of ,things1 as ,likeness and ,unlikeness1 ,maniness and ,oneness1 ,rest and ,motion1 and the like1 and then should show that these can mix and separate again1 ,i should be wonderfully surprised1 ,o ,zeno3 for ,i reckon that ,i have tolerably well made myself master of these subjects#cbc4 ,i should be much more surprised if any one could show me this contradiction involved in the ,ideas themselves2 in the object of the ,reason1 as well as in ,visible objects4 ,it may be remarked that ,socrates delivers all this argumentation with the repetitions which it involves1 and the vehemence of its manner1 without waiting for a reply to any of his interrogations2 instead of making every step the result of a concession of his opponent1 as is the case in the ,dialogues where he is represented as triumphant4 ,every reader of ,plato will recollect also that in those ,dialogues1 the triumph of temper on the part of ,socrates is represented as still more remarkable than the triumph of argument4 ,no vehemence or rudeness on the part of his adversaries prevents his calmly following his reasoning2 and he parries coarseness by compliment4 ,now in this ,dialogue1 it is remarkable that this kind of triumph is given to the adversaries of ,socrates4 ,when ,socrates had thus delivered himself1 says ,pythodorus1 the narrator of the conversation1 we thought that ,parmenides and ,zeno would both be angry4 ,but it was not so4 ,they bestowed entire attention upon him1 and often looked at each other1 and smiled1 as in admiration of ,socrates4 ,and when he had ended1 ,parmenides said3 ',o ,socrates1 what an admirable person you are1 for the earnestness with which you reason6 ,tell me then1 ,do you then believe the doctrine to which you have been referring2--that there are certain ,ideas1 existing independent of ,things2 and that there are1 separate from the ,ideas1 ,things which partake of them8 ,and do you think that there is an ,idea of ,likeness besides the likeness which we have2 and a ,oneness and a ,maniness1 and the like8 ,and an ,idea of the ,right1 and the ,good1 and the ,fair1 and of other such qualities8' ,socrates says that he does hold this2 ,parmenides then asks him1 how far he carries this doctrine of ,ideas1 and propounds to him the difficulties which ,i have already stated2 and when ,socrates is unable to answer him1 lets him off in the kind but patronizing way which ,i have already described4 ,to me1 comparing this with the intellectual and moral attitude of ,socrates in the most dramatic of the other ,platonic ,dialogues1 it is inconceivable1 that this representation of ,socrates should be ,plato's4 ,it is just what ,zeno would have written1 if he had wished to bestow upon his master ,parmenides the calm dignity and irresistible argument which ,plato assigns to ,socrates4 ,and this character is kept up to the end of the ,dialogue4 ,when ,socrates 7 #ai7 has acknowledged that he is at loss which way to turn for his philosophy1 ,parmenides undertakes1 though with kind words1 to explain to him by what fundamental error in the course of his speculative habits he has been misled4 ,he says2 ,you try to make a complete ,theory of ,ideas1 before you have gone through a proper intellectual discipline4 ,the impulse which urges you to such speculations is admirable--is divine4 ,but you must exercise yourself in reasoning which many think trifling1 while you are yet young2 if you do not1 the truth will elude your grasp4 ,socrates asks submissively what is the course of such discipline3 ,parmenides replies1 ,the course pointed out by ,zeno1 as you have heard4 ,and then1 gives him some instructions in what manner he is to test any proposed ,theory4 ,socrates is frightened at the laboriousness and obscurity of the process4 ,he says1 ,you tell me1 ,parmenides1 of an overwhelming course of study2 and ,i do not well comprehend it4 ,give me an example of such an examination of a ,theory4 ,it is too great a labour1 says he1 for one so old as ,i am4 ,well then1 you1 ,zeno1 says ,socrates1 will you not give us such an example8 ,zeno answers1 smiling1 that they had better get it from ,parmenides himself2 and joins in the petition of ,socrates to him1 that he will instruct them4 ,all the company unite in the request4 ,parmenides compares himself to an aged racehorse1 brought to the course after long disuse1 and trembling at the risk2 but finally consents4 ,and as an example of a ,theory to be examined1 takes his own ,doctrine1 that ,all ,things are ,one1 carrying on the ,dialogue thenceforth1 not with ,socrates1 but with ,aristoteles 7not the ,stagirite1 but afterwards one of the ,thirty71 whom he chooses as a younger and more manageable respondent4 ,the discussion of this ,doctrine is of a very subtle kind1 and it would be difficult to make it intelligible to a modern reader4 ,nor is it necessary for my purpose to attempt to do so4 ,it is plain that the discussion is intended seriously1 as an example of true philosophy2 and each step of the process is represented as irresistible4 ,the ,respondent has nothing to say but ,yes2 or ,no2 ,how so8 ,certainly2 ,it does appear2 ,it does not appear4 ,the discussion is carried to a much greater length than all the rest of the ,dialogue2 and the result of the reasoning is summed up by ,parmenides thus3 ,if ,one exist1 it is ,nothing4 ,whether ,one exist or do not exist1 both ,it and ,other ,things both with regard to ,themselves and to ,each other1 ,all and ,everyway are and are not1 appear and appear not4 ,and this also is fully assented to2 and so the ,dialogue ends4 ,i shall not pretend to explain the ,doctrines there examined that ,one exists1 or ,one does not exist1 nor to trace their consequences4 ,but these were ,formul1 as familiar in the ,eleatic school1 as ,ideas in the ,platonic2 and were undoubtedly regarded by the ,megaric contemporaries of ,plato as quite worthy of being discussed1 after the ,theory of ,ideas had been overthrown4 ,this1 accordingly1 appears to be the purport of the ,dialogue2 and it is pursued1 as we see1 without any bitterness toward ,socrates or his disciples2 but with a persuasion that they were poor philosophers1 conceited talkers1 and weak disputants4 ,the external circumstances of the ,dialogue tend1 ,i conceive1 to confirm this opinion1 that it is not ,plato's4 ,the ,dialogue begins1 as the ,republic begins1 with the mention of a ,cephalus1 and two brothers1 ,glaucon and ,adimantus4 ,but this ,cephalus is not the old man of the ,pirus1 of whom we have so charming a picture in the opening of the ,republic4 ,he is from ,clazomen1 and tells us that his fellow-citizens are great lovers of philosophy2 a trait of their character which does not appear elsewhere4 ,even the brothers ,glaucon and ,adimantus are not the two brothers of ,plato who conduct the ,dialogue in the later books of the ,republic3 so at least ,ast argues1 who holds the genuineness of the ,dialogue4 ,this ,glaucon and ,adimantus are most wantonly introduced2 for the sole office they have1 is to say that they have a half-brother ,antiphon1 by a second marriage of their mother4 ,no such half-brother of ,plato1 and no such marriage of his mother1 are noticed in other remains of antiquity4 ,antiphon is represented as having been the friend of ,pythodorus1 who was the host of ,parmenides and ,zeno1 as we have seen4 ,and ,antiphon1 having often heard from ,pythodorus the account of the conversation of his guests with ,socrates1 retained it in his memory1 or in his tablets1 so as to be able to give the full report of it which we have in the ,dialogue ,parmenides#cbd4 ,to me1 all this looks like a clumsy imitation of the ,introductions to the ,platonic ,dialogues4 ,i say nothing of the chronological difficulties which arise from bringing ,parmenides and ,socrates together1 though they are considerable2 for they have been explained more or less satisfactorily2 and certainly in the ,thetetus1 ,socrates is represented as saying that he when very young had seen ,parmenides who was very old#cbe4 ,athenus1 however#cbf1 reckons this among ,plato's fictions4 ,schleiermacher gives up the identification and relation of the persons mentioned in the ,introduction as an unmanageable story4 ,i may add that ,i believe ,cicero1 who refers to so many of ,plato's ,dialogues1 nowhere refers to the ,parmenides4 ,athenus does refer to it2 and in doing so blames ,plato for his coarse imputations on ,zeno and ,parmenides4 ,according to our view1 these are hostile attempts to ascribe rudeness to ,socrates or to ,plato4 ,stallbaum acknowledges that ,aristotle nowhere refers to this ,dialogue4 ,,footnotes3 ,footnote #cba3 ,p4 #aaf4 ,no amount of human knowledge can be adequate which does not solve the phenomena of these absolute certainties4 ,footnote #cbb3 ,prof4 ,butler1 ,lect4 ix4 ,second ,series1 p4 #acf1 appears to think that ,plato had sufficient grounds 7of a theological kind7 for the assumption of such ,ideas2 but ,i see no trace of them4 ,footnote #cbc3 ,i am aware that this translation is different from the common translation4 ,it appears to me to be consistent with the habit of the ,greek language4 ,it slightly leans in favour of my view2 but ,i do not conceive that the argument would be perceptibly weaker1 if the common interpretation were adopted4 ,footnote #cbd3 ,in the ,first ,alcibiades1 ,pythodorus is mentioned as having paid #ajj min to ,zeno for his instructions 7#aai ,a74 ,footnote #cbe3 ,p4 #ahc e4 ,footnote #cbf3 ,deip4 xi4 c4 #ae1 p4 #aje4 ,,appendix ,b4 ,,on ,,plato',s ,,survey ,,of ,,the ,,sciences4 7,cam4 ,phil4 ,soc4 ,,april #bc1 #ahee47 ,a survey by ,plato of the state of the ,sciences1 as existing in his time1 may be regarded as hardly less interesting than ,francis ,bacon's ,review of the condition of the ,sciences of his time1 contained in the ,advancement of ,learning4 ,such a survey we have1 in the seventh book of ,plato's ,republic2 and it will be instructive to examine what the ,sciences then were1 and what ,plato aspired to have them become2 aiding ourselves by the light afforded by the subsequent history of ,science4 ,in the first place1 it is interesting to note1 in the two writers1 ,plato and ,bacon1 the same deep conviction that the large and profound philosophy which they recommended1 had not1 in their judgment1 been pursued in an adequate and worthy manner1 by those who had pursued it at all4 ,the reader of ,bacon will recollect the passage in the ,novum ,organon 7,lib4 ,i4 ,aphorism #hj7 where he speaks with indignation of the way in which philosophy had been degraded and perverted1 by being applied as a mere instrument of utility or of early education3 ,so that the great mother of the ,sciences is thrust down with indignity to the offices of a handmaid2--is made to minister to the labours of medicine or mathematics2 or again1 to give the first preparatory tinge to the immature minds of youth#cbg4 ,in the like spirit1 ,plato says 7,rep4 ,,vi4 #aa1 ,bekker's ed473 ,observe how boldly and fearlessly ,i set about my explanation of my assertion that philosophers ought to rule the world4 ,for ,i begin by saying1 that the ,state must begin to treat the study of philosophy in a way opposite to that now practised4 ,now1 those who meddle at all with this study are put upon it when they are children1 between the lessons which they receive in the farm-yard and in the shop#cbh2 and as soon as they have been introduced to the hardest part of the subject1 are taken off from it1 even those who get the most of philosophy4 ,by the hardest part1 ,i mean1 the discussion of principles--,dialectic#cbi4 ,and in their succeeding years1 if they are willing to listen to a few lectures of those who make philosophy their business1 they think they have done great things1 as if it were something foreign to the business of life4 ,and as they advance towards old age1 with a very few exceptions1 philosophy in them is extinguished3 extinguished far more completely than the ,heraclitean sun1 for theirs is not lighted up again1 as that is every morning3 alluding to the opinion which was propounded1 by way of carrying the doctrine of the unfixity of sensible objects to an extreme2 that the ,sun is extinguished every night and lighted again in the morning4 ,in opposition to this practice1 ,plato holds that philosophy should be the especial employment of men's minds when their bodily strength fails4 ,what ,plato means by ,dialectic1 which he1 in the next ,book1 calls the highest part of philosophy1 and which is1 ,i think1 what he here means by the hardest part of philosophy1 ,i may hereafter consider3 but at present ,i wish to pass in review the ,sciences which he speaks of1 as leading the way to that highest study4 ,these ,sciences are ,arithmetic1 ,plane ,geometry1 ,solid ,geometry1 ,astronomy and ,harmonics4 ,the view in which ,plato here regards the ,sciences is1 as the instruments of that culture of the philosophical spirit which is to make the philosopher the fit and natural ruler of the perfect ,state--the ,platonic ,polity4 ,it is held that to answer this purpose1 the mind must be instructed in something more stable than the knowledge supplied by the senses2--a knowledge of objects which are constantly changing1 and which therefore can be no real permanent ,knowledge1 but only ,opinion4 ,the real and permanent ,knowledge which we thus require is to be found in certain sciences1 which deal with truths necessary and universal1 as we should now describe them3 and which therefore are1 in ,plato's language1 a knowledge of that which really is#ccj4 ,this is the object of the ,sciences of which ,plato speaks4 ,and hence1 when he introduces ,arithmetic1 as the first of the ,sciences which are to be employed in this mental discipline1 he adds 7,,vii4 #h7 that it must be not mere common ,arithmetic1 but a science which leads to speculative truths#cca1 seen by ,intuition#ccb2 not an ,arithmetic which is studied for the sake of buying and selling1 as among tradesmen and shopkeepers1 but for the sake of pure and real ,science#ccc4 ,i shall not dwell upon the details with which he illustrates this view1 but proceed to the other ,sciences which he mentions4 ,geometry is then spoken of1 as obviously the next ,science in order2 and it is asserted that it really does answer the required condition of drawing the mind from visible1 mutable phenomena to a permanent reality4 ,geometers indeed speak of their visible diagrams1 as if their problems were certain practical processes2 to erect a perpendicular2 to construct a square3 and the like4 ,but this language1 though necessary1 is really absurd4 ,the figures are mere aids to their reasonings4 ,their knowledge is really a knowledge not of visible objects1 but of permanent realities3 and thus1 ,geometry is one of the helps by which the mind may be drawn to ,truth2 by which the philosophical spirit may be formed1 which looks upwards instead of downwards4 ,astronomy is suggested as the ,science next in order1 but ,socrates1 the leader of the dialogue1 remarks that there is an intermediate ,science first to be considered4 ,geometry treats of plane figures2 ,astronomy treats of solids in motion1 that is1 of spheres in motion2 for the astronomy of ,plato's time was mainly the doctrine of the sphere4 ,but before treating of solids in motion1 we must have a science which treats of solids simply4 ,after taking space of two dimensions1 we must take space of three dimensions1 length1 breadth and depth1 as in cubes and the like#ccd4 ,but such a ,science1 it is remarked1 has not yet been discovered4 ,plato notes as deficient this branch of knowledge2 to use the expression employed by ,bacon on the like occasions in his ,review4 ,plato goes on to say1 that the cultivators of such a science have not received due encouragement2 and that though scorned and starved by the public1 and not recommended by any obvious utility1 it has still made great progress1 in virtue of its own attractiveness4 ,in fact1 researches in ,solid ,geometry had been pursued with great zeal by ,plato and his friends1 and with remarkable success4 ,the five ,regular ,solids1 the ,tetrahedron or ,pyramid1 ,cube1 ,octahedron1 ,dodecahedron and ,icosahedron1 had been discovered2 and the curious theorem1 that of ,regular ,solids there can be just so many1 these and no others1 was known4 ,the doctrine of these ,solids was already applied in a way1 fanciful and arbitrary1 no doubt1 but ingenious and lively1 to the theory of the ,universe4 ,in the ,timus1 the elements have these forms assigned to them respectively4 ,earth has the ,cube3 ,fire has the ,pyramid3 ,water has the ,octahedron3 ,air has the ,icosahedron3 and the ,dodecahedron is the plan of the ,universe itself4 ,this application of the doctrine of the ,regular ,solids shows that the knowledge of those figures was already established2 and that ,plato had a right to speak of ,solid ,geometry as a real and interesting ,science4 ,and that this subject was so recondite and profound1--that these five ,regular ,solids had so little application in the geometry which has a bearing on man's ordinary thoughts and actions1--made it all the more natural for ,plato to suppose that these solids had a bearing on the constitution of the ,universe2 and we shall find that such a belief in later times found a ready acceptance in the minds of mathematicians who followed in the ,platonic line of speculation4 ,plato next proceeds to consider ,astronomy2 and here we have an amusing touch of philosophical drama4 ,glaucon1 the hearer and pupil in the ,dialogue1 is desirous of showing that he has profited by what his instructor had said about the real uses of ,science4 ,he says ,astronomy is a very good branch of education4 ,it is such a very useful science for seamen and husbandmen and the like4 ,socrates says1 with a smile1 as we may suppose3 ,you are very amusing with your zeal for utility4 ,i suppose you are afraid of being condemned by the good people of ,athens for diffusing ,useless ,knowledge4 ,a little afterwards ,glaucon tries to do better1 but still with no great success4 ,he says1 ,you blamed me for praising ,astronomy awkwardly3 but now ,i will follow your lead4 ,astronomy is one of the sciences which you require1 because it makes men's minds look upwards1 and study things above4 ,any one can see that4 ,well1 says ,socrates1 perhaps any one can see it except me--,i cannot see it4 ,glaucon is surprised1 but ,socrates goes on3 ,your notice of 'the study of things above' is certainly a very magnificent one4 ,you seem to think that if a man bends his head back and looks at the ceiling he 'looks upwards' with his mind as well as his eyes4 ,you may be right and ,i may be wrong3 but ,i have no notion of any science which makes the mind look upwards1 except a science which is about the permanent and the invisible4 ,it makes no difference1 as to that matter1 whether a man gapes and looks up or shuts his mouth and looks down4 ,if a man merely look up and stare at sensible objects1 his mind does not look upwards1 even if he were to pursue his studies swimming on his back in the sea4 ,the ,astronomy1 then1 which merely looks at phenomena does not satisfy ,plato4 ,he wants something more4 ,what is it8 as ,glaucon very naturally asks4 ,plato then describes ,astronomy as a real science 7 #aa74 ,the variegated adornments which appear in the sky1 the visible luminaries1 we must judge to be the most beautiful and the most perfect things of their kind3 but since they are mere visible figures1 we must suppose them to be far inferior to the true objects2 namely1 those spheres which1 with their real proportions of quickness and slowness1 their real number1 their real figures1 revolve and carry luminaries in their revolutions4 ,these objects are to be apprehended by reason and mental conception1 not by vision4 ,and he then goes on to say that the varied figures which the skies present to the eye are to be used as diagrams to assist the study of that higher truth2 just as if any one were to study geometry by means of beautiful diagrams constructed by ,ddalus or any other consummate artist4 ,here then1 ,plato points to a kind of astronomical science which goes beyond the mere arrangement of phenomena3 an astronomy which1 it would seem1 did not exist at the time when he wrote4 ,it is natural to inquire1 whether we can determine more precisely what kind of astronomical science he meant1 and whether such science has been brought into existence since his time4 ,he gives us some further features of the philosophical astronomy which he requires4 ,as you do not expect to find in the most exquisite geometrical diagrams the true evidence of quantities being equal1 or double1 or in any other relation3 so the true astronomer will not think that the proportion of the day to the month1 or the month to the year1 and the like1 are real and immutable things4 ,he will seek a deeper truth than these4 ,we must treat ,astronomy1 like ,geometry1 as a series of problems suggested by visible things4 ,we must apply the intelligent portion of our mind to the subject4 ,here we really come in view of a class of problems which astronomical speculators at certain periods have proposed to themselves4 ,what is the real ground of the proportion of the day to the month1 and of the month to the year1 ,i do not know that any writer of great name has tried to determine3 but to ask the reason of these proportions1 namely1 that of the revolution of the earth on its axis1 of the moon in its orbit1 and of the earth in its orbit1 are questions just of the same kind as to ask the reason of the proportion of the revolutions of the planets in their orbits1 and of the proportion of the orbits themselves4 ,now who has attempted to assign such reasons8 ,of course we shall answer1 ,kepler3 not so much in the ,laws of the ,planetary motions which bear his name1 as in the ,law which at an earlier period he thought he had discovered1 determining the proportion of the distances of the several ,planets from the ,sun4 ,and1 curiously enough1 this solution of a problem which we may conceive ,plato to have had in his mind1 ,kepler gave by means of the ,five ,regular ,solids which ,plato had brought into notice1 and had employed in his theory of the ,universe given in the ,timus4 ,kepler's speculations on the subject just mentioned were given to the world in the ,mysterium ,cosmographicum published in #aeif4 ,in his ,preface1 he says ,in the beginning of the year #aeie ,i brooded with the whole energy of my mind on the subject of the ,copernican system4 ,there were three things in particular of which ,i pertinaciously sought the causes2 why they are not other than they are3 the number1 the size1 and the motion of the orbits4 ,we see how strongly he had his mind impressed with the same thought which ,plato had so confidently uttered3 that there must be some reason for those proportions in the scheme of the ,universe which appear casual and vague4 ,he was confident at this period that he had solved two of the three questions which haunted him2--that he could account for the number and the size of the planetary orbits4 ,his account was given in this way4--,the orbit of the ,earth is a circle2 round the sphere to which this circle belongs describe a dodecahedron2 the sphere including this will give the orbit of ,mars4 ,round ,mars inscribe a tetrahedron2 the circle including this will be the orbit of ,jupiter4 ,describe a cube round ,jupiter's orbit2 the circle including this will be the orbit of ,saturn4 ,now inscribe in the ,earth's orbit an icosahedron3 the circle inscribed in it will be the orbit of ,venus4 ,inscribe an octahedron in the orbit of ,venus2 the circle inscribed in it will be ,mercury's orbit4 ,this is the reason of the number of the planets2 and also of the magnitudes of their orbits4 ,these proportions were only approximations2 and the ,rule thus asserted has been shown to be unfounded1 by the discovery of new ,planets4 ,this ,law of ,kepler has been repudiated by succeeding ,astronomers4 ,so far1 then1 the ,astronomy which ,plato requires as a part of true philosophy has not been brought into being4 ,but are we thence to conclude that the demand for such a kind of ,astronomy was a mere ,platonic imagination8--was a mistake which more recent and sounder views have corrected8 ,we can hardly venture to say that4 ,for the questions which ,kepler thus asked1 and which he answered by the assertion of this erroneous ,law1 are questions of exactly the same kind as those which he asked and answered by means of the true ,laws which still fasten his name upon one of the epochs of astronomical history4 ,if he was wrong in assigning reasons for the number and size of the planetary orbits1 he was right in assigning a reason for the proportion of the motions4 ,this he did in the ,harmonice ,mundi1 published in #afai3 where he established that the squares of the periodic times of the different ,planets are as the cubes of their mean distances from the central ,sun4 ,of this discovery he speaks with a natural exultation1 which succeeding astronomers have thought well founded4 ,he says3 ,what ,i prophesied two and twenty years ago as soon as ,i had discovered the five solids among the heavenly bodies2 what ,i firmly believed before ,i had seen the ,harmonics of ,ptolemy2 what ,i promised my friends in the title of this book 7,on the perfect ,harmony of the celestial motions71 which ,i named before ,i was sure of my discovery2 what sixteen years ago ,i regarded as a thing to be sought2 that for which ,i joined ,tycho ,brahe1 for which ,i settled in ,prague1 for which ,i devoted the best part of my life to astronomical contemplations2 at length ,i have brought to light1 and have recognized its truth beyond my most sanguine expectations4 7,harm4 ,mundi1 ,lib4 ,v47 ,thus the ,platonic notion1 of an ,astronomy which deals with doctrines of a more exact and determinate kind than the obvious relations of phnomena1 may be found to tend either to error or to truth4 ,such aspirations point equally to the five regular solids which ,kepler imagined as determining the planetary orbits1 and to the ,laws of ,kepler in which ,newton detected the effect of universal gravitation4 ,the realities which ,plato looked for1 as something incomparably more real than the visible luminaries1 are found1 when we find geometrical figures1 epicycles and eccentrics1 laws of motion and laws of force1 which explain the appearances4 ,his ,realities are ,theories which account for the ,phenomena1 ,ideas which connect the ,facts4 ,but1 is ,plato right in holding that such ,realities as these are more real than the ,phenomena1 and constitute an ,astronomy of a higher kind than that of mere ,appearances8 ,to this we shall1 of course1 reply that ,theories and ,facts have each their reality1 but that these are realities of different kinds4 ,kepler's ,laws are as real as day and night2 the force of gravity tending to the ,sun is as real as the ,sun2 but not more so4 ,true ,theories and ,facts are equally real1 for true ,theories are ,facts1 and ,facts are familiar ,theories4 ,astronomy is1 as ,plato says1 a series of ,problems suggested by visible ,things2 and the ,thoughts in our own minds which bring the solutions of these ,problems1 have a reality in the ,things which suggest them4 ,but if we try1 as ,plato does1 to separate and oppose to each other the ,astronomy of ,appearances and the ,astronomy of ,theories1 we attempt that which is impossible4 ,there are no ,phenomena which do not exhibit some ,law2 no ,law can be conceived without ,phenomena4 ,the heavens offer a series of ,problems2 but however many of these ,problems we solve1 there remain still innumerable of them unsolved2 and these unsolved ,problems have solutions1 and are not different in kind from those of which the extant solution is most complete4 ,nor can we justly distinguish1 with ,plato1 ,astronomy into transient appearances and permanent truths4 ,the theories of ,astronomy are permanent1 and are manifested in a series of changes3 but the change is perpetual just because the theory is permanent4 ,the perpetual change is the permanent theory4 ,the perpetual changes in the positions and movements of the planets1 for instance1 manifest the permanent machinery3 the machinery of cycles and epicycles1 as ,plato would have said1 and as ,copernicus would have agreed2 while ,kepler1 with a profound admiration for both1 would have asserted that the motions might be represented by ellipses1 more exactly1 if not more truly4 ,the cycles and epicycles1 or the ellipses1 are as real as space and time1 in which the motions take place4 ,but we cannot justly say that space and time and motion are more real than the bodies which move in space and time1 or than the appearances which these bodies present4 ,thus ,plato1 with his tendency to exalt ,ideas above ,facts1--to find a ,reality which is more real than ,phenomena1--to take hold of a permanent ,truth which is more true than truths of observation1--attempts what is impossible4 ,he tries to separate the poles of the ,fundamental ,antithesis1 which1 however antithetical1 are inseparable4 ,at the same time1 we must recollect that this tendency to find a ,reality which is something beyond appearance1 a permanence which is involved in the changes1 is the genuine spring of scientific discovery4 ,such a tendency has been the cause of all the astronomical science which we possess4 ,it appeared in ,plato himself1 in ,hipparchus1 in ,ptolemy1 in ,copernicus1 and most eminently in ,kepler2 and in him perhaps in a manner more accordant with ,plato's aspirations when he found the five ,regular ,solids in the ,universe1 than when he found there the ,conic ,sections which determine the form of the planetary orbits4 ,the pursuit of this tendency has been the source of the mighty and successful labours of succeeding astronomers3 and the anticipations of ,plato on this head were more true than he himself could have conceived4 ,when the above view of the nature of true astronomy has been proposed1 ,glaucon says3 ,that would be a task much more laborious than the astronomy now cultivated4 ,socrates replies3 ,i believe so3 and such tasks must be undertaken1 if our researches are to be good for anything4 ,after ,astronomy1 there comes under review another ,science1 which is treated in the same manner4 ,it is presented as one of the ,sciences which deal with real abstract truth2 and which are therefore suited to that development of the philosophic insight into the highest truth1 which is here ,plato's main object4 ,this ,science is ,harmonics1 the doctrine of the mathematical relations of musical sounds4 ,perhaps it may be more difficult to explain to a general audience1 ,plato's views on this than on the previous subjects3 for though ,harmonics is still acknowledged as a ,science including the mathematical truths to which ,plato here refers1 these truths are less generally known than those of geometry or astronomy4 ,pythagoras is reported to have been the discoverer of the cardinal proposition in this ,mathematics of ,music3--namely1 that the musical notes which the ear recognizes as having that definite and harmonious relation which we call an octave1 a fifth1 a fourth1 a third1 have also1 in some way or other1 the numerical relation of #b to #a1 #c to #b1 #d to #c1 #e to #d4 ,i say some way or other1 because the statements of ancient writers on this subject are physically inexact1 but are right in the essential point1 that those simple numerical ratios are characteristic of the most marked harmonic relations4 ,the numerical ratios really represent the rate of vibration of the air when those harmonics are produced4 ,this perhaps ,plato did not know3 but he knew or assumed that those numerical ratios were cardinal truths in harmony3 and he conceived that the exactness of the ratios rested on grounds deeper and more intellectual than any testimony which the ear could give4 ,this is the main point in his mode of applying the subject1 which will be best understood by translating 7with some abridgement7 what he says4 ,socrates proceeds3 7 #aa near the end47 ,motion appears in many aspects4 ,it would take a very wise man to enumerate them all3 but there are two obvious kinds4 ,one which appears in astronomy1 7the revolutions of the heavenly bodies17 and another which is the echo of that#cce4 ,as the eyes are made for ,astronomy1 so are the ears made for the motion which produces ,harmony#ccf3 and thus we have two sister sciences1 as the ,pythagoreans teach1 and we assent4 7 #ab47 ,to avoid unnecessary labour1 let us first learn what they can tell us1 and see whether anything is to be added to it2 retaining our own view on such subjects3 namely this3--that those whose education we are to superintend--real philosophers--are never to learn any imperfect truths3--anything which does not tend to that point 7exact and permanent truth7 to which all our knowledge ought to tend1 as we said concerning astronomy4 ,now those who cultivate music take a very different course from this4 ,you may see them taking immense pains in measuring musical notes and intervals by the ear1 as the astronomers measure the heavenly motions by the eye4 ,yes1 says ,glaucon1 they apply their ears close to the instrument1 as if they could catch the note by getting near to it1 and talk of some kind of recurrences#ccg4 ,some say they can distinguish an interval1 and that this is the smallest possible interval1 by which others are to be measured2 while others say that the two notes are identical3 both parties alike judging by the ear1 not by the intellect4 ,you mean1 says ,socrates1 those fine musicians who torture their notes1 and screw their pegs1 and pinch their strings1 and speak of the resulting sounds in grand terms of art4 ,we will leave them1 and address our inquiries to our other teachers1 the ,pythagoreans4 ,the expressions about the small interval in ,glaucon's speech appear to me to refer to a curious question1 which we know was discussed among the ,greek mathematicians4 ,if we take a keyed instrument1 and ascend from a key note by two octaves and a third1 7say from ,a#a to ,c#c7 we arrive at the same nominal note1 as if we ascend four times by a fifth 7,a#a to ,e#a1 ,e#a to ,b#b1 ,b#b to ,f#b1 ,f#b to ,c#c74 ,hence one party might call this the same note4 ,but if the ,octaves1 ,fifths1 and ,third be perfectly true intervals1 the notes arrived at in the two ways will not be really the same4 7,in the one case1 the note is 2 in the other 2 which are and #af_/ha1 or in the ratio of #ha to #hj74 ,this small interval by which the two notes really differ1 the ,greeks called a ,comma1 and it was the smallest musical interval which they recognized4 ,plato disdains to see anything important in this controversy2 though the controversy itself is really a curious proof of his doctrine1 that there is a mathematical truth in ,harmony1 higher than instrumental exactness can reach4 ,he goes on to say3 ,the musical teachers are defective in the same way as the astronomical4 ,they do indeed seek numbers in the harmonic notes1 which the ear perceives3 but they do not ascend from them to the ,problem1 ,what are harmonic numbers and what are not1 and what is the reason of each#cch8 ,that1 says ,glaucon1 would be a sublime inquiry4 ,have we in ,harmonics1 as in ,astronomy1 anything in the succeeding ,history of the ,science which illustrates the tendency of ,plato's thoughts1 and the value of such a tendency8 ,it is plain that the tendency was of the same nature as that which induced ,kepler to call his work on ,astronomy ,harmonice ,mundi2 and which led to many of the speculations of that work1 in which harmonical are mixed with geometrical doctrines4 ,and if we are disposed to judge severely of such speculations1 as too fanciful for sound philosophy1 we may recollect that ,newton himself seems to have been willing to find an analogy between harmonic numbers and the different coloured spaces in the spectrum4 ,but ,i will say frankly1 that ,i do not believe there really exists any harmonical relation in either of these cases4 ,nor can the problem proposed by ,plato be considered as having been solved since his time1 any further than the recurrence of vibrations1 when their ratios are so simple1 may be easily conceived as affecting the ear in a peculiar manner4 ,the imperfection of musical scales1 which the comma indicates1 has not been removed2 but we may say that1 in the case of this problem1 as in the other ultimate ,platonic problems1 the duplication of the cube and the quadrature of the circle1 the impossibility of a solution has been already established4 ,the problem of a perfect musical scale is impossible1 because no power of #b can be equal to a power of #c2 and if we further take the multiplier #e1 of course it also cannot bring about an exact equality4 ,this impossibility of a perfect scale being recognized1 the practical problem is what is the system of temperament which will make the scale best suited for musical purposes2 and this problem has been very fully discussed by modern writers4 ,,footnotes3 ,footnote #cbg3 ,accedit et illud quod naturalis philosophia in iis ipsis viris1 qui ei incubuerunt1 vacantem et integrum hominem1 prsertim his recentioribus temporibus1 vix nacta sit2 nisi forte quis monachi alicujus in cellula1 aut nobilis in villula lucubrantis1 exemplum adduxerit2 sed facta est demum naturalis philosophia instar transitus cujusdam et pontisternii ad alia4 ,atque magna ista scientiarum mater ad officia ancill detrusa est2 qu medicin aut mathematicis operibus ministrat1 et rursus qu adolescentium immatura ingenia lavat et imbuat velut tinctura quadam prima1 ut aliam postea felicius et commodius excipiant4 ,footnote #cbh3 1 between house-keeping and money-getting4 ,footnote #cbi3 4 ,footnote #ccj3 ,the ,sciences are to draw the mind from that which grows and perishes to that which really is3 4 ,footnote #cca3 4 ,footnote #ccb3 4 ,footnote #ccc3 ,he adds and for the sake of war2 this point ,i have passed by4 ,plato does not really ascribe much weight to this use of ,science1 as we see in what he says of ,geometry and ,astronomy4 ,footnote #ccd3 1 4 ,footnote #cce3 4 ,footnote #ccf3 4 ,footnote #ccg3 4 ,footnote #cch3 1 c4 ,,appendix ,,bb4 ,,on ,,plato',s ,,notion ,,of ,,dialectic4 7,cam4 ,phil4 ,soc4 ,,may #g1 #ahee47 ,the survey of the sciences1 arithmetic1 plane geometry1 solid geometry1 astronomy and harmonics--which is contained in the seventh ,book of the ,republic 7 #f-ab71 and which has been discussed in the preceding paper1 represents them as instruments in an education1 of which the end is something much higher--as steps in a progression which is to go further4 ,do you not know1 says ,socrates 7 #ab71 that all this is merely a prelude to the strain which we have to learn8 ,and what that strain is1 he forthwith proceeds to indicate4 ,that