,,aspects ,,of ,,science ,,aspects ,,of ,,science ,by ,j4 ,w4 ,n4 ,,sullivan ,,london ,,richard ,,cobden-,,sanderson #ag ,,thavies ,,inn ,copyright #aibc ,,preface ,the papers which make up this volume have been selected because1 although they deal with different aspects of various scientific ideas1 yet they do illustrate1 more or less1 one point of view4 ,that point of view may be described1 perhaps as sthetic1 but rather better as humanistic4 ,scientific ideas have a history2 they arose to satisfy certain human needs2 to see them in their context is to see them as part of the general intellectual and emotional life of man4 ,what they exist to do they do better than does anything else1 and the needs they satisfy are not peculiar to scientific specialists4 ,these papers try to show one or two of the many reasons why1 for people who are not specialists as well as for those who are1 science may be interesting4 ,j4 ,w4 ,n4 ,,sullivan4 ,,contents ,,page ,,the ,,interest ,,of ,,science #i ,a ,,physicist ,,on ,,physics #bc ,,science ,,and ,,culture #cf ,,james ,,clerk ,,maxwell #da ,,assumptions #di ,,on ,,learning ,,science #gb ,,the ,,entente ,,cordiale #gg ,,popular ,,science #hb ,,patient ,,plodders #hi ,,the ,,amateur ,,astronomer #ie ,,scientific ,,citizens #ajj ,,the ,,sceptic ,,and ,,the ,,spirits #aje ,,the ,,scientific ,,mind #aab ,,the ,,scientific ,,contribution #aaf ,,theories ,,and ,,personalities #abb ,,the ,,ideal ,,scientific ,,man #abh ,,parallel ,,straight ,,lines #acc ,,the ,,new ,,scientific ,,horizon #aci ,,the ,,hope ,,of ,,science #ade ,,the ,,return ,,of ,,mystery #aea ,,mathematics ,,and ,,music #aei ,,human ,,testimony #agg ,,the ,,interest ,,of ,,science ,i ,the conception of science as a body of thought embracing the whole of our rational convictions about reality has hardly yet been generally reached4 ,man is still so far from being a rational animal that the application of rational methods of inquiry to all branches of his experience is still instinctively resisted--as if reason were an alien and hostile intruder4 ,beliefs which are held with passion1 being the expression of instinctive preferences1 are felt not to belong to the 8sphere0 of science4 ,on all questions where his passions are strongly engaged1 man prizes certitude and fears knowledge4 ,dispassionate inquiry is welcomed only when the result is indifferent4 ,nearly every great scientific generalisation has incurred the odium theologicum--which is not the exclusive possession of theologians--from the ,copernican hypothesis to the theory of herd instinct4 ,that science1 although continually wounding men1 should nevertheless have progressed1 is evidence that it serves impulses deeply rooted in man's nature4 ,the great scientific innovator1 like the great altruist1 is treated with ignominy by the society whose deepest instincts he lives to serve4 ,science1 the child of irrational impulse1 has inherited something of the parental character4 ,its history reveals it as purblind and fumbling1 with no clear vision of its aim1 no premonition of its imperial state4 ,unlike philosophy1 it did not aspire to universal dominion4 ,it was content to investigate the particular instance1 and did not reject a certain incoherence in explanation rather than accept a generalisation which did not spring from its own ground4 ,it refused foreign assistance1 but kept its independence4 ,that scientific men did not always understand that science must1 from its nature1 be autonomous1 is evident from the history of every particular science4 ,even as late as ,descartes it was considered quite natural to deduce phenomena from metaphysical principles2 and an admixture of mythical elements is not entirely absent from some branches of science1 even at the present day4 ,science has not yet reached full consciousness of its proper ground and aims4 ,the values served by science1 in terms of which its claim to consideration is to be judged1 have become more numerous as science has developed4 ,the earliest scientific researches were concerned wholly with the particular event1 with1 at most1 the vaguest inkling of large perspectives4 ,the savage who discovers that the branch lying partly in the stream is not really bent1 is prompted by the same localised and detached curiosity which led to most of the early scientific discoveries4 ,interest in the oddity of an event is undoubtedly the root of scientific observations4 ,the more closely the events concern us1 the more pregnant they may be with possible pleasure or pain1 the greater the degree of abstraction necessary to see them in their relations4 ,human beings remain miracles to us long after we have learned to predict the motion of a planet4 ,psychology is the latest of the sciences1 not so much because of the intrinsic difficulty of its subject-matter as because our interest in the subject-matter is so vehement that it is almost impossible to be indifferent to the results4 ,an intelligent fish would probably have found most of the painfully won results of human psychology fairly obvious4 ,from the accumulation of facts and the attempt to see them in relation springs the scientific theory4 ,with the construction of theories science enters on a new phase in its development1 and serves a different set of human values4 ,its facts1 the products of local curiosities1 now take on an order1 and serve the desire for comprehension4 ,the apparently dissimilar becomes related2 law supervenes on chaos4 ,the desire for knowledge becomes transformed into the desire for significant knowledge--significant primarily for contemplation1 and secondarily for practice4 ,it is the scientific theory alone that gives to science its true being and makes it worthy of a deep concern4 ,the desire for comprehension is deeply rooted in human nature4 ,religious myths and philosophical systems arose in obedience to this impulse4 ,science also exists to satisfy this craving1 and the terms on which it does so are altogether to its advantage4 ,the fact that it is an extension of common knowledge1 and infers nothing that cannot be verified1 differentiates it from myth1 and is the secret of the grave and serious satisfaction it affords4 ,those accustomed to this homely1 invigorating atmosphere find the rarer air of much traditional philosophy quite insupportable4 ,a certain indifference to other methods of describing reality becomes more evident as the years advance and the domain of science becomes more and more extended4 ,peaceful penetration takes the place of open warfare1 and in face of rival systems men of science feel less inclined to disprove what they feel more at liberty to ignore4 ,science still falls far short of affording complete comprehension or of providing so finished a picture of reality that we feel no need of other speculations4 ,the different sciences do not yet conspire to form one single coherent body of truth4 ,the interstices between them are still sufficiently large to admit foreign interpretations4 ,but the impulse to comprehension1 which created science1 will be justified by it3 we may have so much faith4 ,even that moiety of mankind who care for little beyond pure immediacy will find that science alone can give them much of what they desire4 ,scientific theories possess a value even to those who are strangers to the pleasures of contemplation1 for science has powerful reactions in the world of practice4 ,to those who have lost their birthright it can offer a mess of pottage4 ,besides serving curiosity1 comprehension and practice1 science offers richly satisfying objects to the sthetic impulse4 ,the language of sthetics is not far to seek in the writings of men of science1 and were it not that the word arouses such a proprietary fury1 we should agree1 reviewing their motives and the kind of their satisfactions1 to call them artists4 ,the matter of the highest art1 like that of true science1 is reality1 and the measure in which science falls short as art is the measure in which it is incomplete as science4 ,all good philosophy1 art or science partakes of the nature of the other two4 ,when these three are regarded as one1 each will have reached its apotheosis4 ,,ii ,it is unfortunately true that as a science advances it grows more complex4 ,not only does its language depart more and more from ordinary speech by the accumulation of technical terms1 but the terms in current use at any time are defined in terms of others which are defined in terms of others--something after the manner of the description of the house that ,jack built4 ,the most obvious case of this ,chinese box kind of language is1 of course1 that of mathematics4 ,a mathematical theorem occupying one line of type might very well occupy a volume if written out in ordinary prose in which no terms were used which were not common property4 ,for this reason modern mathematical discoveries1 except in very special instances1 cannot be made intelligible except to mathematicians4 ,to learn the language of a highly developed science like mathematics takes about as long as to learn ,chinese1 but the task of translation into ,english is very much harder4 ,for this reason mathematicians cannot hope for intelligent popular recognition2 they must be content to be regarded either as vaguely impressive figures or else as mild lunatics busied with incomprehensible and probably trifling abstractions4 ,compared with writers1 musicians or painters1 they are1 for social purposes1 mental outlaws4 ,it is apparent1 however1 that mathematics was not always so remote4 ,it was possible for ,voltaire to take an interest which was1 at any rate1 enthusiastic1 in the work of ,newton4 ,this was doubtless due1 in some degree1 to the obviously dramatic quality of ,newton's discoveries1 but it was also due to the fact that his discoveries could be expressed in comparatively simple language4 ,again1 physics and chemistry at that time1 and for some years later1 were not only intelligible to men without special training1 but such men could actually make valuable discoveries in these sciences4 ,as these sciences progressed their language became more and more forbidding and their fundamental notions more and more abstract4 ,men without special training1 but with scientific curiosity1 turned their attention to the biological sciences4 ,they collected birds' eggs and butterflies2 they bought microscopes and wrote little papers on the sea-shells they discovered in a morning's walk4 ,but biology has now developed a technical language1 and the days of the untrained observer are almost over4 ,the one science which is still1 to some extent1 accessible to these amiable people is psychology4 ,it is growing more technical1 it is true1 but the majority of the books dealing with psychology may still be read almost as easily as a treatise on the history of the ,balkans4 ,and the 8psychological0 novelist can still regard himself as being1 from one point of view1 a scientific man4 ,psycho-analysis is1 as yet1 a favourite subject of discussion in advanced drawing-rooms where discussions of the principle of relativity are comparatively rare4 ,the divorce between science and the general intellectual world is unfortunate1 but inevitable4 ,it is unfortunate both for the scientific man and for the general intelligentsia4 ,the scientific man1 mentally companionless except for the little circle of his immediate co-workers1 becomes less complete as a human being2 he fails as a humanist4 ,he too often accepts his outlawed position and turns his special interests into his exclusive interests1 as if1 through some inverted generosity1 he refused to take where he could not give4 ,he may grow to ignore the other intellectual activities of his time1 as ,darwin1 to his distress1 found he had grown to ignore poetry1 or he may actually become intolerant of such activities and so add contempt to the ignorance with which his preoccupations are regarded by the outside world4 ,for the outside world1 also1 this divorce is unfortunate4 ,for science1 in its own way1 satisfies just the same impulses as do other intellectual interests1 and some of them it satisfies more completely and in a richer way4 ,a great waste of mental energy and much inconclusive discussion would be avoided were certain scientific results more generally known1 and1 more particularly1 were the advantages of the scientific method more widely recognised and the method itself more extensively practised4 ,an air of superiority is often noticed in the references of scientific men to certain current discussions4 ,it is a fault of manner1 but one difficult to avoid4 8,inside0 information usually has this effect on the possessor1 and when it is information that cannot be shared the attitude is apt to become chronic4 ,both sides1 then1 are the poorer for their lack of intercourse4 ,but this state of affairs seems to be inevitable4 ,the claims of the ,latin and ,greek literatures to attention1 whether they are justified or not1 have led to the study of these languages being imposed on perhaps the majority of the people in this country who are predominantly interested in intellectual affairs4 ,it is a training which consumes several years3 is a training in the sciences to be added8 ,this is manifestly impossible4 ,even if our whole educational system were radically altered1 only those sciences1 such as biology and psychology1 which may be understood with comparatively little training1 could ever become objects of common knowledge4 ,but sciences where1 in addition to a severe and prolonged discipline1 special aptitude is necessary1 must always be the property of the few4 ,as1 every year1 all the sciences grow more complex1 so the difficulty of obtaining an adequate knowledge of them increases4 ,a dead language may be learnt once for all1 but the language of a science must be learnt afresh every few years4 ,the popular article of ,huxley's day1 the link between the man of science and the general public1 is now the link between the more and less advanced students of the same science4 ,a so-called 8popular0 account of ,relativity ,theory1 for instance1 is like an annotated edition of ,pindar2 a very fair knowledge of the language is assumed beforehand4 ,it might be thought that the process of reduction1 as it were1 could be continued1 until finally an account was prepared where no technical terms were used4 ,but such an account would be1 at best1 like a translation of ,greek poetry2 the essential quality would be gone4 ,such translations have1 of course1 their uses1 but the attraction of science for the scientific man1 like the attraction of a poem for the poet1 is not to be communicated in this way4 ,in art the separation of matter and form is not really possible1 and the same is true of the sciences4 ,,iii ,in their apologias1 which have now become so common1 men of science never weary of pointing out that it is the method of science which is really worthy of adoption by philosophers and that the results of science are merely provisional4 ,the philosopher who bases his system upon the results reached at any given time by any given science has ensured the ultimate downfall of his system4 ,he is sometimes told that the adoption of scientific methods1 on the other hand1 will enable him to make sure progress4 ,at first sight there seems to be a contradiction here1 for if the scientific method is infallible why are the results reached by it provisional8 ,to judge from the history of science1 the scientific method is excellent as a means of obtaining plausible conclusions which are always wrong1 but hardly as a means of reaching the truth4 ,the contradiction is only apparent1 however1 for it will be found that there is a part of every discarded hypothesis which is incorporated in the new theory4 ,the discarded hypothesis proves to have been too general2 the scientific man made a mistake of the same kind as the philosopher who uses the hypothesis as the basis of a general system4 ,it is now known1 for instance1 that ,newton's theory of gravitation is very probably not exactly true2 in most cases1 however1 it remains very nearly true1 and there are large regions of dynamical astronomy which are unaffected by the alteration4 ,the ,newtonian laws of motion1 again1 are not sufficient to describe the motion of bodies moving with very large velocities1 but they are very nearly true for all ordinary velocities4 ,that the theories which have taken the place of those abandoned are exactly true is very improbable2 they are1 however1 nearer the truth4 ,we may say1 therefore1 that while the scientific method may1 quite possibly1 never enable us to reach the exact truth1 successive applications of it enable us to approximate nearer and nearer to the exact truth4 ,in this lies its chief difference from the methods usually adopted in philosophy1 which aim at obtaining1 at one blow1 theories which shall never need revision4 ,it is for this reason that philosophy does not progress4 ,in what1 then1 does the scientific method consist8 ,it would be difficult to give a precise definition2 it has1 however1 two main characteristics1 the choice of facts and the treatment of facts4 ,it does not seem to be generally recognised that scientific men do choose their facts2 there are many people who suppose that all facts are of equal interest to scientific men1 and that information respecting the number of nightingales heard in ,hertfordshire during a certain month1 for instance1 is a contribution to scientific knowledge4 ,it should be obvious1 however1 that a mere random collection of facts is very unlikely to aid either practice or theory4 ,the aim of science is not to form catalogues1 but to form theories describing phenomena1 and to this end some facts are pertinent and a very great number are not4 ,all men1 faced with a problem of any kind1 choose such facts for examination as they consider relevant4 ,sherlock ,holmes often bewildered ,watson by pondering over facts that ,watson considered irrelevant1 but ,watson's surprise was a proof that even he had a standard of relevance4 ,the history of any science shows that the facts first chosen were those most likely to be repeated4 ,such facts obviously lead to statements which have a greater or less degree of generality4 ,that an unsupported stone falls to the ground is a fact of this kind4 ,the facts chosen by the man of science are those that permit generalisation4 ,for this reason they usually differ entirely from the facts of interest to historians4 ,after selecting1 in accordance with this principle1 the facts which are to be examined1 the next step consists in establishing relations between sets of these facts4 ,the precise expression of these relations is called a law of nature1 to use a somewhat old-fashioned terminology4 ,if now all the relations between certain sets of facts can be expressed in one general statement1 that general statement is called a scientific theory4 ,the ultimate aim of the scientific method is to create scientific theories4 ,the scientific theory1 however1 usually introduces an element which has not been or cannot be directly observed1 and also1 as we have seen1 usually proves to have been too hasty a generalisation4 ,its function is to co-ordinate known phenomena and to predict hitherto unobserved phenomena4 ,the extent to which it does this is the measure of its success as a scientific theory1 and1 since the primary object of the scientific theory is to express the harmonies which are found to exist in nature1 we see at once that these theories must have an sthetic value4 ,the measure of the success of a scientific theory is1 in fact1 a measure of its sthetic value1 since it is a measure of the extent to which it has introduced harmony in what was before chaos4 ,it is in its sthetic value that the justification of the scientific theory is to be found1 and with it the justification of the scientific method4 ,since facts without laws would be of no interest1 and laws without theories would have1 at most1 a practical utility1 we see that the motives which guide the scientific man are1 from the beginning1 manifestations of the sthetic impulse4 ,the reason why certain facts and not others interest the scientific man1 the reason why he makes a choice1 is because truth without beauty is as uninteresting to him as to any other artist4 ,in the words of ,poincar3 8,le savant n'tudie pas la nature parce que cela est utile2 il l'tudie parce qu'il y prend plaisir1 et il y prend plaisir parce qu'elle est belle4 ,si la nature n'tait pas belle1 elle ne vaudrait pas la peine d'tre connue1 la vie ne vaudrait pas la peine d'tre vcue40 ,a ,,physicist ,,on ,,physics ,i ,the well-meant and industrious efforts of professional metaphysicians to explain to men of science in what sense science is true1 in what sense it has meaning and in what its value really consists1 practically all suffer from the defect that men of science do not recognise the subject of investigation as being science at all4 ,it is almost true to say that the professional philosopher is only convincing when he is talking about the ,absolute1 for that is a subject with which nobody else is concerned2 but when he devotes his attention to subjects with which other people are familiar1 it often becomes possible to put the book down before finishing it4 ,thus treatises on sthetics are usually convincing to everybody but poets1 painters and musicians1 and philosophical writings on science are probably in great demand amongst classical scholars4 ,nevertheless1 since philosophising on these subjects is an agreeable mental exercise1 we find that some artists are now engaged in developing an sthetic for themselves1 and some men of science are engaged in trying to find out what science is4 ,in each case the work consists chiefly in making explicit processes which are instinctive4 ,this fact is of the greatest importance1 for1 if the instinctive equipment be lacking1 the results will inevitably be unsatisfactory4 ,there are treatises on sthetics1 for instance1 whose chief effect on the poet is to make him doubt whether the author could tell a good poem from a bad one2 this is an absolutely fatal objection4 ,if poets cannot recognise what they call poetry as being the subject of the discussion1 then1 as a discussion of poetry1 that discussion is worthless4 ,practitioners1 whether artists or men of science1 seldom have the inclination to uncover and dissect what is to them an instinctive and delightful process2 but it is quite easy for them to see 7or1 rather1 to feel7 that a suggested explanation is unsatisfactory1 although they may find it wholly impossible to give reasons for their dissatisfaction4 ,nevertheless1 when this dissatisfaction is due to an inability to recognise the subject-matter1 the explanation must be condemned4 ,it is perfectly possible1 for instance1 that psycho-analysis1 by introducing a mother-complex1 an inferiority-complex1 and two or three more1 might 8explain0 the ,ode to a ,nightingale4 ,but if this explanation left out everything which made poets regard that composition as a poem1 it would not be a satisfactory explanation4 ,we have treated this point at some length because ,dr4 ,campbell1 in a recent valuable book on the ,elements of ,physics1 insists that the physics he is talking about is that of physicists4 ,he has endeavoured to supply a criticism of the terms used in ,physics1 to find what is meant by a ,law1 by a ,theory1 what a physicist means when he says a proposition is 8true10 or that something 8exists10 or that a theory has 8meaning40 ,mr4 ,campbell is perfectly aware that all these subjects have already been treated by the professional metaphysician1 but he claims1 and we have no doubt that his claim is just1 that he is speaking not only for himself but for the great majority of scientific men when he says that in these discussions he not only does not recognise the subject-matter1 but he does not recognise any subject-matter4 ,such words as 8reality0 and 8existence10 as they are employed by metaphysicians1 he finds productive of nothing but great discomfort and intense mental confusion4 ,as he unhesitatingly rejects the hypothesis that metaphysicians are imbeciles1 he thinks this confusion can be due only to the fact that these words are used by metaphysicians in senses quite different from those they bear to men of science4 ,he has not been able to explain precisely in what the difference consists1 since he has not been able to discover what meanings metaphysicians attach to these words4 ,accordingly he has confined himself to explaining the meanings these words have in science4 ,the result is a subtle1 fairly clear1 and frequently entertaining piece of analysis4 ,he acknowledges that his two masters have been ,poincar and ,bertrand ,russell1 and he shows complete familiarity with other writers of the kind4 ,but part of his reason for publishing the book1 he tells us1 is that even the mathematical philosophers occasionally misrepresent science as the experimental physicist knows it4 ,that they are mathematicians and not physicists is a little too evident in some of their conclusions4 ,thus ,mach's idea that the object of science is to economise thought is only plausible1 he thinks1 to a mathematician2 and a fundamental proposition that ,russell and ,whitehead find quite necessary to thought ,mr4 ,campbell does not find necessary at all4 ,he thinks it quite likely1 also1 that scientific thinking is illogical1 but not therefore invalid4 ,the point of view1 in fact1 is that there are different kinds of minds with different needs and different satisfactions1 and ,mr4 ,campbell claims that physicists1 for example1 belong to a certain species and that the science of physics is something which exists in the minds of physicists4 ,therefore this book1 as he insists1 is not only written by a physicist1 but it is written for physicists4 ,he is confident that what he has to say will be found an explicit statement of their instinctive processes1 and he thinks the highest compliment that could be paid to his book would be for physicists to say they knew it all before4 ,now it is true that nobody but a physicist could have written this book and that nobody ignorant of physics could understand it4 ,it may also be true that none but a practising physicist could understand it with the intimacy that ,mr4 ,campbell desires4 ,but any reader who is not1 in ,mr4 ,campbell's sense1 half-educated 7the other half consists of science--preferably physics7 will find the book not only valuable1 but delightful4 ,the slight touch of brusquerie that the metaphysician or the equally unfortunate 8half-educated0 person might attribute to ,mr4 ,campbell from the above exposition is not in the least that of the horny-handed son of toil1 but is the half-humorous impatience of a subtle and vigorous thinker who is by no means nave4 ,there is no reason why the audience that reads ,poincar's popular four volumes should not also read this book1 and there are many reasons why it should4 ,many of the questions raised there are here developed more fully2 most of the questions1 in fact1 raised by the speculations of such men as ,poincar1 ,russell1 ,mach1 etc41 in so far as they affect science1 are here given systematic treatment4 ,we hope to devote a future article to the exposition of some of ,mr4 ,campbell's more interesting results2 we are concerned here to indicate the nature and scope of the book4 ,the present volume is in two pretty distinct parts1 the first part being concerned with the propositions of science1 and the second part with measurement4 ,these are to be followed by ,part ,,iii4 on ,space and ,time1 ,part ,,iv4 on ,force1 and ,part ,v4 on ,energy1 although1 regarding these parts1 ,mr4 ,campbell says3 8,i have not the remotest idea when1 if ever1 they will be published40 ,without anticipating a future discussion of the more technical parts of ,mr4 ,campbell's work1 we may refer here1 because of the general interest taken in the subject1 to the explanation he gives of the fact that while the outside world resolutely marks off ,science from ,art1 yet this distinction is not at all clear to scientific men4 ,it is difficult1 for example1 in studying the life of a great man of science1 to resist the conclusion that his incentives and satisfactions are indistinguishable from those of a great artist4 ,yet it seems to be undoubtedly true that a work of ,art is something personal1 whereas ,science is obviously impersonal4 ,mr4 ,campbell asks us to distinguish between truth and meaning4 ,the truth of science is something impersonal1 but its meaning is personal4 ,the achievement of ,newton and ,maxwell is as personal as that of ,giotto1 ,shakespeare and ,bach4 ,their dreams were not less personal1 nor less delightful1 and it is nothing to their discredit that their dreams also came true4 ,and the fact that the meaning of a scientific theory is something that exists1 perhaps1 only for men of science1 has an obvious parallel in ,art4 ,the following passage from ,mr4 ,campbell's book is one to which every man of science would give instant assent3 ,nobody who has any portion of the scientific spirit can fail to remember times when he has thrilled to a new discovery as if it were his own4 ,he has greeted a new theory with the passionate exclamation1 8,it must be true60 ,he has felt that its eternal value is beyond all reasoning1 that it is to be defended1 if need be1 not by the cold-blooded methods of the laboratory or the soulless processes of formal logic1 but1 like the honour of a friend1 by simple affirmation and eloquent appeal4 ,the mood will and should pass2 the impersonal enquiry must be made before the new ideas can be admitted to our complete confidence4 ,but in that one moment we have known the real meaning of science1 we have experienced its highest value2 unless such knowledge and such experience were possible1 science would be without meaning and therefore without truth4 ,,ii ,what kind of ,physics would be developed by a man alone on an island8 ,we are assuming1 of course1 that this favourite figure of speculative writers enjoys the properties usually attributed to him2 he is remarkably intelligent1 and can create by a word any scientific apparatus he requires4 ,the point is that he has no need to take into account the judgments of other people4 ,let us choose an experiment designed to make clear the consequences of his isolated state4 ,suppose our islander1 after looking at a red patch1 glances at a white ceiling4 ,he sees a green patch4 ,now suppose that he heats a copper wire in the flame of a ,bunsen burner4 ,the flame turns green4 ,will our islander proceed to construct a physics which shall embrace both these observations8 ,before we can answer this question we must consider why our own physics distinguishes so sharply between them4 ,in the first place1 it may be said that all observers1 except the man who contemplated a patch of red1 agree that the colour of the ceiling is unchanged1 whereas1 in the case of the copper wire1 all observers agree that the flame has turned green4 ,in the first case1 therefore1 we say that there has occurred a change in the observer1 and in the second case a change in the flame4 ,we invoke the criterion of universal assent4 ,but it can readily be shown that we have not1 in fact1 invoked this criterion1 for in saying that the flame has turned green1 we have left out the testimony of colour-blind persons4 ,not everybody would agree that the flame has turned green1 and on what principle are we to decide between the conflicting opinions of different observers8 ,mr4 ,campbell's examination of this question appears to take us to the root of the matter4 ,universal assent is involved1 but also something more1 and it is the something more which will probably enable our islander to form a physics like our own4 ,let us first consider the way in which universal assent is involved in science4 ,we must obviously leave out judgments of colour2 similarly1 science does not now measure electrical quantities in the manner of ,cavendish1 by comparing the intensities of electric shocks experienced by the observer4 ,science makes a choice of the judgments it shall consider2 it does not even embrace all judgments for which universal assent may be obtained4 ,the judgments on which science is based1 and for which universal agreement may be obtained1 are divided by ,mr4 ,campbell into three groups3 7#a7 ,judgments of simultaneity1 consecutiveness and 8betweenness0 in time2#a 7#b7 ,judgments of coincidence and betweenness in space2 7#c7 ,judgments of number1 such as1 ,the number of the group ,a is equal to1 greater than or less than1 the number of the group ,b4 ,now it is judgments of this kind that are involved in physical observations3 the deflection of a spot of light on a scale1 the reading of a stop-watch1 and so on4 ,these judgments are fundamental to science and are such that universal assent may be obtained for them4 ,let us now consider the case of the copper wire in the ,bunsen flame4 ,we have said that not all people will agree that the flame has turned green4 ,but the light from the ,bunsen has other properties than its colour2 it has a measurable refrangibility and a measurable wave-length4 ,the important point for physics is that all observers1 both 8normal0 and colour-blind1 would agree on these measurements1 since they are connected with the fundamental judgments mentioned above4 ,the fact that different observers associate these same measurements with different colours is a fact of no importance for physics2 8colour0 is not a notion essential to physics at all2 when phrases containing such words as 8red0 or 8yellow0 occur in physics they may always be replaced by words depending for their meaning solely on fundamental time1 space and number judgments4 ,it is for this reason1 then1 that science builds on perfectly sure foundations2 its foundations can only be denied by an imposter1 that is1 by one whose actions show that he actually believes what he says he denies4 ,now1 how does this apply to our islander8 ,we may assume that he can measure refrangibility and wave-length4 ,he finds that1 in these particulars1 the light from the ceiling is unaltered1 while the light from the ,bunsen flame is altered4 ,but these observations have no greater support than his colour judgments4 ,on both occasions the only testimony is his own4 ,but he would notice a great difference directly he began to establish the laws connecting these phenomena4 ,the laws derived from the second set of observations would be much more satisfactory than those derived from the first set4 ,he would undoubtedly prefer them and would unhesitatingly adopt them4 ,when it is put in this way1 there certainly seems something arbitrary about the process by which science selects its fundamental judgments4 ,they are selected because they fall neatly and satisfactorily into laws4 ,mr4 ,campbell further suggests that the laws used in science are selected from amongst other possible laws because the selected laws fit into theories1 8the form of which is dictated chiefly by preconceived ideas of what a theory should be40 ,it may be stated at once that ,mr4 ,campbell admits the presence of an arbitrary element in science1 but it is precisely his case that this arbitrary element gives to science its value4 ,we cannot here summarise his exposition1 because it would be unintelligible except to readers with a scientific training1 since ,mr4 ,campbell has adopted the very sound method of analysing the actual laws and theories current in physics4 ,we may indicate1 however1 the general lines of his investigation4 ,he attempts to analyse the kind of relation involved in a scientific 8law40 ,it has been generally assumed by philosophers that this relation is the 8causal0 relation1 but1 in fact1 it is very doubtful whether this relation is ever used in the statement of laws4 ,it is a very special kind of relation1 and its supposed importance to science seems to rest on a confusion between the psychological process in an observer performing an experiment and the relation stated to exist between his observations4 ,thus1 in ,ohm's ,law1 does the potential difference enter as cause or effect of the current8 ,the question is sufficient to show that the causal relation is not concerned4 ,mr4 ,campbell admits that he has not succeeded in making a final analysis of the propositions called laws1 but we think that he has certainly established several points of great value4 ,it is more to our present purpose1 however1 that this analysis shows more clearly how an arbitrary element enters into scientific laws4 ,a law does not simply relate concepts in a manner consistent with observation2 it would be perfectly possible1 for instance1 to replace ,ohm's ,law1 expressing simple proportionality between current and potential difference1 by a much more complicated expression which should agree equally well with observation4 ,there are always several laws which will satisfy the observations2 the one that is chosen is chosen for its simplicity1 i4e41 because of the mental satisfaction it affords4 ,the fact that it does fit the observations gives it what ,mr4 ,campbell calls its 8truth10 and the fact that it affords intellectual satisfaction gives it what he calls its 8meaning40 ,when we pass from laws to theories we find that the element of 8meaning0 becomes much more prominent4 ,now the truth of a law is something that rests on universal assent2 this is not the case1 however1 for the meaning of a law4 ,it may be that the contemplation of ,ohm's ,law gives you no satisfaction whatever2 if it satisfies me1 however1 then to me it has meaning4 ,it is only necessary1 therefore1 that scientific laws should have meaning for scientific men2 their truth1 however1 is the same for all4 ,when we come to consider theories we find that1 concerning their meaning1 there is much more difference of opinion4 ,this difference1 in fact1 almost follows national lines1 so that of the two great classes of theories1 the 8mechanical0 and the 8mathematical10 the former is largely a product of ,british physicists1 while continental physicists prefer the second type4 ,mr4 ,campbell analyses very acutely the differences between the two classes as well as the elements they have in common4 ,as he says1 there may be a 8taste0 for certain kinds of theories1 as there is a taste for oysters4 ,the result of this analysis is to show very clearly in what respects science is impersonal and in what respects personal2 it also helps to make clear what science is4 ,it is true that the impersonal element in science is the most important1 in this sense1 that if any law or theory can be shown not to be true1 then1 however much meaning it may have1 it must be at once rejected4 ,it is also true that it is the meaning of laws and theories1 particularly theories1 which gives them their value to scientific men4 ,we therefore reach once more the conclusion1 sufficiently familiar1 but seldom so satisfactorily prepared1 that the value of science is in the sthetic satisfactions it affords4 ,in ,mr4 ,campbell's words1 8,science is the noblest of the arts40 ,,footnotes3 ,footnote #a3 ,assuming1 in accordance with the principle of ,relativity1 that all observers have the same motion4 ,,science ,,and ,,culture ,the influence of scientific discoveries on that vaguely defined complex of beliefs and intellectual interests called culture seems1 at first sight1 to have something paradoxical about it4 ,there can be no question that this influence is very widespread1 and there can be as little question that ignorance of scientific discoveries is equally widespread4 ,if our admittedly cultured classes were submitted to such a questionnaire as the workers in ,sheffield were recently called upon to answer1 we should doubtless find that such questions as ,who was ,dante8 ,who was ,plato8 would act like holes in a dam2 but it is to be feared that the questions under the heading ,science would evoke the merest trickle of information4 ,and yet many of the questions in other parts of the questionnaire would be answered very differently were it not for those scientific discoveries of which the examinee can give no satisfactory description4 ,the apparent paradox is resolved by remembering that it is only the broadest generalisations of science1 and only certain aspects of those1 which exert a marked influence on the rest of a man's beliefs4 ,the varied and highly complicated studies which make up modern astronomy1 for instance1 can be known1 in any real sense1 to but a few specialists2 the one significant thing1 for purposes of general culture1 that emerges from these studies1 is that the earth is materially insignificant in the universe4 ,we need not mind if so much knowledge and no more percolates through the barriers of a literary education2 the damage is done2 the rest of the man's beliefs begin to be profoundly affected4 ,in the papers on geology and biology the majority of cultured people would fail2 they would all be amused1 however1 at the idea that the earth was formed in #djjd ,b4,c4 and that man was a special and separate creation4 ,psychological studies have not yet reached1 perhaps1 a great and easily understood generalisation1 but there is a growing charity vis--vis the 8criminal classes0 and other moral outcasts4 ,our ,victorian parents' hearty condemnation of everybody they disliked is now just a little more difficult4 ,such generalisations as we have been mentioning are important to general culture because of what we may call their perspective effect4 ,their bearing on the rest of a man's mental furniture is not direct2 they put the furniture in a different setting4 ,a change of residence1 if the difference between the two houses be sufficiently marked1 may well lead to a change of habits1 and the furniture which looked quite well in four rooms may seem a little inadequate in forty4 ,those writers who declare that there is no 8real0 conflict between science and religion1 for instance1 may be perfectly good logicians2 the point is whether a particular religion looks adequate in the modern universe of science4 ,it is not a question of destroying the furniture2 it is whether the contents of a bijou villa adequately furnish ,salisbury ,plain4 ,the influence of science on philosophy is similarly indirect4 ,perhaps there is no philosophy which does not still find defenders2 our objection to many of these philosophies is not that they are illogical1 but that they look so funny4 ,when we come to study the influence of science on the arts we see that there is yet another way in which science modifies culture4 ,many of the pleasurable emotions associated with the arts are not unknown to the student of science4 ,the study of such sciences as astronomy1 physics or biology awakens emotions not readily distinguishable from those evoked by even the greatest works of art4 ,it is as if the universe with which science deals was itself a work of art2 it is1 to an increasing number of people1 the greatest of all works of art4 ,such students often acquire a new standard of sthetic excellence4 ,darwin's indifference to poetry in his later years was probably the result1 not of the atrophy of a faculty1 but of its fuller exercise elsewhere4 ,the young ,william ,thomson1 reading at night in the library1 and drawing great breaths of rapture over ,lagrange's ,mcanique ,analytique1 was experiencing emotions probably not very different from those of ,swinburne when reading ,shakespeare4 ,before such satisfactions become accessible to the ordinary cultured classes more is required than that vague acquaintance with outstanding generalities to which we have referred4 ,in such a science as astronomy the mere results are often sufficiently attractive to rouse pleasurable emotions in the reader1 although the actual march of the investigation by which the results were obtained is often of equal interest4 ,at the present day both results and the broad lines of the investigations are in many cases accessible to the ordinary cultured person1 with the result that his intellectual interests are added to1 or at least find a new field for deployment4 ,a greater number of sthetic objects people his world1 and it may even happen that the new arrivals affect the estimate in which he held the old4 ,he may discover an unsuspected futility in some of his earlier occupations2 he may1 in fact1 change his ideals of culture4 ,but it is1 in truth1 impossible to trace precisely the effect on an individual of a new belief or of a new interest4 ,psychologists have made us aware of the fact that the mind is not only immensely complex1 but that the connections between its elements are often of the most unsuspected character4 ,destruction of an old belief or the grafting of a new interest may issue in results