these sciences do not suffice1 you must be aware3 for--those who are masters of such sciences--do they seem to you to be good in dialectic8 2 ,in truth1 says ,glaucon1 they are not1 with very few exceptions1 so far as ,i have fallen in with them4 ,and yet1 said ,i1 if persons cannot give and receive a reason1 they cannot attain that knowledge which1 as we have said1 men ought to have4 ,here it is evident that to give and to receive a reason1 is a phrase employed as coinciding1 in a general way at least1 with being good in dialectic2 and accordingly1 this is soon after asserted in another form1 the verb being now used instead of the adjective4 ,it is dialectic discussion 1 which executes the strain which we have been preparing4 ,it is further said that it is a progress to clear intellectual light1 which corresponds to the progress of bodily vision in proceeding from the darkened cave described in the beginning of the ,book to the light of day4 ,this progress1 it is added1 of course you call ,dialectic 4 ,plato further says1 that other sciences cannot properly be called sciences4 ,they begin from certain assumptions1 and give us only the consequences which follow from reasoning on such assumptions4 ,but these assumptions they cannot prove4 ,to do so is not in the province of each science4 ,it belongs to a higher science3 to the science of ,real ,existences4 ,you call the man ,dialectical1 who requires a reason of the essence of each thing#cci4 ,and as ,dialectic gives an account of other real existences1 so does it of that most important reality1 the true guide of ,life and of ,philosophy1 the ,real ,good4 ,he who cannot follow this through all the windings of the battle of ,life1 knows nothing to any purpose4 ,and thus ,dialectic is the pinnacle1 the top stone of the edifice of the sciences#cdj4 ,dialectic is here defined or described by ,plato according to the subject with which it treats1 and the object with which it is to be pursued3 but in other parts of the ,platonic ,dialogues1 ,dialectic appears rather to imply a certain method of investigation2--to describe the form rather than the matter of discussion2 and it will perhaps be worth while to compare these different accounts of ,dialectic4 7,phdrus47 ,one of the cardinal passages on this ,point is in the ,phdrus1 and may be briefly quoted4 ,phdrus1 in the ,dialogue which bears his name1 appears at first as an admirer of ,lysias1 a celebrated writer of orations1 the contemporary of ,plato4 ,in order to expose this writer's style of composition as frigid and shallow1 a specimen of it is given1 and ,socrates not only criticises this1 but delivers1 as rival compositions1 two discourses on the same subject4 ,of these discourses1 given as the inspiration of the moment1 the first is animated and vigorous2 the second goes still further1 and clothes its meaning in a gorgeous dress of poetical and mythical images4 ,phdrus acknowledges that his favourite is outshone2 and ,socrates then proceeds to point out that the real superiority of his own discourse consists in its having a dialectical structure1 beneath its outward aspect of imagery and enthusiasm4 ,he says3 7 #aji1 ,bekker4 ,it is to be remembered that the subject of all the discourses was ,love1 under certain supposed conditions47 ,the rest of the performance may be taken as play3 but there were1 in what was thus thrown out by a random impulse1 two features1 of which1 if any one could reduce the effect to an art1 it would be a very agreeable and useful task4 ,what are they8 ,phdrus asks4 ,in the first place1 ,socrates replies1 the taking a connected view of the scattered elements of a subject1 so as to bring them into one ,idea2 and thus to give a definition of the subject1 so as to make it clear what we are speaking of2 as was then done in regard to ,love4 ,a definition was given of it1 what it is3 whether the definition was good or bad1 at any rate there was a definition4 ,and hence1 in what followed1 we were able to say what was clear and consistent with itself4 ,and what1 ,phdrus asks1 was the other feature8 ,the dividing the subject into kinds or elements1 according to the nature of the thing itself3--not breaking its natural members1 like a bad carver who cannot hit the joint4 ,so the two discourses which we have delivered1 took the irrational part of the mind1 as their common subject2 and as the body has two different sides1 the right and the left1 with the same names for its parts2 so the two discourses took the irrational portion of man2 and the one took the left-hand portion1 and divided this again1 and again subdivided it1 till1 among the subdivisions1 it found a left-handed kind of ,love1 of which nothing but ill was to be said4 ,while the discourse that followed out the right-hand side of phrenzy1 7the irrational portion of man's nature17 was led to something which bore the name of ,love like the other1 but which is divine1 and was praised as the source of the greatest blessing4 ,now ,i1 ,socrates goes on to say1 am a great admirer of these processes of division and comprehension1 by which ,i endeavour to speak and to think correctly4 ,and if ,i can find any one who is able to see clearly what is by nature reducible to one and manifested in many elements1 ,i follow his footsteps as a divine guide4 ,those who can do this1 ,i call--whether rightly or not1 ,god knows--but ,i have hitherto been in the habit of calling them dialectical men4 ,it is of no consequence to our present purpose whether either of the discourses of ,socrates in the ,phdrus1 or the two together1 as is here assumed1 do contain a just division and subdivision of that part of the human soul which is distinguishable from ,reason1 and do thus exhibit1 in its true relations1 the affection of ,love4 ,it is evident that division and subdivision of this kind is here presented as1 in ,plato's opinion1 a most valuable method2 and those who could successfully practise this method are those whom he admires as dialectical men4 ,this is here his ,dialectic4 7,sophistes47 ,we are naturally led to ask whether this method of dividing a subject as the best way of examining it1 be in any other part of the ,platonic ,dialogues more fully explained than it is in the ,phdrus2 or whether any rules are given for this kind of ,dialectic4 ,to this we may reply1 that in the ,dialogue entitled ,the ,sophist1 a method of dividing a subject1 in order to examine it1 is explained and exemplified with extraordinary copiousness and ingenuity4 ,the object proposed in that ,dialogue is1 to define what a ,sophist is2 and with that view1 the principal speaker1 7who is represented as an ,eleatic stranger17 begins by first exemplifying what is his method of framing a definition1 and by applying it to define an ,angler4 ,the course followed1 though it now reads like a burlesque of philosophical methods1 appears to have been at that time a bona fide attempt to be philosophical and methodical4 ,it proceeds thus3 ,we have to inquire concerning ,angling4 ,is it an ,art8 ,it is4 ,now what kind of art8 ,all art is an art of making or an art of getting3 7,poietic or ,ktetic47 ,it is ,ktetic4 ,now the art of getting1 is the art of getting by exchange or by capture3 7,metabletic or ,chirotic47 ,getting by capture is by contest or by chase3 7,agonistic or ,thereutic47 ,getting by chase is a chase of lifeless or of living things3 7the first has no name1 the second is ,zootheric47 ,the chase of living things is the chase of land animals or of water animals3 7,pezotheric or ,enygrotheric47 ,chase of water animals is of birds or of fish3 7,ornithothereutic and ,halieutic47 ,chase of fish is by inclosing or by striking them3 7,hercotheric or ,plectic47 ,we strike them by day with pointed instruments1 or by night1 using torches3 7hence the division ,ankistreutic and ,pyreutic47 ,of ,ankistreutic1 one kind consists in spearing the fish downwards from above1 the other in twitching them upwards from below3 7these two arts are ,triodontic and ,aspalieutic47 ,and thus we have1 what we sought1 the notion and the description of angling3 namely that it is a ,ktetic1 ,chirotic1 ,thereutic1 ,zootheric1 ,enygrotheric1 ,halieutic1 ,plectic1 ,ankistreutic1 ,aspalieutic ,art4 ,several other examples are given of this ingenious mode of definition1 but they are all introduced with reference to the definition of the ,sophist4 ,and it will further illustrate this method to show how1 according to it1 the ,sophist is related to the ,angler4 ,the ,sophistical ,art is an art of getting1 by capture1 living things1 namely men4 ,it is thus a ,ktetic1 ,chirotic1 ,thereutic art1 and so far agrees with that of the ,angler4 ,but here the two arts diverge1 since that of the ,sophist is ,pezotheric1 that of the ,angler ,enygrotheric4 ,to determine the ,sophist still more exactly1 observe that the chase of land animals is either of tame animals 7including man7 or of wild animals3 7,hemerotheric and ,agriotheric47 ,the chase of tame animals is either by violence1 7as kidnapping1 tyranny1 and war in general17 or by persuasion1 7as by the arts of speech27 that is1 it is ,biaiotheric or ,pithanurgic4 ,the art of persuasion is a private or a public proceeding3 7,idiothereutic or ,demosiothereutic47 ,the art of private persuasion is accompanied with the giving of presents1 7as lovers do17 or with the receiving of pay3 7thus it is ,dorophoric or ,mistharneutic47 ,to receive pay as the result of persuasion1 is the course1 either of those who merely earn their bread by supplying pleasure1 namely flatterers1 whose art is ,hedyntic2 or of those who profess for pay to teach virtue4 ,and who are they8 ,plainly the ,sophists4 ,and thus ,sophistic is that kind of ,ktetic1 ,chirotic1 ,thereutic1 ,zootheric1 ,pezotheric1 ,hemerotheric1 ,pithanurgic1 ,idiothereutic1 ,mistharneutic art1 which professes to teach virtue1 and takes money on that account4 ,the same process is pursued along several other lines of inquiry3 and at the end of each of them the ,sophist is detected1 involved in a number of somewhat obnoxious characteristics4 ,this process of division it will be observed1 is at every step bifurcate1 or as it is called1 dichotomous4 ,applied as it is in these examples1 it is rather the vehicle of satire than of philosophy4 ,yet1 ,i have no doubt that this bifurcate method was admired by some of the philosophers of ,plato's time1 as a clever and effective philosophical invention4 ,we may the more readily believe this1 inasmuch as one of the most acute persons of our own time1 who has come nearer than any other to the ancient heads of sects in the submission with which his followers have accepted his doctrines1 has taken up this ,dichotomous ,method1 and praised it as the only philosophical mode of dividing a subject4 ,i refer to ,mr4 ,jeremy ,bentham's ,chrestomathia 7published originally in #ahaf71 in which this exhaustive bifurcate method1 as he calls it1 was applied to classify sciences and arts1 with a view to a scheme of education4 ,how exactly the method1 as recommended by him1 agrees with the method illustrated in the ,sophist1 an examination of any of his examples will show4 ,thus to take ,mineralogy as an example3 according to ,bentham1 ,ontology is ,cnoscopic or ,idioscopic3 the ,idioscopic is ,somatoscopic or ,pneumatoscopic2 the ,somatoscopic is ,pososcopic or ,poioscopic3 ,poioscopic is ,physiurgoscopic or ,anthropurgoscopic3 ,physiurgoscopic is ,uranoscopic or ,epigeoscopic3 ,epigeoscopic is ,abioscopic or ,embioscopic4 ,and thus ,mineralogy is the ,science ,idioscopic1 ,somatoscopic1 ,poioscopic1 ,physiurgoscopic1 ,epigeoscopic1 ,abioscopic3 inasmuch as it is the science which regards bodies1 with reference to their qualities1--bodies1 namely1 the works of nature1 terrestrial1 lifeless4 ,i conceive that this bifurcate method is not really philosophical or valuable3 but that is not our business here4 ,what we have to consider is whether this is what ,plato meant by the term ,dialectic4 ,the general description of ,dialectic in the ,sophistes agrees very closely with that quoted from the ,phdrus1 that it is the separation of a subject according to its natural divisions4 ,thus1 see in the ,sophist the passage #hc3 ,to divide a subject according to the kinds of things1 so as neither to make the same kind different nor different kinds identical1 is the office of the ,dialectical ,science4 ,and this is illustrated by observing that it is the office of the science of ,grammar to determine what letters may be combined and what may not2 it is the office of the science of ,music to determine what sounds differing as acute and grave1 may be combined1 and what may not3 and in like manner it is the office of the science of ,dialectic to determine what kinds may be combined in one subject and what may not4 ,and the proof is still further explained4 ,in many of the ,platonic ,dialogues1 the ,dialectic which ,socrates is thus represented as approving1 appears to include the form of ,dialogue1 as well as the subdivision of the subject into its various branches4 ,socrates is presented as attaching so much importance to this form1 that in the ,protagoras 7 #fe7 he rises to depart1 because his opponent will not conform to this practice4 ,and generally in ,plato1 ,dialectic is opposed to ,rhetoric1 as a string of short questions and answers to a continuous dissertation4 ,xenophon also seems to imply 7,mem4 ,,iv4 #e1 #aa7 that ,socrates included in his notion of ,dialectic the form of ,dialogue as well as the division of the subject4 ,but that the method of close ,dialogue was not called ,dialectic by the author of the ,sophist1 we have good evidence in the work itself4 ,among other notions which are analysed by the bifurcate division here exhibited1 is that of getting by contest 7,agonistic1 previously given as a division of ,ktetic74 ,now getting by contest may be by peaceful trial of superiority1 or by fight3 7,hamilletic or ,machelic74 ,the fight may be of body against body1 or of words against words3 these may be called ,biastic and ,amphisbetic4 ,the fight of words about right and wrong1 may be by long discourses opposed to each other1 as in judicial cases2 or by short questions and answers3 the former may be called ,dicanic1 the latter ,antilogic4 ,of these colloquies1 about right and wrong1 some are natural and spontaneous1 others artificial and studied3 the former need no special name2 the latter are commonly called ,eristic4 ,of ,eristic colloquies1 some are a source of expense to those who hold them1 some of gain3 that is1 they are ,chrematophthoric or ,chrematistic3 the former1 the occupation of those who talk for pleasure's and for company's sake1 is ,adoleschic1 wasteful garrulity2 the latter1 that of those who talk for the sake of gain1 is ,sophistic4 ,and thus ,sophistic is an art ,eristic1 which is part of ,antilogic1 which is part of ,amphisbetic1 which is part of ,agonistic1 which is part of ,chirotic1 which is a part of ,ktetic4 7 #bc47 ,we may notice here an indication that satire rather than exact reason directs these analyses2 in that ,sophistic1 which was before a part of the thereutic branch of chirotic and ktetic1 is here a part of the other branch1 agonistic4 ,but the remark which ,i especially wish to make here is1 that the art of discussing points of right and wrong by short questions and answers1 being here brought into view1 is not called ,dialectic1 which we might have expected2 but ,antilogic4 ,it would seem therefore that the ,author of the ,sophist did not understand by ,dialectic such a process as ,socrates describes in ,xenophon2 7,mem4 ,,iv4 #e1 #aa1 #ab27 where he says it was called ,dialectic1 because it was followed by persons dividing things into their kinds in conversation3 7 37or such as the ,socrates of ,plato insisted upon in the ,protagoras and the ,gorgias4 ,of the two elements which the ,dialectical ,process of ,socrates implied1 ,division of the subject and ,dialogue1 the author of the ,sophistes does not claim the name of ,dialectic for either1 and seems to reject it for the second4 ,but without insisting upon the name1 are we to suppose that the ,dichotomous ,method of the ,sophistes ,dialogue1 7,i may add of the ,politicus1 for the method is the same in this ,dialogue also17 is the method of division of a subject according to its natural members1 of which ,plato speaks in the ,phdrus8 ,if the ,sophistes be the work of ,plato1 the answer is difficult either way4 ,if this method be ,plato's ,dialectic1 how came he to omit to say so there8 how came he even to seem to deny it8 ,but on the other hand1 if this dichotomous division be a different process from the division called ,dialectic in the ,phdrus1 had ,plato two methods of division of a subject8 and yet has he never spoken of them as two1 or marked their distinction8 ,this difficulty would be removed if we were to adopt the opinion1 to which others1 on other grounds1 have been led1 that the ,sophistes1 though of ,plato's time1 is not ,plato's work4 ,the grounds of this opinion are1--that the doctrines of the ,sophistes are not ,platonic3 7the doctrine of ,ideas is strongly impugned and weakly defended37 ,socrates is not the principal speaker1 but an ,eleatic stranger3 and there is1 in the ,dialogue1 none of the dramatic character which we generally have in ,plato4 ,the ,dialogue seems to be the work of some ,eleatic opponent of ,plato1 rather than his4 7,rep4 ,b4 ,,vii47 ,but we can have no doubt that the ,phdrus contains ,plato's real view of the nature of ,dialectic1 as to its form2 let us see how this agrees with the view of ,dialectic1 as to its matter and object1 given in the seventh ,book of the ,republic4 ,according to ,plato1 ,real ,existences are the objects of the exact sciences 7as number and figure1 of ,arithmetic and ,geometry74 ,the things which are the objects of sense transitory phenomena1 which have no reality1 because no permanence4 ,dialectic deals with ,realities in a more general manner4 ,this doctrine is everywhere inculcated by ,plato1 and particularly in this part of the ,republic4 ,he does not tell us how we are to obtain a view of the higher realities1 which are the objects of ,dialectic3 only he here assumes that it will result from the education which he enjoins4 ,he says 7 #ac7 that the ,dialectic ,process 7 7 alone leads to true science3 it makes no assumptions1 but goes to ,first ,principles1 that its doctrines may be firmly grounded3 and thus it purges the eye of the soul1 which was immersed in barbaric mud1 and turns it upward2 using for this purpose the aid of the sciences which have been mentioned4 ,but when ,glaucon inquires about the details of this ,dialectic1 ,socrates says he will not then answer the inquiry4 ,we may venture to say1 that it does not appear that he had any answer ready4 ,let us consider for a moment what is said about a philosophy rendering a reason for the ,first ,principles of each ,science1 which the ,science itself cannot do4 ,that there is room for such a branch of philosophy in some sciences1 we easily see4 ,geometry1 for instance1 proceeds from ,axioms1 ,definitions and ,postulates2 but by the very nature of these terms1 does not prove these ,first ,principles4 ,these--the ,axioms1 ,definitions and ,postulates1--are1 ,i conceive1 what ,plato here calls the ,hypotheses upon which ,geometry proceeds1 and for which it is not the business of ,geometry to render a reason4 ,according to him1 it is the business of ,dialectic to give a just account of these ,hypotheses4 ,what then is ,dialectic8 7,aristotle47 ,it is1 ,i think1 well worthy of remark1 that ,aristotle1 giving an account in many respects different from that of ,plato1 of the nature of ,dialectic1 is still led in the same manner to consider ,dialectic as the branch of philosophy which renders a reason for ,first ,principles4 ,in the ,topics1 we have a distinction drawn between reasoning demonstrative1 and reasoning dialectical3 and the distinction is this3--7,top4 ,i4 #a7 that demonstration is by syllogisms from true first principles1 or from true deductions from such principles2 and that the ,dialectical ,syllogism is that which syllogizes from probable propositions 7 74 ,and he adds that probable propositions are those which are accepted by all1 or by the greatest part1 or by the wise4 ,in the next chapter1 he speaks of the uses of ,dialectic1 which1 he says1 are three1 mental discipline1 debates1 and philosophical science4 ,and he adds 7,top4 ,i4 #b1 #f7 that it is also useful with reference to the ,first ,principles in each ,science3 for from the appropriate ,principles of each science we cannot deduce anything concerning ,first ,principles1 since these principles are the beginning of reasoning4 ,but from the probable principles in each province of science we must reason concerning ,first ,principles3 and this is either the peculiar office of ,dialectic1 or the office most appropriate to it2 for it is a process of investigation1 and must lead to the ,principles of all methods4 ,that a demonstrative science1 as such1 does not explain the origin of its own ,first ,principles1 is undoubtedly true4 ,geometry does not undertake to give a reason for the ,axioms1 ,definitions1 and ,postulates4 ,this has been attempted1 both in ancient and in modern times1 by the ,metaphysicians4 ,but the ,metaphysics employed on such subjects has not commonly been called ,dialectic4 ,the term has certainly been usually employed rather as describing a ,method1 than as determining the subject of investigation4 ,of the ,faculty which apprehends ,first ,principles1 both according to ,plato and to ,aristotle1 ,i will hereafter say a few words4 ,the object of the dichotomous process pursued in the ,sophistes1 and its result in each case1 is a ,definition4 ,definition also was one of the main features of the inquiries pursued by ,socrates1 ,induction being the other2 and indeed in many cases ,induction was a series of steps which ended in ,definition4 ,and ,aristotle also taught a peculiar method1 the object and result of which was the construction of ,definitions3--namely his ,categories4 ,this method is one of division1 but very different from the divisions of the ,sophistes4 ,his method begins by dividing the whole subject of possible inquiry into ten heads or ,categories--,substance1 ,quantity1 ,quality1 ,relation1 ,place1 ,time1 ,position1 ,habit1 ,action1 ,passion4 ,these again are subdivided3 thus ,quality is ,habit or ,disposition1 ,power1 ,affection1 ,form4 ,and we have an example of the application of this method to the construction of a ,definition in the ,ethics2 where he determines ,virtue to be a ,habit with certain additional limitations4 ,thus the ,induction of ,socrates1 the ,dichotomy of the ,eleatics1 the ,categories of ,aristotle1 may all be considered as methods by which we proceed to the construction of ,definitions4 ,if1 by any method1 ,plato could proceed to the construction of a ,definition1 or rather of an ,idea1 of the ,absolute ,realities on which ,first ,principles depend1 such a method would correspond with the notion of ,dialectic in the ,republic4 ,and if it was a method of division like the ,eleatic or ,aristotelic1 it would correspond with the notion of ,dialectic in the ,phdrus4 ,that ,plato's notion1 however1 cannot have been exactly either of these is1 ,i think1 plain4 ,the colloquial method of stimulating and testing the progress of the student in ,dialectic is implied1 in the sequel of this discussion of the effect of scientific study4 ,and the method of ,dialogue1 as the instrument of instruction1 being thus supposed1 the continuation of the account in the ,republic1 implies that ,plato expected persons to be made dialectical by the study of the exact sciences in a comprehensive spirit4 ,after insisting on ,geometry and other sciences1 he says 7,rep4 ,,vii4 #af73 ,the synoptical man is dialectical2 and he who is not the one1 is not the other4 ,but1 we may ask1 does a knowledge of sciences lead naturally to a knowledge of ,ideas1 as absolute realities from which ,first ,principles flow8 ,and supposing this to be true1 as the ,platonic ,philosophy supposes1 is the ,idea of the ,good1 as the source of moral truths1 to be thus attained to8 ,that it is1 is the teaching of ,plato1 here and elsewhere2 but have the speculations of subsequent philosophers in the same direction given any confirmation of this lofty assumption8 ,in reply to this inquiry1 ,i should venture to say1 that this assumption appears to be a remnant of the ,socratic doctrine from which ,plato began his speculations1 that ,virtue is a kind of knowledge2 and that all attempts to verify the assumption have failed4 ,what ,plato added to the ,socratic notion was1 that the inquiry after ,the ,good1 the ,supreme ,good1 was to be aided by the analogy or suggestions of those sciences which deal with necessary and eternal truths2 the supreme good being of the nature of those necessary and eternal truths4 ,this notion is a striking one1 as a suggestion1 but it has always failed1 ,i think1 in the attempts to work it out4 ,those who in modern times1 as ,cudworth and ,samuel ,clarke1 have supposed an analogy between the necessary truths of ,geometry and the truths of ,morality1 though they have used the like expressions concerning the one and the other class of truths1 have failed to convey clear doctrines and steady convictions to their readers2 and have now1 ,i believe1 few or no followers4 ,the result of our investigation appears to be1 that though ,plato added much to the matter by means of which the mind was to be improved and disciplined in its research after ,principles and ,definitions1 he did not establish any form of ,method according to which the inquiry must be conducted1 and by which it might be aided4 ,the most definite notion of ,dialectic still remained the same with the original informal view which ,socrates had taken of it1 as ,xenophon tells us1 7,mem4 ,,iv4 #e1 #aa7 when he says3 ,he said that ,dialectic 7 7 was so called because it is an inquiry pursued by persons who take counsel together1 separating the subjects considered according to their kinds 774 ,he held accordingly that men should try to be well prepared for such a process1 and should pursue it with diligence3 by this means1 he thought1 they would become good men1 fitted for responsible offices of command1 and truly dialectical 774 ,and this is1 ,i conceive1 the answer to ,mr4 ,grote's interrogatory exclamation 7,vol4 ,,viii4 p4 #egg73 ,surely the ,etymology here given by ,xenophon or ,socrates of the word 77 cannot be considered as satisfactory4 ,the two notions1 of investigatory ,dialogue1 and ,distribution of notions according to their kinds1 which are thus asserted to be connected in etymology1 were1 among the followers of ,socrates1 connected in fact2 the dialectic dialogue was supposed to involve of course the dialectic division of the subject4 ,,footnotes3 ,footnote #cci3 2 7 #ad74 ,footnote #cdj3 4 7 #ad74 ,,appendix ,c4 ,,of ,,the ,,intellectual ,,powers ,,according ,,to ,,plato4 7,cam4 ,phil4 ,soc4 ,,nov4 #aj1 #ahef47 ,in the ,seventh ,book of ,plato's ,republic1 we have certain sciences described as the instruments of a philosophical and intellectual education2 and we have a certain other intellectual employment spoken of1 namely1 ,dialectic1 as the means of carrying the mind beyond these sciences1 and of enabling it to see the sources of those truths which the sciences assume as their first principles4 ,these points have been discussed in the two preceding papers4 ,but this scheme of the highest kind of philosophical education proceeds upon a certain view of the nature and degrees of knowledge1 and of the powers by which we know2 which view had been presented in a great measure in the ,sixth ,book2 this view ,i shall now attempt to illustrate4 ,to analyse the knowing powers of man is a task so difficult1 that we need not be surprised if there is much obscurity in this portion of ,plato's writings4 ,but as a reason for examining what he has said1 we must recollect that if there be in it anything on this subject which was true then1 it is true still2 and also1 that if we know any truth on that subject now1 we shall find something corresponding to that truth in the best speculations of sagacious ancient writers1 like ,plato4 ,it may therefore be worth while to discuss the ,platonic doctrines on this matter1 and to inquire how they are to be expressed in modern phraseology4 ,plato's doctrine will perhaps be most clearly understood1 if we begin by considering the diagram by which he illustrates the different degrees of knowledge#cda4 ,he sets out from the distinction of visible and intelligible things4 ,there are visible objects1 squares and triangles1 for instance2 but these are not the squares and triangles about which the ,geometer reasons4 ,the exactness of his reasoning does not depend on the exactness of his diagrams4 ,he reasons from certain mental squares and triangles1 as he conceives and understands them4 ,thus there are visible and there are intelligible things4 ,there is a visible and an intelligible world#cdb3 and there are two different regions about which our knowledge is concerned4 ,now take a line divided into two unequal segments to represent these two regions3 and again1 divide each segment in the same ratio4 ,the parts of each segment are to represent differences of clearness and distinctness1 and in the visible world these parts are things and images4 ,by images ,i mean shadows1 and reflections in water1 and in polished bodies2 and by things1 ,i mean that of which these images are the resemblances2 as animals1 plants1 things made by man4 ,this difference corresponds to the difference of ,knowledge and mere ,opinion2 and the ,opinable is to the ,knowable as the ,image to the ,reality4 ,this analogy is assented to by ,glaucon2 and thus there is assumed a ground for a further construction of the diagram4 ,now1 he says1 we have to divide the segment which represents ,intelligible ,things in the same way in which we have divided that which represents ,visible ,things4 ,the one part must represent the knowledge which the mind gets by dealing as it were with images1 and by reasoning downwards from ,principles2 the other that which it has by dealing with the ,ideas themselves1 and going to ,first ,principles4 ,the one part depends upon assumptions or hypotheses#cdc1 the other is unhypothetical or absolute truth4 ,one kind of ,intelligible ,things1 then1 is ,conceptions2 for instance1 geometrical conceptions of figures1 by means of which we reason downwards1 assuming certain ,first ,principles4 ,now the other kind of ,intelligible ,things is this3--that which the ,reason includes in virtue of its power of reasoning1 when it regards the assumptions of the ,sciences as1 what they are1 assumptions only2 and uses them as occasions and starting points1 that from these it may ascend to the absolute1 71 unhypothetical17 which does not depend upon assumption1 but is the origin of scientific truth4 ,the ,reason takes hold of this first principle of truth2 and availing itself of all the connections and relations of this principle1 it proceeds to the conclusion2 using no sensible image in doing this1 but contemplating the ,ideas alone2 and with these ,ideas the process begins1 goes on1 and terminates4 ,this account of the matter will probably seem to require at least further explanation2 and that accordingly is acknowledged in the ,dialogue itself4 ,glaucon says3 ,i apprehend your meaning in a certain degree1 but not very clearly1 for the matter is somewhat abstruse4 ,you wish to prove that the knowledge which1 by the ,reason1 we acquire1 of ,real ,existence and ,intelligible ,things1 is of a higher degree of certainty than the knowledge which belongs to what are commonly called ,sciences4 ,such sciences1 you say1 have certain assumptions for their bases2 and these assumptions are1 by the students of such sciences1 apprehended1 not by ,sense 7that is1 the ,bodily ,senses71 but by a ,mental ,operation1--by ,conception4 ,but inasmuch as such students ascend no higher than the assumptions1 and do not go to the ,first ,principles of ,truth1 they do not seem to you to have true knowledge--intuitive insight--,nous--on the subject of their reasonings1 though the subjects are intelligible1 along with their principle4 ,and you call this habit and practice of the ,geometers and others by the name ,conception1 not ,intuition#cdd2 taking ,conception to be something between ,opinion on the one side1 and ,intuitive ,insight on the other4 ,you have explained it well1 said ,i4 ,and now consider the four sections 7of the line7 of which we have spoken1 as corresponding to four affections in the mind4 ,intuition1 the highest2 ,conception1 the next2 the third1 ,belief2 and the fourth1 ,conjecture 7from likenesses72 and arrange them in order1 so that they may have more or less of certainty1 as their objects have more or less of truth#cde4 ,i understand1 said he4 ,i agree to what you say1 and ,i arrange them as you direct4 ,and so the ,sixth ,book ends3 and the ,seventh ,book opens with the celebrated image of the ,cave1 in which men are confined1 and see all external objects only by the shadows which they cast on the walls of their prison4 ,and this imperfect knowledge of things is to the true vision of them1 which is attained by those who ascend to the light of day1 as the ordinary knowledge of men is to the knowledge attainable by those whose minds are purged and illuminated by a true philosophy4 ,confining ourselves at present to the part of ,plato's speculations which we have mentioned1 namely1 the degrees of knowledge1 and the division of our knowing faculties1 we may understand1 and may in a great degree accept1 ,plato's scheme4 ,we have already 7in the preceding papers7 seen that1 by the knowledge of real things1 he means1 in the first place1 the knowledge of universal and necessary truths1 such as ,geometry and the other exact sciences deal with4 ,these we call sciences of ,demonstration2 and we are in the habit of contrasting the knowledge which constitutes such sciences with the knowledge obtained by the ,senses1 by ,experience or mere ,observation4 ,this distinction of ,demonstrative and ,empirical knowledge is a cardinal point in ,plato's scheme also2 the former alone being allowed to deserve the name of ,knowledge1 and the latter being only ,opinion4 ,the ,objects with which ,demonstration deals may be termed ,conceptions1 and the objects with which ,observation or ,sense has to do1 however much speculation may reduce them to mere ,sensations1 are commonly described as ,things4 ,of these ,things1 there may be ,shadows or ,images1 as ,plato says2 and as we may obtain a certain kind of knowledge1 namely ,opinion or ,belief1 by seeing the ,things themselves1 we may obtain an inferior kind of ,opinion or ,belief by seeing their ,images1 which kind of opinion we may for the moment call ,conjecture4 ,whether then we regard the distinctions of knowledge itself or of the objects of it1 we have three terms before us4 ,if we consider the kinds of knowledge1 they are ,demonstration3 ,belief3 ,conjecture4 ,if the objects of this knowledge1 they are ,conceptions3 ,things3 ,images4 ,but in each of these ,series1 the first term is evidently wanting3 for ,demonstration supposes ,principles to reason from4 ,conceptions suppose some basis in the mind which gives them their evidence4 ,what then is the first term in each of these two ,series8 ,the ,principles of ,demonstration must be seen by ,intuition4 ,conceptions derive their properties from certain powers or attributes of the mind which we may term ,ideas4 ,therefore the two series are ,intuition3 ,demonstration3 ,belief3 ,conjecture4 ,ideas3 ,conceptions3 ,things3 ,images4 ,plato further teaches that the two former terms in each ,series belong to the ,intelligible1 the two latter to the ,visible ,world3 and he supposes that the ratio of these two primary segments of the line is the same as the ratio in which each segment is divided#cdf4 ,in using the term ,ideas to describe the mental sources from which ,conceptions derive their validity in demonstration1 ,i am employing a phraseology which ,i have already introduced in the ,philosophy of the ,inductive ,sciences4 ,but independently altogether of this1 ,i do not see what other term could be employed to denote the mental objects1 attributes1 or powers1 whatever they be1 from which ,conceptions derive their evidence1 as ,demonstrative ,truths derive their evidence from ,intuitive ,truths4 ,that the ,scheme just presented is ,plato's doctrine on this subject1 ,i do not conceive there can be any doubt4 ,there is a little want of precision in his phraseology1 arising from his mixing together the two series4 ,in fact1 his final series ,nosis3 ,dianoia3 ,pistis3 ,eikasia2 is made by putting in the second place1 instead of ,demonstration1 which is the process pursued1 or ,science1 which is the knowledge obtained1 ,conception1 which is the object with which the mind deals4 ,such deviations from exact symmetry and correlation in speaking of the faculties of the mind1 are almost unavoidable in every language4 ,and there is yet another source of such inaccuracies of language2 for we have to speak1 not only of the process of acquiring knowledge1 and of the objects with which the mind deals1 but of the ,faculties of the mind which are thus employed4 ,thus ,intuition is the ,process2 ,ideas are the ,object1 in the first term of our series4 ,the ,faculty also we may call ,intuition2 but the ,greek offers a distinction4 ,nosis is the ,process of ,intuition2 but the ,faculty is ,nous4 ,if we wish to preserve this distinction in ,english1 what must we call the ,faculty8 ,i conceive we must call it the ,intuitive ,reason1 a term well known to our older philosophical writers#cdg4 ,again3 taking the second term of the series1 ,demonstration is the process1 ,science1 the result2 and ,conceptions are the objects with which the mind deals4 ,but what is the ,faculty thus employed8 ,what is the ,faculty employed in ,demonstration8 ,the same philosophical writers of whom ,i spoke would have answered at once1 the ,discursive ,reason2 and ,i do not know that1 even now1 we can suggest any better term4 ,the ,faculty employed in acquiring the two lower kinds of knowledge1 the ,faculty which deals with ,things and their ,images is1 of course1 ,sense1 or ,sensation4 ,the assertion of a ,faculty of the mind by which it apprehends ,truth1 which ,faculty is higher than the ,discursive ,reason1 as the ,truth apprehended by it is higher than mere ,demonstrative ,truth1 agrees 7as it will at once occur to several of my readers7 with the doctrine taught and insisted upon by the late ,samuel ,taylor ,coleridge4 ,and so far as he was the means of inculcating this doctrine1 which1 as we see1 is the doctrine