as unlike their cause as the butterfly is unlike the chrysalis4 ,the effect of the impact of science on the old culture cannot be foreseen2 it has1 however1 already produced such changes that the culture of the comparatively near future will probably differ from ours by more than ours differs from that of ,babylon4 ,,james ,,clerk ,,maxwell ,the place that will be held by ,james ,clerk ,maxwell in the history of physics is not easy to determine4 ,that it will be a very high place is obvious1 that he will emerge as the greatest of the physicists of the nineteenth century is probable1 but the student of ,maxwell must feel that this kind of ranking is somehow irrelevant1 or likely to become irrelevant1 to his peculiar effect4 ,the unique impression produced by ,maxwell's achievement is not adequately described by being referred to his 8originality40 ,there are different ways of being original2 it is not a sufficiently penetrating term4 ,a number of ,maxwell's scientific contemporaries were original men1 but one is conscious that they had more in common with one another than ,maxwell had with them4 ,an exception from this statement is found in ,w4 ,k4 ,clifford1 who1 as has often been remarked1 had a genius curiously akin to ,maxwell's4 ,both men were exceptionally independent thinkers1 both men resisted the attraction of the high road2 both men1 if the term may be permitted1 had a personal and unique angle of approach to the problems of their time4 ,but this1 though true1 is not a sufficient description4 ,it is important that in neither case do we feel their individual quality to be an eccentricity2 their work has a power1 and1 still more1 a comprehensive serenity1 which is never the product of mere oddity--the oddity1 for instance1 of a ,samuel ,butler4 ,if we try to get closer to this elusive and important characteristic we do not meet with much success2 but we may suggest that the ideas of these men have the effect of springing from an unusually rich1 subtle and comprehensive context4 ,the fundamental ideas of the science of their time were subtly modified by reception into these minds2 they were connected in a personal and unusual web of implications4 ,it is doubtless worth noting in this connection that ,maxwell1 unlike most of the scientific men of his time1 was genuinely interested in metaphysical speculation4 ,this was not merely another interest of his2 it was1 at most1 another field of attention2 he brought the same attitude of mind to all the objects with which he was concerned4 ,we cannot make an exception even in the case of his religious views2 to this man the problems of metaphysics1 of physics1 of morality1 are almost arbitrary divisions of the one object of his thought4 ,he was expressing a real difference from himself when he said that some men seem to have water-tight compartments in their minds4 ,when we study the kind of homogeneity characteristic of ,maxwell's mental life it is easy to understand those who call him a mystic4 ,even as a purely scientific man1 his rational faculty1 as evidenced by his mathematical reasoning1 was a distinctly more fallible thing than his intuition4 ,this is not to say that he was not a fine mathematician1 but it is his intuitive grasp of a physical problem which gives him his high position1 and not his purely mathematical verifications4 ,his mathematics1 in fact1 was not always impeccable1 as ,sir ,joseph ,larmor points out in the new edition of ,matter and ,motion4 ,but it is characteristic of ,maxwell1 that1 even when his proofs were faulty1 his results were usually sound4 ,his own way of confirming a difficult intuition was not to provide a formal mathematical verification1 but to make appeal to easier intuitions--in fact1 to construct mechanical models4 ,he always liked to see the way things worked4 ,it is important to remember that this desire for a particular kind of verification was not due to any lack of power to form abstractions2 it was due to something quite different1 to a lack of ease when faced by a purely logical chain of deduction4 ,on ,maxwell's famous ,treatise on ,electricity and ,magnetism1 ,poincar comments that its difficulty resides precisely in its great abstraction4 ,it is this presentation of his theory to which one has to turn2 nevertheless ,maxwell1 as if for his private satisfaction1 developed some extremely complicated models which seemed to him to make his theory clearer4 ,it was doubtless this combination1 a great power of abstraction on the one hand1 and a desire for very definite1 even unnecessarily definite1 confirmation on the other1 which enabled him to be at once extremely original and remarkably sound4 ,in his boyhood he was constantly making all kinds of experiments with common substances1 drawing complicated diagrams1 constructing solid geometrical figures1 even knitting elaborate pieces of wool-work2 practically all these pursuits were dictated by the same desire1 the desire to see an abstract principle embodied in a concrete instance4 ,no man was less at the mercy of words4 ,but it was1 nevertheless1 the abstract principle with which ,maxwell was concerned2 he merely wished to be quite sure that he understood it4 ,his occasional trick of supplying an unexpectedly simple proof of a difficult theorem is due to this habit of realisation4 ,platitudes acquired a wealth of implication in ,maxwell's hands4 ,during his student life at ,cambridge1 when he seems to have been chiefly occupied in making a survey of things in general1 we find the same desire to reduce everything to a few principles2 but the principles must first stand a rigorous examination4 ,merely vague unifications provoked his irony1 and where no principle could be made to work1 then1 in spite of his love for coherent and inclusive systems1 he would admit ignorance4 ,and1 in spite of his need for principles1 and the tenacity with which he clung to those that met his need1 he claimed no 8absolute0 quality for his beliefs4 ,in his own words1 8,nothing is to be holy ground consecrated to ,stationary ,faith1 whether positive or negative40 ,and1 later1 8,again1 ,i assert the ,right of ,trespass on any plot of ,holy ,ground which any man has set apart44440 ,such questioning as ,maxwell applied to himself was to be applied to all other men4 ,he was conservative1 but not on exterior authority4 ,his scepticism was1 in truth1 very profound1 and it was always present4 ,it informs his criticism1 which is often extremely penetrating4 ,the letters he wrote on the death of his friend ,pomeroy1 shortly after ,maxwell had become a ,fellow of ,trinity1 are very instructive from this point of view4 ,his distrust of the 8rationalisations0 that men give of their beliefs extends to the beliefs themselves4 ,as he says1 men 8are ignorant even of their own true faith till something brings it into action40 ,this was a deep-rooted conviction with him1 and is responsible for the flavour of irony which is never long absent from his comments on philosophic matters1 indefatigable student as he was4 ,he can direct this scepticism against himself1 as in the entry in his programme of future study3 8#d4 ,metaphysics--,kant's ,kritik of ,pure ,reason in ,german1 read with a determination to make it agree with ,sir ,w4 ,hamilton40 ,on another occasion he writes to a friend pointing out that1 in reading an author1 he had to find out first of all1 not what the author meant1 but that it was not what he was convinced must be meant4 ,a little experience of criticism persuades us that this is1 indeed1 a very necessary procedure4 ,this aspect of ,maxwell1 as a critic at large1 as it were1 would well repay study1 and it is unfortunate that our material for it is contained in a scarcely ideal biography4 ,he differed from the run of scientific men1 whose absorption in one pursuit makes their mental life unrepresentative2 his chief problems are not found in his scientific writings1 and they are the problems of us all4 ,there was nothing superficial in ,maxwell1 and he had no easily won conclusions4 ,it is the path he followed that gives interest to his goal4 ,we should like to know1 for instance1 what experiences1 what reflections1 enabled him to write3 8,long ago ,i felt like a peasant in a country overrun with soldiers1 and saw nothing but carnage and danger4 ,since then ,i have learned at least that some soldiers in the field die nobly1 and that all are summoned there for a cause40 ,that ,maxwell1 either suddenly or gradually1 developed a mystic consciousness of life1 is borne out by many passages of his correspondence4 ,we can attach no other significance to his description of his 8nostrum03 8an abandonment of wilfulness without extinction of will1 but rather by means of a great development of will1 whereby1 instead of being consciously free and really in subjection to unknown laws1 it becomes consciously acting by law1 and really free from the interference of unrecognised laws02 and his letters to his wife1 dealing with passages from the ,bible1 abound in interpretations which are indubitably mystical4 ,yet we have no evidence that he was acquainted with the literature and terminology of mysticism2 he is speaking of personal experiences1 not of acquired doctrines4 ,the maintenance of a mystical outlook on life1 together with a perfect realisation of the implications of physical science1 was accomplished1 in ,maxwell's case1 by denying the ordinary conception of the direction of scientific progress4 ,it is the idea which would inevitably occur to him1 for it is the peculiar merit of his own work that it was not the result of straightforward progress4 ,he made a new way of thinking necessary just as1 in our own time1 ,quantum ,theory and ,relativity ,theory have fundamentally disturbed our most unquestionable assumptions4 ,the way ,maxwell actually approached the problem we have mentioned was by insisting on what he called1 by a mathematical analogy1 the 8singular points0 of existences1 that is1 the points where the equations break down1 and he postulated that the more there were of these singular points the higher the rank of the existence4 ,at a 8singular point0 influences which are usually negligible may assume a dominating importance1 and ,maxwell saw the science of the future as being largely concerned with these lapses in continuity--as1 in fact1 science since his time has been4 ,in this way he escaped determinism4 ,in his own words3 ,if1 therefore1 those cultivators of physical science from whom the intelligent public deduce their conception of the physicist1 and whose style is recognized as marking with a scientific stamp the doctrines they promulgate1 are led in the pursuit of the arcana of science to the study of the singularities and instabilities1 rather than the continuities and stabilities of things1 the promotion of natural knowledge may tend to remove that prejudice in favour of determinism which seems to arise from assuming that the physical science of the future is a mere magnified image of that of the past4 ,this speculation1 the problem of evil1 and in what sense the individual may be said to persist in ,time1 are the kind of questions which concerned him during the last years of his life4 ,it would be merely fanciful to mention these things as evidence of that 8context0 of which we spoke1 but we think it is possible to understand more intimately the origin of the ,electromagnetic ,theory of ,light if we remember that it originated in a mind which also constantly entertained these other1 and apparently disconnected1 speculations4 ,,assumptions ,i ,it has been remarked that man's senses were given him1 not to philosophise with1 but to help him in the struggle for existence2 ,boltzmann1 the great ,german physicist1 was frankly distrustful of many of the natural motions of the mind4 ,he could admit that ,science1 although often very abstract1 had a certain validity1 since it issues in the prediction of events which are accessible to sense perception4 ,but philosophy1 he insisted1 was in an altogether different case1 and he thought the chances considerable that its impalpable conclusions were the merest moonshine4 ,it is a speculation that must have exercised everyone who has whole-heartedly accepted the evolutionary account of the rise of intelligence4 ,why should this instrument be adapted to other than its original uses8 ,doubts of this kind1 however1 are both too vague and too comprehensive to serve any useful purpose4 ,they do not tell us in what way and to what extent our intelligence is untrustworthy2 they do not enable us to make one step towards drawing up an ,index of ,forbidden ,subjects4 ,at the most they enable a man with a constitutional dislike of philosophic speculations to indulge his contempt for that occupation with an easy conscience4 ,nevertheless1 a tincture of this doubt is very wholesome1 and more particularly if it be the result of an acquaintance with the history of human thought rather than the product of a kind of lazy a priori scepticism4 ,a student of the history of science1 for instance1 is inevitably led to reflect on the curious nature of the barriers to further advance which the mind itself has set up4 ,it is as if the mind could only take exercise within some imaginary prisoner's yard1 and that the great advances were really the result of liberations4 ,these liberations are only partial2 the mythical boundaries are set a little further off1 but it is agreed that the high walls exist4 ,it is interesting to review the progress of ,science from this point of view1 to see it as a gradual secession from unwarrantable assumptions4 ,the exceedingly cautious1 the almost groping character1 of the advance of knowledge1 becomes very apparent4 ,and1 although such a survey may lead us to become very conscious of this particular mental limitation1 we are not one whit nearer being enfranchised4 ,it is still the prerogative of genius to be innocent1 to turn surprised eyes on one of our most arbitrary assumptions1 and to say3 ,but that is not necessary4 ,the history of ,astronomy1 of course1 provides some of the best examples of mental prison yards4 ,that the planets must move in circles because the circle is the perfect figure is an assumption now sufficiently remote from our acquired sense of probability to seem exceedingly strange4 ,that it was an assumption possessing a high degree of obviousness is apparent from the fact that even ,copernicus did not question it4 ,the attempt to enter into this assumption1 to see it as obviously reasonable1 would be a useful exercise for the historian1 since it involves1 very largely1 a reconstitution of the mental life of that age4 ,it acquired its obvious character from the fact that it fitted in2 it was the natural companion of a great number of other equally obvious assumptions2 it was not an isolated eccentricity of the mind4 ,it is for that reason that ,copernicus never freed himself from it1 and that ,kepler only succeeded after a difficult struggle4 ,kepler was required to question not merely an isolated doctrine1 but to escape from a veritable ,zeitgeist4 ,the ,inquisitorial examination of ,galileo1 also1 was not directed merely to correcting the erroneous statement of an isolated fact2 it was1 in truth1 a whole system of thought that stood on trial4 ,it is this double aspect of any given abandoned assumption that accounts for our unimaginative surprise on learning that very intelligent men once mistook it for an obvious truth4 ,we are judging the assumption1 not on its own merits1 as it were1 but from the standpoint of an alien system of thought4 ,we can form a juster estimate of the degree of credulity manifested by the contemporaries of ,copernicus by considering assumptions that have been but recently questioned1 or rather1 which have only recently been generally questioned4 ,the assumptions regarding animal psychology form a vivid example4 ,such men as ,darwin and ,romanes found it quite natural to assume that the emotions and many of the intellectual processes of which they were conscious in themselves furnished an adequate key to animal behaviour4 ,it is an assumption which the average educated man of to-day makes quite readily1 although he may not share ,aristotle's views on the perfection of circles4 ,we now know that there is no reason whatever to suppose1 for example1 that the psychology of snails has the slightest resemblance to the psychology of human beings4 ,we may be confident that1 in a very few years1 the assumptions of ,darwin and most other people will appear almost inexplicably gratuitous4 ,it will take longer1 we think1 for the ,freudian ideas about man himself to become acclimatised2 man will take a long time to learn that in trusting his immediate awareness of himself he is making a number of unwarrantable assumptions4 ,the system of thought into which his present assumptions fit is so profound and extensive that it is impossible1 even now1 to picture the thoroughly enfranchised man4 ,a general acceptance of the ,einsteinian ideas of space and time is easier to predict4 ,the current conceptions of space and time1 although ,euclidean when reduced to a logical scheme1 are not1 in fact1 present as a logical scheme in the mind of the ordinary man4 ,he is sufficiently vague about his fundamental assumptions to offer no strenuous resistance to their subtle modification4 ,we think that part of his general bewilderment about ,einstein's space and time is due to his bewilderment on thinking about space and time at all4 ,his assumptions on these questions1 whatever those assumptions may be1 are not really part of a general scheme of beliefs4 ,nothing that greatly concerns him is incompatible with non-,euclidean geometry1 and we confidently expect that the grandchildren of the ordinary man will as blandly believe they have swallowed ,einstein as the contemporary ordinary man believes he has swallowed ,euclid4 ,for an assumption which is not an integral part of a general scheme of thought is readily abandoned4 ,it is the lopping of connections which the mind resists4 ,it is no paradox to say that the mathematician and philosopher finds it harder to accept ,einstein than does the ordinary man4 ,that is because the mathematician's acceptance involves both believing more and disbelieving more4 ,,ii ,probability is1 of course1 the guide of life4 ,if all our assumptions were expressed1 we should find the phrase 8it is reasonable to suppose0 occurred more frequently than any other1 whether we were engaged in crossing a street or in writing a philosophical essay4 ,yet our perception of the reasonableness of anything rests on a sentiment which is often very delicate and extremely difficult to define4 ,the mathematicians have succeeded in giving exact expression to some of the simplest manifestations of this sentiment1 but most of the cases we are called upon to solve in ordinary daily life cannot be dealt with by their analysis4 ,it is the great strength of science that it builds wholly upon this sentiment4 ,we are not called upon to 8transcend0 reason by faith2 we are asked to believe nothing that sins against our sense of probability4 ,it is admitted1 of course1 that there are scientific theories that do not sound reasonable on a first hearing2 indeed1 they sometimes outrage common sense1 and every scientific engineer knows the difficulty of persuading the 8practical0 man that the obvious thing is not always the right thing4 ,nevertheless1 it is claimed for science that1 on the evidence1 its conclusions are the most reasonable ones even when they are wrong4 ,the sense of what is reasonable depends upon the evidence1 but the word 8evidence0 must often be taken to include a great deal of which the mind is not fully conscious4 ,it was at one time thought quite reasonable that the heavenly bodies should move in circles round the earth4 ,the belief was not wholly a matter of astronomical evidence4 ,it was considered that there was something peculiarly and inherently reasonable in circular motion for heavenly bodies4 ,we can see that this expectation was connected with the sthetic properties of the circle1 and we now think that expectations based on such considerations are1 in astronomical matters1 illegitimate4 ,something akin to such considerations still plays a part in science1 however1 although in a less obvious form4 ,other things being equal1 a simple explanation of natural phenomena is preferred to a more complicated one1 although1 as ,fresnel remarked1 there is no a priori reason to suppose that ,nature takes any account of analytical difficulties4 ,the history of the ,copernican theory of the solar system is instructive from this point of view4 ,the notion that the ,earth and other planets went round the sun immediately made a number of puzzling things clear4 ,it seemed1 on the whole1 a very reasonable notion4 ,it was attended1 however1 by one great difficulty4 ,if1 at the end of six months1 the earth were really at opposite ends of a long line1 it should follow that the stars1 viewed from these two points1 should seem to shift their relative positions in the sky1 just as the trees in a wood seem to change their relative positions as we pass them in a train4 ,tycho ,brahe1 one of the greatest astronomers who ever lived1 was so impressed by the fact that this expected change does not occur1 that he could not accept the ,copernican theory as it stood4 ,he invented a curious hybrid theory of his own1 according to which1 while the other planets went round the sun1 they1 together with the sun1 revolved round the earth4 ,he does not seem to have made many converts to this view2 it somehow offends one's sense of probability4 ,the ,copernican hypothesis persisted1 in spite of the difficulty we have mentioned1 but not without causing considerable mental discomfort4 ,when ,horrebow at last thought that he had obtained evidence of the apparent annual motion of the stars he published his discovery under the title ,copernicus ,triumphans4 ,it was found1 however1 that the supposed differences were caused by temperature changes affecting the observer's clock1 and the old difficulty persisted4 ,it might be thought that the correct solution was obvious2 one had only to assume that the stars are so far away that1 with such instruments as were then used1 their apparent motion is imperceptible4 ,we now know that this solution is the right solution1 but in the eighteenth century it did not appear a