of ,plato1 and ,i might add1 of ,aristotle1 and of many other philosophers1 let him have due honour4 ,but in his desire to impress the doctrine upon men's minds1 he combined it with several other tenets1 which will not bear examination4 ,he held that the two ,faculties by which these two kinds of truth are apprehended1 and which1 as ,i have said1 our philosophical writers call the ,intuitive ,reason and the ,discursive ,reason1 may be called1 and ought to be called1 respectively1 ,the ,reason and ,the ,understanding2 and that the second of these is of the nature of the ,instinct of animals1 so as to be something intermediate between ,reason and ,instinct4 ,these opinions1 ,i may venture to say1 are altogether erroneous4 ,the ,intuitive ,reason and the ,discursive ,reason are not1 by any ,english writers1 called the ,reason and the ,understanding2 and accordingly1 ,coleridge has had to alter all the passages1 namely1 those taken from ,leighton1 ,harrington1 and ,bacon1 from which his exposition proceeds4 ,the ,understanding is so far from being especially the ,discursive or ,reasoning ,faculty1 that it is1 in universal usage1 and by our best writers1 opposed to the ,discursive or ,reasoning ,faculty4 ,thus this is expressly declared by ,sir ,john ,davis in his poem ,on the ,immortality of the ,soul4 ,he says1 of the soul1 ,when she rates things1 and moves from ground to ground1 ,the name of ,reason 7,ratio7 she acquires from this3 ,but when by reason she truth hath found1 ,and standeth fixt1 she ,understanding is4 ,instead of the ,reason being fixed1 and the ,understanding discursive1 as ,mr4 ,coleridge says1 the ,reason is distinctively discursive2 that is1 it obtains conclusions by running from one point to another4 ,this is what is meant by ,discursus2 or1 taking the full term1 ,discursus ,rationis1 ,discourse of ,reason4 ,understanding is fixed1 that is1 it dwells upon one view of a subject1 and not upon the steps by which that view is obtained4 ,the verb to reason1 implies the substantive1 the ,reason1 though it is not coextensive with it3 for as ,i have said1 there is the ,intuitive ,reason as well as the ,discursive ,reason4 ,but it is by the ,faculty of ,reason that we are capable of reasoning2 though undoubtedly the practice or the pretence of reasoning may be carried so far as to seem at variance with reason in the more familiar sense of the term2 as is the case also in ,french4 ,moliere's ,crisale says 7in the ,femmes ,savantes71 ,raisonner est l'emploi de toute ma maison1 ,et le raisonnement en bannit la ,raison4 ,if ,mr4 ,coleridge's assertion were true1 that the ,understanding is the discursive and the ,reason the fixed faculty1 we should be justified in saying that ,the ,understanding is the faculty by which we reason1 and the ,reason is the faculty by which we understand4 ,but this is not so4 ,nor is the ,understanding of the nature of ,instinct1 nor does it approach nearer than the ,reason to the nature of ,instinct1 but the contrary4 ,the ,instincts of animals bear a very obscure resemblance to any of man's speculative ,faculties2 but so far as there is any such resemblance1 ,instinct is an obscure image of ,reason1 not of ,understanding4 ,animals are said to act as if they reasoned1 rather than as if they understood4 ,the verb understand is especially applied to man as distinguished from animals4 ,mr4 ,coleridge tells a tale from ,huber1 of certain bees which1 to prevent a piece of honey from falling1 balanced it by their weight1 while they built a pillar to support it4 ,they did this by ,instinct1 not understanding what they did2 men1 doing the same1 would have understood what they were doing4 ,our ,translation of the ,scriptures1 in making it the special distinction of man and animals1 that he has ,understanding and they have not1 speaks quite consistently with good philosophy and good ,english4 ,mr4 ,coleridge's object in his speculations is nearly the same as ,plato's2 namely1 to declare that there is a truth of a higher kind than can be obtained by mere reasoning2 and also to claim1 as portions of this higher truth1 certain fundamental doctrines of ,morality4 ,among these1 ,mr4 ,coleridge places the ,authority of ,conscience1 and ,plato1 the ,supreme ,good4 ,mr4 ,coleridge also holds1 as ,plato held1 that the ,reason of man1 in its highest and most comprehensive form1 is a portion of a ,supreme and ,universal ,reason2 and leads to ,truth1 not in virtue of its special attributes in each person1 but by its own nature4 ,many of the opinions which are combined with these doctrines1 both in ,plato and in ,coleridge1 are such as we should1 ,i think1 find it impossible to accept1 upon a careful philosophical examination of them2 but on these ,i shall not here dwell4 ,i will only further observe1 that if any one were to doubt whether the term is rightly rendered ,intuitive ,reason1 we may find proof of the propriety of such a rendering in the remarkable discussion concerning the ,intellectual ,virtues1 which we have in the ,sixth ,book of the ,nicomachean ,ethics4 ,it can hardly be questioned that ,aristotle had in his mind1 in writing that passage1 the doctrines of ,plato1 as expounded in the passage just examined1 and similar passages4 ,aristotle there says that there are five ,intellectual ,virtues1 or ,faculties by which the ,mind aims at ,truth in asserting or denying3--namely1 ,art1 ,science1 ,prudence1 ,wisdom1 ,nous4 ,in this enumeration1 passing over ,art1 ,prudence1 and ,wisdom1 as virtues which are mainly concerned from practical life1 we have1 in the region of speculative ,truth1 a distinction propounded between ,science and ,nous3 and this distinction is further explained 7c4 #f7 by the remarks that ,science reasons with ,principles2 and that these ,principles cannot be given by ,science1 because ,science reasons from them2 nor by ,art1 nor ,prudence1 for these are conversant with matters contingent1 not with matters demonstrable2 nor can the ,first ,principles of the ,reasonings of ,science be given by ,wisdom1 for ,wisdom herself has often to reason from ,principles4 ,therefore the ,first ,principles of ,demonstrative ,reasoning must be given by a peculiar ,faculty1 ,nous4 ,as we have said1 ,intuitive ,reason is the most appropriate ,english term for this ,faculty4 ,the view thus given of that higher kind of ,knowledge which ,plato and ,aristotle place above ordinary ,science1 as being the ,knowledge of and ,faculty of learning ,first ,principles1 will enable us to explain some expressions which might otherwise be misunderstood4 ,socrates1 in the concluding part of this ,sixth ,book of the ,republic1 says1 that this kind of knowledge is that of which the ,reason 77 takes hold1 in virtue of its power of reasoning#cdh4 ,here we are plainly not to understand that we arrive at ,first ,principles by reasoning3 for the very opposite is true1 and is here taught2--namely1 that ,first ,principles are not what we reason to1 but what we reason from4 ,the meaning of this passage plainly is1 that ,first ,principles are those of which the ,reason takes hold in virtue of its power of reasoning2--they are the conditions which must exist in order to make any reasoning possible3--they are the propositions which the ,reason must involve implicitly1 in order that we may reason explicitly2--they are the intuitive roots of the dialectical power4 ,in accordance with the views now explained1 ,plato's ,diagram may be thus further expanded4 ,the term is not used in this part of the ,republic2 but1 as is well known1 occurs in its peculiar ,platonic sense in the ,tenth ,book4 ---------------------------------------- ---------------------------- ,intelligible ,world4 4 ,visible ,world4 4 ---------------------------------------- --------------------------- ,object ,ideas ,conceptions ,things ,images 444 ---------------------------------------- --------------------------- ,process ,intuition ,demonstration ,belief ,conjecture ---------------------------------------- --------------------------- ,faculty,intuitive ,reason ,discursive ,reason ,sensation ---------------------------------------- --------------------------- ,,footnotes3 ,footnote #cda3 ,pol4 vi4 #ai4 ,footnote #cdb3 ,he adds1 ,this oraton1 this visible world1 ,i will not say has any connexion with ouranon1 heaven1 that ,i may not be accused of playing upon words4 ,footnote #cdc3 ,it is plain that ,plato1 by ,hypotheses1 in this place1 means the usual foundations of ,arithmetic and ,geometry2 namely1 ,definitions and ,postulates4 ,he says that the arithmeticians and geometers take as hypotheses 7h7 odd and even1 and the three kinds of angles 7right1 acute1 and obtuse72 and figures1 7as a triangle1 a square17 and the like4 ,i say his hypotheses are the ,definitions and ,postulates1 not the ,axioms3 for the ,axioms of ,arithmetic and ,geometry belong to the ,higher ,faculty1 which ascends to ,first ,principles4 ,but this ,faculty operates rather in using these axioms than in enunciating them4 ,it knows them implicitly rather than expresses them explicitly4 ,footnote #cdd3 ' 4 ,footnote #cde3 ,the ,diagram1 as here described1 would be this3 ---------------------------------------- -------------- ,intelligible ,world4 ,visible ,world4 ---------------------------------------- ------------ ,intuition4 ,conception4 ,things4 ,images4 ---------------------------------------- ------------ ,plato supposes the whole1 and each of the two parts1 to be divided in the same ratio1 in order that the analogy of the division in each case may be represented4 ,footnote #cdf3 ,the four segments might be as #d3 #b3 #b3 #a2 or as #i3 #f3 #f3 #d2 or generally1 as a3 ar3 ar3 ar#b4 ,footnote #cdg3 ,hence the mind ,reason receives ,intuitive or ,discursive4 ,,milton4 ,footnote #cdh3 4 ,,appendix ,d4 ,,criticism ,,of ,,aristotle',s ,,account ,,of ,,induction4 7,cam4 ,phil4 ,soc4 ,,feb4 #aa1 #ahej47 ,the ,cambridge ,philosophical ,society has willingly admitted among its proceedings not only contributions to science1 but also to the philosophy of science2 and it is to be presumed that this willingness will not be less if the speculations concerning the philosophy of science which are offered to the ,society involve a reference to ancient authors4 ,induction1 the process by which general truths are collected from particular examples1 is one main point in such philosophy3 and the comparison of the views of ,induction entertained by ancient and modern writers has already attracted much notice4 ,i do not intend now to go into this subject at any length2 but there is a cardinal passage on the subject in ,aristotle's ,analytics1 7,analyt4 ,prior4 ,,ii4 #be7 which ,i wish to explain and discuss4 ,i will first translate it1 making such emendations as are requisite to render it intelligible and consistent1 of which ,i shall afterwards give an account4 ,i will number the sentences of this chapter of ,aristotle in order that ,i may afterwards be able to refer to them readily4 #a4 ,we must now proceed to observe that we have to examine not only syllogisms according to the aforesaid figures1--syllogisms logical and demonstrative1--but also rhetorical syllogisms1--and1 speaking generally1 any kind of proof by which belief is influenced1 following any method4 #b4 ,all belief arises either from ,syllogism or from ,induction3 we must now therefore treat of ,induction4 #c4 ,induction1 and the ,inductive ,syllogism1 is when by means of one extreme term we infer the other extreme term to be true of the middle term4 #d4 ,thus if ,a1 ,c1 be the extremes1 and ,b the mean1 we have to show1 by means of ,c1 that ,a is true of ,b4 #e4 ,thus let ,a be long-lived2 ,b1 that which has no gall-bladder2 and ,c1 particular long-lived animals1 as elephant1 horse1 mule4 #f4 ,then every ,c is ,a1 for all the animals above named are long-lived4 #g4 ,also every ,c is ,b1 for all those animals are destitute of gall-bladder4 #h4 ,if then ,b and ,c are convertible1 and the mean 7,b7 does not extend further than extreme 7,c71 it necessarily follows that every ,b is ,a4 #i4 ,for it was shown before1 that1 if any two things be true of the same1 and if either of them be convertible with the extreme1 the other of the things predicated is true of the convertible 7extreme74 #aj4 ,but we must conceive that ,c consists of a collection of all the particular cases2 for ,induction is applied to all the cases4 #aa4 ,but such a syllogism is an inference of a first truth and immediate proposition4 #ab4 ,for when there is a mean term1 there is a demonstrative syllogism through the mean2 but when there is not a mean1 there is proof by ,induction4 #ac4 ,and in a certain way1 ,induction is contrary to ,syllogism2 for ,syllogism proves1 by the middle term1 that the extreme is true of the third thing3 but ,induction proves1 by means of the third thing1 that the extreme is true of the mean4 #ad4 ,and ,syllogism concluding by means of a middle term is prior by nature and more usual to us2 but the proof by ,induction1 is more luminous4 ,i think that the chapter1 thus interpreted1 is quite coherent and intelligible2 although at first there seems to be some confusion1 from the author sometimes saying that ,induction is a kind of ,syllogism1 and at other times that it is not4 ,the amount of the doctrine is this4 ,when we collect a general proposition by ,induction from particular cases1 as for instance1 that all animals destitute of gall-bladder 7acholous71 are long-lived1 7if this proposition were true1 of which hereafter17 we may express the process in the form of a ,syllogism1 if we will agree to make a collection of particular cases our middle term1 and assume that the proposition in which the second extreme term occurs is convertible4 ,thus the known propositions are ,elephant1 horse1 mule1 c41 are long-lived4 ,elephant1 horse1 mule1 c41 are acholous4 ,but if we suppose that the latter proposition is convertible1 we shall have these propositions3 ,elephant1 horse1 mule1 c41 are long-lived4 ,all acholous animals are elephant1 horse1 mule1 c41 from whence we infer1 quite rigorously as to form1 ,all acholous animals are long-lived4 ,this mode of putting the ,inductive inference shows both the strong and the weak point of the illustration of ,induction by means of ,syllogism4 ,the strong point is this1 that we make the inference perfect as to form1 by including an indefinite collection of particular cases1 elephant1 horse1 mule1 c41 in a single term1 ,c4 ,the ,syllogism then is ,all ,c are long-lived4 ,all acholous animals are ,c4 ,therefore all acholous animals are long-lived4 ,the weak point of this illustration is1 that1 at least in some instances1 when the number of actual cases is necessarily indefinite1 the representation of them as a single thing involves an unauthorized step4 ,in order to give the reasoning which really passes in the mind1 we must say ,elephant1 horse1 c41 are long-lived4 ,all acholous animals are as elephant1 horse1 c41 ,therefore all acholous animals are long-lived4 ,this as must be introduced in order that the all ,c of the first proposition may be justified by the ,c of the second4 ,this step is1 ,i say1 necessarily unauthorized1 where the number of particular cases is indefinite2 as in the instance before us1 the species of acholous animals4 ,we do not know how many such species there are1 yet we wish to be able to assert that all acholous animals are long-lived4 ,in the proof of such a proposition1 put in a syllogistic form1 there must necessarily be a logical defect2 and the above discussion shows that this defect is the substitution of the proposition1 ,all acholous animals are as elephant1 c41 for the converse of the experimentally proved proposition1 elephant1 c41 are acholous4 ,in instances in which the number of particular cases is limited1 the necessary existence of a logical flaw in the syllogistic translation of the process is not so evident4 ,but in truth1 such a flaw exists in all cases of ,induction proper3 7for ,induction by mere enumeration can hardly be called ,induction74 ,i will1 however1 consider for a moment the instance of a celebrated proposition which has often been taken as an example of ,induction1 and in which the number of particular cases is1 or at least is at present supposed to be1 limited4 ,kepler's laws1 for instance the law that the planets describe ellipses1 may be regarded as examples of ,induction4 ,the law was inferred1 we will suppose1 from an examination of the orbits of ,mars1 ,earth1 ,venus4 ,and the syllogistic illustration which ,aristotle gives1 will1 with the necessary addition to it1 stand thus1 ,mars1 ,earth1 ,venus describe ellipses4 ,mars1 ,earth1 ,venus are planets4 ,assuming the convertibility of this last proposition1 and its universality1 7which is the necessary addition in order to make ,aristotle's syllogism valid7 we say ,all the planets are as ,mars1 ,earth1 ,venus4 ,whence it follows that all the planets describe ellipses4 ,if1 instead of this assumed universality1 the astronomer had made a real enumeration1 and had established the fact of each particular1 he would be able to say ,saturn1 ,jupiter1 ,mars1 ,earth1 ,venus1 ,mercury1 describe ellipses4 ,saturn1 ,jupiter1 ,mars1 ,earth1 ,venus1 ,mercury are all the planets4 ,and he would obviously be entitled to convert the second proposition1 and then to conclude that ,all the planets describe ellipses4 ,but then1 if this were given as an illustration of ,induction by means of syllogism1 we should have to remark1 in the first place1 that the conclusion that all the planets describe ellipses1 adds nothing to the major proposition1 that ,s41 ,j41 ,m41 ,e41 ,v41 m41 do so4 ,it is merely the same proposition expressed in other words1 so long as ,s41 ,j41 ,m41 ,e41 ,v41 m41 are supposed to be all the planets4 ,and in the next place we have to make a remark which is more important2 that the minor1 in such an example1 must generally be either a very precarious truth1 or1 as appears in this case1 a transitory error4 ,for that the planets known at any time are all the planets1 must always be a doubtful assertion1 liable to be overthrown to-night by an astronomical observation4 ,and the assertion1 as received in ,kepler's time1 has been overthrown4 ,for ,saturn1 ,jupiter1 ,mars1 ,earth1 ,venus1 ,mercury1 are not all the planets4 ,not only have several new ones been discovered at intervals1 as ,uranus1 ,ceres1 ,juno1 ,pallas1 ,vesta1 but we have new ones discovered every day2 and any conclusion depending upon this premiss that ,a1 ,b1 ,c1 ,d1 ,e1 ,f1 ,g1 ,h1 to ,z are all the planets1 is likely to be falsified in a few years by the discovery of ,a1 ,b1 ,c1 c4 ,if1 therefore1 this were the syllogistic analysis of ,induction1 ,kepler's discovery rested upon a false proposition2 and even if the analysis were now made conformable to our present knowledge1 that induction1 analysed as above1 would still involve a proposition which to-morrow may show to be false4 ,but yet no one1 ,i suppose1 doubts that ,kepler's discovery was really a discovery--the establishment of a scientific truth on solid grounds2 or1 that it is a scientific truth for us1 notwithstanding that we are constantly discovering new planets4 ,therefore the syllogistic analysis of it now discussed 7namely1 that which introduces simple enumeration as a step7 is not the right analysis1 and does not represent the grounds of the ,inductive ,truth1 that all the planets describe ellipses4 ,it may be said that all the planets discovered since ,kepler's time conform to his law1 and thus confirm his discovery4 ,this we grant3 but they only confirm the discovery1 they do not make it2 they are not its groundwork4 ,it was a discovery before these new cases were known2 it was an inductive truth without them4 ,still1 an objector might urge1 if any one of these new planets had contradicted the law1 it would have overturned the discovery4 ,but this is too boldly said4 ,a discovery which is so precise1 so complex 7in the phenomena which it explains71 so supported by innumerable observations extending through space and time1 is not so easily overturned4 ,if we find that ,uranus1 or that ,encke's comet1 deviates from ,kepler's and ,newton's laws1 we do not infer that these laws must be false2 we say that there must be some disturbing cause in these cases4 ,we seek1 and we find these disturbing causes3 in the case of ,uranus1 a new planet2 in the case of ,encke's comet1 a resisting medium4 ,even in this case therefore1 though the number of particulars is limited1 the ,induction was not made by a simple enumeration of all the particulars4 ,it was made from a few cases1 and when the law was discerned to be true in these1 it was extended to all2 the conversion and assumed universality of the proposition that these are planets1 giving us the proposition which we need for the syllogistic exhibition of ,induction1 all the planets are as these4 ,i venture to say further1 that it is plain1 that ,aristotle did not regard ,induction as the result of simple enumeration4 ,this is plain1 in the first place1 from his example4 ,any proposition with regard to a special class of animals1 cannot be proved by simple enumeration3 for the number of particular cases1 that is1 of animal species in the class1 is indefinite at any period of zoological discovery1 and must be regarded as infinite4 ,in the next place1 ,aristotle says 7 #aj of the above extract71 ,we must conceive that ,c consists of a collection of all the particular cases2 for induction is applied to all the cases4 ,we must conceive 77 that ,c in the major1 consists of all the cases1 in order that the conclusion may be true of all the cases2 but we cannot observe all the cases4 ,but the evident proof that ,aristotle does not contemplate in this chapter an ,induction by simple enumeration1 is the contrast in which he places ,induction and ,syllogism4 ,for ,induction by simple enumeration stands in no contrast to ,syllogism4 ,the ,syllogism of such ,induction is quite logical and conclusive4 ,but ,induction from a comparatively small number of particular cases to a general law1 does stand in opposition to ,syllogism4 ,it gives us a truth1--a truth which1 as ,aristotle says 7 #ad71 is more luminous than a truth proved syllogistically1 though ,syllogism may be more natural and usual4 ,it gives us 7 #aa7 immediate propositions1 obtained directly from observation1 and not by a chain of reasoning3 first truths1 the principles from which syllogistic reasonings may be deduced4 ,the ,syllogism proves by means of a middle term 7 #ac7 that the extreme is true of a third thing3 thus1 7acholous being the middle term73 ,acholous animals are long-lived3 ,all elephants are acholous animals3 ,therefore all elephants are long-lived4 ,but ,induction proves by means of a third thing 7namely1 particular cases7 that the extreme is true of the mean2 thus 7acholous1 still being the middle term7 ,elephants are long-lived3 ,elephants are acholous animals3 ,therefore acholous animals are long-lived4 ,it may be objected1 such reasoning as this is quite inconclusive3 and the answer is1 that this is precisely what we1 and as ,i believe1 ,aristotle1 are here pointing out4 ,induction is inconclusive as reasoning4 ,it is not reasoning3 it is another way of getting at truth4 ,as we have seen1 no reasoning can prove such an inductive truth as this1 that all planets describe ellipses4 ,it is known from observation1 but it is not demonstrated4 ,nevertheless1 no one doubts its universal truth1 7except1 as aforesaid1 when disturbing causes intervene74 ,and thence1 ,induction is1 as ,aristotle says1 opposed to syllogistic reasoning1 and yet is a means of discovering truth3 not only so1 but a means of discovering primary truths1 immediately derived from observation4 ,i have elsewhere taught that all ,induction involves a ,conception of the mind applied to facts4 ,it may be asked whether this applies in such a case as that given by ,aristotle4 ,and ,i reply1 that ,aristotle's instance is a very instructive example of what ,i mean4 ,the ,conception which is applied to the facts in order to make the induction possible is the want of the gall-bladder2--and ,aristotle supplies us with a special term for this conception2 acholous#cdi4 ,but1 it may be said1 that the animals observed1 the elephant1 horse1 mule1 c41 are acholous1 is a mere fact of observation1 not a ,conception4 ,i reply that it is a ,selected ,fact1 a fact selected and compared in several cases1 which is what we mean by a ,conception4 ,that there is needed for such selection and comparison a certain activity of the mind1 is evident2 but this also may become more clear by dwelling a little further on the subject4 ,suppose that ,aristotle1 having a desire to know what class of animals are long-lived1 had dissected for that purpose many animals2 elephants1 horses1 cows1 sheep1 goats1 deer and the like4 ,how many resemblances1 how many differences1 must he have observed in their anatomy6 ,he was very likely long in fixing upon any one resemblance which was common to all the long-lived4 ,probably he tried several other characters1 before he tried the presence and absence of the gall-bladder3--perhaps1 trying such characters1 he found them succeed for a few cases1 and then fail in others1 so that he had to reject them as useless for his purpose4 ,all the while1 the absence of the gall-bladder in the long-lived animals was a fact3 but it was of no use to him1 because he had not selected it and drawn it forth from the mass of other facts4 ,he was looking for a mean term to connect his first extreme1 long-lived1 with his second1 the special cases4 ,he sought this middle term in the entrails of the many animals which he used as extremes3 it was there1 but he could not find it4 ,the fact existed1 but it was of no use for the purpose of ,induction1 because it did not become a special ,conception in his mind4 ,he considered the animals in various points of view1 it may be1 as ruminant1 as horned1 as hoofed1 and the contrary2 but not as acholous and the contrary4 ,when he looked at animals in that point of view1--when he took up that character as the ground of distinction1 he forthwith imagined that he found a separation of long-lived and short-lived animals4 ,when that ,fact became a ,conception1 he obtained an inductive truth1 or1 at any rate1 an inductive proposition4 ,he obtained an inductive proposition by applying the ,conception acholous to his observation of animals4 ,this ,conception divided them into two classes2 and these classes were1 he fancied1 long-lived and short-lived respectively4 ,that it was the ,conception1 and not the ,fact which enabled him to obtain his inductive proposition1 is further plain from this1 that the supposed ,fact is not a fact4 ,acholous animals are not longer-lived than others4 ,the presence or absence of the gall-bladder is no character of longevity4 ,it is true1 that in one familiar class of animals1 the herbivorous kind1 there is a sort of first seeming of the truth of ,aristotle's asserted rule3 for the horse and mule which have not the gall-bladder are longer-lived than the cow1 sheep1 and goat1 which have it4 ,but if we pursue the investigation further1 the rule soon fails4 ,the deer-tribe that want the gall-bladder are not longer-lived than the other ruminating animals which have it4 ,and as a conspicuous evidence of the falsity of the rule1 man and the elephant are perhaps1 for their size1 the longest-lived animals1 and of these1 man has1 and the elephant has not1 the organ in question4 ,the inductive proposition1 then1 is false2 but what we have mainly to consider is1 where the fallacy enters1 according to ,aristotle's analysis of ,induction into ,syllogism4 ,for the two premisses are still true2 that elephants1 c41 are long-lived2 and that elephants1 c41 are acholous4 ,and it is plain that the fallacy comes in with that conversion and generalization of the latter proposition1 which we have noted as necessary to ,aristotle's illustration of ,induction4 ,when we say ,all acholous animals are as elephants1 c41 that is1 as those in their biological conditions1 we say what is not true4 ,aristotle's condition 7 #h7 is not complied with1 that the middle term shall not extend beyond the extreme4 ,for the character acholous does extend beyond the elephant and the animals biologically resembling it2 it extends to deer1 c41 which are not like elephants and horses1 in the point in question4 ,and thus1 we see that the assumed conversion and generalization of the minor proposition1 is the seat of the fallacy of false ,inductions1 as it is the seat of the peculiar logical character of true ,inductions4 ,as true ,inductive ,propositions cannot be logically demonstrated by syllogistic rules1 so they cannot be discovered by any rule4 ,there is no formula for the discovery of inductive truth4 ,it is caught by a peculiar sagacity1 or power of divination1 for which no precepts can be given4 ,but from what has been said1 we see that this sagacity shows itself in the discovery of propositions which are both true1 and convertible in the sense above explained4 ,both these steps may be difficult4 ,the former is often very laborious3 and when the labour has been expended1 and a true proposition obtained1 it may turn out useless1 because the proposition is not convertible4 ,it was a matter of great labour to ,kepler to prove 7from calculation of observations7 that ,mars moves elliptically4 ,before he proved this1 he had tried to prove many similar propositions3--that ,mars moved according to the bisection of the eccentricity1--according to the vicarious hypothesis1--according to the physical hypothesis1--and the like2 but none of these was found to be exactly true4 ,the proposition that ,mars moves elliptically was proved to be true4 ,but still1 there was the question1 ,is it convertible8 ,do all the planets move as ,mars moves8 ,this was proved1 7suppose17 to be true1 for the ,earth and ,venus4 ,but still the question remains1 ,do all the planets move as ,mars1 ,earth1 ,venus1 do8 ,the inductive generalizing impulse boldly answers1 ,yes1 to this question2 though the rules of ,syllogism do not authorize the answer1 and though there remain untried cases4 ,the inductive ,philosopher tries the cases as fast as they occur1 in order to confirm his previous conviction2 but if he had to wait for belief and conviction till he had tried every case1 he never could have belief or conviction of such a proposition at all4 ,he is prepared to modify or add to his inductive truth according as new cases and new observations instruct him2 but he does not fear that new cases or new observations will overturn an inductive proposition established by exact comparison of many complex and various phenomena4 ,aristotle's example offers somewhat similar reflections4 ,he had to establish a proposition concerning long-lived animals1 which should be true1 and should be susceptible of generalized conversion4 ,to prove that the elephant1 horse and mule are destitute of gall-bladder required1 at least1 the labour of anatomizing those animals in the seat of that organ4 ,but this labour was not enough2 for he would find those animals to agree in many other things besides in being acholous4 ,he must have selected that character somewhat at a venture4 ,and the guess was wrong1 as a little more labour would have shown him2 if for instance he had dissected deer3 for they are acholous1 and yet short-lived4 ,a trial of this kind would have shown him that the extreme term1 acholous1 did extend beyond the mean1 namely1 animals such as elephant1 horse1 mule2 and therefore1 that the conversion was not allowable1 and that the ,induction was untenable4 ,in truth1 there is no relation between bile and longevity#cej1 and this example given by ,aristotle of generalization from induction is an unfortunate one4 99 99 99 99 99 ,in discussing this passage of ,aristotle1 ,i have made two alterations in the text1 one of which is necessary on account of the fact2 the other on account of the sense4 ,in the received text1 the particular examples of long-lived animals given are man1 horse1 and mule 7' 1 1 1 1 74 ,and it is afterwards said that all these are acholous3 7 1 1 74 ,but man has a gall-bladder3 and the fact was well known in ,aristotle's time1 for instance1 to ,hippocrates2 so that it is not likely that ,aristotle would have made the mistake which the text contains4 ,but at any rate1 it is a mistake2 if not of the transcriber1 of ,aristotle2 and it is impossible to reason about the passage1 without correcting the mistake4 ,the substitution of for makes the reasoning coherent2 but of course1 any other acholous long-lived animal would do so equally well4 ,the other emendation which ,i have made is in #f4 ,in the received text #f and #g stand thus3 #f4 ,then every ,c is ,a1 for every acholous animal is long-lived 7 1 74 #g4 ,also every ,c is ,b1 for all ,c is destitute of bile4 ,whence it may be inferred1 says ,aristotle1 under certain conditions1 that every ,b is ,a 7 7 that is1 that every acholous animal is long-lived4 ,but this conclusion is1 according to the common reading1 identical with the major premiss2 so that the passage is manifestly corrupt4 ,i correct it by substituting for 1 2 and thus reading for every ,c is long-lived3 just as in the parallel sentence1 #g1 we have 1 1 4 ,in this way the reasoning becomes quite clear4 ,the corrupt substitution of for may have been made in various ways2 which ,i need not suggest4 ,as my business is with the sense of the passage1 and as it makes no sense without the change1 and very good sense with it1 ,i cannot hesitate to make the emendation4 ,and these emendations being made1 ,aristotle's view of the nature and force of ,induction becomes1 ,i think1 perfectly clear and very instructive4 99 99 99 99 99 ,,additional ,,note4 ,i take the liberty of adding to this ,memoir the following remarks1 for which ,i am indebted to ,mr4 ,edleston1 ,fellow of ,trinity ,college4 ,several of the earlier editions of ,aristotle have instead of in the passage referred to in the above paper3 ex4 gr4 7#a7 ,the edition printed at ,basle1 #aeci 7after ,erasmus73 4 7#b7 ,basil 7,erasmus7 #aeej4 4 7#c7 ,burana's ,latin version1 ,venet4 #aeeb1 has omne enim ,c longvum4 7#d7 ,sylburg1 ,francf4 #aehg is printed in brackets thus3 4 7#e7 ,so also in ,casaubon's edition1 #aeij4 7#f7 ,casaub4 #afje 1 7though the ,latin version has vacans bile27 not 1 as the edition of #aeij4 7#g7 ,in the edition printed ,aurel4 ,allobr4 #afjg1 1 as in 7#d7 and 7#e74 7#h7 ,du ,val's editions1 ,paris1 #afai1 #afbi1 #afed 1 though in ,pacius's translation in the adjacent column we find vacans bile4 7#i7 ,in the critical notes to ,waitz's edition of the ,organon 7,lips4 #ahdd7 it is stated that post del4 4 n1 implying apparently1 that in the ,,ms4 marked n1 the letter 1 which had been originally written after 1 had been erased4 99 99 99 99 99 ,the following passages throw light upon the question whether ought or ought not to be retained in the passage discussed in the ,memoir4 7,a7 ,aristot4 ,de ,animalibus ,histor4 ,,ii4 #ae1 #i 7,bekk471 1 1 1 1 4444 1 444 7,b7 ,conf4 ,ib4 ,i4 #ag1 #aj1 #aa4 7,in the beginning of ,chap4 #af1 he says that the external of man are 1 ' 4 1 1 4447 7,c7 ,id ,de ,part4 ,animal4 ,,iv4 #b1 #b4 1 44444 1 ' 1 4 ' 1 ' 4 44444 7,d7 ,ib4 #aa4 1 4 ' 1 1 4 1 444 7,e7 ,the elephant and man are mentioned together as long-lived animals 7,de ,long4 et ,brev4 ,vit1 ,,iv4 #b1 and ,de ,generat4 ,animal4 ,,iv4 #aj1 #b47 99 99 99 99 99 ,the following is the import of these passages3 7,a7 ,of viviparous quadrupeds1 the deer1 roe1 horse1 mule1 ass1 seal1 and some of the swine have not the gall-bladder4444 ,the elephant also has the liver without gall-bladder1 c4 7,b7 ,the external parts of man are well known3 the internal parts are far from being so4 ,the parts of man are in a great measure unknown2 so that we must judge concerning them by reference to the analogy of other animals4444 7,c7 ,some animals are altogether destitute of gall-bladder1 as the horse1 the mule1 the ass1 the deer1 the roe4444 ,but in some kinds it appears that some have it1 and some have it not1 as the mice kind4 ,and among these is man2 for some men appear to have a gall-bladder on the liver1 and some not to have one4 ,and thus there is a doubt as to the species in general2 for those who have happened to examine examples of either kind1 hold that all the cases are of that kind4 7,d7 ,those of the ancients speak most plausibly1 who say that the absence of the gall-bladder is the cause of long life2 looking at animals with uncloven hoof1 and deer3 for these are destitute of gall-bladder1 and live a long time4 ,and further1 those animals in which the ancients had not the opportunity of ascertaining that they have not the gall-bladder1 as the dolphin1 and the camel1 are also long-lived animals4 ,it appears1 from these passages1 that ,aristotle was aware that some persons had asserted man to have a gall-bladder1 but that he also conceived this not to be universally true4 ,he may have inclined to the opinion1 that the opposite case was the more usual1 and may have written in the passage which ,i have been discussing4 ,another mistake of his is the reckoning deer among long-lived animals4 ,it appears probable1 from the context of the passages 7,c7 and 7,d71 that the conjecture of a connexion between absence of the gall-bladder and length of life was suggested by some such notion as this3--that the gall1 from its bitterness1 is the cause of irritation1 mental and bodily1 and that irritation is adverse to longevity4 ,the opinion is ascribed to the ancients1 not claimed by ,aristotle as his own4 ,,footnotes3 ,footnote #cej3 ,mr4 ,owen1 to whom ,i am indebted for the physiological part of this criticism1 tells me1 ,all mammalia have bile1 the carnivora in greater proportion than the herbivora3 the gall-bladder is a comparatively unimportant accessory to the biliary apparatus2 adjusting it to certain modifications of stomach and intestine3 there is no relation between natural longevity and bile4 ,neither has the presence or absence of the gall-bladder any connexion with age4 ,man and the elephant are perhaps for their size the longest lived animals1 and the latest at coming to maturity3 one has the gall-bladder1 and the other not4 ,,appendix ,e4 ,,on ,,the ,,fundamental ,,antithesis ,,of ,,philosophy4 7,cam4 ,phil4 ,soc4 ,,feb4 #e1 #ahdd47 #a4 ,all persons who have attended in any degree to the views generally current of the nature of reasoning are familiar with the distinction of necessary truths and truths of experience2 and few such persons1 or at least few students of mathematics1 require to have this distinction explained or enforced4 ,all geometricians are satisfied that the geometrical truths with which they are conversant are necessarily true3 they not only are true1 but they must be true4 ,the meaning of the terms being understood1 and the proof being gone through1 the truth of the proposition must be assented to4 ,that parallelograms upon the same base and between the same parallels are equal2--that angles in the same segment are equal2--these are propositions which we learn to be true by demonstrations deduced from definitions and axioms2 and which1 when we have thus learnt them1 we see could not be otherwise4 ,on the other hand1 there are other truths which we learn from experience2 as for instance1 that the stars revolve round the pole in one day2 and that the moon goes through her phases from full to full again in thirty days4 ,these truths we see to be true2 but we know them only by experience4 ,men never could have discovered them without looking at the stars and the moon2 and having so learnt them1 still no one will pretend to say that they are necessarily true4 ,for aught we can see1 things might have been otherwise2 and if we had been placed in another part of the solar system1 then1 according to the opinions of astronomers1 experience would have presented them otherwise4 #b4 ,i take the astronomical truths of experience to contrast with the geometrical necessary truths1 as being both of a familiar definite sort2 we may easily find other examples of both kinds of truth4 ,the truths which regard numbers are necessary truths4 ,it is a necessary truth1 that #bg and #ch are equal to #fe2 that half the sum of two numbers added to half their difference is equal to the greater number4 ,on the other hand1 that sugar will dissolve in water2 that plants cannot live without light2 and in short1 the whole body of our knowledge in chemistry1 physiology1 and the other inductive sciences1 consists of truths of experience4 ,if there be any science which offer to us truths of an ambiguous kind1 with regard to which we may for a moment doubt whether they are necessary or experiential1 we will defer the consideration of them till we have marked the distinction of the two kinds more clearly4 #c4 ,one mode in which we may express the difference of necessary truths and truths of experience1 is1 that necessary truths are those of which we cannot distinctly conceive the contrary4 ,we can very readily conceive the contrary of experiential truths4 ,we can conceive the stars moving about the pole or across the sky in any kind of curves with any velocities2 we can conceive the moon always appearing during the whole month as a luminous disk1 as she might do if her light were inherent and not borrowed4 ,but we cannot conceive one of the parallelograms on the same base and between the same parallels larger than the other2 for we find that1 if we attempt to do this1 when we separate the parallelograms into parts1 we have to conceive one triangle larger than another1 both having all their parts equal2 which we cannot conceive at all1 if we conceive the triangles distinctly4 ,we make this impossibility more clear by conceiving the triangles to be placed so that two sides of the one coincide with two sides of the other2 and it is then seen1 that in order to conceive the triangles unequal1 we must conceive the two bases which have the same extremities both ways1 to be different lines1 though both straight lines4 ,this it is impossible to conceive3 we assent to the impossibility as an axiom1 when it is expressed by saying1 that two straight lines cannot inclose a space2 and thus we cannot distinctly conceive the contrary of the proposition just mentioned respecting parallelograms4 #d4 ,but it is necessary1 in applying this distinction1 to bear in mind the terms of it2--that we cannot distinctly conceive the contrary of a necessary truth4 ,for in a certain loose1 indistinct way1 persons conceive the contrary of necessary geometrical truths1 when they erroneously conceive false propositions to be true4 ,thus1 ,hobbes erroneously held that he had discovered a means of geometrically doubling the cube1 as it is called1 that is1 finding two mean proportionals between two given lines2 a problem which cannot be solved by plane geometry4 ,hobbes not only proposed a construction for this purpose1 but obstinately maintained that it was right1 when it had been proved to be wrong4 ,but then1 the discussion showed how indistinct the geometrical conceptions of ,hobbes were2 for when his critics had proved that one of the lines in his diagram would not meet the other in the point which his reasoning supposed1 but in another point near to it2 he maintained1 in reply1 that one of these points was large enough to include the other1 so that they might be considered as the same point4 ,such a mode of conceiving the opposite of a geometrical truth1 forms no exception to the assertion1 that this opposite cannot be distinctly conceived4 #e4 ,in like manner1 the indistinct conceptions of children and of rude savages do not invalidate the distinction of necessary and experiential truths4 ,children and savages make mistakes even with regard to numbers2 and might easily happen to assert that #bg and #ch are equal to #fc or #fd4 ,but such mistakes cannot make such arithmetical truths cease to be necessary truths4 ,when any person conceives these numbers and their addition distinctly1 by resolving them into parts1 or in any other way1 he sees that their sum is necessarily #fe4 ,if1 on the ground of the possibility of children and savages conceiving something different1 it be held that this is not a necessary truth1 it must be held on the same ground1 that it is not a necessary truth that #g and #d are equal to #aa2 for children and savages might be found so unfamiliar with numbers as not to reject the assertion that #g and #d are #aj1 or even that #d and #c are #f1 or #h4 ,but ,i suppose that no persons would on such grounds hold that these arithmetical truths are truths known only by experience4 #f4 ,necessary truths are established1 as has already been said1 by demonstration1 proceeding from definitions and axioms1 according to exact and rigorous inferences of reason4 ,truths of experience are collected from what we see1 also according to inferences of reason1 but proceeding in a less exact and rigorous mode of proof4 ,the former depend upon the relations of the ideas which we have in our minds3 the latter depend upon the appearances or phenomena1 which present themselves to our senses4 ,necessary truths are formed from our thoughts1 the elements of the world within us2 experiential truths are collected from things1 the elements of the world without us4 ,the truths of experience1 as they appear to us in the external world1 we call ,facts2 and when we are able to find among our ideas a train which will conform themselves to the apparent facts1 we call this a ,theory4 #g4 ,this distinction and opposition1 thus expressed in various forms2 as ,necessary and ,experiential ,truth1 ,ideas and ,senses1 ,thoughts and ,things1 ,theory and ,fact1 may be termed the ,fundamental ,antithesis of ,philosophy2 for almost all the discussions of philosophers have been employed in asserting or denying1 explaining or obscuring this antithesis4 ,it may be expressed in many other ways2 but is not difficult1 under all these different forms1 to recognize the same opposition3 and the same remarks apply to it under its various forms1 with corresponding modifications4 ,thus1 as we have already seen1 the antithesis agrees with that of ,reasoning and ,observation3 again1 it is identical with the opposition of ,reflection and ,sensation3 again1 sensation deals with ,objects2 facts involve ,objects1 and generally all things without us are ,objects3--,objects of sensation1 of observation4 ,on the other hand1 we ourselves who thus observe objects1 and in whom sensation is1 may be called the ,subjects of sensation and observation4 ,and this distinction of ,subject and ,object is one of the most general ways of expressing the fundamental antithesis1 although not yet perhaps quite familiar in ,english4 ,i shall not scruple however to speak of the ,subjective and ,objective element of this antithesis1 where the expressions are convenient4 #h4 ,all these forms of antithesis1 and the familiar references to them which men make in all discussions1 show the fundamental and necessary character of the antithesis4 ,we can have no knowledge without the union1 no philosophy without the separation1 of the two elements4 ,we can have no knowledge1 except we have both impressions on our senses from the world without1 and thoughts from our minds within3--except we attend to things1 and to our ideas2--except we are passive to receive impressions1 and active to compare1 combine1 and mould them4 ,but on the other hand1 philosophy seeks to distinguish the impressions of our senses from the thoughts of our minds2--to point out the difference of ideas and things2--to separate the active from the passive faculties of our being4 ,the two elements1 sensations and ideas1 are both requisite to the existence of our knowledge1 as both matter and form are requisite to the existence of a body4 ,but philosophy considers the matter and the form separately4 ,the properties of the form are the subject of geometry1 the properties of the matter are the subject of chemistry or mechanics4 #i4 ,but though philosophy considers these elements of knowledge separately1 they cannot really be separated1 any more than can matter and form4 ,we cannot exhibit matter without form1 or form without matter2 and just as little can we exhibit sensations without ideas1 or ideas without sensations2--the passive or the active faculties of the mind detached from each other4 ,in every act of my knowledge1 there must be concerned the things whereof ,i know1 and thoughts of me who know3 ,i must both passively receive or have received impressions1 and ,i must actively combine them and reason on them4 ,no apprehension of things is purely ideal3 no experience of external things is purely sensational4 ,if they be conceived as things1 the mind must have been awakened to the conviction of things by sensation3 if they be conceived as things1 the expressions of the senses must have been bound together by conceptions4 ,if we think of any thing1 we must recognize the existence both of thoughts and of things4 ,the fundamental antithesis of philosophy is an antithesis of inseparable elements4 #aj4 ,not only cannot these elements be separately exhibited1 but they cannot be separately conceived and described4 ,the description of them must always imply their relation2 and the names by which they are denoted will consequently always bear a relative significance4 ,and thus the terms which denote the fundamental antithesis of philosophy cannot be applied absolutely and exclusively in any case4 ,we may illustrate this by a consideration of some of the common modes of expressing the antithesis of which we speak4 ,the terms ,theory and ,fact are often emphatically used as opposed to each other3 and they are rightly so used4 ,but yet it is impossible to say absolutely in any case1 ,this is a ,fact and not a ,theory2 this is a ,theory and not a ,fact1 meaning by ,theory1 true ,theory4 ,is it a fact or a theory that the stars appear to revolve round the pole8 ,is it a fact or a theory that the earth is a globe revolving round its axis8 ,is it a fact or a theory that the earth revolves round the sun8 ,is it a fact or a theory that the sun attracts the earth8 ,is it a fact or a theory that a loadstone attracts a needle8 ,in all these cases1 some persons would answer one way and some persons another4 ,a person who has never watched the stars1 and has only seen them from time to time1 considers their circular motion round the pole as a theory1 just as he considers the motion of the sun in the ecliptic as a theory1 or the apparent motion of the inferior planets round the sun in the zodiac4 ,a person who has compared the measures of different parts of the earth1 and who knows that these measures cannot be conceived distinctly without supposing the earth a globe1 considers its globular form a fact1 just as much as the square form of his chamber4 ,a person to whom the grounds of believing the earth to revolve round its axis and round the sun1 are as familiar as the grounds for believing the movements of the mail-coaches in this country1 conceives the former events to be facts1 just as steadily as the latter4 ,and a person who1 believing the fact of the earth's annual motion1 refers it distinctly to its mechanical course1 conceives the sun's attraction as a fact1 just as he conceives as a fact the action of the wind which turns the sails of a mill4 ,we see then1 that in these cases we cannot apply absolutely and exclusively either of the terms1 ,fact or ,theory4 ,theory and ,fact are the elements which correspond to our ,ideas and our ,senses4 ,the ,facts are facts so far as the ,ideas have been combined with the sensations and absorbed in them3 the ,theories are ,theories so far as the ,ideas are kept distinct from the sensations1 and so far as it is considered as still a question whether they can be made to agree with them4 ,a true ,theory is a fact1 a ,fact is a familiar theory4 ,in like manner1 if we take the terms ,reasoning and ,observation2 at first sight they appear to be very distinct4 ,our observation of the world without us1 our reasonings in our own minds1 appear to be clearly separated and opposed4 ,but yet we shall find that we cannot apply these terms absolutely and exclusively4 ,i see a book lying a few feet from me3 is this a matter of observation8 ,at first1 perhaps1 we might be inclined to say that it clearly is so4 ,but yet1 all of us1 who have paid any attention to the process of vision1 and to the mode in which we are enabled to judge of the distance of objects1 and to judge them to be distant objects at all1 know that this judgment involves inferences drawn from various sensations2--from the impressions on our two eyes2--from our muscular sensations2 and the like4 ,these inferences are of the nature of reasoning1 as much as when we judge of the distance of an object on the other side of a river by looking at it from different points1 and stepping the distance between them4 ,or again3 we observe the setting sun illuminate a gilded weathercock2 but this is as much a matter of reasoning as when we observe the phases of the moon1 and infer that she is illuminated by the sun4 ,all observation involves inferences1 and inference is reasoning4 #aa4 ,even the simplest terms by which the antithesis is expressed cannot be applied3 ideas and sensations1 thoughts and things1 subject and object1 cannot in any case be applied absolutely and exclusively4 ,our sensations require ideas to bind them together1 namely1 ideas of space1 time1 number1 and the like4 ,if not so bound together1 sensations do not give us any apprehension of things or objects4 ,all things1 all objects1 must exist in space and in time--must be one or many4 ,now space1 time1 number1 are not sensations or things4 ,they are something different from1 and opposed to sensations and things4 ,we have termed them ideas4 ,it may be said they are relations of things1 or of sensations4 ,but granting this form of expression1 still a relation is not a thing or a sensation2 and therefore we must still have another and opposite element1 along with our sensations4 ,and yet1 though we have thus these two elements in every act of perception1 we cannot designate any portion of the act as absolutely and exclusively belonging to one of the elements4 ,perception involves sensation1 along with ideas of time1 space1 and the like2 or1 if any one prefers the expression1 involves sensations along with the apprehension of relations4 ,perception is sensation1 along with such ideas as make sensation into an apprehension of things or objects4 #ab4 ,and as perception of objects implies ideas1 as observation implies reasoning2 so1 on the other hand1 ideas cannot exist where sensation has not been3 reasoning cannot go on when there has not been previous observation4 ,this is evident from the necessary order of development of the human faculties4 ,sensation necessarily exists from the first moments of our existence1 and is constantly at work4 ,observation begins before we can suppose the existence of any reasoning which is not involved in observation4 ,hence1 at whatever period we consider our ideas1 we must consider them as having been already engaged in connecting our sensations1 and as modified by this employment4 ,by being so employed1 our ideas are unfolded and defined1 and such development and definition cannot be separated from the ideas themselves4 ,we cannot conceive space without boundaries or forms2 now forms involve sensations4 ,we cannot conceive time without events which mark the course of time2 but events involve sensations4 ,we cannot conceive number without conceiving things which are numbered2 and things imply sensations4 ,and the forms1 things1 events1 which are thus implied in our ideas1 having been the objects of sensation constantly in every part of our life1 have modified1 unfolded and fixed our ideas1 to an extent which we cannot estimate1 but which we must suppose to be essential to the processes which at present go on in our minds4 ,we cannot say that objects create ideas2 for to perceive objects we must already have ideas4 ,but we may say1 that objects and the constant perception of objects have so far modified our ideas1 that we cannot1 even in thought1 separate our ideas from the perception of objects4 ,we cannot say of any ideas1 as of the idea of space1 or time1 or number1 that they are absolutely and exclusively ideas4 ,we cannot conceive what space1 or time1 or number would be in our minds1 if we had never perceived any thing or things in space or time4 ,we cannot conceive ourselves in such a condition as never to have perceived any thing or things in space or time4 ,but1 on the other hand1 just as little can we conceive ourselves becoming acquainted with space and time or numbers as objects of sensation4 ,we cannot reason without having the operations of our minds affected by previous sensations2 but we cannot conceive reasoning to be merely a series of sensations4 ,in order to be used in reasoning1 sensation must become observation2 and1 as we have seen1 observation already involves reasoning4 ,in order to be connected by our ideas1 sensations must be things or objects1 and things or objects already include ideas4 ,and thus1 as we have said1 none of the terms by which the fundamental antithesis is expressed can be absolutely and exclusively applied4 #ac4 ,i now proceed to make one or two remarks suggested by the views which have thus been presented4 ,and first ,i remark1 that since1 as we have just seen1 none of the terms which express the fundamental antithesis can be applied absolutely and exclusively1 the absolute application of the antithesis in any particular case can never be a conclusive or immoveable principle4 ,this remark is the more necessary to be borne in mind1 as the terms of this antithesis are often used in a vehement and peremptory manner4 ,thus we are often told that such a thing is a ,fact and not a ,theory1 with all the emphasis which1 in speaking or writing1 tone or italics or capitals can give4 ,we see from what has been said1 that when this is urged1 before we can estimate the truth1 or the value of the assertion1 we must ask to whom is it a fact8 what habits of thought1 what previous information1 what ideas does it imply1 to conceive the fact as a fact8 ,does not the apprehension of the fact imply assumptions which may with equal justice be called theory1 and which are perhaps false theory8 in which case1 the fact is no fact4 ,did not the ancients assert it as a fact1 that the earth stood still1 and the stars moved8 and can any fact have stronger apparent evidence to justify persons in asserting it emphatically than this had8 ,these remarks are by no means urged in order to show that no fact can be certainly known to be true2 but only to show that no fact can be certainly shown to be a fact merely by calling it a fact1 however emphatically4 ,there is by no means any ground of general skepticism with regard to truth involved in the doctrine of the necessary combination of two elements in all our knowledge4 ,on the contrary1 ideas are requisite to the essence1 and things to the reality of our knowledge in every case4 ,the proportions of geometry and arithmetic are examples of knowledge respecting our ideas of space and number1 with regard to which there is no room for doubt4 ,the doctrines of astronomy are examples of truths not less certain respecting the external world4 #ad4 ,i remark further1 that since in every act of knowledge1 observation or perception1 both the elements of the fundamental antithesis are involved1 and involved in a manner inseparable even in our conceptions1 it must always be possible to derive one of these elements from the other1 if we are satisfied to accept1 as proof of such derivation1 that one always co-exists with and implies the other4 ,thus an opponent may say1 that our ideas of space1 time1 and number1 are derived from our sensations or perceptions1 because we never were in a condition in which we had the ideas of space and time1 and had not sensations or perceptions4 ,but then1 we may reply to this1 that we no sooner perceive objects than we perceive them as existing in space and time1 and therefore the ideas of space and time are not derived from the perceptions4 ,in the same manner1 an opponent may say1 that all knowledge which is involved in our reasonings is the result of experience2 for instance1 our knowledge of geometry4 ,for every geometrical principle is presented to us by experience as true2 beginning with the simplest1 from which all others are derived by processes of exact reasoning4 ,but to this we reply1 that experience cannot be the origin of such knowledge2 for though experience shows that such principles are true1 it cannot show that they must be true1 which we also know4 ,we never have seen1 as a matter of observation1 two straight lines inclosing a space2 but we venture to say further1 without the smallest hesitation1 that we never shall see it2 and if any one were to tell us that1 according to his experience1 such a form was often seen1 we should only suppose that he did not know what he was talking of4 ,no number of acts of experience can add to the certainty of our knowledge in this respect2 which shows that our knowledge is not made up of acts of experience4 ,we cannot test such knowledge by experience2 for if we were to try to do so1 we must first know that the lines with which we make the trial are straight2 and we have no test of straightness better than this1 that two such lines cannot inclose a space4 ,since then1 experience can neither destroy1 add to1 nor test our axiomatic knowledge1 such knowledge cannot be derived from experience4 ,since no one act of experience can affect our knowledge1 no numbers of acts of experience can make it4 #ae4 ,to this a reply has been offered1 that it is a characteristic property of geometric forms that the ideas of them exactly resemble the sensations2 so that these ideas are as fit subjects of experimentation as the realities themselves2 and that by such experimentation we learn the truth of the axioms of geometry4 ,i might very reasonably ask those who use this language to explain how a particular class of ideas can be said to resemble sensations2 how1 if they do1 we can know it to be so2 how we can prove this resemblance to belong to geometrical ideas and sensations2 and how it comes to be an especial characteristic of those4 ,but ,i will put the argument in another way4 ,experiment can only show what is1 not what must be4 ,if experimentation on ideas shows what must be1 it is different from what is commonly called experience4 ,i may add1 that not only the mere use of our senses cannot show that the axioms of geometry must be true1 but that1 without the light of our ideas1 it cannot even show that they are true4 ,if we had a segment of a circle a mile long and an inch wide1 we should have two lines inclosing a space2 but we could not1 by seeing or touching any part of either of them1 discover that it was a bent line4 #af4 ,that mathematical truths are not derived from experience is perhaps still more evident1 if greater evidence be possible1 in the case of numbers4 ,we assert that #g and #h are #ae4 ,we find it so1 if we try with counters1 or in any other way4 ,but we do not1 on that account1 say that the knowledge is derived from experience4 ,we refer to our conceptions of seven1 of eight1 and of addition1 and as soon as we possess these conceptions distinctly1 we see that the sum must be fifteen4 ,we cannot be said to make a trial1 for we should not believe the apparent result of the trial if it were different4 ,if any one were to say that the multiplication table is a table of the results of experience1 we should know that he could not be able to go along with us in our researches into the foundations of human knowledge2 nor1 indeed1 to pursue with success any speculations on the subject4 #ag4 ,attempts have also been made to explain the origin of axiomatic truths by referring them to the association of ideas4 ,but this is one of the cases in which the word association has been applied so widely and loosely1 that no sense can be attached to it4 ,those who have written with any degree of distinctness on the subject1 have truly taught1 that the habitual association of the ideas leads us to believe a connexion of the things3 but they have never told us that this association gave us the power of forming the ideas4 ,association may determine belief1 but it cannot determine the possibility of our conceptions4 ,the ,african king did not believe that water could become solid1 because he had never seen it in that state4 ,but that accident did not make it impossible to conceive it so1 any more than it is impossible for us to conceive frozen quicksilver1 or melted diamond1 or liquefied air2 which we may never have seen1 but have no difficulty in conceiving4 ,if there were a tropical philosopher really incapable of conceiving water solidified1 he must have been brought into that mental condition by abstruse speculations on the necessary relations of solidity and fluidity1 not by the association of ideas4 #ah4 ,to return to the results of the nature of the ,fundamental ,antithesis4 ,as by assuming universal and indissoluble connexion of ideas with perceptions1 of knowledge with experience1 as an evidence of derivation1 we may assert the former to be derived from the latter1 so might we1 on the same ground1 assert the latter to be derived from the former4 ,we see all forms in space2 and we might hence assert all forms to be mere modifications of our idea of space4 ,we see all events happen in time2 and we might hence assert all events to be merely limitations and boundary-marks of our idea of time4 ,we conceive all collections of things as two or three1 or some other number3 it might hence be asserted that we have an original idea of number1 which is reflected in external things4 ,in this case1 as in the other1 we are met at once by the impossibility of this being a complete account of our knowledge4 ,our ideas of space1 of time1 of number1 however distinctly reflected to us with limitations and modifications1 must be reflected1 limited and modified by something different from themselves4 ,we must have visible or tangible forms to limit space1 perceived events to mark time1 distinguishable objects to exemplify number4 ,but still1 in forms1 and events1 and objects1 we have a knowledge which they themselves cannot give us4 ,for we know1 without attending to them1 that whatever they are1 they will conform and must conform to the truths of geometry and arithmetic4 ,there is an ideal portion in all our knowledge of the external world2 and if we were resolved to reduce all our knowledge to one of its two antithetical elements1 we might say that all our knowledge consists in the relation of our ideas4 ,wherever there is necessary truth1 there must be something more than sensation can supply3 and the necessary truths of geometry and arithmetic show us that our knowledge of objects in space and time depends upon necessary relations of ideas1 whatever other element it may involve4 #ai4 ,this remark may be carried much further than the domain of geometry and arithmetic4 ,our knowledge of matter may at first sight appear to be altogether derived from the senses4 ,yet we cannot derive from the senses our knowledge of a truth which we accept as universally certain2--namely1 that we cannot by any process add to or diminish the quantity of matter in the world4 ,this truth neither is nor can be derived from experience2 for the experiments which we make to verify it pre-suppose its truth4 ,when the philosopher was asked what was the weight of smoke1 he bade the inquirer subtract the weight of the ashes from the weight of the fuel4 ,every one who thinks clearly of the changes which take place in matter1 assents to the justice of this reply3 and this1 not because any one had found by trial that such was the weight of the smoke produced in combustion1 but because the weight lost was assumed to have gone into some other form of matter1 not to have been destroyed4 ,when men began to use the balance in chemical analysis1 they did not prove by trial1 but took for granted1 as self-evident1 that the weight of the whole must be found in the aggregate weight of the elements4 ,thus it is involved in the idea of matter that its amount continues unchanged in all changes which take place in its consistence4 ,this is a necessary truth3 and thus our knowledge of matter1 as collected from chemical experiments1 is also a modification of our idea of matter as the material of the world incapable of addition or diminution4 #bj4 ,a similar remark may be made with regard to the mechanical properties of matter4 ,our knowledge of these is reduced1 in our reasonings1 to principles which we call the laws of motion4 ,these laws of motion1 as ,i have endeavoured to show#cea1 depend upon the idea of ,cause1 and involve necessary truths1 which are necessarily implied in the idea of cause2--namely1 that every change of motion must have a cause--that the effect is measured by the cause2--that reaction is equal and opposite to action4 ,these principles are not derived from experience4 ,no one1 ,i suppose1 would derive from experience the principle1 that every event must have a cause4 ,every attempt to see the traces of cause in the world assumes this principle4 ,i do not say that these principles are anterior to experience2 for ,i have already1 ,i hope1 shown1 that neither of the two elements of our knowledge is1 or can be1 anterior to the other4 ,but the two elements are co-ordinate in the development of the human mind2 and the ideal element may be said to be the origin of our knowledge with the more propriety of the two1 inasmuch as our knowledge is the relation of ideas4 ,the other element of knowledge1 in which sensation is concerned1 and which embodies1 limits1 and defines the necessary truths which express the relations of our ideas1 may be properly termed experience2 and ,i have1 in the discussion just quoted1 endeavoured to show how the principles concerning mechanical causation1 which ,i have just stated1 are1 by observation and experiment1 limited and defined1 so that they become the laws of motion4 ,and thus we see that such knowledge is derived from ideas1 in a sense quite as general and rigorous1 to say the least1 as that in which it is derived from experience4 #ba4 ,i will take another example of this2 although it is one less familiar1 and the consideration of it perhaps a little more difficult and obscure4 ,the objects which we find in the world1 for instance1 minerals and plants1 are of different kinds2 and according to their kinds1 they are called by various names1 by means of which we know what we mean when we speak of them4 ,the discrimination of these kinds of objects1 according to their different forms and other properties1 is the business of chemistry and botany4 ,and this business of discrimination1 and of consequent classification1 has been carried on from the first periods of the development of the human mind1 by an industrious and comprehensive series of observations and experiments2 the only way in which any portion of the task could have been effected4 ,but as the foundation of all this labour1 and as a necessary assumption during every part of its progress1 there has been in men's minds the principle1 that objects are so distinguishable by resemblances and differences1 that they may be named1 and known by their names4 ,this principle is involved in the idea of a ,name2 and without it no progress could have been made4 ,the principle may be briefly stated thus3--,intelligible ,names of kinds are possible4 ,if we suppose this not to be so1 language can no longer exist1 nor could the business of human life go on4 ,if instead of having certain definite kinds of minerals1 gold1 iron1 copper and the like1 of which the external forms and characters are constantly connected with the same properties and qualities1 there were no connexion between the appearance and the properties of the object2--if what seemed externally iron might turn out to resemble lead in its hardness2 and what seemed to be gold during many trials1 might at the next trial be found to be like copper2 not only all the uses of these minerals would fail1 but they would not be distinguishable kinds of things1 and the names would be unmeaning4 ,and if this entire uncertainty as to kind and properties prevailed for all objects1 the world would no longer be a world to which language was applicable4 ,to man1 thus unable to distinguish objects into kinds1 and call them by names1 all knowledge would be impossible1 and all definite apprehension of external objects would fade away into an inconceivable confusion4 ,in the very apprehension of objects as intelligibly sorted1 there is involved a principle which springs within us1 contemporaneous1 in its efficacy1 with our first intelligent perception of the kinds of things of which the world consists4 ,we assume1 as a necessary basis of our knowledge1 that things are of definite kinds2 and the aim of chemistry1 botany1 and other sciences is to find marks of these kinds2 and along with these1 to learn their definitely-distinguished properties4 ,even here1 therefore1 where so large a portion of our knowledge comes from experience and observation1 we cannot proceed without a necessary truth derived from our ideas1 as our fundamental principle of knowledge4 #bb4 ,what the marks are1 which distinguish the constant differences of kinds of things 7definite marks1 selected from among many unessential appearances71 and what their definite properties are1 when they are so distinguished1 are parts of our knowledge to be learnt from observation1 by various processes2 for instance1 among others1 by chemical analysis4 ,we find the differences of bodies1 as shown by such analysis1 to be of this nature3--that there are various elementary bodies1 which1 combining in different definite proportions1 form kinds of bodies definitely different4 ,but1 in arriving at this conclusion1 we introduce a new idea1 that of ,elementary ,composition1 which is not extracted from the phenomena1 but supplied by the mind1 and introduced in order to make the phenomena intelligible4 ,that this notion of elementary composition is not supplied by the chemical phenomena of combustion1 mixture1 c4 as merely an observed fact1 we see from this2 that men had in ancient times performed many experiments in which elementary composition was concerned1 and had not seen the fact4 ,it never was truly seen till modern times2 and when seen1 it gave a new aspect to the whole body of known facts4 ,this idea of elementary composition1 then1 is supplied by the mind1 in order to make the facts of chemical analysis and synthesis intelligible as analysis and synthesis4 ,and this idea being so supplied1 there enters into our knowledge along with it a corresponding necessary principle2--,that the elementary composition of a body determines its kind and properties4 ,this is1 ,i say1 a principle assumed1 as a consequence of the idea of composition1 not a result of experience2 for when bodies have been divided into their kinds1 we take for granted that the analysis of a single specimen may serve to determine the analysis of all bodies of the same kind3 and without this assumption1 chemical knowledge with regard to the kinds of bodies would not be possible4 ,it has been said that we take only one experiment to determine the composition of any particular kind of body1 because we have a thousand experiments to determine that bodies of the same kind have the same composition4 ,but this is not so4 ,our belief in the principle that bodies of the same kind have the same composition is not established by experiments1 but is assumed as a necessary consequence of the ideas of ,kind and of ,composition4 ,if1 in our experiments1 we found that bodies supposed to be of the same kind had not the same composition1 we should not at all doubt of the principle just stated1 but conclude at once that the bodies were not of the same kind2--that the marks by which the kinds are distinguished had been wrongly stated4 ,this is what has very frequently happened in the course of the investigations of chemists and mineralogists4 ,and thus we have it1 not as an experiential fact1 but as a necessary principle of chemical philosophy1 that the ,elementary ,composition of a body determines its ,kind and ,properties4 #bc4 ,how bodies differ in their elementary composition1 experiment must teach us1 as we have already said1 that experiment has taught us4 ,but as we have also said1 whatever be the nature of this difference1 kinds must be definite1 in order that language may be possible3 and hence1 whatever be the terms in which we are taught by experiment to express the elementary composition of bodies1 the result must be conformable to this principle1 ,that the differences of elementary composition are definite4 ,the law to which we are led by experiment is1 that the elements of bodies continue in definite proportions according to weight4 ,experiments add other laws2 as for instance1 that of multiple proportions in different kinds of bodies composed of the same elements2 but of these we do not here speak4 #bd4 ,we are thus led to see that in our knowledge of mechanics1 chemistry1 and the like1 there are involved certain necessary principles1 derived from our ideas1 and not from experience4 ,but to this it may be objected1 that the parts of our knowledge in which these principles are involved has1 in historical fact1 all been acquired by experience4 ,the laws of motion1 the doctrine