reasonable solution4 ,it was felt that if the stars were really at such immense distances as this hypothesis required1 then ,nature showed a grave lack of economy in space4 ,such enormous stellar distances pointed1 so far as these astronomers could see1 to a most unreasonable waste of space4 ,no farmer would behave in such a fashion1 and although the eighteenth-century astronomers would have denied that they viewed the universe as a gigantic farm1 yet this delicate and elusive notion of what is reasonable was1 in this case1 greatly influenced by farming considerations4 ,it is not possible to form reasonable expectations except on the basis of experience1 and sometimes the most irrelevant considerations play a part in our estimate4 ,as instruments improved1 however1 the expected motion was observed1 and the distances of some stars calculated4 ,they proved to be enormous2 the great waste of space does occur4 ,god is not a farmer4 ,this being established1 one could approach the general problem of stellar distribution free from certain prepossessions4 ,one's sense of the reasonable acquired a different orientation1 as it were4 ,but it still remains reasonable to suppose that the brighter stars are1 on the whole1 nearer to us than the fainter stars4 ,this assumption must1 however1 be employed with caution4 ,if a list be formed of the nearest stars from amongst those whose distances have actually been determined1 we reach some rather unexpected results4 ,knowing the apparent magnitudes of these stars1 and their distances1 we can calculate their actual luminosity compared with the sun as a standard4 ,the apparent magnitudes range from ,sirius1 which is considerably brighter than a first-magnitude star1 to stars of more than the ninth magnitude1 that is1 to stars quite invisible to the naked eye4 ,some of the nearest stars may be fainter yet1 for determinations of the distances of stars fainter than magnitude #i4e are lacking4 ,the actual luminosities of these stars range from forty-eight times that of the sun to four-thousandths that of the sun4 ,the actual distribution of the nearer stars is not at all that which would appear reasonable if we were guided by considerations of apparent brightness4 ,some of the very brightest stars1 such as ,canopus1 must be at inconceivable distances1 and their actual brightness must be thousands of times1 perhaps very many thousands of times1 that of the sun4 ,here again our unsophisticated notion of what is reasonable is apt to be more of a hindrance than a help4 ,excellent as a guide through not too unfamiliar country1 it is apt to lead us sadly astray when we advance into completely unknown territory4 ,nevertheless1 it is the only guide we have4 ,,iii ,if we contrast ancient with modern scientific theories we find that the chief distinguishing characteristic of the former is that they employ principles drawn from other branches of knowledge or speculation4 ,it would be1 perhaps1 rash to say that modern science1 in all its branches1 is yet completely autonomous2 sometimes1 for instance1 it seems to make assumptions which are the result of an uncritical philosophy1 but even the grossest of these examples1 compared with many celebrated early scientific theories1 shows how great is the purification that has been effected4 ,the chief error of the old speculators consisted in imagining that the world is a more obvious unity than we have now any reason to suppose4 ,hence they were always willing to argue by 8analogy10 comparing terms between which we cannot now find the slightest resemblance4 ,the method was not only illegitimate1 but sometimes led to quite unnecessary complexities of explanation4 ,the ,ptolemaic system of astronomy1 for instance1 conceived as the theory that the heavenly bodies revolve round the earth1 was a perfectly reasonable and satisfactory theory4 ,it was capable of explaining all the observed planetary motions1 except a few minute irregularities requiring precise measurements for their detection4 ,its proper development required1 of course1 complete docility in face of the facts4 ,but in its actual development it was forced to accommodate itself to quite other considerations4 ,it had to take into account the venerable principle that1 the celestial bodies being obviously sublime1 incorrupt and perfect1 their orbits must be perfect and described with uniform velocities4 ,the only possible perfect orbit was as obviously a circle4 ,hence the ,ptolemaic theory was loaded with the task of explaining the observed heavenly motions on two grounds3 first1 that the earth was stationary and at the centre of the system1 and second1 that the planetary orbits were circular and described with unvarying velocities4 ,alternative hypotheses were not only stupid but impious4 ,the task thus set to the early astronomers was one of considerable difficulty4 ,the observed path of a planet1 say ,mars1 or ,jupiter1 or ,saturn1 is by no means simple4 ,if its motion amongst the stars be watched from night to night it is seen to be moving sometimes from east to west and sometimes from west to east4 ,further1 in changing its direction of motion it does not retrace its path amongst the stars4 ,its actual observed path exhibits irregular loops1 and1 more rarely1 a twisted line4 ,it was at once obvious that a circular orbit1 traversed with uniform velocity1 would not suffice to explain these appearances4 ,nevertheless1 the principle must be preserved4 ,the astronomers overcame this difficulty by a device that strikes one as being almost disingenuous4 ,they imagined a small circle whose centre traversed the circumference of the big circle with a constant velocity and round whose own circumference the planet moved with a constant velocity4 ,by assigning suitable velocities to these two motions the crude features of the planet's actual observed motion could be represented--it would sometimes be retrograde and sometimes direct4 ,this is ingenious1 but it is questionable whether it preserves the principle4 ,the planet's motion is obtained by circular motions1 it is true1 but it is not itself a circular motion with reference to the earth as centre4 ,the astronomers have entered on a slippery path4 ,we view them with the same suspicion with which we watch a ,broad ,churchman expounding the ,thirty-,nine ,articles4 ,but they had to go further4 ,the theoretical and the observed motions did not fit well enough4 ,on the little circle it was necessary to imagine a still smaller circle1 and to place the planet on its circumference4 ,after all1 this interpretation of 8circular motion0 once admitted1 there was no reason why it should not be followed up4 ,but progress in this direction soon came to a halt4 ,it became evident that this method would not1 by itself1 reconcile observation and theory4 ,the principle had to be strained again1 and this time in an almost indefensible manner4 ,it was declared that the big circle was eccentric with respect to the earth and that the little circles were eccentric with respect to their supposed former centres4 ,this assertion must have been a great strain on the faith of the orthodox believer4 ,he may well have wondered whether1 by this time1 the pure doctrine of his fathers had not been subtly undermined4 ,circular motion was still preserved1 in a way1 it is true1 but with so many circles1 and their centres all over the place--this must have appeared something very different from what he supposed the principle to mean4 ,the same difficulty was felt by simple minds in modern times1 when the correct explanations of statements in ,genesis were worked out by the theologians4 ,and just as the simple story of the ,creation in ,genesis became transformed into an extremely obscure and ambiguous anticipation of the discoveries of ,geology1 so the interpretation of circular motion advanced from complexity to complexity4 ,immutable principles must exist1 of course--it is part of the glory of man that he should have been able to discover so many of them--but they sometimes seem more trouble than they are worth4 ,the old astronomers found that yet again a more liberal interpretation must be given to the principle of circular motion4 ,this time it was found that the circles do not all lie in one plane4 ,each circle has its own plane1 which may be inclined at any angle to the others4 ,by this time the theorists1 whom we might call the 8commentators10 had forged a very powerful method4 ,circles could be multiplied2 their centres could be placed anywhere2 their planes could be inclined at any angle4 ,the rich content of the principle of circular motion was now fully revealed4 ,with all these variables to play with a very close correspondence between theory and observation was effected4 ,the rise of the 8higher criticism0 of this system leads to the history of modern astronomy4 ,it is to be noted1 however1 that the first higher critic1 like the first higher critics in other departments1 was not wholly emancipated from his early teaching4 ,copernicus effected the immense revolution of placing the sun in the centre of the system1 but he did not abandon circular motion4 ,so he had to retain parts of the epicyclic apparatus4 ,the revolution was first completely effected by ,kepler1 but even he conducted his early researches as a semi-believer1 a kind of very ,broad ,churchman4 ,he made nineteen successive attempts to explain the motions of ,mars by the arrangements of eccentric and epicyclic motions1 and only then did he frankly throw the great principle of circular motion overboard1 and state that the actual paths of the planets were ellipses4 ,and so1 in a few years1 a great immutable principle1 a whole system of beliefs1 the industry and thought of generations went for nothing1 and now exist merely as an occasional cold reference in a treatise on ,astronomy to the ,ptolemaic system as a 8monument of misplaced ingenuity40 ,,iv ,we may divide scientific theories into two classes1 which have recently been distinguished by ,einstein as theories of construction and theories of principle4 ,his own theory of relativity is a theory of principle1 and its attraction resides in its logical perfection4 ,such theories1 whatever charm they may have for the logician1 are not1 man being constituted as he is1 felt to be sufficient4 ,a principle which natural phenomena obey1 and which enables equations to be deduced expressing the relations between phenomena1 is1 to a few austere souls1 all with which science need concern itself1 but the majority of men require1 in addition1 something they call an 8explanation0 of the relations deduced from the principle4 ,they desire to see events described in terms with which they are familiar4 ,thus1 a description of the behaviour of the material universe in terms of the mutual impacts of little billiard balls would afford genuine satisfaction to the mind1 and important advances have been made in science by the attempt to describe phenomena in these terms4 ,the assumptions which underlie some such attempts may seem1 to the logician1 preposterous1 but there is no doubt that the mind is impelled to make such assumptions4 ,our familiarity with the motions of matter in bulk makes it quite natural that we should endeavour to give1 as far as possible1 dynamical explanations of events1 although1 if we stop to ask ourselves why nature should be flexible enough to admit of descriptions in such terms1 we are at a loss for an answer4 ,the history of theories of the ther is particularly instructive from this point of view1 because the irrational nature of the impulse is here most clearly apparent4 ,the attempt to explain phenomena in terms of an ther has led to some very remarkable theories of the nature of matter itself4 ,it has been supposed1 for instance1 that the ultimate particles of matter are vortical whirls in the ther1 or1 again1 points of a very special kind of strain in the ther4 ,nevertheless1 a theory of the ther is regarded as unsatisfactory which is not couched in terms of the observed behaviour of ordinary matter as we know it4 ,a dynamical explanation is always sought after1 and a great part of the scientific effort of the nineteenth century was devoted to describing the ther as an elastic solid4 ,but men of science were not content with showing that the laws of dynamics could be applied to the ther2 many of them endeavoured to devise models which should represent1 on a large scale1 the actual construction of the ther4 ,it is difficult to know to what extent their authors supposed these models to correspond to the reality2 it is probably not sufficient1 however1 to say that they regarded them merely as furnishing useful tools for subsequent investigations4 ,the models were usually extremely complicated1 for1 from the very beginning1 the ther proved somewhat recalcitrant to this attempt to represent it as an elastic solid4 ,the most obvious objection to this representation was provided by the observed motions of the planets4 ,it could be proved that1 if there were any resistance to their motions round the sun1 it must be excessively minute1 and how was this to be combined with the hypothesis that they were moving with great speed through an elastic solid8 ,the answer was found in cobbler's wax4 ,sir ,george ,stokes noticed that cobbler's wax1 although rigid enough to be capable of elastic vibration1 is yet sufficiently plastic to permit other bodies to pass slowly through it4 ,we have only to imagine that in the ther these qualities are much exaggerated1 and the motion of the planets presents no difficulty4 ,if no substance like cobbler's wax happened to be known it is difficult to know what satisfactory answer could be returned to the objection4 ,here we have the first glimpse of the remarkable combination of qualities with which it was found necessary to dower the ther4 ,the mathematical examination of the properties of the ther1 undertaken by such men as ,navier1 ,cauchy1 ,poisson1 ,green1 was continually leading to queer and unsatisfactory results1 unsatisfactory1 that is1 in the light of our experience of the properties of matter4 ,cauchy1 in particular1 deduced a number of remarkable physical properties which were irreconcilable with one another1 although one of his theories1 that of the ther considered as a kind of foam1 attracted the attention of ,lord ,kelvin4 ,with the rise of ,maxwell's electromagnetic theory1 the elastic solid ther received less attention4 ,maxwell himself1 in his great treatise1 gives no mechanical explanation of his theory2 he merely shows that an infinite number of mechanical explanations are possible4 ,with the publication of ,einstein's first principle of relativity in #aije1 however1 the ther began to disappear2 and now1 with the generalised theory of relativity1 it has become a mere ghost4 ,there are still sturdy champions of the ther1 and1 indeed1 it seems a pity to have to abandon the mechanical explanations it promised4 ,but possibly the attempt to find dynamical explanations of this kind is doomed to failure2 perhaps1 after all1 nature is not flexible enough4 ,the orientation of modern science is in another direction4 ,it is towards a more abstract class of theories altogether--theories which tell us nothing about the mechanism of a process1 but tell us the principles the process must obey4 ,such theories effect a vast unification of knowledge4 ,they are magnificently comprehensive1 and it is possible that they contain all that we can really know1 although men will long be reluctant to abandon all hope of ever approaching reality with the intimacy that the theory of the ther seemed to promise4 ,v ,whether or not it be true that the proper study of mankind is man1 it is certain that he finds great difficulty in studying anything else4 ,his first impulse1 when he thinks about the universe at large1 is to consider it in reference to himself1 and to explain it in terms of his own actions and desires4 ,in ,astronomy1 for example1 it long seemed quite reasonable that in the peculiarities of men's bodies should be found the system on which the universe is constructed4 ,the arguments of ,galileo's contemporaries amuse us now1 for we have learned modesty1 but the tendency to explain all things in purely human terms1 as it were1 is by no means yet extinct1 and is still a hindrance to science4 ,it is even hinted that man's explanation of himself is not free from bias2 psychologists inform us that a man's account of his own actions is not always to be trusted1 that the true springs of his conduct are usually those he would blush to own4 ,but if we are to say that man's speculations about the universe show an overwhelming sense of his own importance we must allow him also a certain generosity4 ,until quite recent times he was willing to dower almost anything1 animate or inanimate1 with his own attributes4 ,he credited stones with life and trees with desire1 while the whole animal world were his brothers4 ,he could admire the loving sentiments of the dove and weep for the sorrows of the crab4 ,a pathetic confidence in man as the type and exemplar of the universe informed nearly all the early writings on animal psychology1 and ,descartes' theory that animals were automatic roused a sentimental indignation which has not yet subsided4 ,nevertheless1 comparatively recent investigations tend to overthrow the natural assumption that worms and insects are little men inhabiting strange bodies4 ,the modern biologist refuses to be conscience-stricken when referred to the industry of the bee or the conjugal perfections of the dove4 ,it is only recently that he has become so heartless4 ,darwin1 in a celebrated passage1 describes with simple reverence the mutual affection existing between snails4 ,the intelligence of these little creatures was also estimated highly by ,romanes4 ,loeb1 the great ,american biologist1 did much to upset this nave anthropomorphism4 ,he took some worms who are 8always attracted by light10 and showed that this movement did not testify to a 8more light0 cry in these little souls1 but was a purely automatic proceeding4 ,the worm places itself so that both sides of its body are equally illuminated4 ,it is a mechanical action due to the influence of light on the living matter of its body4 ,if there are two lights the worm passes between them1 thus securing equal illumination of its two sides4 ,the crab which1 being held by a claw1 sheds that claw and hurries to the nearest rock for shelter1 is found to do the same thing after its eyes or brain have been destroyed4 ,dr4 ,georges ,bohn1 who has made many experiments to determine how far the actions of the lower animals are purely mechanical1 gives an interesting account of a certain parasitic worm which attaches itself to the fish called the torpedo4 ,he finds 7#a7 that if the amount of salt in the water be varied the reactions of the worm alter2 7#b7 that if light be allowed to play first on one part and then on another part of the worm1 its reactions alter2 7#c7 if the animal has already taken up its position1 attached to the glass1 for instance1 and a shadow be passed over the top of the vessel1 the whole body of the worm turns itself into the vertical in such a way that if the shadow were caused by a passing torpedo1 the worm could attach itself to the fish4 ,if1 however1 it be already attached to a torpedo1 it does not raise itself at a passing shadow4 ,here1 then1 is an association between the region of the body excited by light and the part fixed to the fish4 ,it was found1 also1 that the crab which abandons its claw only does so when held by a certain part4 ,the action appears to be purely automatic4 ,if it were dependent in any way on the crab's simultaneous visual perceptions1 for instance1 an associative phenomon would be established4 ,but experimental tests find no such correspondence4 ,as the result of numerous experiments of this kind biologists have become very wary of offering psychical explanations of the actions of the lower animals4 ,even when genuine associations are established one must be careful not to interpret them in terms of human psychology4 ,in the very description of experiments an unwarrantable turn may be given to the phenomena by the fact that words of ordinary language inevitably call up associations which may be out of place in the discussion4 ,to say that an amba learns to reject certain foreign particles in a solution1 for instance1 is a statement that requires careful interpretation4 ,how are we to picture an amba learning something8 ,but1 indeed1 the danger of anthropomorphic interpretations becomes very obvious when we reflect on the purely physical phenomena which accompany man's own emotions4 ,if the ,james-,lange theory be correct1 it is in terms of these physical phenomena that we must understand man's emotions4 ,now consider the example given in ,washburn's book1 ,the ,animal ,mind4 ,an angry man has a quickened heartbeat1 altered breathing1 a change in muscular tension1 and a change in the blood4 ,consider a wasp4 ,it has no lungs1 but breathes through its trache2 the circulation of its blood is fundamentally different from that in man2 all its muscles are attached internally because its skeleton is everywhere external4 ,what1 then1 is an 8angry0 wasp8 ,it seems clear that if a man is to study anything but man he must forget himself as far as possible4 ,,on ,,learning ,,science ,it is a well-known fact that a really intelligent child finds great difficulty in believing that the earth is round4 ,stupid children1 on the other hand1 believe anything they are told4 ,the difficulty experienced by the first child is due to the fact that1 in however elementary a way1 it is conscious of the implications of the statement4 ,the stupid child seems to be unaware that the statement has any implications2 it seems able to accept almost any statement in some curiously bare1 unrelated fashion4 ,hermann ,bahr has an interesting and amusing story of how profoundly his faith in his father was shaken when the latter1 propos of a sunset1 told the young boy that in reality it was the earth that turned round and not the sun4 ,completely overwhelming objections to this statement rose instantly in young ,hermann's mind1 and1 outraged by this insult to his intelligence1 he preserved a hurt and dignified silence that lasted for days4 ,we notice the same essential difference in schoolboys and university students1 and1 in fact1 in men of any age4 ,perhaps the majority of men1 and less certainly of children1 have but little sense of the implications of a statement4 ,the sense of implications does not necessarily involve the ability to discover the implications--that is a comparatively rare gift4 ,it acts rather in a negative manner1 making the student restless under a subtly illogical presentation of a case1 or leaving the schoolboy frankly mutinous at the end of a sermon4 ,it is not a gift which makes a rapid learner1 although its absence will prevent a man from ever knowing a subject properly4 ,it is unfortunate that education1 as practised in this country1 does not sufficiently take into account this very desirable inhibition4 ,the text-book plays a very large part in contemporary education1 and most text-books are designed for those who can swallow statements at great speed4 ,that delicate web of doubt1 of half-seen alternative explanations1 which comes into the mind of the intelligent student when confronted with the highly dogmatic statements and somewhat perfunctory 8proofs0 of many modern text-books1 counts as sheer loss in the examination race4 ,this is especially true of scientific text-books1 which are usually conceived on an entirely wrong plan1 judged from the standpoint of rational education4 ,statements which are the final expression of very difficult and slowly acquired abstractions are presented in all their nakedness1 and followed by a collection of 8examples40 ,the glib student learns these statements as if he were learning a foreign language1 and soon masters the tricks necessary to apply them4 ,i have known such students able to solve very difficult problems and yet entirely unable to meet1 in any way1 a sceptical attack upon the fundamental theorem they employ4 ,the fact is that this method of teaching science is psychologically unnatural1 and the knowledge acquired on this method is largely sham knowledge4 ,while it may not be true that the child passes through 8cultural epochs0 in its mental growth1 it is true that it will feel many of the hesitations and difficulties experienced by the men who first formulated the concepts now presented to it for its instant acceptance4 ,it is for this reason that the best method of teaching a science is probably the historic method4 ,in this way not only are many doubts fairly met instead of being merely repressed1 but the exact porte of a statement and possible lines of extension are much more clearly seen4 ,the effect of the modern text-book is to make the intelligent student feel that he is remarkably unintelligent2 the text-book writer is so terribly cocksure4 ,but if the historic method must be rejected as too lengthy one may plead for its partial application4 ,let the text-book give the broad outlines1 and let the student supplement these by reading1 wherever possible1 the standard memoirs written by the original discoverers4 ,in this way he will gain something much more valuable than a more thorough acquaintance with his subject2 he will learn something of the mental gesture of the true man of science1 something very different from the glittering efficiency of the text-book writer4 ,consider1 for instance1 the following passage from ,newton1 writing on the theory of light3 ,he discusses a corpuscular theory1 and continues3 ,but they1 that like not this1 may suppose light any other corporeal emanation1 or any impulse or motion of any other medium or thereal spirit diffused through the main body of ther1 or what else they can imagine proper for this purpose4 ,to avoid dispute1 and make this hypothesis general1 let every man here take his fancy2 only whatever light be1 ,i suppose it consists of rays differing from one another in contingent circumstances1 as bigness1 form1 or vigour4 ,the subject here becomes alive in a way it never does in the text-book4 ,it is of the greatest importance that the student should see1 not merely the results1 but the avenues of approach4 ,he will gain more confidence in his own powers and more interest in the subject4 ,for those people also who1 without being students1 take an interest in science1 the reading of original memoirs may be recommended4 ,much of the science they learn in this way will be wrong1 but they will see it as something thoroughly human and1 it may be1 as something thoroughly sympathetic4 ,the text-book has an air of infallibility which is very repellent1 and it is difficult to avoid associating this with the scientific man4 ,but it is merely a manifestation of the same tendency that produces stereotyped restaurants4 ,a reading of the old memoirs shows science as tentative1 imaginative1 courageous4 ,they show that the man of science is a humanist4 ,,the ,,entente ,,cordiale ,those who are interested in current 8serious0 literature1 and more particularly that branch of it which deals in a speculative way with those vague but impressive problems which have always haunted men1 the existence of ,god1 the 8meaning0 of the ,universe and so on1 cannot have failed to notice the unaccustomed prestige now enjoyed by science4 ,the supposed contributions of science to these discussions are now listened to with a gravity and politeness1 with a kind of serious hush1 which was formerly reserved for quotations from ,plato and ,aristotle4 ,compared with the crude materialists of ,huxley's day1 it is evident that the modern man of science has greatly improved his social standing2 he now frequently talks to the best people1 on equal terms1 on such subjects as the ,good and the ,beautiful4 ,the underbred1 pushing1 clamorous self-assertion of the ,victorian scientist is a rare note in these improving conversations between philosophers and men of science4 ,a man like ,haeckel is dismissed as a mere vulgarian2 no one would trouble to refute him2 his loud voice and hob-nailed boots are sufficient condemnation4 ,even ,huxley is felt to be a rather noisy person2 the modern expositor of the relations of ,science and ,religion or ,science and ,philosophy no longer borrows his technique from the ,hyde ,park orator2 he has adopted rather the insinuating charm of the curate4 ,there are1 of course1 survivals on both sides2 sweetness and light are not yet universal2 the general atmosphere of mutual forbearance and respect is still occasionally marred by the harsh note of some exceptionally fanatic or insensitive partisan4 ,one or two grave lapses of this kind may be detected amongst the mass of recent books devoted to cosmical questions4 ,there are still one or two literary men and philosophers who hint at those dreadful early days of science1 before it went to ,oxford1 and there are still one or two provincial men of science1 farouche1 suspicious1 who attend a modern cultured salon carrying their obsolete life-preserver in their pocket4 ,but on the whole good manners prevail everywhere4 ,it is realised that there is no reason why anybody should feel awkward at meeting anybody else in a world which is so indulgent of the difference between a man's private and public capacities4 ,to be on amiable terms with everybody is worth a sacrifice1 and in our relief at escaping from the ferocious savagery of the ,victorian controversialists we may well endure the minor discomforts of a reconciliation between science1 philosophy and religion so effective as to render indistinguishable the separate persons of this trinity4 ,the particular advantage of this amalgamation that concerns us here is the fact that it has brought a new branch of literature into existence4 ,as is usual in an amalgamation1 each member profits by the custom brought by the others1 until finally a composite article is evolved which is1 as it were1 simultaneously buff and blue4 ,that is how we get these very curious and interesting modern works on cosmical questions--works which seem to result from a close collaboration between1 say1 a professor of physics1 an archdeacon and a ,bond ,street crystal-gazer4 ,a very comprehensive ,weltanschauung is thereby afforded1 and doubtless a truly 8balanced0 mind must result from the perusal of such works1 but we may doubt whether each component1 as it were1 is presented in its purity4 ,the advantages of association are only obtained by a certain loss of individuality4 ,we cannot speak for the philosophy and religion of these works1 but we are impelled to these reflections by detecting a certain quality which pervades the scientific part of the expositions4 ,it is1 as we have admitted1 a good thing for science that it has been taken up in this way4 ,it moves in an atmosphere of culture2 it finds itself being described in chapters headed with ,greek quotations2 it is complimented on its strong vein of poetry2 its peculiarities are explained1 inaccurately but sympathetically1 in columns of literary causerie1 and the unexpected but gratifying discovery is made that it by no means lacks the bump of reverence and proper respect for constituted authority4 ,yet1 kindly as are the surrounding faces1 and pleasant as is the consciousness that one's clothes and accent excite no comment1 there is1 on the part of many scientific men1 a persistent uneasy feeling that one has gained this position on false pretences4 ,it is these remarkable modern books to which we have referred which render the feeling acute4 ,at the same time1 it is very difficult to state precisely the elements of this feeling4 ,we understand1 however1 that there are young poets and novelists who experience very much the same emotion when one of the great 8official0 men of letters talks about literature4 ,it appears that such people often get everything subtly wrong1 that their criticism never pierces to the real heart of the matter1 that they make literature at once more pompous and more tame than it really is4 ,these new cultured expositors of science affect one very much like that4 ,their indisputable intelligence and their wide knowledge do not save them2 they lack something--it may be a mere familiar way of talking--which marks the practitioner2 we feel they touch their subject with padded fingers4 ,we attribute no occult influence to laboratories1 but we think the expositor of science who is not also a creator is something like that curiously unconvincing creature--the theoretical sailor who has never been to sea4 ,for that reason we are uneasy in the presence of these numerous modern expositions4 ,such work of the kind as was done in the old days was done by real men of science in their spare time4 ,they had the competence1 if also something of the crudity1 of the workman in the factory who explains to you how his machine works4 ,the modern writers are so much more like those frock-coated 8attendants0 at ,exhibitions4 ,one is oppressed with the same suavity1 the same incredible readiness1 the same secret doubt whether he has ever handled a tool in his life4444 ,such being our estimate of our modern teachers1 we may be permitted to be sceptical concerning the complete satisfactoriness of their account of the present disposition and relations of science4 ,when they vouch for the complete respectability and harmlessness of science we wonder if they are not a little too kind4 ,we have an absurd nervousness1 as in the presence of a reformed burglar4 ,he looks well-dressed enough and his hands are not impossibly horny2 moreover1 we are told that the two very respectable gentlemen with him find him a most charming companion4 ,we are prejudiced1 we suppose2 but to our thinking there is a coarseness about the jaw1 an occasional hard glint in the eye1 which would make us reluctant to accept him as1 at any rate1 a sleeping companion4 ,we wonder if those two gentlemen1 the one reverend and the other nearly so1 ever feel a little apprehensive during the night8 ,,popular ,,science ,the ,victorian ,age was unquestionably the great age of physical science4 ,it was not only the number and quality of the scientific men whose working lives were covered by this period that were responsible for this--although no period in history makes a braver show--but it was due also to the fact that the scientific discoveries of that age were often of the kind that rouses a vast amount of public attention4 ,the attention of a cultured minority was no new thing in the history of science4 ,newton's discoveries1 largely through the influence of his indefatigable populariser ,voltaire1 speedily became1 in a more or less adequate form1 the common property of the cultured part of ,europe4 ,but from the time of ,newton to that of ,davy there was no such general attention paid to science2 ,england and the ,continent largely lost touch1 even technical students working in comparative isolation1 so that the great ,french advances in ,newtonian philosophy were not appreciated for several years in ,england1 and the cultured public in ,england itself no longer considered the intelligent observation of scientific progress to be one of its chief duties4 ,it never did regain this outlook2 science1 becoming increasingly technical1 became more and more completely the affair of a small and specialised class1 until1 by the middle of the nineteenth century1 it was the most dissociated of intellectual activities4 ,the great recrudescence of general interest in science was brought about by the discovery that this dissociation was merely a consequence of lack of attention1 and that1 in fact1 scientific discovery was not unconnected with the major interests of mankind4 ,the publication in #ahei of ,darwin's ,origin of ,species persuaded the men of that time1 rightly or wrongly1 that science and religion were very intimately connected1 and science1 at one blow1 obtained a degree of public attention without precedent in its history4 ,the interest thus evoked was not always very intelligent1 but it was intense and widely diffused2 it extended to other branches of science1 influenced the educational system of the country and gave rise to an enormous extension of 8popular0 science lectures and articles4 ,this popular interest was of a different kind from the leisurely interest previously shown by the cultured classes4 ,the latter was1 indeed1 much more genuinely an interest in science for its own sake2 the former had a different emotional basis and was merely the diversion of an interest in religious or social questions4 ,there is a controversial air about nearly all the popular scientific writings of that time2 the scientific man1 like his audience1 was fully aware that he was talking about a good deal more than the ostensible subject of discussion4 ,science1 the creature of the least popular of man's activities1 patient and unprejudiced ratiocination1 became associated with violent emotions4 ,with ,biology and ,geology this association was inevitable and immediate2 their subject-matter happened to be that of the first few chapters of ,genesis4 ,but the more exact sciences1 when public attention turned their way1 could offer no such excitements4 ,they seem to have compromised by specialising on 8marvels40 ,the 8,marvels of ,science0 became a familiar heading1 and the unsophisticated public were stunned by figures3 the distances of the stars1 the number of molecules in a cubic centimetre of water1 the weight1 in tons1 of the earth1 the incredible minuteness of light-waves1 and so on1 the whole object of such discourses being1 as ,maxwell unkindly put it1 to prevent the audience realising that intellectual exhaustion had set in until the hour had elapsed4 ,we readily admit that popular science of a very different kind was also provided4 ,faraday1 ,kelvin1 ,huxley1 ,tyndall1 ,maxwell himself1 did their best to make the lay public acquainted with scientific methods as well as results1 to present their results as part of a coherent theory instead of as items in catalogue of marvels4 ,but it is the marvel-mongers who have proved most tenacious of life1 so that 8popular0 science has now become a term of contempt1 and any statement whatever1 provided it has the right marvellous flavour1 may be printed in our newspapers as scientific information4 ,in ,america such marvellous statements1 not only inaccurate but meaningless1 occupy pages of the ,sunday supplements1 so that that meritorious organ1 ,the ,scientific ,american1 has to announce1 in self-defence1 that it publishes1 not 8popular0 science1 but merely non-technical science4 ,in our own country that sober periodical ,nature used to print extracts from the more marvellous scientific items provided by the daily press1 thus furnishing a little light relief from its own austere pages4 ,the fact that this quackery exists is not unimportant4 ,if it does no more1 it often leads to a waste of time1 for there has been more than one worthy gentleman who has imagined himself to be attacking the pernicious doctrines of science1 when1 as his argument makes clear1 it is this kind of quackery he has in mind4 ,the cure for this kind of thing would seem to be the development of a conscience in newspaper editors1 unless we prefer to wait patiently until a tincture of science forms part of the education of an ,english adult4 ,but1 turning to the popular but accurate scientific article1 we may ask what purpose it serves4 ,should its object be to supply the deficiencies of a defective general education1 to provide an easy introduction to science8 ,doubtless such articles or lectures have served such a purpose2 ,faraday himself1 as we know1 was won over to science by the blandishments of ,mrs4 ,somerville1 and there is more than one case where the current of a man's life has been definitely changed by a lantern lecture4 ,it is1 nevertheless1 a mistake to suppose that the attentive perusal of a number of popular science articles is equivalent to a scientific education1 a mistake which is unfortunately very common4 ,the fact is that the scientific treatise and the popular science article1 so far from being rivals1 serve entirely different ends1 and may be read with profit by the same man4 ,broadly speaking1 the function of the popular science article is to present science in its humanistic aspect4 ,it should1 while dealing with as definite a scientific problem as the author chooses1 hint at the relations between this problem and the other interests of mankind4 ,very often these relations are implicit in the subject2 such subjects are1 in fact1 usually chosen1 and for that reason4 ,but there is another type of article which has for its object the exposition of relations which are not obvious1 and this exposition may be the result of a genuine and valuable intellectual effort on the part of the writer4 ,such articles are really essays in criticism and are not essentially different from the best type of literary criticism4 ,some of the best articles of this kind--some of those by ,w4 ,k4 ,clifford1 for example--are as truly 8research0 work as is the technical paper4 ,a third type of article may1 either by way of history or by way of logic1 show the position occupied by a given theory or fact in a scheme of knowledge4 ,this type is usually of more interest to the scientific student than to the general reader1 since a general acquaintance with the whole subject is presupposed1 and in this connection it is interesting to note that a powerful plea has recently been made for the more effective endowment of the teaching of the history of science4 ,if a popular science article serves none of these three purposes1 it must inevitably be nothing but the description of a 8marvel40 ,in competent hands this may be agreeable enough2 the appetite for marvels is vigorous and universal1 and its indulgence cannot be condemned as a vice4 ,to look at a marvel for the pleasure of gaping is not1 however1 a very intelligent occupation1 and1 to judge from the number and kind of phenomena unhesitatingly ascribed to 8the electricity in the air10 merely increases credulity4 ,regarded as a marvel1 wireless telegraphy is1 of course1 merely a miracle1 a fact extensively exploited by spiritualists4 ,the human tendency to seize on the merely marvellous should1 in fact1 be carefully allowed for by the writer of popular science articles2 he should1 if anything1 be even more reserved and pedantically precise than when addressing a scientific audience2 an incautiously flamboyant remark is very likely to be seized upon to support some preposterous philosophy or religion4 ,usually1 however1 the popular science writer yields to the temptation1 to pater his audience1 to make himself more readable1 as readability is now understood1 and so he may1 while speaking the truth1 have all the effect of telling a lie4 ,thus the division between the genuine and the quack science article is not1 in practice1 clearly defined4 ,the difference between the writers is definite enough2 but it is writer and public together which make the popular science article4 ,lack of education is just as great a hindrance to perception as is lack of sensitiveness4 ,the poet may be subtly and completely misunderstood because his audience lacks sensitiveness1 and1 to compare small things with great1 the conscientious retailer of scientific information may be in a like case for a different reason4 ,so that if it is true that the best type of poetry is that written by the poet 8for himself10 it is perhaps true that the best type of popular science article is written for a similar reason--because the writer is genuinely interested in working out certain speculations or treating certain facts in a certain way4 ,some of the very best popular articles--those by ,helmholtz1 for example--are of this kind1 and have achieved a relative immortality1 although1 like the poetry which is read chiefly by poets1 they are probably read chiefly by scientific men4 ,,patient ,,plodders ,it is a melancholy fact that the estimable qualities of patience and industry do not1 by themselves1 enable their possessor to attain eminence in the arts4 ,there is very good reason to suppose that character1 particularly a certain simple type of integrity and sincerity1 is necessary to great artistic achievement1 but it is certain that such gifts are not sufficient2 they must be allied with very unusual mental qualities4 ,in the sciences1 however1 we often find work of very great importance being performed by men of quite average intelligence1 but of exceptional tenacity4 ,a pure heart seems to be all that is necessary4 ,this is not true1 of course1 of the mathematical sciences--mathematicians1 like musicians1 are 8born0--but it is