of definite proportions1 and the like1 have all become known by experiment and observation2 and so far from being seen as necessary truths1 have been discovered by long-continued labours and trials1 and through innumerable vicissitudes of confusion1 error1 and imperfect truth4 ,this is perfectly true3 but does not at all disprove what has been said4 ,perception of external objects and experience1 experiment and observation are needed1 not only1 as we have said1 to supply the objective element of all knowledge--to embody1 limit1 define1 and modify our ideas2 but this intercourse with objects is also requisite to unfold and fix our ideas themselves4 ,as we have already said1 ideas and facts can never be separated4 ,our ideas cannot be exercised and developed in any other form than in their combination with facts1 and therefore the trials1 corrections1 controversies1 by which the matter of our knowledge is collected1 is also the only way in which the form of it can be rightly fashioned4 ,experience is requisite to the clearness and distinctness of our ideas1 not because they are derived from experience1 but because they can only be exercised upon experience4 ,and this consideration sufficiently explains how it is that experiment and observation have been the means1 and the only means1 by which men have been led to a knowledge of the laws of nature4 ,in reality1 however1 the necessary principles which flow from our ideas1 and which are the basis of such knowledge1 have not only been inevitably assumed in the course of such investigations1 but have been often expressly promulgated in words by clear-minded philosophers1 long before their true interpretation was assigned by experiment4 ,this has happened with regard to such principles as those above mentioned2 ,that every event must have a cause2 ,that reaction is equal and opposite to action2 ,that the quantity of matter in the world cannot be increased or diminished3 and there would be no difficulty in finding similar enunciations of the other principles above mentioned2--,that the kinds of things have definite differences1 and that these differences depend upon their elementary composition4 ,in general1 however1 it may be allowed1 that the necessary principles which are involved in those laws of nature of which we have a knowledge become then only clearly known1 when the laws of nature are discovered which thus involve the necessary ideal element4 #be4 ,but since this is allowed1 it may be further asked1 how we are to distinguish between the necessary principle which is derived from our ideas1 and the law of nature which is learnt by experience4 ,and to this we reply1 that the necessary principle may be known by the condition which we have already mentioned as belonging to such principles3 444 that it is impossible distinctly to conceive the contrary4 ,we cannot conceive an event without a cause1 except we abandon all distinct idea of cause2 we cannot distinctly conceive two straight lines inclosing space2 and if we seem to conceive this1 it is only because we conceive indistinctly4 ,we cannot conceive #e and #c making #g or #i2 if a person were to say that he could conceive this1 we should know that he was a person of immature or rude or bewildered ideas1 whose conceptions had no distinctness4 ,and thus we may take it as the mark of a necessary truth1 that we cannot conceive the contrary distinctly4 #bf4 ,if it be asked what is the test of distinct conception 7since it is upon the distinctness of conception that the matter depends71 we may consider what answer we should give to this question if it were asked with regard to the truths of geometry4 ,if we doubted whether anyone had these distinct conceptions which enable him to see the necessary nature of geometrical truth1 we should inquire if he could understand the axioms as axioms1 and could follow1 as demonstrative1 the reasonings which are founded upon them4 ,if this were so1 we should be ready to pronounce that he had distinct ideas of space1 in the sense now supposed4 ,and the same answer may be given in any other case4 ,that reasoner has distinct conceptions of mechanical causes who can see the axioms of mechanics as axioms1 and can follow the demonstrations derived from them as demonstrations4 ,if it be said that the science1 as presented to him1 may be erroneously constructed2 that the axioms may not be axioms1 and therefore the demonstrations may be futile1 we still reply1 that the same might be said with regard to geometry3 and yet that the possibility of this does not lead us to doubt either of the truth or of the necessary nature of the propositions contained in ,euclid's ,elements4 ,we may add further1 that although1 no doubt1 the authors of elementary books maybe persons of confused minds1 who present as axioms what are not axiomatic truths2 yet that in general1 what is presented as an axiom by a thoughtful man1 though it may include some false interpretation or application of our ideas1 will also generally include some principle which really is necessarily true1 and which would still be involved in the axiom1 if it were corrected so as to be true instead of false4 ,and thus we still say1 that if in any department of science a man can conceive distinctly at all1 there are principles the contrary of which he cannot distinctly conceive1 and which are therefore necessary truths4 #bg4 ,but on this it may be asked1 whether truth can thus depend upon the particular state of mind of the person who contemplates it2 and whether that can be a necessary truth which is not so to all men4 ,and to this we again reply1 by referring to geometry and arithmetic4 ,it is plain that truths may be necessary truths which are not so to all men1 when we include men of confused and perplexed intellects2 for to such men it is not a necessary truth that two straight lines cannot inclose a space1 or that #ad and #ag are #ca4 ,it need not be wondered at1 therefore1 if to such men it does not appear a necessary truth that reaction is equal and opposite to action1 or that the quantity of matter in the world cannot be increased or diminished4 ,and this view of knowledge and truth does not make it depend upon the state of mind of the student1 any more than geometrical knowledge and geometrical truth1 by the confession of all1 depend upon that state4 ,we know that a man cannot have any knowledge of geometry without so much of attention to the matter of the science1 and so much of care in the management of his own thoughts1 as is requisite to keep his ideas distinct and clear4 ,but we do not1 on that account1 think of maintaining that geometrical truth depends merely upon the state of the student's mind4 ,we conceive that he knows it because it is true1 not that it is true because he knows it4 ,we are not surprised that attention and care and repeated thought should be requisite to the clear apprehension of truth4 ,for such care and such repetition are requisite to the distinctness and clearness of our ideas3 and yet the relations of these ideas1 and their consequences1 are not produced by the efforts of attention or repetition which we exert4 ,they are in themselves something which we may discover1 but cannot make or change4 ,the idea of space1 for instance1 which is the basis of geometry1 cannot give rise to any doubtful propositions4 ,what is inconsistent with the idea of space cannot be truly obtained from our ideas by any efforts of thought or curiosity2 if we blunder into any conclusion inconsistent with the idea of space1 our knowledge1 so far as this goes1 is no knowledge3 any more than our observation of the external world would be knowledge1 if1 from haste or inattention1 or imperfection of sense1 we were to mistake the object which we see before us4 #bh4 ,but further3 not only has truth this reality1 which makes it independent of our mistakes1 that it must be what is really consistent with our ideas2 but also1 a further reality1 to which the term is more obviously applicable1 arising from the principle already explained1 that ideas and perceptions are inseparable4 ,for since1 when we contemplate our ideas1 they have been frequently embodied and exemplified in objects1 and thus have been fixed and modified2 and since this compound aspect is that under which we constantly have them before us1 and free from which they cannot be exhibited2 our attempts to make our ideas clear and distinct will constantly lead us to contemplate them as they are manifested in those external forms in which they are involved4 ,thus in studying geometrical truth1 we shall be led to contemplate it as exhibited in visible and tangible figures2--not as if these could be sources of truth1 but as enabling us more readily to compare the aspects which our ideas1 applied to the world of objects1 may assume4 ,and thus we have an additional indication of the reality of geometrical truth1 in the necessary possibility of its being capable of being exhibited in a visible or tangible form4 ,and yet even this test by no means supersedes the necessity of distinct ideas1 in order to a knowledge of geometrical truth4 ,for in the case of the duplication of the cube by ,hobbes1 mentioned above1 the diagram which he drew made two points appear to coincide1 which did not really1 and by the nature of our idea of space1 coincide2 and thus confirmed him in his error4 ,thus the inseparable nature of the ,fundamental ,antithesis of ,ideas and ,things gives reality to our knowledge1 and makes objective reality a corrective of our subjective imperfections in the pursuit of knowledge4 ,but this objective exhibition of knowledge can by no means supersede a complete development of the subjective condition1 namely1 distinctness of ideas4 ,and that there is a subjective condition1 by no means makes knowledge altogether subjective1 and thus deprives it of reality2 because1 as we have said1 the subjective and the objective elements are inseparably bound together in the fundamental antithesis4 #bi4 ,it would be easy to apply these remarks to other cases1 for instance1 to the case of the principle we have just mentioned1 that the differences of elementary composition of different kinds of bodies must be definite4 ,we have stated that this principle is necessarily true2--that the contrary proposition cannot be distinctly conceived4 ,but by whom8 ,evidently1 according to the preceding reasoning1 by a person who distinctly conceives ,kinds1 as marked by intelligible names1 and ,composition1 as determining the kinds of bodies4 ,persons new to chemical and classificatory science may not possess these ideas distinctly2 or rather1 cannot possess them distinctly2 and therefore cannot apprehend the impossibility of conceiving the opposite of the above principle2 just as the schoolboy cannot apprehend the impossibility of the numbers in his multiplication table being other than they are4 ,but this inaptitude to conceive1 in either case1 does not alter the necessary character of the truth3 although1 in one case1 the truth is obvious to all except schoolboys and the like1 and the other is probably not clear to any except those who have attentively studied the philosophy of elementary compositions4 ,at the same time1 this difference of apprehension of the truth in different persons does not make the truth doubtful or dependent upon personal qualifications2 for in proportion as persons attain to distinct ideas1 they will see the truth2 and cannot1 with such ideas1 see anything as truth which is not truth4 ,when the relations of elements in a compound become as familiar to a person as the relations of factors in a multiplication table1 he will then see what are the necessary axioms of chemistry1 as he now sees the necessary axioms of arithmetic4 #cj4 ,there is also one other remark which ,i will here make4 ,in the progress of science1 both the elements of our knowledge are constantly expanded and augmented4 ,by the exercise of observation and experiment1 we have a perpetual accumulation of facts1 the materials of knowledge1 the objective element4 ,by thought and discussion1 we have a perpetual development of man's ideas going on3 theories are framed1 the materials of knowledge are shaped into form2 the subjective element is evolved2 and by the necessary coincidence of the objective and subjective elements1 the matter and the form1 the theory and the facts1 each of these processes furthers and corrects the other3 each element moulds and unfolds the other4 ,now it follows1 from this constant development of the ideal portion of our knowledge1 that we shall constantly be brought in view of new ,necessary ,principles1 the expression of the conditions belonging to the ,ideas which enter into our expanding knowledge4 ,these principles1 at first dimly seen and hesitatingly asserted1 at last become clearly and plainly self-evident4 ,such is the case with the principles which are the basis of the laws of motion4 ,such may soon be the case with the principles which are the basis of the philosophy of chemistry4 ,such may hereafter be the case with the principles which are to be the basis of the philosophy of the connected and related polarities of chemistry1 electricity1 galvanism1 magnetism4 ,that knowledge is possible in these cases1 we know2 that our knowledge may be reduced to principles1 gradually more simple1 we also know2 that we have reached the last stage of simplicity of our principles1 few cultivators of the subject will be disposed to maintain2 and that the additional steps which lead towards very simple and general principles will also lead to principles which recommend themselves by a kind of axiomatic character1 those who judge from the analogy of the past history of science will hardly doubt4 ,that the principles thus axiomatic in their form1 do also express some relation of our ideas1 of which experiment and observation have given a true and real interpretation1 is the doctrine which ,i have here attempted to establish and illustrate in the most clear and undoubted of the existing sciences2 and the evidence of this doctrine in those cases seems to be unexceptionable1 and to leave no room to doubt that such is the universal type of the progress of science4 ,such a doctrine1 as we have now seen1 is closely connected with the views here presented of the nature of the ,fundamental ,antithesis of ,philosophy1 which ,i have endeavoured to illustrate4 ,,footnotes3 ,footnote #cea3 ,hist4 ,sc4 ,ind4 b4 iii4 ,,appendix ,f4 ,,remarks ,,on ,a ,,review ,,of ,,the ,,philosophy ,,of ,,the ,,inductive ,,sciences4 ,trinity ,lodge1 ,april #aath1 #ahdd4 ,,my ,,dear ,,herschel1 ,being about to send you a copy of a paper on a philosophical question just printed in the ,transactions of our ,cambridge ,society1 ,i am tempted to add1 as a private communication1 a few ,remarks on another aspect of the same question4 ,these ,remarks ,i think ,i may properly address to you4 ,they will refer to an ,article in the ,quarterly ,review for ,june1 #ahda1 respecting my ,history and ,philosophy of the ,inductive ,sciences2 and without assigning any other reason1 ,i may say that the interest ,i know you to take in speculations on such subjects makes me confident that you will give a reasonable attention to what ,i may have to say on the subject of that ,article4 ,with the ,reviewal itself1 ,i am so far from having any quarrel1 that when it appeared ,i received it as affording all that ,i hoped from ,public ,criticism4 ,the degree and the kind of admiration bestowed upon my works by a writer so familiar with science1 so comprehensive in his views1 and so equitable in his decisions1 as the ,reviewer manifestly was1 ,i accepted as giving my work a stamp of acknowledged value which few other hands could have bestowed4 ,you may perhaps recollect1 however1 that the ,reviewer dissented altogether from some of the general views which ,i had maintained1 and especially from a general view which is also1 in the main1 that presented in the accompanying ,memoir1 namely1 that1 besides ,facts1 ,ideas are an indispensable source of our knowledge2 that ,ideas are the ground of necessary truth2 that the ,idea of ,space1 in particular1 is the ground of the necessary truths of geometry4 ,this question1 and especially as limited to the last form1 will be the subject of my ,remarks in the first place2 and ,i wish to consider the ,reviewer's objections with the respect which their subtlety and depth of thought well deserve4 ,the ,reviewer makes objections to the account which ,i have given of the source whence geometrical truth derives its characters of being necessary and universal2 but he is not one of those metaphysicians who deny those characters to the truths of geometry4 ,he allows in the most ample manner that the truths of geometry are necessary4 ,the question between us therefore is from what this character is derived4 ,the ,reviewer prefers1 indeed1 to have it considered that the question is not concerning the necessity1 but1 as he says1 the universality of these truths2 or rather1 the nature and grounds of our conviction of their universality4 ,he might have said1 with equal justice1 the nature and grounds of our conviction of their necessity4 ,for his objection to the term necessity in this case--that all the propositions about realities are necessarily true1 since every reality must be consistent with itself1 7p4 #bjf7--;does not apply to our conviction of necessity1 since we may not be able to see what are the properties of real things2 and therefore may have no conviction of their necessity4 ,it may be a necessary property of salt to be soluble1 but we see no such necessity2 and therefore the assertion of such a property is not one of the necessary truths with which we are here concerned4 ,but to turn back to the necessary or universal truths of geometry1 and the ground of those attributes3 ,the main difference between the ,author and the ,reviewer is brought into view1 when the ,reviewer discusses the general argument which ,i had used1 in order to show that truths which we see to be necessary and universal cannot be derived from experience4 ,the argument is this1-- ,experience must always consist of a limited number of observations2 and however numerous these may be1 they can show nothing with regard to the infinite number of cases in which the experiment has not been made4444 ,truths can only be known to be general1 not universal1 if they depend upon experience alone4 ,experience cannot bestow that universality which she herself cannot have2 nor that necessity of which she has no comprehension4 7,phil4 i4 pp4 #fj1 #fa47 ,here is that which must be considered as the cardinal argument on this subject4 ,it is therefore important to attend to the answer which the ,reviewer makes to it4 ,he says1-- ,we conceive that a full answer to this argument is afforded by the nature of the inductive propensity1--by the irresistible impulse of the mind to generalize ad infinitum1 when nothing in the nature of limitation or opposition offers itself to the imagination2 and by our involuntary application of the law of continuity to fill up1 by the same ideal substance of truth1 every interval which uncontradicted experience may have left blank in our inductive conclusion4 7p4 #bjg47 ,now here we have two rival explanations of the same thing1--the conviction of the universality of geometrical truths4 ,the one explanation is1 that this universality is imposed upon such truths by their involving a certain element1 derived from the universal mode of activity of the mind when apprehending such truths1 which element ,i have termed an ,idea4 ,the other explanation is1 that this universality arises from the inductive propensity--from the irresistible impulse to generalize ad infinitum--from the involuntary application of the law of continuity--from the filling up all intervals with the same ideal substance of truth4 ,with regard to these two explanations1 ,i may observe1 that so far as they are thus stated they do not necessarily differ4 ,they both agree in expressing this2 that the ground of the universality of geometrical truths is a certain law of the mind's activity1 which determines its procedure when it is concerned in apprehending the external world4 ,one explanation says1 that we impress upon the external world the relations of our ideas1 and thus believe more than we see1--the other says1 that we have an irresistible impulse to introduce into our conviction a relation between what we do observe and what we do not1 namely1 to generalize ad infinitum from what we do see4 ,one explanation says1 that we perceive all external objects as included in absolute ideal space1--the other1 that we fill up the intervals of the objects which we perceive with the same ideal substance of truth4 ,both sets of expressions may perhaps be admissible2 and if admitted1 may be understood as expressing the same opinions1 or opinions which have much in common4 ,the ,author's expressions have the advantage1 which ought to belong to them1 as the expressions employed in a systematic work1 of being fixed expressions1 technical phrases1 intentionally selected1 uniformly and steadily employed whenever the occasion recurs4 ,the ,reviewer's expressions are more lively and figurative1 and such as well become an occasional composition2 but hardly such as could be systematically applied to the subject in a regular treatise4 ,we could not1 as a standard and technical phrase1 talk of filling up the intervals of observation with the same ideal substance of truth2 and the inevitable impulse to generalize would hardly sufficiently express that we generalize according to a certain idea1 namely1 the idea of space4 ,perhaps that which is suggested to us as the common import of the two sets of expressions may be conveyed by some other phrase1 in a manner free from the objections which lie against both the ,author's and the ,critic's terms4 ,perhaps the mental idea governing our experience1 and the irresistible impulse to generalize our observation1 may both be superseded by our speaking of a law of the mind's activity1 which is really implied in both4 ,there operates1 in observing the external world1 a law of the mind's activity1 by which it connects its observations2 and this law of the mind's activity may be spoken of either as the idea of space1 or as the irresistible impulse to generalize the relations of space which it observes4 ,and this expression--the laws of the mind's activity--thus opposed to that merely passive function by which the mind receives the impressions of sense1 may be applied to other ideas as well as to the idea of space1 and to the impulse to generalize in other truths as well as those of geometry4 ,so far1 it would seem1 that the ,author and the ,critic may be brought into much nearer agreement than at first seemed likely1 with regard to the grounds of the necessity and universality in our knowledge4 ,but even if we adopt this conciliatory suggestion1 and speak of the necessity and universality of certain truths as arising from the laws of the mind's activity1 we cannot1 without producing great confusion1 allow ourselves to say1 as the ,critic says1 that these truths are thus derived from experience1 or from observation4 ,it will1 ,i say1 be found fatal to all philosophical precision of thought and language1 to say that the fundamental truths of geometry1 the axioms1 with the conviction of their necessary truth1 are derived from experience4 ,let us take any axiomatic truth of geometry1 and ask ourselves if this is not so4 ,it is1 for example1 an axiom in geometry that if a straight line cut one of two parallel straight lines1 it must cut the other also4 ,is this truth derived or derivable from observation of actual parallel lines1 and a line cutting them1 exhibited to our senses8 ,let those who say that we do acquire this truth by observation1 imagine to themselves the mode in which the observation must be made4 ,we have before us two parallel straight lines1 and we see that a straight line which cuts the one cuts the other also4 ,we see this again in another case1 it may be the angles and the distances being different1 and in a third1 and in a fourth2 and so on2 and generalizing1 we are irresistibly led to believe the assertion to be universally true4 ,but can any one really imagine this to be the mode in which we arrive at this truth8 ,we see1 says this explanation1 two parallel straight lines1 cut by a third4 ,but how do we know that the observed lines are parallel8 ,if we apply any test of parallelism1 we must assume some property of parallels1 and thus involve some axiom on the subject1 which we have no more right to assume than the one now under consideration4 ,we should thus destroy our explanation as an account of the mode of arriving at independent geometrical axioms4 ,but probably those who would give such an explanation would not do this4 ,they would not suppose that in observing this property of parallels we try by measurement whether the lines are parallel4 ,they would say1 ,i conceive1 that we suppose lines to be parallel1 and that then we see that the straight line which cuts the one must cut the other4 ,that when we make this supposition1 we are persuaded of the truth of the conclusion1 is certain4 ,but what ,i have to remark is1 that this being so1 the conclusion is the result1 not of observation1 but of the hypothesis4 ,the geometrical truth here spoken of1 after this admission1 no longer flows from experience1 but from supposition4 ,it is not that we ascertain the lines to be parallel1 and then find that they have this property3 but we suppose the lines to be parallel1 and therefore they have this property4 ,this is not a truth of experience4 ,this1 it may be said1 is so evident that it cannot have been overlooked by a very acute reasoner1 such as you describe your ,critic to be4 ,what1 it may be asked1 is the answer which he gives to so palpable an objection as this8 ,how does he understand his assertion that we learn the truth of geometrical axioms from experience 7p4 #bjh71 so as to make it tenable on his own principles8 ,what account does he give of the origin of such axioms which makes them in any sense to be derived from experience8 ,in justice to the ,reviewer's fairness 7which is unimpeachable throughout his argumentation7 it must be stated that he does give an account in which he professes to show how this is done4 ,and the main step of his explanation consists in introducing the conception of direction1 and unity of direction4 ,he says 7p4 #bjh71 ,the unity of direction1 or that we cannot march from a given point by more than one path direct to the same object1 is a matter of practical experience1 long before it can by possibility become matter of abstract thought4 ,we might ask here1 as in the former case1 how this can be a matter of experience1 except we have some independent test of directness8 and we might demand to know what this test is4 ,or do we not rather1 here as in the other case1 suppose the directness of the path2 and is not the singleness of the direct path a consequence1 not of its observed form1 but of its hypothetical directness2 and thus by no means a result of experience8 ,but we may put our remark upon this deduction of the geometrical axiom in another form4 ,we generalize1 it is said1 the observations which we have made ever since we were born4 ,but this term generalize is far too vague to pass for an explanation1 without being itself explained4 ,we are impelled to believe that to be true in general which we see to be true in particular4 ,but how do we see any truth8 ,how do we pick out any proposition with respect to a diagram which we see before us8 ,we see in particular1 and state in general1 some truth respecting straight lines1 or parallel lines1 or concerning direction4 ,but where do we find the conception of straightness1 or parallelism1 or direction8 ,these conceptions are not upon the surface of things4 ,the child does not1 from his birth1 see straightness and parallelism so as to know that he sees them4 ,how then does his experience bear upon a proposition in which these conceptions are involved8 ,it is said that it is a matter of experience long before it is a matter of abstract thought4 ,but how can there be any experience by which we learn these properties of a straight line1 till our thoughts are at least so abstract as to conceive what straightness is8 ,if it be said that this conception grows with our experience1 and is gradually unfolded with our unfolding materials of knowledge1 so as to give import and significance to them3 ,i need make no objection to such a statement1 except this--that this power of unfolding out of the mind conceptions which give meaning to our experience1 is something in addition to the mere employment of our senses upon the external world4 ,it is what ,i have called the ideal part of our knowledge4 ,it implies1 not only an impulse to generalize from experience1 but also an impulse to form conceptions by which generalization is possible4 ,it requires1 not only that nothing should oppose the tendency1 but that the direction in which the tendency is to operate should be determined by the laws of the mind's activity2 by an internal1 not by an external agency4 ,one main ground on which the ,reviewer is disposed to quarrel with and reject several of the expressions used in the ,philosophy2--such as that space is an idea1 a form of our perception1 and the like1--is this2 that such expressions appear to deprive the external world of its reality2 to make it1 or at least most of its properties1 a creation of the observing mind4 ,he quotes the following argument which is urged in the ,philosophy1 in order to prove that space is not a notion obtained from experience3 ,experience gives us information concerning things without us1 but our apprehending them as without us takes for granted their existence in space4 ,experience acquaints us with the form1 position1 magnitude1 c4 of particular objects1 but that they have form1 position1 magnitude1 pre-supposes that they are in space4 ,from this statement he altogether dissents4 ,no1 says he1 the reason why we apprehend things as without us is that they are without us4 ,we take for granted that they exist in space1 because they do so exist1 and because such their existence is a matter of direct perception1 which can neither be explained in words nor contravened in imagination3 because1 in short1 space is a reality1 and not a mere matter of convention or imagination4 ,now1 if by calling space an idea1 we suggest any doubt of its reality and of the reality of the external world1 we certainly run the risk of misleading our readers2 for the external world is real if anything be real3 the bodies which exist in space are things1 if things are anywhere to be found4 ,that bodies do exist in space1 and that that is the reason why we apprehend them as existing in space1 ,i readily grant4 ,but ,i conceive that the term ,idea ought not to suggest any such doubt of the reality of the knowledge in which it is involved4 ,ideas are always1 in our knowledge1 conjoined with facts4 ,our real knowledge is knowledge1 because it involves ideas1 real1 because it involves facts4 ,we apprehend things as existing in space because they do so exist3 and our idea of space enables us so to observe them1 and so to conceive them4 ,but we want1 further1 a reason why1 apprehending them as they are1 we also apprehend1 that in certain relations they could not be otherwise 7that two straight linear objects could not inclose a space1 for instance74 ,this circumstance is no way accounted for by saying that we apprehend them as they are2 and is1 ,i presume to say1 inexplicable1 except by supposing that it arises from some property of the observing mind3--an ,idea1 as ,i have termed it1--an irresistible ,impulse to generalize1 as the ,reviewer expresses it4 ,or1 as ,i have suggested1 we may adopt a third phrase1 a ,law of the mind's activity3 and in order that no question may remain1 whether we ascribe reality to the objects and relations which we observe1 we may describe it as a ,law of the mind's activity in apprehending what is4 ,and thus the real existence of the object1 and the ideal element which our apprehension of it introduces1 would both be clearly asserted4 ,i am ready to use expressions which recognize the reality of space and other external things more emphatically than those expressions which ,i have employed in the ,philosophy1 if expressions can be found which1 while they do this1 enable us to explain the possibility of knowledge1 and to analyze the structure of truth4 ,it is1 indeed1 extremely difficult to find1 in speaking of this subject1 expressions which are satisfactory4 ,the reality of the objects which we perceive is a profound1 apparently an insoluble problem#ceb4 ,we cannot but suppose that existence is something different from our knowledge of existence3--that which exists1 does not exist merely in our knowing that it does3--truth is truth whether we know it or not4 ,yet how can we conceive truth1 otherwise than as something known8 ,how can we conceive things as existing1 without conceiving them as objects of perception8 ,ideas and ,things are constantly opposed1 yet necessarily co-existent4 ,how they are thus opposite and yet identical1 is the ultimate problem of all philosophy4 ,the successive phases of philosophy have consisted in separating and again uniting these two opposite elements2 in dwelling sometimes upon the one and sometimes upon the other1 as the principal or original or only element2 and then in discovering that such an account of the state of the case was insufficient4 ,knowledge requires ideas4 ,reality requires things4 ,ideas and things co-exist4 ,truth is1 and is known4 ,but the complete explanation of these points appears to be beyond our reach4 ,at least it is not necessary for the purposes of our philosophy4 ,the separation of ideas and sensations in order to discover the conditions of knowledge is our main task4 ,how ideas and sensations are united so as to form things1 does not so immediately concern us4 ,i have stated that we may1 without giving up any material portion of the ,philosophy of ,science to which ,i have been led1 express the conclusions in other phraseology2 and that instead of saying that all our knowledge involves certain ,fundamental ,ideas1 the sources from which all universal truth is derived1 we may say that there are certain ,laws of ,mental ,activity according to which alone all the real relations of things are apprehended4 ,if this alteration in the phraseology will make the doctrines more generally intelligible or acceptable1 there is no reason why it should not be adopted4 ,but ,i may remark1 that a main purpose of the ,philosophy was not merely to prove that there are such ,fundamental ,ideas or ,laws of mental activity1 but to enumerate those of them which are involved in the existing sciences2 and to state the fundamental truths to which the fundamental ideas lead4 ,this was the task which was attempted2 and if this have been executed with any tolerable success1 it may perhaps be received as a contribution to the philosophy of science1 of which the value is not small1 in whatever terms it be expressed4 ,and this enumeration of fundamental ideas1 and of truths derived from them1 must have something to correspond to it1 in any other mode of expressing that view of the nature of knowledge which we are led to adopt4 ,if instead of ,fundamental ,ideas1 we speak of ,impulses of generalization1 or of ,laws of mental activity1 we must still distinguish such ,impulses1 or such ,laws1 according to the distinctions of ideas to which the survey of science led us4 ,we shall thus have a series of groups of ,laws1 or of classes of generalizing ,impulses1 corresponding to the series of ,fundamental ,ideas already given4 ,if we employ the language of the ,reviewer1 we shall have one generalizing ,impulse which suggests relations of ,space2 another which directs us to properties of ,numbers2 another which deals with ,time2 another with ,cause3 another which groups objects according to ,likeness2 another which suggests a purpose as a necessary relation among them2 to which may be added1 even while we confine ourselves to the physical sciences1 several others1 as may be seen in the ,philosophy4 ,now when the fundamental conditions and elements of truth are thus arranged into groups1 it is not a matter of so much consequence to decide whether each group shall be said to be bound together by an idea or by an impulse of generalization2 as it is to see that1 if this happen in virtue of ideas1 here are so many distinct ideas which enter into the structure of science1 and give universality to its matter2 and again1 if this happen in virtue of an irresistible impulse of generalization in each case1 we have so many different kinds of impulses of generalization4 ,the main purpose in the ,philosophy was to analyze scientific truth into its conditions and elements2 and ,i did not content myself with saying that those elements are ,sensations and ,ideas2 the ,ideas being that element which makes universal knowledge conceivable and possible4 ,i went further3 ,i enumerated the ,ideas which thus enter into science4 ,i showed that in the sciences which ,i passed in review1 the most acute and profound inquirers had taken for granted that certain truths in each science are of universal and necessary validity1 and ,i endeavoured to select the idea in which this universality and necessity resided1 and to separate it from all other ideas involved in other sciences4 ,if therefore it be thought better to say that those principles in each science upon which1 as upon the axioms in geometry1 the universality and necessity of scientific truth depends1 are arrived at1 not by ideas1 but by an irresistible impulse of generalization1 those who employ such phraseology1 if they make a classification of such impulses corresponding to my classification of ideas1 will still adopt the greater part of my philosophy1 altering only the phraseology4 ,or if1 as ,i suggested1 instead of ,fundamental ,ideas1 we use the phrase ,laws of ,mental ,activity1 then our primary intellectual ,code--the ,constitution of our minds1 as it may be termed--will consist of a ,body of ,laws of which the ,titles correspond with the ,fundamental ,ideas of the ,philosophy4 ,my object was1 from the writings of the most sagacious and profound philosophers who have laboured on each science1 to extract such a code1 such a constitution4 ,if ,i have in any degree succeeded in this1 the result must have a reality and a value independently of all forms of expression4 ,still ,i do not think that any language can ever serve for such legislation1 in which the two elements of truth are not distinguished4 ,even if we adopt the phraseology which ,i have just employed1 we shall have to recollect that ,law and ,fact must be kept distinct1 and that the ,constitution has its ,principles as well as its ,history4 ,but ,i will not longer detain you by seeking other modes of expressing the ,fundamental ,antithesis to which the accompanying ,memoir refers4 ,the ,remarks which ,i here send you were written three years ago1 on the appearance of the ,review which ,i have quoted4 ,if ,i succeed in obtaining for them a few minutes' attention from you and a few other friends1 ,i shall be glad that they have been preserved4 ,i am1 my dear ,herschel1 always truly yours1 ,w4 ,,whewell4 ,p4,s4 ,i have abstained from sending you a large portion of my ,remarks as originally written4 ,i had gone on to show that1 in my ,philosophy1 ,i had not only enumerated and analyzed a great number of different ,fundamental ,ideas which belong to the different existing sciences1 but that ,i had also shown in what manner these ideas enter into their respective sciences2 namely1 by the statement or use of ,axioms1 which involve the ideas1 and which form the basis of each science when systematically exhibited4 ,a number of these ,axioms belonging to most of the physical sciences1 are stated in the ,philosophy4 ,i might have added also that ,i have attempted to classify the historical steps by which such ,axioms are brought into view and applied4 ,but it is not necessary to dwell upon these points1 in order to illustrate the difference and the agreement between the ,reviewer and me4 ,sir ,john ,f4 ,w4 ,herschel1 ,bart4 c4 ,,appendix ,g4 ,,on ,,the ,,transformation ,,of ,,hypotheses ,,in ,,the ,,history ,,of ,,science4 7,cam4 ,phil4 ,soc4 ,,may #ai1 #ahea47 #a4 ,the history of science suggests the reflection that it is very difficult for the same person at the same time to do justice to two conflicting theories4 ,take for example the ,cartesian hypothesis of vortices and the ,newtonian doctrine of universal gravitation4 ,the adherents of the earlier opinion resisted the evidence of the ,newtonian theory with a degree of obstinacy and captiousness which now appears to us quite marvellous3 while on the other hand1 since the complete triumph of the ,newtonians1 they have been unwilling to allow any merit at all to the doctrine of vortices4 ,it cannot but seem strange1 to a calm observer of such changes1 that in a matter which depends upon mathematical proofs1 the whole body of the mathematical world should pass over1 as in this and similar cases they seem to have done1 from an opinion confidently held1 to its opposite4 ,no doubt this must be1 in part1 ascribed to the lasting effects of education and early prejudice4 ,the old opinion passes away with the old generation3 the new theory grows to its full vigour when its congenital disciples grow to be masters4 ,john ,bernoulli continues a ,cartesian to the last2 ,daniel1 his son1 is a ,newtonian from the first4 ,newton's doctrines are adopted at once in ,england1 for they are the solution of a problem at which his contemporaries have been labouring for years4 ,they find no adherents in ,france1 where ,descartes is supposed to have already explained the constitution of the world2 and ,fontenelle1 the secretary of the ,academy of ,sciences at ,paris1 dies a ,cartesian seventy years after the publication of ,newton's ,principia4 ,this is1 no doubt1 a part of the explanation of the pertinacity with which opinions are held1 both before and after a scientific revolution3 but this is not the whole1 nor perhaps the most instructive aspect of the subject4 ,there is another feature in the change1 which explains1 in some degree1 how it is possible that1 in subjects1 mainly at least mathematical1 and therefore claiming demonstrative evidence1 mathematicians should hold different and even opposite opinions4 ,and the object of the present paper is to point out this feature in the successions of theories1 and to illustrate it by some prominent examples drawn from the history of science4 #b4 ,the feature to which ,i refer is this2 that when a prevalent theory is found to be untenable1 and consequently1 is succeeded by a different1 or even by an opposite one1 the change is not made suddenly1 or completed at once1 at least in the minds of the most tenacious adherents of the earlier doctrine2 but is effected by a transformation1 or series of transformations1 of the earlier hypothesis1 by means of which it is gradually brought nearer and nearer to the second2 and thus1 the defenders of the ancient doctrine are able to go on as if still asserting their first opinions1 and to continue to press their points of advantage1 if they have any1 against the new theory4 ,they borrow1 or imitate1 and in some way accommodate to their original hypothesis1 the new explanations which the new theory gives1 of the observed facts2 and thus they maintain a sort of verbal consistency2 till the original hypothesis becomes inextricably confused1 or breaks down under the weight of the auxiliary hypotheses thus fastened upon it1 in order to make it consistent with the facts4 ,this often-occurring course of events might be illustrated from the history of the astronomical theory of epicycles and eccentrics1 as is well known4 ,but my present purpose is to give one or two brief illustrations of a somewhat similar tendency from other parts of scientific history2 and in the first place1 from that part which has already been referred to1 the battle of the ,cartesian and ,newtonian systems4 #c4 ,the part of the ,cartesian system of vortices which is most familiarly known to general readers is the explanation of the motions of the planets by supposing them carried round the sun by a kind of whirlpool of fluid matter in which they are immersed3 and the explanation of the motions of the satellites round their primaries by similar subordinate whirlpools1 turning round the primary1 and carried1 along with it1 by the primary vortex4 ,but it should be borne in mind that a part of the ,cartesian hypothesis which was considered quite as important as the cosmical explanation1 was the explanation which it was held to afford of terrestrial gravity4 ,terrestrial gravity was asserted to arise from the motion of the vortex of subtle matter which revolved round the earth's axis and filled the surrounding space4 ,it was maintained that by the rotation of such a vortex1 the particles of the subtle matter would exert a centrifugal force1 and by virtue of that force1 tend to recede from the center3 and it was held that all bodies which were near the earth1 and therefore immersed in the vortex1 would be pressed towards the center by the effort of the subtle matter to recede from the center#cec4 ,these two assumed effects of the ,cartesian vortices--to carry bodies in their stream1 as straws are carried round by a whirlpool1 and to press bodies to the center by the centrifugal effort of the whirling matter--must be considered separately1 because they were modified separately1 as the progress of discussion drove the ,cartesians from point to point4 ,the former effect indeed1 the dragging force of the vortex1 as we may call it1 would not bear working out on mechanical principles at all2 for as soon as the law of motion was acknowledged 7which ,descartes himself was one of the loudest in proclaiming71 that a body in motion keeps all the motion which it has1 and receives in addition all that is impressed upon it2 as soon1 in short1 as philosophers rejected the notion of an inertness in matter which constantly retards its movements1--it was plain that a planet perpetually dragged onwards in its orbit by a fluid moving quicker than itself1 must be perpetually accelerated2 and therefore could not follow those constantly-recurring cycles of quicker and slower motion which the planets exhibit to us4 ,the ,cartesian mathematicians1 then1 left untouched the calculation of the progressive motion of the planets2 and1 clinging to the assumption that a vortex would produce a tendency of bodies to the center1 made various successive efforts to construct their vortices in such a manner that the centripetal forces produced by them should coincide with those which the phenomena required1 and therefore of course1 in the end1 with those which the ,newtonian theory asserted4 ,in truth1 the ,cartesian vortex was a bad piece of machinery for producing a central force3 from the first1 objections were made to the sufficiency of its mechanism1 and most of these objections were very unsatisfactorily answered1 even granting the additional machinery which its defenders demanded4 ,one formidable objection was soon started1 and continued to the last to be the torment of the ,cartesians4 ,if terrestrial gravity1 it was urged1 arise from the centrifugal force of a vortex which revolves about the earth's axis1 terrestrial gravity ought to act in planes perpendicular to the earth's axis1 instead of tending to the earth's center4 ,this objection was taken by ,james ,bernoulli#ced1 and by ,huyghens#cee not long after the publication of ,descartes's ,principia4 ,huyghens 7who adopted the theory of vortices with modifications of his own7 supposes that there are particles of the fluid matter which move about the earth in every possible direction1 within the spherical space which includes terrestrial objects2 and that the greater part of these motions being in spherical surfaces concentric with the earth1 produces a tendency towards the earth's center4 ,this was a procedure tolerably arbitrary1 but it was the best which could be done4 ,saurin1 a little later#cef1 gave nearly the same solution of this difficulty4 ,the solution1 identifying a vortex of some kind with a central force1 made the hypothesis of vortices applicable wherever central forces existed2 but then1 in return1 it deprived the image of a vortex of all that clearness and simplicity which had been its first great recommendation4 ,but still there remained difficulties not less formidable4 ,according to this explanation of gravity1 since the tendency of bodies to the earth's center arose from the superior centrifugal force of the whirling matter which pushed them inward as water pushes a light body upward1 bodies ought to tend more strongly to the center in proportion as they are less dense4 ,the rarest bodies should be the heaviest2 contrary to what we find4 ,descartes's original solution of this difficulty has a certain degree of ingenuity4 ,according to him 7,princip4 ,,iv4 #bc7 a terrestrial body consists of particles of the third element1 and the more it has of such particles1 the more it excludes the parts of the celestial matter1 from the revolution of which matter gravity arises2 and therefore the denser is the terrestrial body1 and the heavier it will be4 ,but though this might satisfy him1 it could not satisfy the mathematicians who followed him1 and tried to reduce his system to calculation on mechanical principles4 ,for how could they do this1 if the celestial matter1 by the operation of which the phenomena of force and motion were produced1 was so entirely different from ordinary matter1 which alone had supplied men with experimental illustrations of mechanical principles8 ,in order that the celestial matter1 by its whirling1 might produce the gravity of heavy bodies1 it was mechanically necessary that it must be very dense2 and dense in the ordinary sense of the term2 for it was by regarding density in the ordinary sense of the term that the mechanical necessity had been established4 ,the ,cartesians tried to escape this result 7,huyghens1 ,pesanteur1 p4 #afa1 and ,john ,bernoulli1 ,nouvelles ,penses1 ,art4 #ca7 by saying that there were two meanings of density and rarity2 that some fluids might be rare by having their particles far asunder1 others1 by having their particles very small though in contact4 ,but it is difficult to think that they could1 as persons well acquainted with mechanical principles1 satisfy themselves with this distinction2 for they could hardly fail to see that the mechanical effect of any portion of fluid depends upon the total mass moved1 not on the size of its particles4 ,attempts made to exemplify the vortices experimentally only showed more clearly the force of this difficulty4 ,huyghens had found that certain bodies immersed in a whirling fluid tended to the center of the vortex4 ,but when ,saulmon#ceg a little later made similar experiments1 he had the mortification of finding that the heaviest bodies had the greatest tendency to recede from the axis of the vortex4 ,the result is1 as the ,secretary of the ,academy 7,fontenelle7 says1 exactly the opposite of what we could have wished1 for the ,cartesian system of gravity3 but we are not to despair2 sometimes in such researches disappointment leads to ultimate success4 ,but1 passing by this difficulty1 and assuming that in some way or other a centripetal force arises from the centrifugal force of the vortex1 the ,cartesian mathematicians were naturally led to calculate the circumstances of the vortex on mechanical principles2 especially ,huyghens1 who had successfully studied the subject of centrifugal force4 ,accordingly1 in his little treatise on the ,cause of ,gravitation 7p4 #adc71 he calculates the velocity of the fluid matter of the vortex1 and finds that1 at a point in the equator1 it is #ag times the velocity of the earth's rotation4 ,it may naturally be asked1 how it comes to pass that a stream of fluid1 dense enough to produce the gravity of bodies by its centrifugal force1 moving with a velocity #ag times that of the earth 7and therefore moving round the earth in #he minutes71 does not sweep all terrestrial objects before it4 ,but to this ,huyghens had already replied 7p4 #acg71 that there are particles of the fluid moving in all directions1 and therefore that they neutralize each other's action1 so far as lateral motion is concerned4 ,and thus1 as early as this treatise of ,huyghens1 that is1 in three years from the publication of ,newton's ,principia1 a vortex is made to mean nothing more than some machinery or other for producing a central force4 ,and this is so much the case1 that ,huyghens commends 7p4 #afe71 as confirming his own calculation of the velocity of his vortex1 ,newton's proof that at the ,moon's orbit the centripetal force is equal to the centrifugal2 and that thus1 this force is less than the centripetal force at the earth's surface in the inverse proportion of the squares of the distances4 ,john ,bernoulli1 in the same manner1 but with far less clearness and less candour1 has treated the hypothesis of vortices as being principally a hypothetical cause of central force4 ,he had repeated occasions given him of propounding his inventions for propping up the ,cartesian doctrine1 by the subjects proposed for prizes by the ,paris ,academy of ,sciences2 in which competition ,cartesian speculations were favourably received4 ,thus the subject of the ,prize ,essays for #agcj was1 the explanation of the ,elliptical ,form of the planetary orbits and of the ,motion of their ,aphelia1 and the prize was assigned to ,john ,bernoulli1 who gave the explanation on ,cartesian principles4 ,he explains the elliptical figure1 not as ,descartes himself had done1 by supposing the vortex which carries the planet round the sun to be itself squeezed into an elliptical form by the pressure of contiguous vortices2 but he supposes the planet1 while it is carried round by the vortex1 to have a limited oscillatory motion to and from the center1 produced by its being originally1 not at the distance at which it would float in equilibrium in the vortex1 but above or below that point4 ,on this supposition1 the planet would oscillate to and from the center1 ,bernoulli says1 like the mercury when deranged in a barometer3 and it is evident that such an oscillation1 combined with a motion round the center1 might produce an oval curve1 either with a fixed or with a moveable aphelion4 ,all this however merely amounts to a possibility that the oval may be an ellipse1 not to a proof that it will be so2 nor does ,bernoulli advance further4 ,it was necessary that the vortices should be adjusted in such a manner as to account for ,kepler's laws2 and this was to be done by making the velocity of each stratum of the vortex depend in a suitable manner on its radius4 ,the ,abb de ,molires attempted this on the supposition of elliptical vortices1 but could not reconcile ,kepler's first two laws1 of equal elliptical areas in equal times1 with his third law1 that the squares of the periodic times are as the cubes of the mean distances#ceh4 ,bernoulli1 with his circular vortices1 could accommodate the velocities at different distances so that they should explain ,kepler's laws4 ,he pretended to prove that ,newton's investigations respecting vortices 7in the ninth ,section of the ,second ,book of the ,principia7 were mechanically erroneous2 and in truth1 it must be allowed that1 besides several arbitrary assumptions1 there are some errors of reasoning in them4 ,but for the most part1 the more enlightened ,cartesians were content to accept ,newton's account of the motions and forces of the solar system as part of their scheme2 and to say only that the hypothesis of vortices explained the origin of the ,newtonian forces2 and that thus theirs was a philosophy of a higher kind4 ,thus it is asserted 7,mm4 ,acad4 #agcd71 that ,m4 de ,molires retains the beautiful theory of ,newton entire1 only he renders it in a sort less ,newtonian1 by disentangling it from attraction1 and transferring it from a vacuum into a plenum4 ,this plenum1 though not its native region1 frees it from the need of attraction1 which is all the better for it4 ,these points were the main charms of the ,cartesian doctrine in the eyes of its followers2--the getting rid of attractions1 which were represented as a revival of the ,aristotelian occult qualities1 substantial forms1 or whatever else was the most disparaging way of describing the bad philosophy of the dark ages#cei2--;and the providing some material intermedium1 by means of which a body may affect another at a distance2 and thus avoid the reproach urged against the ,newtonians1 that they made a body act where it was not4 ,and we are the less called upon to deny that this last feature in the ,newtonian theory was a difficulty1 inasmuch as ,newton himself was never unwilling to allow that gravity might be merely an effect produced by some ulterior cause4 ,with such admissions on the two sides1 it is plain that the ,newtonian and ,cartesian systems would coincide1 if the hypothesis of vortices could be modified in such a way as to produce the force of gravitation4 ,all attempts to do this1 however1 failed3 and even ,john ,bernoulli1 the most obstinate of the mathematical champions of the vortices1 was obliged to give them up4 ,in his ,prize ,essay for #agcd1 7on the ,inclinations of the ,planetary ,orbits#cfj17 he says 7,art4 ,,viii471 ,the gravitation of the ,planets towards the center of the ,sun and the weight of bodies towards the center of the earth has not1 for its cause1 either the attraction of ,m4 ,newton1 or the centrifugal force of the matter of the vortex according to ,m4 ,descartes2 and he then goes on to assert that these forces are produced by a perpetual torrent of matter tending to the center on all sides1 and carrying all bodies with it4 ,such a hypothesis is very difficult to refute4 ,it has been taken up in more modern times by ,le ,sage#cfa1 with some modifications2 and may be made to account for the principal facts of the universal gravitation of matter4 ,the great difficulty in the way of such a hypothesis is1 the overwhelming thought of the whole universe filled with torrents of an invisible but material and tangible substance1 rushing in every direction in infinitely prolonged straight lines and with immense velocity4 ,whence can such matter come1 and whither can it go8 ,where can be its perpetual and infinitely distant fountain1 and where the ocean into which it pours itself when its infinite course is ended8 ,a revolving whirlpool is easily conceived and easily supplied2 but the central torrent of ,bernoulli1 the infinite streams of particles of ,le ,sage1 are an explanation far more inconceivable than the thing explained4 ,but however the hypothesis of vortices1 or some hypothesis substituted for it1 was adjusted to explain the facts of attraction to a center1 this was really nearly all that was meant by a vortex or a tourbillon1 when the system was applied4 ,thus in the case of the last act of homage to the ,cartesian theory which the ,french ,academy rendered in the distribution of its prizes1 the designation of a ,cartesian ,essay in #agda 7along with three ,newtonian ones7 as worthy of a prize for an explanation of the ,tides2 the difference of high and low water was not explained1 as ,descartes has explained it1 by the pressure1 on the ocean1 of the terrestrial vortex1 forced into a strait where it passes under the ,moon2 but the waters were supposed to rise towards the ,moon1 the terrestrial vortex being disturbed and broken by the ,moon1 and therefore less effective in forcing them down4 ,and in giving an account of a ,tourmaline from ,ceylon 7,acad4 ,sc4 #agag71 when it has been ascertained that it attracts and repels substances1 the writer adds1 as a matter of course1 ,it would seem that it has a vortex4 ,as another example1 the elasticity of a body was ascribed to vortices between its particles3 and in general1 as ,i have said1 a vortex implied what we now imply by speaking of a central force4 #d4 ,in the same manner vortices were ascribed to the ,magnet1 in order to account for its attractions and repulsions4 ,but we may note a circumstance which gave a special turn to the hypothesis of vortices as applied to this subject1 and which may serve as a further illustration of the manner in which a transition may be made from one to the other of two rival hypotheses4 ,if iron filings be brought near a magnet1 in such a manner as to be at liberty to assume the position which its polar action assigns to them2 7for instance1 by strewing them upon a sheet of paper while the two poles of the magnet are close below the paper27 they will arrange themselves in certain curves1 each proceeding from the ,n4 to the ,s4 pole of the magnet1 like the meridians in a map of the globe4 ,it is easily shown1 on the supposition of magnetic attraction and repulsion1 that these magnetic curves1 as they are termed1 are each a curve whose tangent at every point is the direction of a small line or particle1 as determined by the attraction and repulsion of the two poles4 ,but if we suppose a magnetic vortex constantly to flow out of one pole and into the other1 in streams which follow such curves1 it is evident that such a vortex1 being supposed to exercise material pressure and impulse1 would arrange the iron filings in corresponding streams1 and would thus produce the phenomenon which ,i have described4 ,and the hypothesis of central torrents of ,bernoulli or ,le ,sage which ,i have referred to1 would1 in its application to magnets1 really become this hypothesis of a magnetic vortex1 if we further suppose that the matter of the torrents which proceed to one pole and from the other1 mingles its streams1 so as at each point to produce a stream in the resulting direction4 ,of course we shall have to suppose two sets of magnetic torrents2--a boreal torrent1 proceeding to the north pole1 and from the south pole of a magnet2 and an austral torrent proceeding to the south and from the north pole3--and with these suppositions1 we make a transition from the hypothesis of attraction and repulsion1 to the ,cartesian hypothesis of vortices1 or at least1 torrents1 which determine bodies to their magnetic positions by impulse4 ,of course it is to be expected that1 in this as in the other case1 when we follow the hypothesis of impulse into detail1 it will need to be loaded with so many subsidiary hypotheses1 in order to accommodate it to the phenomena1 that it will no longer seem tenable4 ,but the plausibility of the hypothesis in its first application cannot be denied3--for1 it may be observed1 the two opposite streams would counteract each other so as to produce no local motion1 only direction4 ,and this case may put us on our guard against other suggestions of forces acting in curve lines1 which may at first sight appear to be discerned in magnetic and electric phenomena4 ,probably such curve lines will all be found to be only resulting lines1 arising from the direct action and combination of elementary attraction and repulsion4 #e4 ,there is another case in which it would not be difficult to devise a mode of transition from one to the other of two rival theories2 namely1 in the case of the emission theory and the undulation theory of ,light4 ,indeed several steps of such a transition have already appeared in the history of optical speculation2 and the conclusive objection to the emission theory of light1 as to the ,cartesian theory of vortices1 is1 that no amount of additional hypotheses will reconcile it to the phenomena4 ,its defenders had to go on adding one piece of machinery after another1 as new classes of facts came into view1 till it became more complex and unmechanical than the theory of epicycles and eccentrics at its worst period4 ,otherwise1 as ,i have said1 there was nothing to prevent the emission theory from migrating into the undulatory theory1 and as the theory of vortices did into the theory of attraction4 ,for the emissionists allow that rays may interfere2 and that these interferences may be modified by alternate fits in the rays2 now these fits are already a kind of undulation4 ,then again the phenomena of polarized light show that the fits or undulations must have a transverse character3 and there is no reason why emitted rays should not be subject to fits of transverse modification as well as to any other fits4 ,in short1 we may add to the emitted rays of the one theory1 all the properties which belong to the undulations of the other1 and thus account for all the phenomena on the emission theory2 with this limitation only1 that the emission will have no share in the explanation1 and the undulations will have the whole4 ,if1 instead of conceiving the universe full of a stationary ether1 we suppose it to be full of etherial particles moving in every direction2 and if we suppose1 in the one case and in the other1 this ether to be susceptible of undulations proceeding from every luminous point2 the results of the two hypotheses will be the same2 and all we shall have to say is1 that the supposition of the emissive motion of the particles is superfluous and useless4 #f4 ,this view of the manner in which rival theories pass into one another appears to be so unfamiliar to those who have only slightly attended to the history of science1 that ,i have thought it might be worth while to illustrate it by a few examples4 ,it might be said1 for instance1 by such persons#cfb1 ,either the planets are not moved by vortices1 or they do not move by the law by which heavy bodies fall4 ,it is impossible that both opinions can be true4 ,but it appears1 by what has been said above1 that the ,cartesians did hold both opinions to be true2 and one with just as much reason as the other1 on their assumptions4 ,it might be said in the same manner1 ,either it is false that the planets are made to describe their orbits by the above quasi-,cartesian theory of ,bernoulli1 or it is false that they obey the ,newtonian theory of gravitation4 ,but this would be said quite erroneously2 for if the hypothesis of ,bernoulli be true1 it is so because it agrees in its result with the theory of ,newton4 ,it is not only possible that both opinions may be true1 but it is certain that if the first be so1 the second is4 ,it might be said again1 ,either the planets describe their orbits by an inherent virtue1 or according to the ,newton theory4 ,but this again would be erroneous1 for the ,newtonian doctrine decided nothing as to whether the force of gravitation was inherent or not4 ,cotes held that it was1 though ,newton strongly protested against being supposed to hold such an opinion4 ,the word inherent is no part of the physical theory1 and will be asserted or denied according to our metaphysical views of the essential attributes of matter and force4 ,of course1 the possibility of two rival hypotheses being true1 one of which takes the explanation a step higher than the other1 is not affected by the impossibility of two contradictory assertions of the same order of generality being both true4 ,if there be a new-discovered comet1 and if one astronomer asserts that it will return once in every twenty years1 and another1 that it will return once in every thirty years1 both cannot be right4 ,but if an astronomer says that though its interval was in the last instance #cj years1 it will only be #bj years to the next return1 in consequence of perturbation and resistance1 he may be perfectly right4 ,and thus1 when different and rival explanations of the same phenomena are held1 till one of them1 though long defended by ingenious men1 is at last driven out of the field by the pressure of facts1 the defeated hypothesis is transformed before it is extinguished4 ,before it has disappeared1 it has been modified so as to have all palpable falsities squeezed out of it1 and subsidiary provisions added1 in order to reconcile it with the phenomena4 ,it has1 in short1 been penetrated1 infiltrated1 and metamorphosed by the surrounding medium of truth1 before the merely arbitrary and erroneous residuum has been finally ejected out of the body of permanent and certain knowledge4 ,,footnotes3 ,footnote #ceb3 ,these remarks were written in #ahda4 ,the accompanying ,memoir contains a further discussion of this problem4 ,,appendix ,h4 ,,on ,,hegel',s ,,criticism ,,of ,,newton',s ,,principia4 7,cam4 ,phil4 ,soc4 ,,may #ba1 #ahdi47 ,the ,newtonian doctrine of universal gravitation1 as the cause of the motions which take place in the solar system1 is so entirely established in our minds1 and the fallacy of all the ordinary arguments against it is so clearly understood among us1 that it would undoubtedly be deemed a waste of time to argue such questions in this place1 so far as physical truth is concerned4 ,but since in other parts of ,europe1 there are teachers of philosophy whose reputation and influence are very great1 and who are sometimes referred to among our own countrymen as the authors of new and valuable views of truth1 and who yet reject the ,newtonian opinions1 and deny the validity of the proofs commonly given of them1 it may be worth while to attend for a few minutes to the declarations of such teachers1 as a feature in the present condition of ,european philosophy4 ,i the more readily assume that the ,cambridge ,philosophical ,society will not think a communication on such a subject devoid of interest1 in consequence of the favourable reception which it has given to philosophical speculations still more abstract1 which ,i have on previous occasions offered to it4 ,i will therefore proceed to make some remarks on the opinions concerning the ,newtonian doctrine of gravitation1 delivered by the celebrated ,hegel1 of ,berlin1 than whom no philosopher in modern1 and perhaps hardly any even in ancient times1 has had his teaching received with more reverential submission by his disciples1 or been followed by a more numerous and zealous band of scholars bent upon diffusing and applying his principles4 ,the passages to which ,i shall principally refer are taken from one of his works which is called the ,encyclopdia 7,encyklopdie71 of which the ,first ,part is the ,science of ,logic1 the ,second1 the ,philosophy of ,nature1 the ,third1 the ,philosophy of ,spirit4 ,the ,second ,part1 with which ,i am here concerned1 has for an aliter title1 ,lectures on ,natural ,philosophy 7,vorlesungen ber ,natur-philosophie71 and would through its whole extent offer abundant material for criticism1 by referring it to principles with which we are here familiar3 but ,i shall for the present confine myself to that part which refers to the subject which ,i have mentioned1 the ,newtonian ,doctrine of ,gravitation1 #bfi1 #bgj1 of the work4 ,nor shall ,i1 with regard to this part1 think it necessary to give a continuous and complete criticism of all the passages bearing upon the subject2 but only such specimens1 and such remarks thereon1 as may suffice to show in a general manner the value and the character of ,hegel's declarations on such questions4 ,i do not pretend to offer here any opinion upon the value and character of ,hegel's philosophy in general3 but ,i think it not unlikely that some impression on that head may be suggested by the examination1 here offered1 of some points in which we can have no doubt where the truth lies2 and ,i am not at all persuaded that a like examination of many other parts of the ,hegelian ,encyclopdia1 would not confirm the impression which we shall receive from the parts now to be considered4 ,hegel both criticises the ,newtonian doctrines1 or what he states as such2 and also1 not denying the truth of the laws of phenomena which he refers to1 for instance ,kepler's laws1 offers his own proof of these laws4 ,i shall make a few brief remarks on each of these portions of the pages before me4 ,and ,i would beg it to be understood that where ,i may happen to put my remarks in a short1 and what may seem a peremptory form1 ,i do so for the sake of saving time2 knowing that among us1 upon subjects so familiar1 a few words will suffice4 ,for the same reason1 ,i shall take passages from ,hegel1 not in the order in which they occur1 but in the order in which they best illustrate what ,i have to say4 ,i shall do ,hegel no injustice by this mode of proceeding3 for ,i will annex a faithful translation1 so far as ,i can make one1 of the whole of the passages referred to1 with the context4 ,no one will be surprised that a ,german1 or indeed any lover of science1 should speak with admiration of the discovery of ,kepler's laws1 as a great event in the history of ,astronomy1 and a glorious distinction to the discoverer4 ,but to say that the glory of the discovery of the proof of these laws has been unjustly transferred from ,kepler to ,newton1 is quite another matter4 ,this is what ,hegel says 7a7#cfc4 ,and we have to consider the reasons which he assigns for saying so4 ,he says 7b7 that it is allowed by mathematicians that the ,newtonian ,formula maybe derived from the ,keplerian laws1 and hence he seems to infer that the ,newtonian law is not an additional truth4 ,that is1 he does not allow that the discovery of the cause which produces a certain phenomenal law is anything additional to the discovery of the law itself4 ,the ,newtonian formula may be derived from the ,keplerian law4 ,it was professedly so derived2 but derived by introducing the ,idea of ,force1 which ,idea and its consequences were not introduced and developed till after ,kepler's time4 ,the ,newtonian formula may be derived from the ,keplerian law4 ,and the ,keplerian law may be derived1 and was derived1 from the observations of the ,greek astronomers and their successors2 but was not the less a new and great discovery on that account4 ,but let us see what he says further of this derivation of the ,newtonian formula from the ,keplerian ,law4 ,it is evident that by calling it a formula1 he means to imply1 what he also asserts1 that it is no new law1 but only a new form 7and a bad one7 of a previously known truth4 ,how is the ,newtonian formula1 that is1 the law of the inverse squares of the central force1 derived from the ,keplerian law of the cubes of the distances proportional to the squares of the times8 ,this1 says ,hegel1 is the immediate derivation4 7c74--,by ,kepler's law1 ,a being the distance and ,t the periodic time1 ,a#c_/,t#b is constant4 ,but ,newton calls ,a_/,t#b universal gravitation2 whence it easily follows that gravitation is inversely as ,a#b4 ,this is ,hegel's way of representing ,newton's proof4 ,reading it1 any one who had never read the ,principia might suppose that ,newton defined gravitation to be ,a_/,t#b4 ,we1 who have read the ,principia1 know that ,newton proves that in circles1 the central force 7not the universal gravitation7 is as ,a_/,t#b3 that he proves this1 by setting out from the idea of force1 as that which deflects a body from the tangent1 and makes it describe a curved line3 and that in this way1 he passes from ,kepler's laws of mere motion to his own law of ,force4 ,but ,hegel does not see any value in this4 ,such a mode of treating the subject he says 7i7 offers to us a tangled web1 formed of the ,lines of the mere geometrical construction1 to which a physical meaning of independent forces is given4 ,that a measure of forces is found in such lines as the sagitta of the arc described in a given time1 7not such a meaning arbitrarily given to them17 is certainly true1 and is very distinctly proved in ,newton1 and in all our elementary books4 ,but1 says ,hegel1 as further showing the artificial nature of the ,newtonian formul1 7h7 ,analysis has long been able to derive the ,newtonian expression and the laws therewith connected out of the ,form of the ,keplerian ,laws2 an assertion1 to verify which he refers to ,francur's ,mcanique4 ,this is apparently in order to show that the lines of the ,newtonian construction are superfluous4 ,we know very well that analysis does not always refer to visible representations of such lines3 but we know too1 7and ,francur would testify to this also17 that the analytical proofs contain equivalents to the ,newtonian lines4 ,we1 in this place1 are too familiar with the substitution of analytical for geometrical proofs1 to be led to suppose that such a substitution affects the substance of the truth proved4 ,the conversion of ,newton's geometrical proofs of his discoveries into analytical processes by succeeding writers1 has not made them cease to be discoveries3 and accordingly1 those who have taken the most prominent share in such a conversion1 have been the most ardent admirers of ,newton's genius and good fortune4 ,so much for ,newton's comparison of the ,forces in different circular orbits1 and for ,hegel's power of understanding and criticising it4 ,now let us look at the motion in different parts of the same elliptical orbit1 as a further illustration of the value of ,hegel's criticism4 ,in an elliptical orbit the velocity alternately increases and diminishes4 ,this follows necessarily from ,kepler's law of the equal description of the areas1 and so ,newton explains it4 ,hegel1 however1 treats of this acceleration and retardation as a separate fact1 and talks of another explanation of it1 founded upon ,centripetal and ,centrifugal ,force 7o74 ,where he finds this explanation1 ,i know not2 certainly not in ,newton1 who in the second and third