very obviously true of what are called the 8observational0 sciences4 ,a history of ,astronomy1 in particular1 is interesting from this point of view4 ,the fact that the whole of our knowledge of the heavens comes through the sense of sight1 and that we cannot experiment1 in the ordinary way1 upon the heavenly bodies1 means that the patient observer1 by merely accumulating observations1 is performing an absolutely essential function4 ,there is no other subject which yields such rich rewards to mere patience4 ,there is no other subject which has so long a record of valuable discoveries achieved by purely average ability4 ,it is interesting to notice how often a telescope and a capacity for sitting still have made their owners immortal4 ,in the region of stellar astronomy the minuteness of the phenomena which may be observed has narrowed possible competitors to those possessing large instruments1 and that usually means public institutions and professional astronomers4 ,but the history of our knowledge of the nearer heavenly bodies1 the sun1 the planets and the moon1 owes much to the industrious amateur4 ,no history of planetary and lunar discoveries would be complete without mention of ,schrter1 the 8,oberamtmann0 of ,lilienthal1 who watched the moon and planets incessantly for thirty-four years with a patience only equalled by his enthusiasm4 ,he died of a 8broken heart10 the result of a ,french atrocity1 for after firing1 on the night of ,april #bj1 #ahac1 the ,vale of ,lilies and thereby destroying1 amongst other things1 the whole of ,schrter's books and writings1 the ,french army under ,vandamme broke into and pillaged his observatory4 ,the old man1 then sixty-eight years of age1 had not the means to repair the catastrophe1 and1 deprived of his one great interest1 he died three years later1 leaving1 amongst his published works1 some of the most long-winded and entertaining observations in the history of astronomy4 ,but although ,schrter is undoubtedly the most amusing of all amateur observers1 he has had his prototypes in all countries4 ,francis ,baily1 the 8philosopher of ,newbury10 is a good example of our more sober ,english product4 ,we may have doubts as to what sort of chief magistrate old ,schrter was1 but we know that ,baily took his profession of stockbroking with the utmost seriousness4 ,he did not allow astronomy to interfere with business4 ,beginning in #agii1 he remained on the ,stock ,exchange in ,london for twenty-four years1 devoting his leisure largely to solar observations1 particularly those connected with eclipses4 ,it is with two of these phenomena1 the first annular1 a ring of the sun being visible round the moon1 and the second total1 that ,baily's name is particularly associated1 in each case for the vivid and accurate account he gave of what he witnessed4 ,the first phenomenon1 a ring of bright points extending round that part of the moon's circumference which has just entered on the solar disc1 is merely a consequence of the lunar edge being serrated with mountains4 ,these 8,baily's beads10 as they were called1 were successful1 however1 in stimulating interest in the physical aspect of eclipses1 with the result that the next total eclipse1 that of #ahdb1 was looked for with an unprecedented degree of enthusiasm4 ,astronomers like ,airy1 ,otto ,struve and ,arago travelled to ,central or ,southern ,europe to observe the eclipse1 and the indefatigable ,mr4 ,baily accompanied them4 ,he fitted up his telescope in an upper room of the ,university of ,pavia4 ,the result was magnificent4 ,at the instant of totality the sun appeared decorated with a glorious aurole1 the famous corona4 ,it was not1 of course1 an unknown phenomenon1 but it had never before excited so much attention4 ,mr4 ,baily1 in particular1 was moved to write a most eloquent description of this flaming object4 ,he calls it splendid and astonishing1 but continues3 8,yet ,i must confess that there was at the same time something in its singular and wonderful appearance that was appalling2 and ,i can readily imagine that uncivilised nations may occasionally have become alarmed and terrified at such an object44440 ,besides being a specialist on eclipses1 ,baily was an untiring editor of star-catalogues1 and he also made no fewer than #b1aec laborious experiments1 on ,cavendish's method1 to determine the density of the earth4 ,he was indeed a zealous worker in what ,sir ,john ,herschel called the 8archology of astronomy40 ,he was noted for his unvarying health1 undisturbed equanimity and methodical habits4 ,another testimonial to the importance of such qualities in astronomical discovery is furnished by the career of ,heinrich ,schwabe1 of ,dessau4 ,in the hope of escaping his fate as an apothecary he bought a small telescope in #ahbf1 and began to observe the sun1 being advised to do so by a friend4 ,he continued to observe the sun daily 7weather and health permitting7 for forty-three years4 ,every day he counted the number of spots visible on the surface of the sun4 ,it was a simple occupation1 but it led to important consequences4 ,his immense record of sun-spot statistics showed that the increase and decrease in the number of sun-spots did not occur in a random manner1 but fell into periods1 maxima alternating with minima1 a complete period occupying about ten years4 ,this figure has been modified since1 but the fact of sun-spot periodicity is established and is at the present time one of the most suggestive and probably far-reaching of solar phenomena4 ,schwabe displayed no striking quality of mind or character beyond an almost incomprehensible patience4 ,he was buoyed up in his spot-counting1 however1 by the hope of discovering a planet between ,mercury and the sun1 and in order to distinguish between the tiny disc of the planet crossing the face of the sun and a sun-spot1 he found it necessary1 in virtue of his instrumental equipment1 to count the spots4 ,when he found that1 as a consequence of this pastime1 he was world-famous1 he likened himself to ,saul who1 going forth to seek his father's asses1 discovered a kingdom4 ,his magnificent serenity of body and mind enabled him to attain the age of eighty-six4 ,part of his mantle fell on ,richard ,carrington 7born #ahbf71 who built an observatory at ,redhill with the intention of devoting himself to a study of sun-spots throughout a complete cycle4 ,he failed to finish the cycle completely1 as the death of his father made it necessary for him to divert his energies to controlling a brewery4 ,he achieved results of great importance1 however4 ,his observations were concerned with the positions and movements of the spots1 and from a series of #e1bij such observations he was enabled1 amongst other things1 to clear up the uncertainties attending the period of rotation of the sun4 ,galileo1 apparently not appreciating the importance of the matter1 had said that the sun rotated in 8about a lunar month10 and a number of other observers gave figures varying from #bg to #be days4 ,carrington illuminated this darkness by remarking that there is no single period of rotation for the sun4 ,the polar regions rotate more slowly than those in the neighbourhood of the equator2 the equator rotates in a little less than twenty-five days1 while in latitude #ej the period is twenty-seven and a-half days4 ,thus the mystery was cleared up and a fresh direction given to solar investigation4 ,it is difficult to say whether ,astronomy still offers such rewards to industry4 ,it is probable1 however1 that it still yields more to character1 as distinguished from ability1 than any other science1 and incomparably more1 alas6 than the arts4 ,,the ,,amateur ,,astronomer ,the indifference of the ,englishman is1 considered pragmatically1 the same thing as tolerance4 ,it bestows freedom and leaves every man1 within fairly wide limits1 at ease to pursue his bent4 ,there is doubtless a relation between this ,english characteristic and the fact that ,england1 above any other country1 is the home of the amateur4 ,in ,england1 compared with the ,continent1 there are comparatively few men whose dominant activity is their exclusive activity4 ,there are many fair specialists1 but there are few specialised men4 ,there are countries such as ,france1 where the ,gemeinplatz of intelligent men is probably larger and more richly furnished than it is in ,england1 but it is comparatively difficult to meet the type of man who is an eminent lawyer1 an authority on ,eastern poisons1 and a really good judge of horseflesh4 ,such manifestations of a national quality may sometimes appear almost grotesque1 but we believe that the quality of which they are partial manifestations is the most splendid and individual characteristic of the ,english intellect4 ,it is not a quality which produces many thrice-armed specialists1 but it is a quality which produces a great number of amateurs4 ,the ,english amateur in the arts belongs to a family well worth consideration1 but our more immediate concern is with the amateur in science4 ,there was a time when the scientific amateur abounded in ,england4 ,in the time of ,huxley and his contemporaries1 as we see from their letters1 amateur zoologists1 botanists1 and1 more rarely1 amateur mathematicians and physicists1 were scattered all over ,england and occasionally had something of interest1 or even of value1 to report4 ,in the days when ,r4 ,a4 ,proctor edited ,knowledge the country seemed to be full of reverend gentlemen who owned small observatories and home-made telescopes4 ,this large and interesting family seems now to be making towards extinction4 ,the increasing complexity of the various sciences1 to say nothing of the variety and cost of modern apparatus1 has made anything but trifling discoveries difficult to the verge of impossibility for an amateur equipment4 ,perhaps the amateur who has suffered least from these changes is the amateur astronomer4 ,there is good reason for supposing that his numbers have increased4 ,in this branch of science the ,english amateur has always been particularly strong1 and this cannot be attributed to the official encouragement accorded astronomy in this country4 ,there are many more amateur astronomers in ,england than in ,france1 although astronomy counts for more in ,france than in ,england1 and although1 since ,newton1 ,france has played the leading rle in the history of astronomy4 ,the popularity of amateur astronomy in ,england certainly needs explanation1 for it is a pursuit attended by many disappointments in so capricious a climate1 and ,englishmen have few opportunities of seeing a really impressive display of stars4 ,perhaps the ,englishman is sufficient of a ,northerner to be profoundly attracted by the sheer vastness and the mystery of stellar phenomena4 ,then the actual telescope and its accessories probably appeal to the ,english love of mechanism4 ,there are few instruments more delightful in themselves than a properly mounted telescope of moderate aperture4 ,its adjustment affords a pleasure as refined as that given by operating a small hand printing-press1 and superior to that of mending a bicycle4 ,every telescope has its distinctive 8performance10 and one can grow as enthusiastically partisan about makes of telescopes as one can about makes of motor-cars or pianos4 ,whether or not these be the reasons it is certain that astronomy is the science which most attracts the ,english amateur4 ,the existence of the ,british ,astronomical ,association1 an amateur society with some hundreds of members1 is sufficient proof of this4 ,it would perhaps be difficult to justify by the results the amount of time and money spent in amateur stargazing1 if one estimated results from the severe standpoint of the professional astronomer4 ,but if one adopts a broader outlook and estimates the results in rather more human terms1 then there is probably no pursuit which affords more innocent pleasure and provides1 in itself1 a more liberal education4 ,it is said that the vast photographic telescopes of the present day have rendered the small instrument valueless4 ,even ,mr4 ,hinks1 in his excellent volume ,astronomy in the ,home ,university ,library1 says that the would-be amateur would do well to hesitate before buying a small telescope1 and that a measuring machine1 to measure photographs taken by big instruments1 would be a far better investment4 ,this is the severely professional point of view2 it is to mistake the psychology of the amateur observer4 ,the amateur likes to think that he might some day make a discovery1 but that is only by the way4 ,his real joy is in doing precisely what the professional cannot do1 and that is to enjoy the spectacle of the heavens4 ,the ordinary run of work in a big observatory is not much more exciting than work in an ordinary business office4 ,to sit up half the night measuring photographs would conceivably add to scientific knowledge1 and there are doubtless stern men who are willing to do it4 ,these1 like computers1 are the martyrs of science4 ,the average amateur will continue to prefer his present pleasant1 if ineffectual1 method of adding to scientific knowledge4 ,it is to be feared that1 as one result of the war1 this amiable occupation will decline4 ,a little before the war the amateur could purchase a modest but thoroughly good1 instrument at a reasonable price4 ,the same instrument to-day would cost at least twice as much1 and there would probably be an interval of several months between the order and the delivery4 ,one large firm of optical instrument makers announces that it is not now making astronomical telescopes at all4 ,at the present time1 when astronomy is entering on perhaps the most pregnant phase in its history1 and when men are more than ever attracted by anything which promises escape from the fret of daily life1 this lessening of the opportunities for acquaintance with the most serene of the sciences is a minor calamity4 ,the decline in amateur astronomy will probably have no appreciable reaction on the progress of science1 but it will lead to a real1 if small decrease in the intellectual pleasures and spiritual wealth of the nation4 ,,scientific ,,citizens ,it would be an entertaining pursuit to compile the characteristics of the man of science--usually a ,professor--as he is depicted in popular fiction1 on the stage1 and in the writings of exasperated conservatives in religious and social matters4 ,it would be found that these characteristics combine to give one dominant and entirely untruthful impression3 the man of science is represented as being scientific on all occasions4 ,we may ignore the inferior school that portrays him as being constantly obsessed by his work--like ,dickens' learned gentleman who mistook the nature of a dark lantern--and confine our attention to the ,professor who is represented1 not as imbecile1 but merely as homogeneous4 ,this imaginary individual is never to be diverted from his passion for precise statement and strictly logical inference4 ,whether the subject be politics or the state of the weather1 he brings the same preliminary scepticism1 the same demands for verification1 that he carries into his scientific researches4 ,as we have said1 this picture is untruthful2 we think1 however1 that this is an unfortunate fact1 and that it is highly desirable that men of science should begin to live up to the story-teller's conception of them4 ,we think that1 at the present stage of man's evolution1 science is the one activity in which he displays himself as a truly rational creature4 ,the reason is1 of course1 that success is granted on no other terms2 in everything else1 philosophy1 theology1 politics1 reason is usually the handmaid to prejudice4 ,the penalties that visit error in these fields are not so swift nor so unambiguous4 ,the ideal of truthfulness is probably more rigorous with the scientist1 qua scientist1 than with any other kind of man4 ,but it would appear that this dispassionate rationality is hardly won and precariously maintained4 ,outside his laboratory the scientist may1 and usually does1 show himself as simple1 as kindly1 as credulous1 as irrational as any other man4 ,on ,bolshevism1 ,disestablishment1 the ,morality of the ,public ,parks1 his opinions will be indistinguishable from those of any other comfortable member of the lower middle class2 that is to say that opinions on all such matters are 8distributed0 amongst scientific men according to the same statistical rules as they are distributed amongst ordinary citizens4 ,outside their views on purely scientific matters there is nothing characteristic of men of science4 ,the ,royal ,society may conceivably issue a unanimous report on some scientific matter2 it would issue a unanimous report on nothing else whatever4 ,now on the assumption that men of science are truly rational beings this is a very strange state of affairs4 ,dispassionate attempts to sift evidence1 to argue correctly and to base judgments solely on the outcome of these processes could hardly result in so remarkable a multiplicity of opinions4 ,we must assume that1 for scientific men as a body1 their 8scientific0 methods of thought function only within very narrow limits4 ,as a distinct community they are far less coherent than1 for instance1 the community of artists--musicians1 poets1 painters4 ,the community of artists1 with the exception of a few prosperous members1 exhibits a really remarkable homogeneity in matters outside art4 ,doubtless this homogeneity is based on feeling--unless we are prepared to admit that artists1 as a whole1 are more rational than are men of science--and it is probable that the scientist's difference from his fellow-citizens is more an intellectual than an emotional difference4 ,but it is surprising that greater emotional sensitiveness should prove so much more pervasive and dominating a peculiarity than greater intellectual subtlety4 ,it is time that men of science assumed a greater position in the general community4 ,if a scientific training has a tithe of the general educational value that is claimed for it1 it is time we had some evidence of that fact4 ,men of science must adopt a higher ideal of personal honour4 ,at present the man who will conduct a laboratory experiment with meticulous precision and describe his results in an agony of honesty will be content to be a prejudiced observer and a slovenly and inaccurate thinker in all other matters4 ,this is the chief reason1 we are convinced1 why men of science count for so little in public affairs4 ,if the ,royal ,society elected its own member of ,parliament1 who would bother about the political opinion so expressed8 ,what greater weight would it have than the political opinion of an equal number of moderately prosperous ordinary citizens8 ,does not the scientific man waggle his head just as solemnly over his morning newspaper as does any unsophisticated voter8 ,we plead for the development of a class consciousness on the part of the man of science4 ,we want scientific men to regard their ideal of evidence1 their conception of proof1 their really admirable scientific detachment1 not merely as rules making for success in their particular game1 but as principles applicable to every subject that concerns a citizen4 ,why should a man of science be merely a ,liberal or a ,conservative in politics8 ,the alternative belongs to the stage of mental development that explained the material universe by saying that its moving principle was fire1 or1 alternatively1 water4 ,we expect a more sober contribution to political questions from1 say1 a distinguished physicist1 than the panacea 8,shoot the miners40 ,all the questions on which scientific men now adopt 8sides0 as uncritically as any simple dupe of the daily press are amenable to scientific investigation4 ,they can reach a solution only by the application of scientific methods1 and the modern world badly needs deliverance from the method of charms and incantations by which these questions are at present treated4 ,how long are these vital matters to remain in the hands of the witch-doctors8 ,with scientific men content to sit in the circle and help beat the tom-toms what hope is there of real advance founded on real knowledge8 ,the artists cannot help us2 they are useful indicators of the value of the product1 as it were2 they look pleased or they look disgusted1 and that is very helpful in showing us where we are4 ,it is the scientific man who must show us how to go somewhere else4 ,so we plead for the conscious formation of a community of men of science1 for scientific men who are at least as pervasively and constantly scientific as a good ,jesuit is ,roman ,catholic4 ,,the ,,sceptic ,,and ,,the ,,spirits ,it is only youth that has the energy to be bothered with everything4 ,there comes a time when one's mind is 8made up0 on all sorts of things that were once matters of inquiry2 we have profited by experience2 we know that some things are not worth investigating4 ,it is one of the marvellous laws of growth that this increase in wisdom should accompany physical decay4 ,as our teeth and hair start to fall out our judgment grows riper4 ,the law of growth is not really as simple as this1 for there are many silly old men and there are one or two wise youths4 ,the rich1 mellow1 balanced period is never reached by some people3 ,solomon1 on the other hand1 was noted for his wisdom while still a young man4 ,there is1 it must be admitted1 something mechanical about old men's wisdom4 ,truth is one1 of course1 so that we should expect a certain unanimity4 ,the answers of the old can usually be predicted4 ,wisdom can be simulated2 all that one lacks is the conviction1 the spirit that animates the letter4 ,deep conviction is a very impressive quality1 especially to youth1 which secretly doubts everything4 ,the man of strong convictions is a cause of optimism in others1 for life would appear a sad cheat if the payment for sixty years of it did not include one certainty4 ,youth's certainties make as much noise1 but everybody detects the bluff4 ,a fearful man shouts to hearten himself1 as all the world knows4 ,between the certainties of youth and age there is scepticism1 a fine fleur of brief life1 an exquisite tempering of the soul1 neither too soft nor too hard1 an infinite flexibility4 ,it is a state of intense activity2 life lived at this pace cannot long endure2 the tired spirit relaxes and one finds rest either in credulity or in dogmatism1 accident determining which attitude affords the soundest slumber4 ,it is not always easy to detect the true sceptic2 that honourable title has often been wrongly bestowed--,voltaire1 for instance1 was a dogmatist4 ,sceptics exist in all ages1 but they are more clearly revealed at those periods that see the birth of some new inquiry4 ,it is essential to their indubitable manifestation that the inquiry should be attended by the passionate interest of a large number of people4 ,at the present day a very good test inquiry is spiritualism4 ,it is a very much better test than ,free ,trade and ,tariff ,reform1 for1 owing to its comparative remoteness1 the true sceptic of that alternative might live and die in obscurity4 ,but spiritualism is a subject on which no one is genuinely indifferent and towards which hardly anyone is genuinely sceptical4 ,dispassionate inquiry on this1 as on all matters where human interests are strongly engaged1 is usually a pretence4 ,we need not suppose that the great ones of the ,psychical ,research ,society are less credulous than the majority of believers or less intolerant than their louder opponents2 it is merely that1 their traditions being scientific1 they have better manners4 ,psychical literature1 as a whole1 is as wearisome as theological literature1 as incredible but less amusing than the lives of the saints4 ,we lack the quality1 be it faith1 hope or charity1 which would enable us to share these strange excitements4 ,the 8exposers10 on the other hand1 are too sturdy in their common sense4 ,we hear the mallet fall1 but we are not always sure that the eggshell is broken4 ,it is a situation for the sceptic4 ,in the late ,lord ,rayleigh's presidential address to the ,psychical ,research ,society we find that the sceptic has at last appeared4 ,it is merely a record of his own experiences1 very plain1 very simple1 and1 like the experiences themselves1 singularly elusive4 ,many years ago1 in a friend's rooms at ,cambridge1 he witnessed an exhibition of the powers of ,madame ,card1 the hypnotist4 ,when she had completed her passes over the closed eyes of those present she asked them to open their eyes4 8,i and some others experienced no difficulty2 and naturally she discarded us and developed her powers over those--about half the sitters--who had failed or found difficulty40 ,from hypnotism he passed to spiritualism1 his interest aroused by ,sir ,william ,crookes' experiences4 ,he induced the medium1 ,mrs4 ,jencken1 and her husband1 to visit his country house as guests4 ,he describes the results as disappointing3 ,i do not mean that very little happened1 or that what did happen was always easy to explain4 ,but most of the happenings were trifling1 and not such as to preclude the idea of trickery4 ,one's coat-tails would be pulled1 paper cutters1 etc41 would fly about1 knocks would shake our chairs1 and so on4 ,i do not count messages1 usually of no interest1 which were spelt out alphabetically by raps that seemed to come from the neighbourhood of the medium's feet4 ,perhaps what struck us most were lights which on one or two occasions floated about4 ,they were real enough1 but rather difficult to locate1 though ,i do not think they were ever more than six or eight feet away from us4 ,another incident was the gradual tipping over of a rather heavy table at which they had been sitting4 8,mrs4 ,jencken1 as well as ourselves i4e4 ,lady ,rayleigh and himself4 ,the husband was not admitted to these sances was apparently standing quite clear of it40 ,he found it very difficult to reproduce the phenomenon himself1 using both hands4 ,he endeavoured to 8improve0 the conditions for some experiments4 ,after being shown some writing1 8supposed to be spirit writing10 he arranged paper and pencils inside a large glass retort1 which he then hermetically sealed4 ,nothing then appeared on the paper at these sances4 8,possibly this was too much to expect4 ,i may add that on recently inspecting the retort ,i find that the opportunity has remained neglected for forty-five years40 ,and so he has left the matter4 ,the experiences were certainly strange1 yes1 but in his judgment1 not strange enough4 ,on the other hand1 he is reluctant to believe they were due to fraud1 and he is quite convinced that he was not a victim of hallucinations4 ,if ,mrs4 ,jencken were a clever fraud 8her acting was as wonderful as her conjuring40 ,she practically never made an intelligent remark on any occasion4 8,her interests seemed to be limited to the spirits and her baby40 ,in investigating this subject he finds that the attitude of convinced believers makes a difficulty4 ,they 8take no pains over the details of evidence on which everything depends40 ,others attribute all these phenomena to the devil and will have nothing to do with them4 8,i have sometimes pointed out that if during the long hours of sances we could keep the devil occupied in so comparatively harmless a manner we deserved well of our neighbours40 ,the general disbelief in scientific circles that meteorites really came from outer space occurs to him4 ,this disbelief was due1 he points out1 to the impossibility of producing the phenomena at pleasure in our laboratories4 ,nevertheless1 the disbelief was unjustified4 ,spirit manifestations may be1 he thinks1 just such sporadic phenomena4 ,the situation is made worse by the fact that there has undoubtedly been a great deal of fraud in connection with spiritualist phenomena4 ,eusapia ,palladino1 for instance1 undoubtedly practised deception1 8but that is not the last word40 ,telepathy puzzles him4 ,if there is such a means of communication1 why should ,nature have adopted the laborious method of building up our very complicated senses8 ,an antelope in danger from a lion1 for instance1 depends on his senses and speed4 8,but would it not be simpler if he could know something telepathically of the lion's intention1 even if it were no more than vague apprehension warning him to be on the move80 ,he advises the society to continue their investigations1 and mentions that it is quality1 not quantity1 that is so desirable in evidence4 ,he concludes by saying that he fears his attitude1 or want of attitude1 will be disappointing to some members of the society4 ,he suggests that after forty-five years of hesitation 8it may require some personal experience of a compelling kind to break the crust40 ,he apologises for this4 8,some of those who know me best think that ,i ought to be more convinced than ,i am4 ,perhaps they are right40 ,there he leaves us4 ,we do not believe more or disbelieve less1 yet we are completely satisfied4 ,his massive sincerity1 his obvious competence and1 above all1 that impression of exquisite balance1 have charmed us4 ,so far as present evidence is concerned we feel that while he has said nothing he has also said the last word4 ,that is the function of the sceptic4 ,,the ,,scientific ,,mind ,it is quite common1 in reading and in conversation1 to find references to the 8scientific mind10 but it is difficult to ascertain precisely how this mental structure is supposed to differ from other sorts of mind4 ,the difficulty of defining an object does not1 perhaps1 affect the probability of the existence of the object2 although it is difficult for some people to refrain from concluding that because a man cannot define what he means he does not mean anything4 ,we must suppose that there is some particular kind of mind called the scientific mind1 in spite of the fact that the numerous references to it tell us little about it except that it is somewhat extensively disliked4 ,so far as can be judged from a superficial comparison of different references1 the 8scientific mind0 is characterised by an inordinate appetite for facts and an absence of generosity in drawing conclusions from facts4 ,in ordinary times this absence of generosity is dismissed by most people as quibbling1 while in time of war it becomes unpatriotic4 ,during the war every ,englishman was supposed to believe a great number of things on very slender evidence or even on no evidence4 ,it was considered that a right patriotic feeling not only could1 but should1 supply the place of evidence1 and lead to correct conclusions4 ,the majority of people in every class of the community found themselves able to adopt this method of thought without discomfort1 and it became evident that the scientific mind is as rare amongst scientific men as amongst any other men1 while those who could not give this supreme proof of patriotism were found pretty evenly distributed amongst the different classes4 ,as a type of mind1 therefore1 it is not peculiar to scientific men nor do they all possess it4 ,it cannot be regarded as a distinguishing mark of this class4 ,but while a just1 cautious temperament need not belong to the man of science as a human being1 it might be thought that1 as a mental habit1 it is necessary to his work4 ,there is much truth in this1 although it is not wholly true4 ,alternative explanations are not always explored by scientists1 and if1 as sometimes happens1 the alternative explanations are wrong1 the scientific man may have reached a correct result although he worked in a partisan spirit4 ,but while the characteristics of what is popularly known as the scientific mind are not peculiar to scientific men1 it is true that1 in their actual scientific work1 these characteristics have a greater survival value than they possess in almost any other kind of work4 ,the extent to which mental habits may be local1 confined to some only of a man's mental activities1 has been made apparent by the war4 ,the majority of men's minds are split up into water-tight compartments in a way truly astonishing1 and the various eloquent addresses on the moral value of scientific studies now make melancholy reading4 ,we must assume of scientific men1 as of any other class1 that such qualities of fairness and deliberation as they exhibit in their work are imposed upon them as conditions of success1 and are not1 in general1 the natural manifestations of an exceptionally delicate moral sensibility4 ,if we adopt ,william ,james' classification of human beings into tender-minded and tough-minded the dividing line runs through the scientific camp as through any other4 ,we see this most clearly in the case of mathematicians1 for idealist or empiricist assumptions seem to be equally reconcilable with the results4 ,such sciences as physics and chemistry seem1 at first glance1 to be given over to the tough-minded2 the official language1 as it were1 is the language of the tough-minded1 but directly controversy arises on a point having philosophical bearings we see the dichotomy establish itself4 ,nevertheless1 it remains true that while scientific men1 as human beings1 are of all sorts1 they do exhibit1 in their own work1 a degree of mental honesty which is unusual4 ,it is easy to see that this virtue1 at any rate1 has a strictly utilitarian basis4 ,a scientific man is honest because he cannot succeed on any other terms in the long run4 ,the experimental verification always looms ahead4 ,he cannot1 like the mystic who maintains his opinion in face of the world1 take refuge in the deeper insight4 ,his results are communicable and verifiable or they are not science4 ,philosophies may be constructed which no man can verify and no man can refute4 ,their authors may1 with complete assurance1 remain satisfied of their truth and lament the universal blindness of mankind1 just as a poet may present a front of unconquerable self-esteem to the ignorant derision of the world4 ,but the whole claim of science is that it is communicable and capable of verification4 ,it is found1 as a matter of experience1 that results of this kind are not usually obtained unless a certain mental habit is first acquired4 ,it is this mental habit which is usually called the scientific mind4 ,where it is the outcome of a natural predisposition it may be classed as a moral quality1 and1 as such1 is not peculiar to1 or widely distributed amongst1 scientific men4 ,but as a tool1 as a kind of technique1 it is of more obvious value and is more extensively employed in the sciences than in any other human activities4 ,,the ,,scientific ,,contribution ,for something like seventy years science has been the dominant intellectual activity of the ,western world4 ,during that period the range of its material has greatly increased until now the scientific method is regarded as the method proper to almost any investigation4 ,philosophy is still a partial exception1 but there is a strong tendency to regard such philosophic problems as are not susceptible to the application of the scientific method as being essentially incapable of solution1 or else as incorrectly stated4 ,but although the prestige of science is so great1 and the general attitude towards it so reverential1 there is still much confusion respecting its function and achievement4 ,its relations to other human interests and activities are not yet clearly defined4 ,the attempts to define them by allotting to science its 8sphere0 have proved1 in the result1 to be so ill-judged that it is now considered safer to waive the question of limitations altogether4 ,the question is not settled4 ,everything is left open1 but it is not therefore assumed that science contains or will contain all we know or all we need to know4 ,science is not yet the one object of our contemplation3 we have a number of interests which still lead separate lives4 ,the separation is not complete4 ,science1 if not openly1 then indirectly1 has invaded every province of the mind1 and even a modern musical composition counts ,copernicus as well as ,beethoven amongst its ancestors4 ,but it is admitted1 of course1 that we are not usually reminded of astronomy in listening to music2 there is a sense in which music1 and many other things1 are autonomous4 ,but it is interesting to notice that science1 to a greater extent than any other pursuit1 can be isolated1 although its historical direction has been influenced1 of course1 by social and political accidents4 ,science has given generously1 but has taken comparatively little1 and its few borrowings are in process of being handed back with regret as being1 after all1 unsuitable4 ,what1 then1 is the precise nature and extent of the contribution of science to our total stock8 ,although we do not intend its practical applications by this question1 we cannot wholly ignore them4 ,it is impossible completely to separate the 8material0 and 8spiritual0 aspects of life1 and the sum of the practical applications of science has even profoundly affected much of our abstract thinking4 ,where it has not originated questions it has at least made them acute1 if by no other process than by creating or transforming social conditions4 ,it is easy to trace the ancestry of whole schools of social philosophy to the steam engine and the dynamo1 and it is probable that the influence of future applications will be even more extensive4 ,the morality1 art and philosophy of1 for example1 a disease-less world1 where the average span of human life was two or three times its present value1 would certainly differ greatly from our own4 ,we cannot1 then1 ignore the practical applications of science1 although they are not1 in themselves1 pertinent to our question4 ,but when we turn to consider the direct spiritual value of science we are conscious1 at the outset1 of some hesitation4 ,it was a common article of the ,victorian scientist's creed that scientific study was1 in itself1 an 8ennobling0 and purifying influence4 ,he stressed the complete detachment required1 in scientific research1 from all prepossessions2 the man of science was completely candid1 completely docile in face of the facts4 ,until one became as a little child it was no use entering a laboratory4 ,we have realised since then that scientific men are human1 and have their full share of the unfortunate characteristics proper to that state4 ,but it remains true that the scientific ideal of detachment and the scientific ideal of evidence are higher than the corresponding ideals elsewhere4 ,in spite of the evidence furnished by our newspapers we may1 if we are optimists1 believe that science is gradually infecting the whole community with its conception of these ideals4 ,if this is indeed the case it must be counted a direct and very important moral gain1 as an indisputably valuable contribution which may be set over against those somewhat ambiguous practical applications4 ,a third contribution is to be found in the large store of sthetic objects provided by science4 ,many of its theories are objects of surpassing beauty4 ,this is particularly true of the mathematical sciences--indeed1 there are a number of mathematicians who have felt impelled to write of their science in a kind of prose-poetry--but it is almost equally true of such a science as ,geology4 ,we can contemplate schemes which1 in their own way1 are as all-embracing as that of the ,divina ,commedia1 and it does not detract from their sthetic charm to know that they are also true4 ,the processes by which the theories are obtained are often as sthetically important as the theories themselves4 ,a subtle1 elaborate and economical piece of reasoning often affords great sthetic pleasure1 none the less real because comparatively few people enjoy it4 ,the fact that the history of a big scientific investigation1 such as the ,electromagnetic ,theory or ,einstein's ,theory of ,relativity1 is not generally regarded as a poem is due merely to an accident of language and education4 ,but we have to admit that most people are affected by these accidents1 and that the sthetic objects provided by science count almost as few admirers as do the 8beauties0 of chess4 ,if we may judge from the number of popular books and articles dealing with science1 there is some hope1 however1 that this particular contribution is receiving more attention4 ,the results of such increased attention will not be simple1 but if it did no more than add fresh sthetic objects1 the contribution would be important4 ,the fourth contribution of science1 both in itself and for its reaction on other interests1 is perhaps the most important of all4 ,this contribution is1 put briefly1 the light thrown by science on man's place in the universe4 ,every branch of science conspires directly to this end4 ,with some the emphasis is on the universe as distinct from man2 others are concerned chiefly with man himself4 ,to the general mind the result has been to make the universe bigger and man smaller1 and this is1 perhaps1 no unfair summary4 ,it is probably difficult1 after hearing a duet sung by an astronomer and a psycho-analyst1 not to feel depressed4 ,but1 such as it is1 there can be no doubt that any conception of man's destiny that is to command attention must conceive that destiny as played against the background of the scientific cosmos4 ,whether the vision be that of a prophet1 philosopher or poet1 it must accept those postulates4 ,the cosmos revealed by science1 both in its direct influence upon the mind and in its almost equally direct influence upon religion1 philosophy and the arts1 is the most important part of the scientific contribution to our spiritual life4 ,so far as philosophers and artists are concerned1 this influence is recognised4 ,it is probably desirable that the influence upon philosophy should increase1 but in the case of the artist we are faced with a special problem4 ,its discussion would be interesting1 the more so in view of the fact that artists themselves have contributed very little that is helpful to its elucidation4 ,we think it essential to its solution to remember that the artist1 like the scientist1 starts with facts4 ,but the system within which the facts are related is entirely different in the two cases4 ,the scientific scheme must1 of course1 be accepted by the artist en bloc if his work is to be more than a pure fantasy4 ,but this is very different from identifying his own scheme with the scientific scheme4 ,that is to fail signally to perceive the limitations of the scientific contribution4 ,an interesting particular case of this problem is to be found in the question of the right relations of the psychological novelist to the science of psycho-analysis4 ,a scientific investigation is often1 as we have said1 a work of art1 but not necessarily a work of literary art4 ,the scientific contribution is very considerable1 but offerings from the older benefactors are still gratefully received4 ,,theories ,,and ,,personalities ,that a scientific theory is1 in some sense1 a personal achievement1 becomes evident when we study a number of theories lying within the same branch of science4 ,the ordinary belief that science is completely impersonal is certainly not true4 ,and yet it is not easy to see how a scientific theory can express the personality of its author2 it is difficult1 that is to say1 to understand in what way a scientific theory can resemble a work of art4 ,it seems that the fact that a scientific theory must have 8objective truth0 renders it an altogether different thing from a work of art4 ,it would be more just to say that the element of objective truth radically differentiates a scientific theory from those works of art which are independent of all experience of life--as certain musical compositions may be1 for instance4 ,but it is not clear that1 in general1 works of art are independent of objective truth2 all those works of art which assume experience claim assent--they do1 in their intention1 claim universal assent--to the truth of their assumptions4 ,the serious artist believes his personal vision to be true2 he will not1 probably1 claim 8absolute0 truth for it1 but neither does a scientific theory profess to be absolutely true4 ,and1 further1 works of art and scientific theories exist to serve the same purpose--to aid comprehension4 ,an artist's chief title to consideration is to be found in the depth and extent of his vision1 in the profundity and range1 that is to say1 of the comprehension he makes possible4 ,the value of a scientific theory is judged by the same criteria4 ,so far1 therefore1 it would appear that the chief difference between a work of art and a scientific theory is to be found in their subject-matter4 ,it cannot even be said that the subject-matter is arranged to serve different