section of the ,principia explains the variation of the velocity in a quite different manner1 as ,i have said2 and nowhere1 ,i think1 employs centrifugal force in his explanations4 ,however1 the notion of centrifugal as acting along with centripetal force is introduced in some treatises1 and may undoubtedly be used with perfect truth and propriety4 ,how far ,hegel can judge when it is so used1 we may see from what he says of the confusion produced by such an explanation1 which is1 he says1 a maximum4 ,in the first place1 he speaks of the motion being uniformly accelerated and retarded in an elliptical orbit1 which1 in any exact use of the word uniformly1 it is not4 ,but passing by this1 he proceeds to criticise an explanation1 not of the variable velocity of the body in its orbit1 but of the alternate access and recess of the body to and from the center4 ,let us overlook this confusion also1 and see what is the value of his criticism on the explanation4 ,he says 7p71 according to this explanation1 in the motion of a planet from the aphelion to the perihelion1 the centrifugal is less than the centripetal force2 and in the perihelion itself the centripetal force is supposed suddenly to become greater than the centrifugal2 and so1 of course1 the body re-ascends to the aphelion4 ,now ,i will not say that this explanation has never been given in a book professing to be scientific2 but ,i have never seen it given2 and it never can have been given but by a very ignorant and foolish person4 ,it goes upon the utterly unmechanical supposition that the approach of a body to the center at any moment depends solely upon the excess of the centripetal over the centrifugal force2 and reversely4 ,but the most elementary knowledge of mechanics shows us that when a body is moving obliquely to the distance from the center1 it approaches to or recedes from the center in virtue of this obliquity1 even if no force at all act4 ,and the total approach to the center is the approach due to this cause1 plus the approach due to the centripetal force1 minus the recess due to the centrifugal force4 ,at the aphelion1 the centripetal is greater than the centrifugal force2 and hence the motion becomes oblique2 and then1 the body approaches to the center on both accounts1 and approaches on account of the obliquity of the path even when the centrifugal has become greater than the centripetal force1 which it becomes before the body reaches the perihelion4 ,this reasoning is so elementary1 that when a person who cannot see this1 writes on the subject with an air of authority1 ,i do not see what can be done but to point out the oversight and leave it4 ,but there is1 says ,hegel 7q71 another way of explaining the motion by means of centripetal and centrifugal forces4 ,the two forces are supposed to increase and decrease gradually1 according to different laws4 ,in this case1 there must be a point where they are equal1 and in equilibrio2 and this being the case1 they will always continue equal1 for there will be no reason for their going out of equilibrium4 ,this1 which is put as another mode of explanation1 is1 in fact1 the same mode2 for1 as ,i have already said1 the centrifugal force1 which is less than the centripetal at the aphelion1 becomes the greater of the two before the perihelion2 and there is an intermediate position1 at which the two forces are equal4 ,but at this point1 is there no reason why1 being equal1 the forces should become unequal8 ,reason abundant3 for the body1 being there1 moves in a line oblique to the distance1 and so changes its distance2 and the centripetal and centrifugal force1 depending upon the distance by different laws1 they forthwith become unequal4 ,but these modes of explanation1 by means of the centripetal and centrifugal forces and their relation1 are not necessary to ,newton's doctrine1 and are nowhere used by ,newton2 and undoubtedly much confusion has been produced in other minds1 as well as ,hegel's1 by speaking of the centrifugal force1 which is a mere intrinsic geometrical result of a body's curvilinear motion round a center1 in conjunction with centripetal force1 which is an extrinsic force1 acting upon the body and urging it to the center4 ,neither ,newton1 nor any intelligent ,newtonian1 ever spoke of the centripetal and centrifugal force as two distinct forces both extrinsic to the motion1 which ,hegel accuses them of doing4 7n7 ,i have spoken of the third and second of ,kepler's laws2 of ,newton's explanations of them1 and of ,hegel's criticism4 ,let us now1 in the same manner1 consider the first law1 that the planets move in ellipses4 ,newton's proof that this was the result of a central force varying inversely as the square of the distance1 was the solution of a problem at which his contemporaries had laboured in vain1 and is commonly looked upon as an important step4 ,but1 says ,hegel1 7d7 the proof gives a conic section generally1 whereas the main point which ought to be proved is1 that the path of the body is an ellipse only1 not a circle or any other conic section4 ,certainly if ,newton had proved that a planet cannot move in a circle1 7which ,hegel says he ought to have done71 his system would have perplexed astronomers1 since there are planets which move in orbits hardly distinguishable from circles1 and the variation of the extremity from planet to planet shows that there is nothing to prevent the excentricity vanishing and the orbit becoming a circle4 ,but1 says ,hegel again1 7e7 the conditions which make the path to be an ellipse rather than any other conic section1 are empirical and extraneous2--the supposed casual strength of the impulsion originally received4 ,certainly the circumstances which determine the amount of excentricity of a planet's orbit are derived from experience1 or rather1 observation4 ,it is not a part of ,newton's system to determine priori what the excentricity of a planet's orbit must be4 ,a system that professes to do this will undoubtedly be one very different from his4 ,and as our knowledge of the excentricity is derived from observation1 it is1 in that sense1 empirical and casual4 ,the strength of the original impulsion is a hypothetical and impartial way of expressing this result of observation4 ,and as we see no reason why the excentricity should be of any certain magnitude1 we see none why the fraction which expresses the excentricity should not become as large as unity1 that is1 why the orbit should not become a parabola2 and accordingly1 some of the bodies which revolve about the same appear to move in orbits of this form3 so little is the motion in an ellipse1 as ,hegel says1 7f7 the only thing to be proved4 ,but ,hegel himself has offered proof of ,kepler's laws1 to which1 considering his objections to ,newton's proofs1 we cannot help turning with some curiosity4 ,and first1 let us look at the proof of the ,proposition which we have been considering1 that the path of a planet is necessarily an ellipse4 ,i will translate ,hegel's language as well as ,i can2 but without answering for the correctness of my translation1 since it does not appear to me to conform to the first condition of translation1 of being intelligible4 ,the translation however1 such as it is1 may help us to form some opinion of the validity and value of ,hegel's proofs as compared with ,newton's4 7r7 ,for absolutely uniform motion1 the circle is the only path4444 ,the circle is the line returning into itself in which all the radii are equal2 there is1 for it1 only one determining quantity1 the radius4 ,but in free motion1 the determination according to space and to time come into view with differences4 ,there must be a difference in the spatial aspect in itself1 and therefore the form requires two determining quantities4 ,hence the form of the path returning into itself is an ellipse4 ,now even if we could regard this as reasoning1 the conclusion does not in the smallest degree follow4 ,a curve returning into itself and determined by two quantities1 may have innumerable forms besides the ellipse2 for instance1 any oval form whatever1 besides that of the conic section4 ,but why must the curve be a curve returning into itself8 ,hegel has professed to prove this previously 7m7 from the determination of particularity and individuality of the bodies in general1 so that they have partly a center in themselves1 and partly at the same time their center in another4 ,without seeking to find any precise meaning in this1 we may ask whether it proves the impossibility of the orbits with moveable apses1 7which do not return into themselves17 such as the planets 7affected by perturbations7 really do describe1 and such as we know that bodies must describe in all cases1 except when the force varies exactly as the square of the distance8 ,it appears to do so3 and it proves this impossibility of known facts at least as much as it proves anything4 ,let us now look at ,hegel's proof of ,kepler's second law1 that the elliptical sectors swept by the radius vector are proportional to the time4 ,it is this3 7s74 ,in the circle1 the arc or angle which is included by the two radii is independent of them4 ,but in the motion of a planet as determined by the conception1 the distance from the center and the arc run over in a certain time must be compounded in one determination1 and must make out a whole4 ,this whole is the sector1 a space of two dimensions4 ,and hence the arc is essentially a ,function of the radius vector2 and the former 7the arc7 being unequal1 brings with it the inequality of the radii4 ,as was said in the former case1 if we could regard this as reasoning1 it would not prove the conclusion1 but only1 that the arc is some function or other of the radii4 ,hegel indeed offers 7t7 a reason why there must be an arc involved4 ,this arises1 he says1 from the determinateness of the nature of motion1 at one while as time in the root1 at another while as space in the square4 ,but here the quadratic character of the space is1 by the returning of the line of motion into itself1 limited to a sector4 ,probably my readers have had a sufficient specimen of ,hegel's mode of dealing with these matters4 ,i will however add his proof of ,kepler's third law1 that the cubes of the distances are as the squares of the times4 ,hegel's proof in this case 7u7 has a reference to a previous doctrine concerning falling bodies1 in which time and space have1 he says1 a relation to each other as root and square4 ,falling bodies however are the case of only half-free motion1 and the determination is incomplete4 ,but in the case of absolute motion1 the domain of free masses1 the determination attains its totality4 ,the time as the root is a mere empirical magnitude3 but as a component of the developed ,totality1 it is a ,totality in itself3 it produces itself1 and therein has a reference to itself4 ,and in this process1 ,time1 being itself the dimensionless element1 only comes to a formal identity with itself and reaches the square3 ,space1 on the other hand1 as a positive external relation1 comes to the full dimensions of the conception of space1 that is1 the cube4 ,the ,realization of the two conceptions 7space and time7 preserves their original difference4 ,this is the third ,keplerian law1 the relation of the ,cubes of the distances to the squares of the times4 ,and this1 he adds1 7v7 with remarkable complacency1 represents simply and immediately the reason of the thing3--while on the contrary1 the ,newtonian ,formula1 by means of which the ,law is changed into a ,law for the ,force of ,gravity1 shows the distortion and inversion of ,reflexion1 which stops half-way4 ,i am not able to assign any precise meaning to the ,reflexion1 which is here used as a term of condemnation1 applicable especially to the ,newtonian doctrine4 ,it is repeatedly applied in the same manner by ,hegel4 ,thus he says1 7g7 that what ,kepler expresses in a simple and sublime manner in the form of ,laws of the ,celestial ,motions1 ,newton has metamorphosed into the ,reflexion-,form of the ,force of ,gravitation4 ,though ,hegel thus denies ,newton all merit with regard to the explanation of ,kepler's laws by means of the gravitation of the planets to the sun1 he allows that to the ,keplerian ,laws ,newton added the ,principle of ,perturbations 7k74 ,this ,principle he accepts to a certain extent1 transforming the expression of it after his peculiar fashion4 ,it lies1 he says1 7l7 in this3 that matter in general assigns a center for itself3 the collective bodies of the system recognise a reference to their sun1 and all the individual bodies1 according to the relative positions into which they are brought by their motions1 form a momentary relation of their gravity towards each other4 ,this must appear to us a very loose and insufficient way of stating the ,principle of ,perturbations1 but loose as it is1 it recognises that the ,perturbations depend upon the gravity of the planets one to another1 and to the sun4 ,and if the ,perturbations depend upon these forces1 one can hardly suppose that any one who allows this will deny that the primary undisturbed motions depend upon these forces1 and must be explained by means of them2 yet this is what ,hegel denies4 ,it is evident1 on looking at ,hegel's mode of reasoning on such subjects1 that his views approach towards those of ,aristotle and the ,aristotelians2 according to which motions were divided into natural and unnatural2--the celestial motions were circular and uniform in their nature2--and the like4 ,perhaps it may be worth while to show how completely ,hegel adheres to these ancient views1 by an extract from the additions to the ,articles on ,celestial ,motions1 made in the last edition of the ,encyclopdia4 ,he says 7w71 ,the motion of the heavenly bodies is not a being pulled this way and that1 as is imagined 7by the ,newtonians74 ,they go along1 as the ancients said1 like blessed gods4 ,the celestial conformity is not such a one as has the principle of rest or motion external to itself4 ,it is not right to say because a stone is inert1 and the whole earth consists of stones1 and the other heavenly bodies are of the same nature as the earth1 therefore the heavenly bodies are inert4 ,this conclusion makes the properties of the whole the same as those of the part4 ,impulse1 ,pressure1 ,resistance1 ,friction1 ,pulling1 and the like1 are valid only for other than celestial matter4 ,there can be no doubt that this is a very different doctrine from that of ,newton4 ,i will only add to these specimens of ,hegel's physics1 a specimen of the logic by which he refutes the ,newtonian argument which has just been adduced2 namely1 that the celestial bodies are matter1 and that matter1 as we see in terrestrial matter1 is inert4 ,he says 7x71 ,doubtless both are matter1 as a good thought and a bad thought are both thoughts2 but the bad one is not therefore good1 because it is a thought4 ,,appendix ,,to ,,the ,,memoir ,,on ,,hegel',s ,,criticism ,,of ,,newton',s ,,principia4 ,,hegel4 ,encyclopdia 7#bnd ,ed4 #ahbg71 ,part ,,xi4 p4 #bej4 ,c4 ,absolute ,mechanics4 #bfi4 ,gravitation is the true and determinate conception of material ,corporeity1 which 7,conception7 is realized to the ,idea 7zur ,idee74 ,general ,corporeity is separable essentially into particular ,bodies1 and connects itself with the ,element of ,individuality or subjectivity1 as apparent 7phenomenal7 presence in the ,motion1 which by this means is immediately a system of several ,bodies4 ,universal gravitation must1 as to itself1 be recognised as a profound thought1 although it was principally as apprehended in the sphere of ,reflexion that it eminently attracted notice and confidence on account of the quantitative determinations therewith connected1 and was supposed to find its confirmation in ,experiments 7,erfahrung7 pursued from the ,solar ,system down to the phenomena of ,capillary ,tubes4--,but ,gravitation contradicts immediately the ,law of ,inertia1 for in virtue of it 7,gravitation7 matter tends out of itself to the other 7matter74--,in the ,conception of ,weight1 there are1 as has been shown1 involved the two elements--,self-existence1 and ,continuity1 which takes away self-existence4 ,these elements of the ,conception1 however1 experience a fate1 as particular forces1 corresponding to ,attractive and ,repulsive ,force1 and are thereby apprehended in nearer determination1 as ,centripetal and ,centrifugal ,force1 which 7,forces7 like weight1 act upon ,bodies1 independent of each other1 and are supposed to come in contact accidentally in a third thing1 ,body4 ,by this means1 what there is of profound in the thought of universal weight is again reduced to nothing2 and ,conception and ,reason cannot make their way into the doctrine of absolute motion1 so long as the so highly-prized discoveries of ,forces are dominant there4 ,in the conclusion which contains the ,idea of ,weight1 namely1 contains this ,idea as the ,conception which1 in the case of motion1 enters into external ,reality through the particularity of the ,bodies1 and at the same time into this ,reality and into their ,ideality and self-regarding ,reflexion1 7,reflexion-in-sich71 the rational identity and inseparability of the elements is involved1 which at other times are represented as independent4 ,motion itself1 as such1 has only its meaning and existence in a system of several bodies1 and those1 such as stand in relation to each other according to different determinations4 #bgj4 ,as to what concerns bodies in which the conception of gravity 7weight7 is realized free by itself1 we say that they have for the determinations of their different nature the elements 7momente7 of their conception4 ,one conception of this kind is the universal center of the abstract reference of a body to itself4 ,opposite to this conception stands the immediate1 extrinsic1 centerless ,individuality1 appearing as ,corporeity similarly independent4 ,those ,bodies however which are particular1 which stand in the determination of extrinsic1 and at the same time of intrinsic relation1 are centers for themselves1 and also have a reference to the first as to their essential unity4 ,the ,planetary ,bodies1 as the immediately concrete1 are in their existence the most complete4 ,men are accustomed to take the ,sun as the most excellent1 inasmuch as the understanding prefers the abstract to the concrete1 and in like manner the fixed stars are esteemed higher than the ,bodies of the ,solar ,system4 ,centerless ,corporeity1 as belonging to externality1 naturally separates itself into the opposition of the lunar and the cometary ,body4 ,the laws of absolutely free motion1 as is well known1 were discovered by ,kepler2--a discovery of immortal fame4 ,kepler has proved these laws in this sense1 that for the empirical data he found their 7a7 general expression4 ,since then1 7a7 it has become a common way of speaking to say that ,newton first found out the proof of these ,laws4 ,it has rarely happened that fame has been more unjustly transferred from the first discoverer to another person4 ,on this subject ,i make the following remarks4 #a4 ,that it is allowed by ,mathematicians that the ,newtonian 7b7 ,formul may be derived from the ,keplerian ,laws4 ,the completely immediate derivation is this3 ,in the third ,keplerian 7c7 ,law1 ,a#c_/,t#b is the constant quantity4 ,this being put as ,a4,a#b_/,t#b and calling1 with ,newton1 ,a_/,t#b universal ,gravitation1 his expression of the effect of gravity in the reciprocal ratio of the square of the distances is obvious4 7d7 #b4 ,that the ,newtonian proof of the ,proposition that a body subjected to the ,law of ,gravitation moves about the central body in an ,ellipse1 gives a ,conic ,section generally1 while the main ,proposition which ought to be proved is that the fall of such a ,body is not a ,circle or any other ,conic ,section1 but an ,ellipse only4 ,moreover1 there are objections which may be made against this proof in itself 7,princ4 ,math4 ,i4 #a4 ,sect4 ,,ii4 7e7 ,prop4 #a72 and although it is the foundation of the ,newtonian ,theory1 analysis has no longer any need of it4 ,the conditions which in the sequel make the path of the ,body to a determinate ,conic ,section1 are referred to an empirical circumstance1 namely1 a particular position of the ,body at a determined moment of time1 and 7f7 the casual strength of an impulsion which it is supposed to have received originally2 so that the circumstance which makes the ,curve be an ,ellipse1 which alone ought to be the thing proved1 is extraneous to the ,formula4 #c4 ,that the ,newtonian ,law of the so-called ,force of ,gravitation is in like manner only proved from experience by ,induction4 7g7 ,the sum of the difference is this1 that what ,kepler expressed in a simple and sublime manner in the ,form of ,laws of the ,celestial ,motions1 ,newton has metamorphosed into the ,reflection-,form of the ,force of ,gravitation4 ,if the ,newtonian ,form has not only its convenience but its necessity in reference 7h7 to the analytical method1 this is only a difference of the mathematical formul2 ,analysis has long been able to derive the ,newtonian expression1 and the ,propositions therewith connected1 out of the ,form of the ,keplerian ,laws2 7on this subject ,i refer 7i7 to the elegant exposition in ,francur's ,trait ,elm4 de ,mcanique1 ,liv4 ,,ii4 ,ch4 xi4 n4 #d47--,the old method of so-called proof is conspicuous as offering to us a tangled web1 formed of the ,lines of the mere geometrical construction1 to which a physical meaning of independent ,forces is given2 and of empty ,reflexion-determinations of the already mentioned ,accelerating ,force and ,vis ,inerti1 and especially of the relation of the so-called gravitation itself to the centripetal force and centrifugal force1 and so on4 ,the remarks which are here made would undoubtedly have need of a further explication to show how well founded they are3 in a ,compendium1 propositions of this kind which do not agree with that which is assumed1 can only have the shape of assertions4 ,indeed1 since they contradict such high authorities1 they must appear as something worse1 as presumptuous assertions4 ,i will not1 on this subject1 support myself by saying1 by the bye1 that an interest in these subjects has occupied me for #be years2 but it is more precisely to the purpose to remark1 that the distinctions and determinations which ,mathematical ,analysis introduces1 and the course which it must take according to its method1 is altogether different from that which a physical reality must have4 ,the ,presuppositions1 the ,course1 and the ,results1 which the ,analysis necessarily has and gives1 remain quite extraneous to the considerations which determine the physical value and the signification of those determinations and of that course4 ,to this it is that attention should be directed4 ,we have to do with a consciousness relative to the deluging of physical ,mechanics with an inconceivable 7unsglichen7 ,metaphysic1 which--contrary to experience and conception--has those mathematical determinations alone for its source4 ,it is recognized that what ,newton--besides the foundation of the analytical treatment1 the development of which1 by the bye1 has of itself rendered superfluous1 or indeed rejected much which belonged to ,newton's essential ,principles and glory--has added to the ,keplerian ,laws is the ,principle of ,perturbations1--a ,principle whose importance we may here accept thus far 7hier in 7k7 sofern anzufhren ist72 namely1 so far as it rests upon the ,proposition that the so-called attraction is an operation of all 7l7 the individual parts of bodies1 as being material4 ,it lies in this1 that matter in general assigns a center for itself 7sich das centrum setzt71 and the figure of the body is an element in the determination of its place2 that collective bodies of the system recognize a reference to their ,sun 7sich ihre ,sonne setzen71 but also the individual bodies themselves1 according to the relative position with regard to each other into which they come by their general motion1 form a momentary relation of their gravity 7schwere7 towards each other1 and are related to each other not only in abstract spatial relations1 but at the same time assign to themselves a joint center1 which however is again resolved into the general center in the universal system4 7m7 ,as to what concerns the features of the path1 to show how the fundamental determinations of ,free ,motion are connected with the ,conception1 cannot here be undertaken in a satisfactory and detailed manner1 and must therefore be left to its fate4 ,the proof from reason of the quantitative determinations of free motion can only rest upon the determinations of ,conceptions of space and time1 the elements whose relation 7intrinsic not extrinsic7 motion is4 ,that1 in the first place1 the motion in general is a motion returning into itself1 is founded on the determination of particularity and individuality of the bodies in general 7 #bfi71 so that partly they have a center in themselves1 and partly at the same time their center in another4 ,these are the determinations of ,conceptions which form the basis of the false representatives of 7n7 ,centripetal ,force and ,centrifugal ,force1 as if each of these were self-existing1 extraneous to the other1 and independent of it2 and as if they only came in contact in their operations and consequently externally4 ,they are1 as has already been mentioned1 the ,lines which must be drawn for the mathematical determinations1 transformed into physical realities4 ,further1 this motion is uniformly accelerated1 7and--as returning into itself--in turn uniformly retarded74 ,in motion as free1 ,time and ,space enter as different things which are to make 7o7 themselves effective in the determination of the motion 7 #bff1 note74 ,in the so-called ,explanation of the uniformly accelerated and retarded motion1 by means of the alternate decrease and increase of the magnitude of the ,centripetal ,force and ,centrifugal ,force1 the confusion which the assumption of 7p7 such independent ,forces produces is at its greatest height4 ,according to this explanation1 in the motion of a ,planet from the ,aphelion to the ,perihelion1 the centrifugal is less than the centripetal force1 and on the contrary1 in the ,perihelion itself1 the centrifugal force is supposed to become greater than the centripetal4 ,for the motion from the ,perihelion to the ,aphelion1 this representation makes the forces pass into the opposite relation in the same manner4 ,it is apparent that such a sudden conversion of the preponderance which a force has obtained over another1 into an inferiority to the other1 cannot be anything taken out of the nature of ,forces4 ,on the contrary it must be concluded1 that a preponderance which one ,force has obtained over another must not only be preserved1 but must go onwards to the complete annihilation of the other ,force1 and the motion must either1 by the ,preponderance of the ,centripetal ,force1 proceed till it ends in rest1 that is1 in the ,collision of the ,planet with the ,central 7q7 ,body1 or till by the ,preponderance of the ,centrifugal ,force it ends in a straight line4 ,but now1 if in place of the suddenness of the conversion1 we suppose a gradual increase of the ,force in question1 then1 since rather the other ,force ought to be assumed as increasing1 we lose the opposition which is assumed for the sake of the explanation2 and if the increase of the one is assumed to be different from that of the other1 7which is the case in some representations17 then there is found at the mean distance between the apsides a point in which the ,forces are in equilibrio4 ,and the transition of the ,forces out of ,equilibrium is a thing just as little without any sufficient reason as the aforesaid suddenness of inversion4 ,and in the whole of this kind of explanation1 we see that the mode of remedying a bad mode of dealing with a subject leads to newer and greater confusion4--,a similar confusion makes its appearance in the explanation of the phnomenon that the pendulum oscillates more slowly at the equator4 ,this phnomenon is ascribed to the ,centrifugal ,force1 which it is asserted must then be greater2 but it is easy to see that we may just as well ascribe it to the augmented gravity1 inasmuch as that holds the pendulum more strongly to the perpendicular line of rest4 #bdj4 7r7 ,and now first1 as to what concerns the ,form of the ,path1 the ,circle only can be conceived as the path of an absolutely uniform motion4 ,conceivable1 as people express it1 no doubt it is1 that an increasing and diminishing motion should take place in a circle4 ,but this conceivableness or possibility means only an abstract capability of being represented1 which leaves out of sight that ,determinate ,thing on which the question turns4 ,the ,circle is the line returning into itself in which all the radii are equal1 that is1 it is completely determined by means of the radius4 ,there is only one ,determination1 and that is the whole ,determination4 ,but in free motion1 in which the ,determinations according to space and according to time come into view with ,differences1 in a qualitative relation to each other1 this ,relation appears in the spatial aspect as a ,difference thereof in itself1 which therefore requires two ,determinations4 ,hereby the ,form of the path returning into itself is essentially an ,ellipse4 7s7 ,the abstract ,determinations which produces the circle appears also in this way1 that the arc or angle which is included by two ,radii is independent of them1 a magnitude with regard to them completely empirical4 ,but since in the motion as determined by the ,conception1 the distance from the center1 and the arc which is run over in a certain time1 must be comprehended in one determinateness1 and make out a whole1 this is the sector1 a space-determination of two dimensions3 in this way1 the arc is essentially a ,function of the ,radius ,vector2 and the former 7the arc7 being unequal1 brings with it the inequality of the ,radii4 ,that the determination with regard to the space by means of the 7t7 time appears as a ,determination of two ,dimensions1--as a ,superficies-,determination1--agrees with what was said before 7 #bff7 respecting ,falling ,bodies1 with regard to the exposition of the same ,determinateness1 at one while as ,time in the root1 at another while as ,space in the ,square4 ,here1 however1 the ,quadratic character of the space is1 by the returning of the ,line of motion into itself1 limited to a ,sector4 ,these are1 as may be seen1 the general principles on which the ,keplerian ,law1 that in equal times equal sectors are cut off1 rests4 ,this ,law becomes1 as is clear1 only the relation of the arc to the ,radius ,vector1 and the ,time enters there as the abstract ,unity1 in which the different ,sectors are compared1 because as ,unity it is the ,determining ,element4 ,but the further relation is that of the ,time1 not as ,unity1 but as a ,quantity in general1--as the time of ,revolution--to the magnitude of the ,path1 or1 what is the same thing1 the distance from the center4 ,as ,root and ,square1 we saw that ,time and ,space had a relation to each other1 in the case of ,falling ,bodies1 the case of half-free motion--because that motion is determined on one side by the conception1 on 7u7 the other by external conditions4 ,but in the case of absolute motion--the domain of free masses--the determination attains its ,totality4 ,the ,time as the ,root is a mere empirical magnitude2 but as a component 7moment7 of the developed ,totality1 it is a ,totality in itself1--it produces itself1 and therein has a reference to itself2 as the ,dimensionless ,element in itself1 it only comes to a formal identity with itself1 the ,square2 ,space1 on the other hand1 as the positive ,distribution 7aussereinander7 comes to the ,dimension of the ,conception1 the ,,cube4 ,their 7v7 ,realization preserves their original difference4 ,this is the third ,keplerian ,law1 the relation of the ,cubes of the ,distances to the ,squares of the ,times2--a ,law which is so great on this account1 that it represents so simply and immediately ,reason as belonging to the thing3 while on the contrary the ,newtonian ,formula1 by means of which the ,law is changed into a ,law for the ,force of ,gravity1 shows the ,distortion1 ,perversion and ,inversion of ,reflexion which stops half-way4 ,additions to new ,edition4 #bfi4 ,the center has no sense without the circumference1 nor the circumference without the center4 ,this makes all physical hypotheses vanish which sometimes proceed from the center1 sometimes from the particular bodies1 and sometimes assign this1 sometimes that1 as the original cause of motion 444 ,it is silly 7lppisch7 to suppose that the centrifugal force1 as a tendency to fly off in a ,tangent1 has been produced by a lateral projection1 a projectile force1 an impulse which they have retained ever since they set out on their journey 7von ,haus aus74 ,such casualty of the motion produced by external causes belongs to inert matter2 as when a stone fastened to a thread which is thrown transversely tries to fly from the thread4 ,we are not to talk in this way of ,forces4 ,if we will speak of ,force1 there is one ,force1 whose elements do not 7w7 draw bodies to different sides as if they were two ,forces4 ,the motion of the heavenly bodies is not a being pulled this way or that1 such as is thus imagined2 it is free motion3 they go along1 as the ancients said1 as blessed ,gods 7sie gehen als selige ,gtter einher74 ,the celestial corporeity is not such a one as has the principle of rest or motion external to itself4 ,because stone is inert1 and all the earth consists of stones1 and the other heavenly bodies are of the same nature1--is a conclusion which makes the properties of the whole the same as those of the part4 ,impulse1 ,pressure1 ,resistance1 ,friction1 ,pulling1 and the like1 are valid 7x7 only for an existence of matter other than the celestial4 ,doubtless that which is common to the two is matter1 as a good thought and a bad thought are both thoughts2 but the bad one is not therefore good1 because it is a thought4 ,,footnotes3 ,footnote #cec3 ,cartes4 ,princip4 iv4 #bc4 ,footnote #ced3 ,jac4 ,bernoulli1 ,nouvelles ,penses sur le ,systme de ,m4 ,descartes1 op4 t4 i4 p4 #bci 7#afhf74 ,footnote #cee3 ,de la ,cause de la ,pesanteur 7#afhi71 p4 #ace4 ,footnote #cef3 ,journal des ,savans1 #agjc4 ,mm4 ,acad4 ,par4 #agji4 ,bulfinger1 in #agbf 7,acad4 ,petrop471 conceived that by making a sphere revolve at the same time about two axes at right angles to each other1 every particle would describe a great circle2 but this is not so4 ,footnote #ceg3 ,acad4 ,par4 #agad1 ,hist4 p4 #ajf4 ,footnote #ceh3 ,acad4 ,par4 #agcc4 ,footnote #cei3 ,acad4 ,sc4 #agji4 ,if we abandon the clear principles of mechanics1 the writer says1 toute la lumire que nous pouvons avoir est teinte1 et nous voil replongs de nouveau dans les anciennes tnbres du ,peripatetisme1 dont le ,ciel nous veuille preserver6 ,it was also objected to the ,newtonian system1 that it did not account for the remarkable facts1 that all the motions of the primary planets1 all the motions of the satellites1 and all the motions of rotation1 including that of the sun1 are in the same direction1 and nearly in the same plane2 facts which have been urged by ,laplace as so strongly recommending the ,nebular ,hypothesis2 and that hypothesis is1 in truth1 a hypothesis of vortices respecting the origin of the system of the world4 ,footnote #cfj3 ,nouvelle ,physique ,cleste1 ,op4 t4 iii4 p4 #afc4 ,the deviation of the orbits of the planets from the plane of the sun's equator was of course a difficulty in the system which supposed that they were carried round by the vortices which the sun's rotation caused1 or at least rendered evident4 ,bernoulli's explanation consists in supposing the planets to have a sort of leeway 7drive des vaisseaux7 in the stream of the vortex4 ,footnote #cfa3 ,see ,hist4 ,sc4 ,ideas1 b4 iii4 c4 ix4 ,art4 #g4 ,footnote #cfb3 ,see ,mill's ,logic1 vol4 i4 p4 #caa1 #bnd ed4 ,footnote #cfc3 ,these letters refer to passages in the ,translation annexed to this ,memoir4 ,,appendix ,k4 ,,demonstration ,,that ,,all ,,matter ,,is ,,heavy4 7,cam4 ,phil4 ,soc4 ,,feb4 #bb1 #ahda47 ,the discussion of the nature of the grounds and proofs of the most general propositions which the physical sciences include1 belongs rather to ,metaphysics than to that course of experimental and mathematical investigation by which the sciences are formed4 ,but such discussions seem by no means unfitted to occupy the attention of the cultivators of physical science4 ,the ideal1 as well as the experimental side of our knowledge must be carefully studied and scrutinized1 in order that its true import may be seen2 and this province of human speculation has been perhaps of late unjustly depreciated and neglected by men of science4 ,yet it can be prosecuted in the most advantageous manner by them only3 for no one can speculate securely and rightly respecting the nature and proofs of the truths of science without a steady possession of some large and solid portions of such truths4 ,a man must be a mathematician1 a mechanical philosopher1 a natural historian1 in order that he may philosophize well concerning mathematics1 and mechanics1 and natural history2 and the mere metaphysician who without such preparation and fitness sets himself to determine the grounds of mathematical or mechanical truths1 or the principles of classification1 will be liable to be led into error at every step4 ,he must speculate by means of general terms1 which he will not be able to use as instruments of discovering and conveying philosophical truth1 because he cannot1 in his own mind1 habitually and familiarly1 embody their import in special examples4 ,acting upon such views1 ,i have already laid before the ,philosophical ,society of ,cambridge essays on such subjects as ,i here refer to2 especially a memoir ,on the ,nature of the ,truth of the ,laws of ,motion1 which was printed by the ,society in its ,transactions4 ,this memoir appears to have excited in other places1 notice of such a kind as to show that the minds of many speculative persons are ready for and inclined towards the discussion of such questions4 ,i am therefore the more willing to bring under consideration another subject of a kind closely related to the one just mentioned4 ,the general questions which all such discussions suggest1 are 7in the existing phase of ,english philosophy7 whether certain proposed scientific truths1 7as the laws of motion17 be necessary truths2 and if they are necessary1 7which ,i have attempted to show that in a certain sense they are17 on what ground their necessity rests4 ,these questions may be discussed in a general form1 as ,i have elsewhere attempted to show4 ,but it may be instructive also to follow the general arguments into the form which they assume in special cases2 and to exhibit1 in a distinct shape1 the incongruities into which the opposite false doctrine leads us1 when applied to particular examples4 ,this accordingly is what ,i propose to do in the present memoir1 with regard to the proposition stated at the head of this paper1 namely1 that all matter is heavy4 ,at first sight it may appear a doctrine altogether untenable to assert that this proposition is a necessary truth3 for1 it may be urged1 we have no difficulty in conceiving matter which is not heavy2 so that matter without weight is a conception not inconsistent with itself2 which it must be if the reverse were a necessary truth4 ,it may be added1 that the possibility of conceiving matter without weight was shown in the controversy which ended in the downfall of the phlogiston theory of chemical composition2 for some of the reasoners on this subject asserted phlogiston to be a body with positive levity instead of gravity1 which hypothesis1 however false1 shows that such a supposition is possible4 ,again1 it may be said that weight and inertia are two separate properties of matter3 that mathematicians measure the quantity of matter by the inertia1 and that we learn by experiment only that the weight is proportional to the inertia2 ,newton's experiments with pendulums of different materials having been made with this very object4 ,i proceed to reply to these arguments4 ,and first1 as to the possibility of conceiving matter without weight1 and the argument thence deduced1 that the universal gravity of matter is not a necessary truth1 ,i remark1 that it is indeed just1 to say that we cannot even distinctly conceive the contrary of a necessary truth to be true2 but that this impossibility can be asserted only of those perfectly distinct conceptions which result from a complete development of the fundamental idea and its consequences4 ,till we reach this stage of development1 the obscurity and indistinctness may prevent our perceiving absolute contradictions1 though they exist4 ,we have abundant store of examples of this1 even in geometry and arithmetic2 where the truths are universally allowed to be necessary1 and where the relations which are impossible1 are also inconceivable1 that is1 not conceivable distinctly4 ,such relations1 though not distinctly conceivable1 still often appear conceivable and possible1 owing to the indistinctness of our ideas4 ,who1 at the first outset of his geometrical studies1 sees any impossibility in supposing the side and the diagonal of a square to have a common measure8 ,yet they can be rigorously proved to be incommensurable1 and therefore the attempt distinctly to conceive a common measure of them must fail4 ,the attempts at the geometrical duplication of the cube1 and the supposed solutions1 7as that of ,hobbes17 have involved absolute contradictions2 yet this has not prevented their being long and obstinately entertained by men1 even of minds acute and clear in other respects4 ,and the same might be shewn to be the case in arithmetic4 ,it is plain1 therefore1 that we cannot1 from the supposed possibility of conceiving matter without weight1 infer that the contrary may not be a necessary truth4 ,our power of judging1 from the compatibility or incompatibility of our conceptions1 whether certain propositions respecting the relations of ideas are true or not1 must depend entirely1 as ,i have said1 upon the degree of development which such ideas have undergone in our minds4 ,some of the relations of our conceptions on any subject are evident upon the first steady contemplation of the fundamental idea by a sound mind3 these are the axioms of the subject4 ,other propositions may be deduced from the axioms by strict logical reasoning4 ,these propositions are no less necessary than the axioms1 though to common minds their evidence is very different4 ,yet as we become familiar with the steps by which these ulterior truths are deduced from the axioms1 their truth also becomes evident1 and the contrary becomes inconceivable4 ,when a person has familiarized himself with the first twenty-six propositions of ,euclid1 and not till then1 it becomes evident to him1 that parallelograms on the same base and between the same parallels are equal2 and he cannot even conceive the contrary4 ,when he has a little further cultivated his geometrical powers1 the equality of the square on the hypothenuse of a right-angled triangle to the squares on the sides1 becomes also evident2 the steps by which it is demonstrated being so familiar to the mind as to be apprehended without a conscious act4 ,and thus1 the contrary of a necessary truth cannot be distinctly conceived2 but the incapacity of forming such a conception is a condition which depends upon cultivation1 being intimately connected with the power of rapidly and clearly perceiving the connection of the necessary truth under consideration with the elementary principles on which it depends4 ,and thus1 again1 it may be that there is an absolute impossibility of conceiving matter without weight2 but then1 this impossibility may not be apparent1 till we have traced our fundamental conceptions of matter into some of their consequences4 ,the question then occurs1 whether we can1 by any steps of reasoning1 point out an inconsistency in the conception of matter without weight4 ,this ,i conceive we may do1 and this ,i shall attempt to show4 ,the general mode of stating the argument is this3--the quantity of matter is measured by those sensible properties of matter which undergo quantitative addition1 subtraction and division1 as the matter is added1 subtracted and divided4 ,the quantity of matter cannot be known in any other way4 ,but this mode of measuring the quantity of matter1 in order to be true at all1 must be universally true4 ,if it were only partially true1 the limits within which it is to be applied would be arbitrary2 and therefore the whole procedure would be arbitrary1 and1 as a method of obtaining philosophical truth1 altogether futile4 ,we may unfold this argument further4 ,let the contrary be supposed1 of that which we assert to be true3 namely1 let it be supposed that while all other kinds of matter are heavy 7and of course heavy in proportion to the quantity of matter71 there is one kind of matter which is absolutely destitute of weight2 as1 for instance1 phlogiston1 or any other element4 ,then where this weightless element 7as we may term it7 is mixed with weighty elements1 we shall have a compound1 in which the weight is no longer proportional to the quantity of matter4 ,if1 for example1 #b measures of heavy matter unite with one measure of phlogiston1 the weight is as #b1 and the quantity of matter as #c4 ,in all such cases1 therefore1 the weight ceases to be the measure of the quantity of matter4 ,and as the proportion of the weighty and the weightless matter may vary in innumerable degrees in such compounds1 the weight affords no criterion at all of the quantity of matter in them4 ,and the smallest admixture of the weightless element is sufficient to prevent the weight from being taken as the measure of the quantity of matter4 ,but on this hypothesis1 how are we to distinguish such compounds from bodies consisting purely of heavy matter8 ,how are we to satisfy ourselves that there is not1 in every body1 some admixture1 small or great1 of the weightless element8 ,if we call this element phlogiston1 how shall we know that the bodies with which we have to do are1 any of them1 absolutely free from phlogiston8 ,we cannot refer to the weight for any such assurance2 for by supposition the presence and absence of phlogiston makes no difference in the weight4 ,nor can any other properties secure us at least from a very small admixture2 for to assert that a mixture of #a in #ajj or #a in #aj of phlogiston would always manifest itself in the properties of the body1 must be an arbitrary procedure1 till we have proved this assertion by experiment3 and we cannot do this till we have learnt some mode of measuring the quantities of matter in bodies and parts of bodies2 which is exactly what we question the possibility of1 in the present hypothesis4 ,thus1 if we assume the existence of an element1 phlogiston1 devoid of weight1 we cannot be sure that every body does not contain some portion of this element2 while we see that if there be an admixture of such an element1 the weight is no longer any criterion of the quantity of matter4 ,and thus we have proved1 that if there be any kind of matter which is not heavy1 the weight can no longer avail us1 in any case or to any extent1 as a measure of the quantity of matter4 ,i may remark1 that the same conclusion is easily extended to the case in which phlogiston is supposed to have absolute levity2 for in that case1 a certain mixture of phlogiston and of heavy matter would have no weight1 and might be substituted for phlogiston in the preceding reasoning4 ,i may remark1 also1 that the same conclusion would follow by the same reasoning1 if any kind of matter1 instead of being void of weight1 were heavy1 indeed1 but not so heavy1 in proportion to its quantity of matter1 as other kinds4 ,on all these hypotheses there would be no possibility of measuring quantity of matter by weight at all1 in any case1 or to any extent4 ,but it may be urged1 that we have not yet reduced the hypothesis of matter without weight to a contradiction2 for that mathematicians measure quantity of matter1 not by weight1 but by the other property1 of which we have spoken1 inertia4 ,to this ,i reply1 that1 practically speaking1 quantity of matter is always measured by weight1 both by mechanicians and chemists3 and as we have proved that this procedure is utterly insecure in all cases1 on the hypothesis of weightless matter1 the practice rests upon a conviction that the hypothesis is false4 ,and yet the practice is universal4 ,every experimenter measures quantity of matter by the balance4 ,no one has ever thought of measuring quantity of matter by its inertia practically3 no one has constructed a measure of quantity of matter in which the matter produces its indications of quantity by its motion4 ,when we have to take into account the inertia of a body1 we inquire what its weight is1 and assume this as the measure of the inertia2 but we never take the contrary course1 and ascertain the inertia first in order to determine by that means the weight4 ,but it may be asked1 ,is it not then true1 and an important scientific truth1 that the quantity of matter is measured by the inertia8 ,is it not true1 and proved by experiment1 that the weight is proportional to the inertia8 ,if this be not the result of ,newton's experiments mentioned above1 what1 it may be demanded1 do they prove8 ,to these questions ,i reply3 ,it is true that quantity of matter is measured by the inertia1 for it is true that inertia is as the quantity of matter4 ,this truth is indeed one of the laws of motion4 ,that weight is proportional to inertia is proved by experiment1 as far as the laws of motion are so proved3 and ,newton's experiments prove one of the laws of motion1 so far as any experiments can prove them1 or are needed to prove them4 ,that inertia is proportional to weight1 is a law equivalent to that law which asserts1 that when pressure produces motion in a given body1 the velocity produced in a given time is as the pressure4 ,for if the velocity be as the pressure1 when the body is given1 the velocity will be constant if the inertia also be as the pressure4 ,for the inertia is understood to be that property of bodies to which1 ceteris paribus1 the velocity impressed is inversely proportional4 ,one body has twice as much inertia as another1 if1 when the same force acts upon it for the same time1 it acquires but half the velocity4 ,this is the fundamental conception of inertia4 ,in ,newton's pendulum experiments1 the pressure producing motion was a certain resolved part of the weight1 and was proportional to the weight4 ,it appeared by the experiments1 that whatever were the material of which the pendulum was formed1 the rate of oscillation was the same2 that is1 the velocity acquired was the same4 ,hence the inertia of the different bodies must have been in each case as the weight3 and thus this assertion is true of all different kinds of bodies4 ,thus it appears that the assertion1 that inertia is universally proportional to weight1 is equivalent to the law of motion1 that the velocity is as the pressure4 ,the conception of inertia 7of which1 as we have said1 the fundamental conception is1 that the velocity impressed is inversely proportional to the inertia17 connects the two propositions so as to make them identical4 ,hence our argument with regard to the universal gravity of matter brings us to the above law of motion1 and is proved by ,newton's experiments in the same sense in which that law of motion is so proved4 ,perhaps some persons might conceive that the identity of weight and inertia is obvious at once2 for both are merely resistance to motion2--inertia1 resistance to all motion 7or change of motion7--weight1 resistance to motion upwards4 ,but there is a difference in these two kinds of resistance to motion4 ,inertia is instantaneous1 weight is continuous resistance4 ,any momentary impulse which acts upon a free body overcomes its inertia1 for it changes its motion2 and this change once effected1 the inertia opposes any return to the former condition1 as well as any additional change4 ,the inertia is thus overcome by a momentary force4 ,but the weight can only be overcome by a continuous force like itself4 ,if an impulse act in opposition to the weight1 it may for a moment neutralize or overcome the weight2 but if it be not continued1 the weight resumes its effect1 and restores the condition which existed before the impulse acted4 ,but weight not only produces rest1 when it is resisted1 but motion1 when it is not resisted4 ,weight is measured by the reaction which would balance it2 but when unbalanced1 it produces motion1 and the velocity of this motion increases constantly4 ,now what determines the velocity thus produced in a given time1 or its rate of increase8 ,what determines it to have one magnitude rather than another8 ,to this we must evidently reply1 the inertia4 ,when weight produces motion1 the inertia is the reaction which makes the motion determinate4 ,the accumulated motion produced by the action of unbalanced weight is as determinate a condition as the equilibrium produced by balanced weight4 ,in both cases the condition of the body acted on is determined by the opposition of the action and reaction4 ,hence inertia is the reaction which opposes the weight1 when unbalanced4 ,but by the conception of action and reaction1 7as mutually determining and determined17 they are measured by each other3 and hence the inertia is necessarily proportional to the weight4 ,but when we have reached this conclusion1 the original objection may be again urged against it4 ,it may be said1 that there must be some fallacy in this reasoning1 for it proves a state of things to be necessary when we can so easily conceive a contrary state of things4 ,is it denied1 the opponent may ask1 that we can readily imagine a state of things in which bodies have no weight8 ,is not the uniform tendency of all bodies in the same direction not only not necessary1 but not even true8 ,for they do in reality tend1 not with equal forces in parallel lines1 but to a center with unequal forces1 according to their position3 and we can conceive these differences of intensity and direction in the force to be greater than they really are2 and can with equal ease suppose the force to disappear altogether4 ,to this ,i reply1 that certainly we may conceive the weight of bodies to vary in intensity and direction1 and by an additional effort of imagination1 may conceive the weight to vanish3 but that in all these suppositions1 even in the extreme one1 we must suppose the rule to be universal4 ,if any bodies have weight1 all bodies must have weight4 ,if the direction of weight be different in different points1 this direction must still vary according to the law of continuity2 and the same is true of the intensity of the weight4 ,for if this were not so1 the rest and motion1 the velocity and direction1 the permanence and change of bodies1 as to their mechanical condition1 would be arbitrary and incoherent3 they would not be subject to mechanical ideas2 that is1 not to ideas at all3 and hence these conditions of objects would in fact be inconceivable4 ,in order that the universe may be possible1 that is1 may fall under the conditions of intelligible conceptions1 we must be able to conceive a body at rest4 ,but the rest of bodies 7except in the absolute negation of all force7 implies the equilibrium of opposite forces4 ,and one of these opposite forces must be a general force1 as weight1 in order that the universe may be governed by general conditions4 ,and this general force1 by the conception of force1 may produce motion1 as well as equilibrium2 and this motion again must be determined1 and determined by general conditions2 which cannot be1 except the communication of motion be regulated by an inertia proportional to the weight4 ,but it will be asked1 ,is it then pretended that ,newton's experiment1 by which it was intended to prove inertia proportional to weight1 does really prove nothing but what may be demonstrated priori8 ,could we know1 without experiment1 that all bodies1--gold1 iron1 wood1 cork1--have inertia proportional to their weight8 ,and to this we reply1 that experiment holds the same place in the establishment of this1 as of the other fundamental doctrines of mechanics4 ,intercourse with the external world is requisite for developing our ideas2 measurement of phenomena is needed to fix our conceptions and to render them precise3 but the result of our experimental studies is1 that we reach a position in which our convictions do not rest upon experiment4 ,we learn by observation truths of which we afterwards see the necessity4 ,this is the case with the laws of motion1 as ,i have repeatedly endeavoured to show4 ,the same will appear to be the case with the proposition1 that bodies of different kinds have their inertia proportional to their weight4 ,for bodies of the same kind have their inertia proportional to their weight1 both quantities being proportional to the quantity of matter4 ,and if we compress the same quantity of matter into half the space1 neither the weight nor the inertia is altered1 because these depend on the quantity of matter alone4 ,but in this way we obtain a body of twice the density2 and in the same manner we obtain a body of any other density4 ,therefore whatever be the density1 the inertia is proportional to the quantity of matter4 ,but the mechanical relations of bodies cannot depend upon any difference of kind1 except a difference of density4 ,for if we suppose any fundamental difference of mechanical nature in the particles or component elements of bodies1 we are led to the same conclusion1 of arbitrary1 and therefore impossible1 results1 which we deduced from this supposition with regard to weight4 ,therefore all bodies of different density1 and hence1 all bodies whatever1 must have their inertia proportional to their weight4 ,hence we see1 that the propositions1 that all bodies are heavy1 and that inertia is proportional to weight1 necessarily follow from those fundamental ideas which we unavoidably employ in all attempts to reason concerning the mechanical relations of bodies4 ,this conclusion may perhaps appear the more startling to many1 because they have been accustomed to expect that fundamental ideas and their relations should be self-evident at our first contemplation of them4 ,this1 however1 is far from being the case1 as ,i have already shown4 ,it is not the first1 but the most complete and developed condition of our conceptions which enables us to see what are axiomatic truths in each province of human speculation4 ,our fundamental ideas are necessary conditions of knowledge1 universal forms of intuition1 inherent types of mental development2 they may even be termed1 if any one chooses1 results of connate intellectual tendencies2 but we cannot term them innate ideas1 without calling up a large array of false opinions4 ,for innate ideas were considered as capable of composition1 but by no means of simplification3 as most perfect in their original condition2 as to be found1 if any where1 in the most uneducated and most uncultivated minds2 as the same in all ages1 nations1 and stages of intellectual culture2 as capable of being referred to at once1 and made the basis of our reasonings1 without any special acuteness or effort3 in all which circumstances the ,fundamental ,ideas of which we have spoken1 are opposed to ,innate ,ideas so understood4 ,i shall not1 however1 here prosecute this subject4 ,i will only remark1 that ,fundamental ,ideas1 as we view them1 are not only not innate1 in any usual or useful sense1 but they are not necessarily ultimate elements of our knowledge4 ,they are the results of our analysis so far as we have yet prosecuted it2 but they may themselves subsequently be analysed4 ,it may hereafter appear1 that what we have treated as different ,fundamental ,ideas have1 in fact1 a connexion1 at some point below the structure which we erect upon them4 ,for instance1 we treat of the mechanical ideas of force1 matter1 and the like1 as distinct from the idea of substance4 ,yet the principle of measuring the quantity of matter by its weight1 which we have deduced from mechanical ideas1 is applied to determine the substances which enter into the composition of bodies4 ,the idea of substance supplies the axiom1 that the whole quantity of matter of a compound body is equal to the sum of the quantities of matter of its elements4 ,the mechanical ideas of force and matter lead us to infer that the quantity both of the whole and its parts must be measured by their weights4 ,substance may1 for some purposes1 be described as that to which properties belong2 matter in like manner may be described as that which resists force4 ,the former involves the ,idea of permanent ,being2 the latter1 the ,idea of ,causation4 ,there may be some elevated point of view from which these ideas may be seen to run together4 ,but even if this be so1 it will by no means affect the validity of reasonings founded upon these notions1 when duly determined and developed4 ,if we once adopt a view of the nature of knowledge which makes necessary truth possible at all1 we need be little embarrassed by finding how closely connected different necessary truths are2 and how often1 in exploring towards their roots1 different branches appear to spring from the same stem4 ,,end ,,of ,,the ,,appendix4 ,cambridge3 ,,printed ,,by ,c4 ,j4 ,,clay1 ,m4,a4 ,,at ,,the ,,university ,,press4 ,,works ,,by ,,william ,,whewell1 ,d4,d4 ,f4,r4,s4 ,,master ,,of ,,trinity ,,college1 ,,cambridge4 ,,history ,,of ,,the ,,inductive ,,sciences4 ,third and ,cheaper ,edition4 ,three ,volumes1 ,small ,octavo1 #bds4 ,,history ,,of ,,scientific ,,ideas1 being the ,first ,part of a ,third ,edition of the ,philosophy of the ,inductive ,sciences1 with ,additions4 ,two ,volumes1 #ads4 ,,novum ,,organon ,,renovatum2 being the ,second ,part of a ,third ,edition of the ,philosophy of the ,inductive ,sciences4 ,with large ,additions4 #gs4 ,,indications ,,of ,,the ,,creator3 ,theological ,extracts from the ,history and the ,philosophy of the ,inductive ,sciences4 ,second ,edition4 #es4 #f;d4 ,,elements ,,of ,,morality1 ,,including ,,polity4 ,third ,edition1 with a ,supplement4 ,two ,volumes1 #aes4 ,,lectures ,,on ,,systematic ,,morality4 #gs4 #f;d4 ,,lectures ,,on ,,the ,,history ,,of ,,moral ,,philosophy ,,in ,,england4 #hs4 ,,of ,a ,,liberal ,,education ,,in ,,general1 and with ,particular ,reference to the ,studies of the ,university of ,cambridge4 ,parts ,i4 and ,,ii41 in ,one ,volume1 #gs4 #f;d4 ,part ,,iii41 sewed1 #bs4 ,,on ,,the ,,principles ,,of ,,english ,,university ,,education4 ,second ,edition4 #es4 ,,college ,,chapel ,,sermons4 #ajs4 #f;d4 ,,notes ,,on ,,german ,,churches4 ,third ,edition4 #abs4 ,,the ,,mechanical ,,euclid4 ,fifth ,edition4 #es4 ,,the ,,mechanics ,,of ,,engineering4 #is4 ,,the ,,doctrine ,,of ,,limits4 ,octavo1 #is4 ,,conic ,,sections4 #bs4 #f;d4 ,,edited ,,by ,,dr4 ,,whewell4 ,,butler',s ,,three ,,sermons ,,on ,,human ,,nature1 and a ,dissertation on ,virtue2 with a ,preface and ,syllabus4 ,third ,edition4 #cs4 #f;d4 ,,butler',s ,,six ,,sermons ,,on ,,moral ,,subjects4 ,with ,preface and ,syllabus4 #cs4 #f;d4 ,,london3 ,,john ,w4 ,,parker ,,and ,,son1 ,,west ,,strand4 ,new ,books and ,new ,editions1 ,published by ,john ,w4 ,parker and ,son1 ,west ,strand4 ,history of ,england1 from the ,fall of ,wolsey to the ,death of ,elizabeth4 ,fifth and ,sixth ,volumes1 containing the ,reigns of ,edward the ,sixth and ,mary4 ,by ,j4 ,,anthony ,,froude4 ,in the ,press4 ,a ,second ,edition of the ,first ,four ,volumes1 containing the ,reign of ,henry ,,viii4 #bl4 #ads4 ,history of ,england1 during the ,reign of ,george the ,third4 ,by ,w4 ,,massey1 ,m4,p4 ,vols4 ,i4 and ,,ii4 #abs4 each4 ,the ,third ,volume in the ,press4 ,history of ,civilization in ,england4 ,by ,,henry ,,thomas ,,buckle4 ,the ,first ,volume4 ,octavo4 ,second ,edition4 #bas4 ,friends in ,council4 ,second ,series4 ,the ,second ,edition4 ,two ,volumes4 #ads4 ,friends in ,council4 ,first ,series4 ,new ,edition4 ,two ,volumes4 #is4 ,on ,liberty4 ,,by ,,john ,,stuart ,,mill4 ,the ,second ,edition4 #gs4 #f;d4 ,the ,recreations of a ,country ,parson2 ,essays ,parochial1 ,architectural1 sthetical1 ,moral1 ,social1 and ,domestic4 ,being a ,selection from the ,contributions of ,a4 ,k4 ,h4 ,b4 to ,fraser's ,magazine4 #is4 ,major ,hodson's ,twelve ,years of a ,soldier's ,life in ,india4 ,edited by his ,brother1 the ,rev4 ,,george ,h4 ,,hodson1 ,m4,a4 ,fellow of ,trinity ,college1 ,cambridge4 ,third ,edition1 with ,additions1 and a ,portrait1 #ajs4 #f;d4 ,the ,saint's ,tragedy4 ,by ,,charles ,,kingsley1 ,chaplain in ,ordinary to the ,queen4 ,the ,third ,edition4 ,foolscap ,octavo4 #es4 ,on the ,classification and ,geographical ,distribution of ,mammalia3 ,on the ,gorilla1 ,on the ,extinction and ,transmutation of ,species4 ,by ,,richard ,,owen1 ,f4,r4,s4 ,octavo4 #es4 ,the ,odes of ,horace4 ,translated into ,english ,verse1 with a ,life and ,notes4 ,by ,,theodore ,,martin4 #gs4 #f;d4 ,arundines ,cami4 ,edited by the ,rev4 ,,henry ,,drury1 ,m4,a4 ,canon of ,salisbury1 ,chaplain to the ,house of ,commons4 ,the ,fifth and ,cheaper ,edition4 ,the ,new ,cratylus4 ,by ,j4 ,w4 ,,donaldson1 ,d4,d4 ,classical ,examiner in the ,university of ,london4 ,the ,third ,edition1 ,revised throughout and considerably ,enlarged4 #bjs4 ,night ,lessons from ,scripture4 ,compiled by the ,author of ',amy ,herbert4' ,demy1 ,red ,edges4 #cs4 ,paley's ,evidences of ,christianity4 ,with ,annotations by the ,archbishop of ,dublin4 ,octavo4 #is4 ,paley's ,moral ,philosophy4 ,with ,annotations by the ,archbishop of ,dublin4 ,octavo4 #gs4 ,the ,good ,news of ,god4 ,sermons by ,,charles ,,kingsley1 ,chaplain in ,ordinary to the ,queen4 ,the ,second ,edition4 #fs4 ,sermons on the ,atonement and other ,subjects1 preached before the ,university of ,cambridge4 ,by ,e4 ,,harold ,,browne1 ,m4,a4 ,norrisian ,professor of ,divinity in the ,university2 ,canon of ,exeter4 ,octavo4 #es4 ,an ,exposition of the ,thirty-nine ,articles1 ,historical and ,doctrinal4 ,by ,professor ,,harold ,,browne4 ,fourth ,edition4 ,octavo1 #afs4 ,critical and ,grammatical ,commentary on ,st4 ,paul's ,epistle to the ,ephesians4 ,by ,,charles ,j4 ,,ellicott1 ,b4,d4 ,professor of ,divinity1 ,king's ,college1 ,london4 ,the ,second ,edition1 ,enlarged4 #hs4 #f;d4 ,lately ,published3 ,i4 ,galatians4 ,second ,edition1 ,enlarged4 #hs4 #f;d4 ,,ii4 ,pastoral ,epistles4 ,second ,edition4 ,in the ,press4 ,,iii4 ,philippians1 ,colossians1 and ,philemon4 #ajs4 #f;d4 ,,iv4 ,thessalonians4 #gs4 #f;d4 ,peloponnesus3 ,notes of ,study and ,travel4 ,by ,w4 ,g4 ,,clark1 ,m4,a4 ,fellow and ,tutor of ,trinity ,college1 ,cambridge4 #ajs4 #f;d4 ,revolutions in ,english ,history4 ,by ,,robert ,,vaughan1 ,d4,d4 ,the ,first ,volume1 ,revolutions of ,race4 #aes4 ,history of the ,literature of ,ancient ,greece4 ,from the ,manuscripts of the late ,professor ,k4 ,o4 ,mller4 ,the first half of the ,translation by the ,right ,hon4 ,sir ,,george ,,cornewall ,,lewis1 ,bart4 ,m4,p4 ,the remainder of the ,translation1 and the ,completion of the ,work1 by ,,john ,,william ,,donaldson1 ,d4,d4 ,three ,volumes1 ,octavo4 #cfs4 ,the new portion separately1 ,two ,volumes1 #bjs4 ,soldiers and their ,science4 ,by ,captain ,,brabazon1 ,r4,a4 #gs4 ,essays written in the ,intervals of ,business4 ,the ,seventh ,edition4 #bs4 #f;d4 ,companions of ,my ,solitude4 ,the ,fifth ,edition4 #cs4 #f;d4 ,on the ,study of ,words4 ,by ,,richard ,,chenevix ,,trench1 ,d4,d4 ,dean of ,westminster4 ,the ,ninth ,edition1 ,revised and ,enlarged4 #ds4 ,a ,select ,glossary of ,english ,words used formerly in ,senses different from their ,present4 ,by ,,richard ,,chenevix ,,trench1 ,d4,d4 ,dean of ,westminster4 ,the ,second ,edition1 ,revised and ,improved4 #ds4 ,intellectual ,education1 and its ,influence on the ,character and ,happiness of ,women4 ,by ,,emily ,,shirreff4 ,octavo4 #ajs4 ,the ,cloister ,life of the ,emperor ,charles the ,fifth4 ,by ,,william ,,stirling1 ,m4,p4 ,the ,third ,edition4 #hs4 ,man and ,his ,dwelling ,place4 ,an ,essay towards the ,interpretation of ,nature4 #is4 ,dissertations and ,discussions1 ,political1 ,philosophical and ,historical4 ,by ,,john ,,stuart ,,mill4 ,two ,volumes4 ,octavo4 #bds4 ,of the ,plurality of ,worlds4 ,an ,essay4 ,the ,fifth ,edition4 #fs4 ,bacon's ,essays4 ,with ,annotations by the ,archbishop of ,dublin4 ,the ,fourth ,edition4 #ajs4 #f;d4 ,extracts from ,jean ,paul ,richter4 ,translated by ,lady ,,chatterton4 #cs4 #f;d4 ,shipwrecks of the ,royal ,navy4 ,by ,w4 ,o4 ,s4 ,,gilly4 ,with ,preface by the ,rev4 ,dr4 ,gilly4 ,the ,third ,edition4 #es4 ,the ,kingdom and ,people of ,siam2 with a ,narrative of the ,mission to that ,country4 ,by ,sir ,,john ,,bowring1 ,f4,r4,s4 ,two ,volumes1 with ,illustrations and ,map4 #cbs4 ,the ,spanish ,conquest in ,america1 and its ,relation to the ,history of ,slavery1 and to the ,government of ,colonies4 ,by ,,arthur ,,helps4 ,octavo4 ,volumes ,i4 ,,ii4 #bhs4 ,volume ,,iii4 #afs4 ,notes on ,hospitals4 ,by ,,florence ,,nightingale4 ,the ,second ,edition4 #es4 ,the ,mediterranean2 ,a ,memoir ,historical1 ,geographical1 and ,nautical4 ,by ,admiral ,w4 ,h4 ,,smyth1 ,d4,c4,l41 ,f4,r4,s4 ,octavo4 #aes4 ,lectures on ,astronomy4 ,by ,,henry ,,moseley1 ,m4,a41 ,f4,r4,s4 ,canon of ,bristol4 ,the ,fourth ,edition4 #cs4 #f;d4 ,elements of ,chemistry4 ,by ,,william ,,allen ,,miller1 ,m4,d41 ,f4,r4,s4 ,professor of ,chemistry1 ,king's ,college1 ,london4 ,complete in ,three ,parts1 with numerous ,illustrations4 #b4 #fs4 #f;d4 ,manual of ,human ,microscopic ,anatomy4 ,by ,,albert ,k,,lliker4 ,with #bhi ,illustrations4 ,octavo4 ,lectures on the ,principles and ,practice of ,physic4 ,by ,,thomas ,,watson1 ,m ,d4 ,physician ,extraordinary to the ,queen4 ,fourth ,edition1 revised4 ,two ,volumes4 ,octavo4 #cds4 ,anatomy1 ,descriptive and ,surgical4 ,by ,,henry ,,gray1 ,f4,r4,s4 ,lecturer on ,anatomy at ,st4 ,george's ,hospital4 ,with #cfc large ,woodcuts1 from ,original ,drawings4 ,royal ,octavo1 #ghb pages4 #bhs4 ,practical ,geodesy3 ,chain ,surveying1 ,surveying ,instruments1 ,levelling1 ,trigonometry1 and ,mining2 ,maritime1 ,estate1 ,parochial1 and ,railroad ,surveying4 ,by ,,butler ,,williams1 ,c4,e4 ,the ,third ,edition1 revised4 ,octavo4 #hs4 #f;d4 ,manual of ,geographical ,science4 ,part the ,second1 ,descriptive ,geography1 containing ,ancient ,geography1 by the ,rev4 ,w4 ,l4 ,,bevan1 ,m4,a4 ,vicar of ,hay1 ,brecon4 ,maritime ,discovery and ,modern ,geography1 by the ,rev4 ,c4 ,g4 ,,nicolay1 ,f4,r4,g4,s4 ,with ,copious ,index4 ,octavo4 #aes4 ,the ,first ,part1 ,octavo1 #ajs4 #f;d4 contains3 ,mathematical ,geography1 by ,m4 ,o',,brien1 ,m4,a4 ,physical ,geography1 by ,d4 ,t4 ,,ansted1 ,m4,a41 ,f4,r4,s4 ,chartography1 by ,j4 ,,jackson1 ,f4,r4,s4 ,geographical ,terminology1 by ,rev4 ,c4 ,g4 ,,nicolay4 ,the ,institutes of ,justinian2 with ,english ,introduction1 ,translation1 and ,notes4 ,by ,,thomas ,c4 ,,sandars1 ,m4,a4 late ,fellow of ,oriel ,college1 ,oxford4 ,the ,second ,edition1 revised4 ,octavo4 #aes4 ,principles of ,political ,economy4 ,by ,,john ,,stuart ,,mill4 ,fourth ,edition4 ,two ,volumes4 ,octavo4 #cjs4 ,the ,senses and the ,intellect4 ,the ,emotions and the ,will3 completing a ,systematic ,exposition of the ,human ,mind4 ,by ,,alexander ,,bain1 ,m4,a41 ,examiner in ,logic and ,moral ,philosophy in the ,university of ,london4 ,octavo4 #aes4 each4 ,babrii ,fabul sope1 e ,codice ,manuscripto ,partem ,secundam nunc primum edidit ,,georgius ,,cornewall ,,lewis1 ,a4,m41 dis ,christi1 in ,universitate ,oxoniensi1 ,alumnus ,honorarius4 #cs4 #f;d4 ,babrii ,fabul sope1 cum ,fabularum deperditarum ,fragmentis1 recensuit et breviter illustravit ,,georgius ,,cornewall ,,lewis1 ,m4,a4 #es4 #f;d4 ,the ,choephor of schylus2 with ,notes4 ,by ,,john ,,conington1 ,m4,a4 ,professor of ,latin1 ,oxford4 #fs4 ,notes upon ,thucydides4 ,by ,,john ,g4 ,,sheppard1 ,m4,a4 ,head ,master of ,kidderminster ,school1 and ,,lewis ,,evans1 ,m4,a4 ,head ,master of ,sandbach ,school4 ,books ,i4 and ,,ii4 #hs4 ,the ,ethics of ,aristotle4 ,by ,sir ,,alexander ,,grant1 ,bart41 ,m4,a4 ,the ,first ,volume1 the ,essays1 #hs4 #f;d4 ,the ,second ,volume1 ,books ,i4--,,vi41 with ,notes1 #abs4 ,the ,politics of ,aristotle2 with ,introduction1 ,essays1 ,notes1 and ,index4 ,by ,r4 ,,congreve1 ,m4,a4 #afs4 ,platonis ,philebus2 with ,introduction1 and ,notes1 ,critical and ,explanatory4 ,by ,,charles ,,badham1 ,d4,d41 ,head ,master of ,birmingham and ,edgbaston ,proprietary ,school4 #es4 ,phdrus1 ,lysis1 and ,protagoras of ,plato1 literally translated4 ,by ,j4 ,,wright1 ,m4,a4 #ds4 #f;d4 ,the ,greek ,testament2 with ,notes1 ,grammatical and ,exegetical4 ,by ,w4 ,,webster1 ,m4,a41 of ,king's ,college1 ,london2 and ,w4 ,f4 ,,wilkinson1 ,m4,a41 ,vicar of ,st4 ,werburgh1 ,derby4 ,volume ,i41 containing the ,four ,gospels and the ,acts of the ,apostles1 #bjs4 ,synonyms of the ,new ,testament4 ,by ,r4 ,,chenevix ,,trench1 ,d4,d4 ,dean of ,westminster4 ,fourth ,edition4 #es4 ,select ,private ,orations of ,demosthenes2 with ,english ,notes4 ,by ,c4 ,t4 ,,penrose1 ,m4,a4 #ds4 ,the ,frogs of ,aristophanes2 with ,english ,notes4 ,by ,rev4 ,h4 ,p4 ,,cookesley1 ,m4,a4 #gs4 ,aristophanes4 ,edited1 with ,notes and ,index1 by ,h4 ,a4 ,,holden1 ,m4,a41 ,head ,master of ,ipswich ,school4 #aes4 ,the ,plays separately1 #as4 each2 ,notul ,critic and ,onomasticon4 #ds4 ,greek ,verses of ,shrewsbury ,school2 with ,account of the ,iambic ,metre1 and ,exercises in ,greek ,tragic ,senarii4 ,edited by ,dr4 ,,kennedy1 ,head ,master4 #hs4 ,antigone of ,sophocles1 in ,greek and ,english2 with ,notes4 ,by ,dr4 ,,donaldson4 #is4 ,agamemnon of schylus1 in ,greek and ,english2 with ,notes4 ,by ,j4 ,,conington1 ,m4,a4 #gs4 #f;d4 schylus translated into ,english ,verse2 with ,notes1 ,life of schylus1 and ,discourse on ,greek ,tragedy4 ,by ,j4 ,s4 ,,blackie1 ,professor of ,greek1 ,edinburgh4 ,two ,volumes1 #dfs4 ,the ,alcestis of ,euripides2 with ,notes4 ,by ,j4 ,h4 ,,monk1 ,d4,d41 ,bishop of ,gloucester and ,bristol4 #ds4 #f;d4 ,pindar2 with ,notes4 ,by ,dr4 ,,donaldson4 #afs4 ,homeric ,ballads4 ,the ,text1 with ,translation in ,verse1 and ,notes4 ,by ,dr4 ,,maginn4 #fs4 ,mller's ,dissertations on the ,eumenides of schylus4 ,second ,edition4 #fs4 #f;d4 ,c4 ,cornelii ,taciti ,opera ad ,codices ,antiquissimos commentario critico edidit ,,franciscus ,,ritter1 ,professor ,bonnensis4 ,four ,volumes1 ,octavo4 #bhs4 ,propertius2 with ,english ,notes4 ,by ,f4 ,a4 ,,paley1 ,editor of schylus4 ,octavo4 #ajs4 #f;d4 ,plautus3 ,aulularia2 with ,notes4 ,by ,j4 ,,hildyard1 ,b4,d4 #gs4 #f;d4 ,plautus3 ,menchmei2 with ,notes4 ,by ,j4 ,,hildyard1 ,b4,d4 #gs4 #f;d4 ,longer ,exercises in ,latin ,prose ,composition2 with a ,commentary and ,remarks on the best mode of forming a correct ,latin ,style4 ,by ,dr4 ,,donaldson4 #fs4 #f;d4 ,elements of ,logic4 ,by ,,richard ,,whately1 ,archbishop of ,dublin4 ,crown #hvo4 #ds4 #f;d4 ,octavo4 #ajs4 #f;d4 ,elements of ,rhetoric4 ,by ,,archbishop ,,whately4 ,crown #hvo4 #ds4 #f;d4 ,octavo4 #ajs4 #f;d4 ,system of ,logic1 ,ratiocinative and ,inductive4 ,by ,,john ,,stuart ,,mill4 ,fourth ,edition4 ,two ,volumes1 ,octavo4 #bes4 ,an ,historical and ,explanatory ,treatise on the ,book of ,common ,prayer4 ,by ,w4 ,g4 ,,humphry1 ,b4,d41 late ,fellow of ,trinity ,college1 ,cambridge4 ,second ,edition1 enlarged4 #gs4 #f;d4 ,churchman's ,guide3 ,a ,copious ,index of ,sermons and other ,works1 by eminent ,church of ,england ,divines2 digested and arranged according to their subjects4 ,by ,j4 ,,forster1 ,m4,a4 ,octavo4 #gs4 ,on ,public ,reading3 ,garrick's ,mode of ,reading the ,liturgy2 with ,notes1 and a ,discourse on ,public ,reading4 ,by ,r4 ,,cull1 ,tutor in ,elocution4 #es4 #f;d4 ,the ,churchman's ,theological ,dictionary4 ,by ,,robert ,,eden1 ,m4,a41 ,chaplain to the ,bishop of ,norwich4 ,demy #abmo4 #es4 ,,london3 ,,john ,w4 ,,parker ,,and ,,son1 ,,west ,,strand4 ,annotated ,edition of the ,english ,poets1 ,,with ,,introductions1 ,,notes1 ,,and ,,memoirs1 ,historical1 ,biographical and ,critical1 ,,by ,,robert ,,bell4 ,,in ,,volumes1 #bs4 #f;d4 ,,each1 ,,bound ,,in ,,cloth4 ,,ancient ,,poems1 ,,ballads1 ,,and ,,songs ,,of ,,the ,,peasantry4 #bs4 #f;d4 ,,greene ,,and ,,marlowe4 #bs4 #f;d4 ,,early ,,ballads ,,illustrative ,,of ,,history1 ,,traditions1 ,,and ,,customs4 #bs4 #f;d4 ,,ben ,,jonson4 #bs4 #f;d4 ,,chaucer4 ,eight ,volumes1 #bjs4 ,,butler4 ,three ,volumes1 #gs4 #f;d4 ,,thomson4 ,two ,volumes1 #es4 ,,dryden4 ,three ,volumes1 #gs4 #f;d4 ,,shakspeare4 #bs4 #f;d4 ,,cowper4 ,three ,volumes4 #gs4 #f;d4 ,,surrey1 ,,minor ,,contemporaneous ,,poets1 ,,and ,,buckhurst4 #bs4 #f;d4 ,,songs ,,from ,,the ,,dramatists2 from the first regular ,comedy to the close of the #ahth ,century4 #bs4 #f;d4 ,,wyatt4 #bs4 #f;d4 ,,oldham4 #bs4 #f;d4 ,,waller4 #bs4 #f;d4 ,,london3 ,,john ,w4 ,,parker ,,and ,,son1 ,,west ,,strand4 99 99 99 99 99 ,transcriber's ,notes ,obvious typographical errors have been silently corrected4 ,other variations in spelling1 punctuation and hyphenation remain unchanged4 ,in the ,table of ,contents ,chap4 ,,xv4 item #c4 is not listed4 ,in the ,table of ,contents ,chap4 ,,xxviii4 item #e4 ,italics are represented thus italics4 ,the identification of the appendices skips ,i and ,j4