ends in the two cases1 for in each case the end which is aimed at is sthetic satisfaction4 ,comprehension is one of the elements of what is loosely termed the sthetic emotion1 and it is the most important element4 ,even when we descend to particulars1 and study the quality of similes in poetry1 and1 indeed1 8ornamentation0 generally1 we shall find the criterion we employ is still the degree of comprehension afforded by the device4 ,but we cannot here work out the analogy in detail4 ,it is sufficient to show that works of art that have a reference to experience1 to an external world1 in short1 are1 in important respects1 similar to scientific theories4 ,since1 then1 a work of art1 although conditioned by experience1 may nevertheless be a personal achievement1 we need have no a priori objection to conceding personality to a scientific theory4 ,in each case it is the method of transformation from what we may call the raw material to the finished product which is the personal thing4 ,the artist's raw material1 whether it be the ,thames in a fog1 a number of incidents from ,holinshed1 or the lives of the inhabitants of a ,russian village1 is no more and no less common property than are the donnes from which a scientific man constructs a theory2 the end product1 also1 in each case1 claims universal assent and bestows comprehension4 ,what is personal is the law of transformation by which the one objective thing is changed into the other objective thing4 ,the law of transformation is different for each individual mind1 and this is as true of scientific men as of any other sort of men4 ,in this sense1 then1 both works of art and scientific theories are personal achievements4 ,a history of science written from this point of view would be instructive4 ,it would be interesting to trace the personal element in each great scientific achievement1 to show what kinds of personalities have dominated us1 to see what meaning eccentricity can have as applied to the thought of a scientific man4 ,but although a detailed history of this kind has not yet been written1 certain national differences have long been recognised4 ,there is almost as marked a difference between ,english and ,french science as between ,english and ,french literature4 ,the ,english scientific mind is1 on the whole1 intuitive1 mobile1 illogical1 and very prone to imagery of a curiously practical kind4 ,the ,french scientific mind1 on the other hand1 likes to simplify the complicated reality to as few terms as possible1 and then to build up an impeccable logical edifice4 ,maxwell was a very fine type of the great ,english man of science1 but we have ,poincar's authority for saying that the great ,treatise on ,electricity and ,magnetism awakens in the ,french reader feelings of distrust4 ,so far from finding an impeccable logical structure1 he finds that different parts of the book are written from different points of view1 and that these points of view are even irreconcilable with one another4 ,maxwell's liking for immensely complicated mechanical models1 designed to illustrate some abstruse equation1 is also a stumbling-block to the ,french reader4 ,what are such models supposed to prove8 ,surely ,maxwell did not suppose that the ther contained trains of geared wheels with 8idle wheels0 in between8 ,what mysterious satisfaction did he derive from such unnecessary and irrelevant pictures8 ,but this curious liking for models is characteristic of the ,english school1 and it is a characteristic that ,continental physicists have never been able to understand4 ,it is doubtless a manifestation of the ,english reluctance to get out of touch with experience4 ,the ,english man of science trusts logic much less than he trusts experience4 ,the ,frenchman has much less respect for experience4 ,he is willing to simplify in a way which1 to the ,english mind1 is almost outrageous--to see the ,universe as a collection of little billiard balls with forces varying inversely as the square of the distance4 ,and on such assumptions he is willing to proceed as far as logic can take him4 ,there is1 indeed1 a school in ,france which asserts that all we can ever know of the ,universe is its equations2 we can never know what they 8mean0 in the ,english sense4 ,from the sthetic point of view there is no doubt that the ,french method is to be preferred4 ,we can all share ,lagrange's satisfaction when he says1 in the ,avertissement to his ,mcanique ,analytique3 8,je me suis propos de rduire la thorie de cette ,science1 et l'art de rsoudre les problmes qui s'y rapportent1 des formules gnrales1 dont le simple dveloppement donne toutes les quations ncessaires pour la solution de chaque problme40 ,but we must remember that when the interest is chiefly in the 8dveloppement0 the assumptions may remain uncriticised4 ,the ,english way is to hold the assumptions tentatively1 and to be always open to the suggestions of experience4 ,the ,german way1 which1 if we are to judge by the work of ,riemann and ,einstein1 seems to be to concentrate an immense critical apparatus on the assumptions1 is equally interesting4 ,the 8philosophic0 tendency which is supposed to characterise ,german thought in other departments1 is certainly apparent in its science4 ,the three tendencies are sufficiently marked to constitute national differences and suggest that a detailed analysis of individual achievements would yield equally interesting results4 ,,the ,,ideal ,,scientific ,,man ,is the scientific man really a distinct kind of man1 or is it merely that science is a distinct occupation8 ,to answer the question we must make the elementary distinction between the scientific man and the man who practises science1 and when we do that the answer is obvious4 ,there is as certainly the 8born0 scientific man as there is the born artist4 ,but in saying this we are referring to ideals4 ,perhaps there has never been a perfect man of science1 and perhaps there has never been a perfect artist4 ,but in order to understand the distinction between one kind of man and another it is helpful to construct ideals--extreme cases which may be used as measuring rods4 ,what1 then1 are the characteristics of the ideal man of science8 ,we may approach the solution by trying to make precise the characteristics which have led us1 vaguely1 to construct the hierarchy we already possess4 ,we feel1 for instance1 that ,henry ,cavendish1 that passionless recluse1 was a much more 8purely scientific0 man than1 say1 ,thomas ,henry ,huxley4 ,if we examine this conviction of ours we make the interesting discovery that it is chiefly for his negative characteristics that we assign this greater purity to ,cavendish4 ,huxley was passionately interested in the questions which concern every good citizen1 in politics1 in social reform1 in religion2 he took sides on these questions and fought for his side4 ,of ,cavendish we can only say that it is inconceivable that he would have taken sides on these questions1 and very difficult to believe that he was even remotely interested in them4 ,take another point4 ,huxley abounded in ordinary human affections4 ,he was a devoted husband1 a good father1 a faithful friend1 a resolute opponent4 ,cavendish never manifested a vestige of any of these qualities4 ,he had no wife1 no children1 no friends1 and never showed the faintest dislike of anybody4 ,huxley was a champion of what he thought the truth1 and strained every nerve to enable it to prevail4 ,cavendish1 who was one of the greatest investigators1 one of the clearest and most subtle minds1 in the history of science1 kept his discoveries to himself4 ,for years ,huxley bore the brunt of the attacks on ,darwin's theory4 ,cavendish blandly watched the growth in popularity of theories he had privately demonstrated to be wrong1 and never stirred a finger to rebut them4 ,and finally1 ,huxley was a man who suffered his alternations of high spirits and despondency1 hope and despair1 while ,cavendish1 from the evidence we have1 was imperturbably serene4 ,now1 the interesting point that emerges from this comparison is that ,cavendish1 in virtue of his scientific purity1 could not have exhibited those qualities which allied ,huxley to the ordinary run of men4 ,a man's characteristics are not disconnected4 ,cavendish's cold passion for knowledge required for its gratification qualities of the spirit as well as of the mind4 ,no man was ever more single in his desire to know2 no man ever was so little hindered by having other interests to serve2 no man1 therefore1 had a greater measure of the purely scientific spirit4 ,this is the important point for our question2 it is comparatively irrelevant that very few men have ever had so great a mind to place at the service of their passion4 ,that his actual scientific standing should be so much greater than ,huxley's is an accident2 he would still have been more purely scientific than ,huxley had his ability been less than ,huxley's4 ,cavendish is all of a piece4 ,his very perfection as a recording and measuring instrument tended to deprive him of 8personality40 ,the less personal he was1 in fact1 the more dispassionately open he could be4 ,other passions were incompatible with his perfection2 they would derange this exquisite instrument4 ,judgments of good and evil would not have been natural to him4 ,his reaction to anything was exhausted in the act of understanding that thing4 ,so far as we have gone1 it would seem that ,nietzsche's description of what he calls the 8objective man0 is exactly what we mean by the ideal man of science4 8,the objective man is in truth a mirror3 accustomed to prostration before everything that wants to be known1 with such desires only as knowing or #8reflecting' implies 4440 he will regard such personality as he has1 ,nietzsche goes on to say1 as accidental and arbitrary4 ,he cannot take himself seriously and devote time to himself4 ,his love is constrained1 his hate artificial4 ,he is only genuine so far as he can be objective2 he is unable to say either 8,yea0 or 8,nay0 to life2 he is concerned solely to understand1 to 8reflect40 ,he says1 with ,leibniz3 8,je ne mprise presque rien40 ,this description is undoubtedly the result of genuine psychological insight4 ,when we try to disentangle the purely scientific element in a man of science we find that1 so far as he is scientific1 he approximates to ,nietzsche's objective man4 ,if this1 then1 is the ideal scientific man1 what place does he occupy8 ,where does he stand in relation to the rest of mankind8 ,according to ,nietzsche he is merely an instrument2 8he is an instrument1 something of a slave1 though certainly the sublimest sort of slave1 but nothing in himself40 ,he is no goal1 no termination1 no complementary man in whom the rest of creation justifies itself4 ,as compared with the true philosopher1 the philosopher in ,nietzsche's sense1 the man who gives a new direction to life1 the ideal man of science is merely the most costly1 the most easily tarnished1 the most exquisite of instruments4 ,we need not quarrel with this valuation1 but we would point out that there is an omission in it4 ,the scientific man is an instrument1 but he is an indispensable instrument4 ,the human race has endured all the different 8new directions0 given to it by the 8true0 philosophers of the past without any marked increase in its spiritual stature4 ,the philosopher1 however commanding1 who would really lead us in any but a circular direction must have knowledge4 ,this knowledge1 to be valuable1 must be clear and trustworthy2 it must be scientific4 ,and if the inspirations and impulses of our leaders should prove to be incompatible with deductions from scientific knowledge1 then we may be sure that the ,promised ,land does not lie their way4 ,the scientific man is merely an instrument4 ,but it is this instrument alone that can show to mankind which1 of all the goals it desires1 are possible goals1 and which1 of all the leaders it trusts1 are trustworthy leaders4 ,the scientific man is an instrument1 but it is by this instrument that those who would use it are first tested4 ,scientific knowledge is1 if you like1 as dispassionate and inhuman as is the universe with which it concerns itself--and it can as little be ignored4 ,,parallel ,,straight ,,lines ,geometry1 it has been satisfactorily shown1 had a purely empirical origin4 ,it appears that the earliest geometrical formul which have been discovered belong to ancient ,egypt1 and that all these formul served a useful purpose4 ,the oldest of them are concerned with the measurements of areas1 a class of problem which the yearly sinking of the ,nile rendered of great importance4 ,the formul obtained by the ancient ,egyptians were usually wrong1 although they were approximately correct2 they evidently rested on no theoretical basis1 but were compendious statements of the results of somewhat rough measurements1 a point of view which is borne out by the fact that no proof1 nor even an attempt at a proof1 is anywhere hinted at4 ,so far as the evidence goes1 it seems to be established that geometry1 as consisting of logical deductions from stated premises1 began with the ,greeks4 ,a number of theorems of a fair degree of complexity had been developed before they were reduced to a system2 before1 that is1 the assumptions on which they were based were made explicit4 ,the task of discovering the necessary and sufficient assumptions on which a system of geometry rests is one of the greatest difficulty2 the necessary combination of subtlety and rigour is rare4 ,the great systematisation of ,greek geometry was effected1 of course1 by ,euclid1 and although his reduction of the system to its essential assumptions was not final1 his performance was such as to awaken the admiration of great mathematicians in every succeeding century4 ,but there is one point in which this great reduction is notably imperfect--the so-called parallel axiom4 ,it says1 essentially1 that through a given point only one line can be drawn parallel to a given straight line4 ,it was felt1 even by the earliest commentators on ,euclid1 that this postulate did not possess quite the same degree of self-evidence as was manifested by the others4 ,it was necessary1 they felt1 to give a proof of this postulate2 they attempted to improve on ,euclid's work in a number of minor ways1 but it was the parallel axiom which they were most concerned to revise2 the proof of this postulate should be contained1 they thought1 in the other postulates4 ,the attempts to supply this proof were all fruitless1 and the sixth century was reached with this nine-hundred-years-old disfigurement still persisting4 ,for some time after the sixth century the world rested from ,euclid's parallel axiom2 indeed1 it rested from geometry altogether1 and the old empirical outlook of the ,egyptians1 and even their formul1 again became current4 ,but the ,greek culture penetrated to the ,arabs1 and with the ,greek culture came the riddle of ,euclid's axiom4 ,again proofs were attempted2 a famous attempt is that of ,nasir ,eddin1 who flourished in the thirteenth century4 ,in #affc ,john ,wallis made the important discovery that unless the parallel axiom be assumed1 similar figures of different sizes are not possible1 that is to say1 that if we are to assume that shape is independent of size1 then we must assume ,euclid's parallel axiom4 ,many of these attempts brought out points of interest1 but none of them were successful4 ,in the year #agcc1 however1 the whole research took on a new complexion with the publication of ,girolamo ,saccheri's ,euclides ab omni naevo vindicatus4 ,the importance of this work consists in the fact that1 although it was written to vindicate ,euclid's parallel axiom once for all1 it contains the first real outline of a non-,euclidean geometry4 ,saccheri was a ,jesuit1 and it was in #afij1 while he was teaching grammar in ,milan1 that he first studied the ,elements of ,euclid4 ,he was a man of very great acumen1 and when he1 in turn1 succumbed to the spell of the parallel postulate1 he brought to bear on it a more subtle and rigorous logic than had yet been applied to it4 ,thirty-six years before he published his treatise on ,euclid he had published a book on logic which gives him a high place as a logician4 ,in it he is particularly concerned with investigating the compatibility of different assumptions or postulates4 ,his method was to determine whether a member of a group of postulates is independent of the others by finding a particular case in which the postulate in question is not true while all the others remain true4 ,if such a case can be found1 it is obvious that the postulate in question cannot be deduced from the others1 else it would be true whenever they were true4 ,this was the method he applied to the parallel postulate of ,euclid4 ,he showed that the parallel postulate is equivalent to saying that the three interior angles of a triangle are equal to two right angles4 ,he proceeds1 therefore1 in accordance with his method1 to develop the consequences of supposing them less than1 or greater than1 two right angles4 ,in the latter case he succeeds in showing that we are led to impossible conclusions1 since he assumed1 as everybody assumed for more than a century after1 that the straight line is of infinite length4 ,but in the former case1 the hypothesis that the interior angles of a triangle are together less than two right angles1 ,saccheri1 although he struggled very hard1 did not succeed in falling into contradictions4 ,he does not seem to have had the boldness necessary completely to trust his own logic1 but the fact remains that1 accepting the rest of ,euclid's axioms and denying the parallel axiom1 he developed a logically consistent geometry4 ,there is reason to suppose that ,saccheri's work had some influence on subsequent thought1 although its full significance was certainly not perceived4 ,the parallel axiom continued to be investigated1 and the total effect of all these efforts was to induce a doubt concerning the absolute necessity of the ,euclidean geometry4 ,such a doubt was very daring2 for two thousand years the postulates of ,euclid had been accepted as absolutely true2 the fact of their existence had profoundly influenced philosophy1 and1 indeed1 theology4 ,but the doubt persisted and grew1 until finally1 early in the nineteenth century1 a perfectly logical and consistent non-,euclidean geometry1 one explicitly denying the parallel postulate1 was published to the world4 ,as so often happens1 the great step was taken by two men independently of one another1 ,lobatschewski1 a ,russian1 and ,bolyai1 a ,hungarian4 ,it appeared1 however1 that both had been preceded by that great mathematical genius1 ,gauss1 although he had been too timid to publish his conclusions4 ,the new geometry developed the consequences of that one of ,saccheri's alternatives which supposed the interior angles of a triangle to be less than two right angles4 ,the whole outlook on geometry now assumed a new complexion4 ,riemann tried the effect of denying the infinity of the straight line and of developing ,saccheri's other alternative4 ,he found he was led to no contradictions4 ,but with ,riemann's work we come to a yet further extension of geometry--the extension to space of four1 five1 or any number of dimensions4 ,and these investigations1 which seemed for some time to constitute the most gratuitous1 although the most profound and subtle1 exercises of the mind1 have now received their complete justification by flowering into the ,generalised ,principle of ,relativity4 ,,the ,,new ,,scientific ,,horizon ,about current scientific speculations there is one characteristic1 subtle1 perhaps1 but profound and far-reaching1 which distinguishes them from the scientific speculations of the ,victorian age4 ,we can best isolate this characteristic by considering it as a particular manifestation of something which is met with in nearly every phase of contemporary life--something which may fairly be called the ,zeitgeist of our time4 ,this spirit is chiefly a sense of unlimited possibilities1 a sense that the radically new and unprecedented may be upon us2 with this feeling comes a recrudescence of the spirit of adventure2 there are unknown paths leading to vague but--probably--splendid goals4 ,in the ,victorian age the main lines of everything were settled2 the chief features of the universe were known4 ,there were matter and energy1 and there was1 of course1 the ther4 ,the astronomical and geological scales were known in broad outline1 and a first survey of the march from amba to man had been taken4 ,the work of future ages was to fill in the details4 ,the universe of the ,victorians was a large and rather grand affair1 but it was sombre4 ,those emotional barometers1 the poets1 in so far as they were aware of the scientific outlook1 either 8transcended0 it or were crushed by it4 ,jules ,laforge furnishes an excellent example of the effect of the ,victorian scientific outlook on an intelligent and sensitive mind4 ,his reaction was to compose funereal dirges on the death of the earth and the extinction of mankind4 ,the universe of the ,victorians was objective1 indifferent1 tracing a purposeless pattern in obedience to 8iron0 laws4 ,it was a universe which held no great surprises4 ,it is obvious that a very different spirit is abroad to-day4 ,at the present time the general consciousness seems to hold that almost anything is possible4 ,in part this may be accounted for1 as in other ages1 by credulity based on ignorance1 but there is also a credulity based on knowledge1 and it is this aspect of the general attitude which deserves attention4 ,the two kinds of credulity may be observed in different believers of the same statements4 ,spiritualism1 for instance1 has its followers amongst those who are unfamiliar with investigations in the subject and amongst those whose belief has been compelled by their very knowledge of the investigations4 ,and disbelievers form two exactly similar classes4 ,there is also a credulity--the most common kind--based on neither ignorance nor knowledge1 but on partial knowledge4 ,thus knowledge1 but incomplete knowledge1 of such phenomena as wireless telegraphy or telephony1 seems to predispose many people to believe 8wonders0 which have no real connection with those phenomena1 but which are merely as inexplicable by partial knowledge4 ,undoubtedly the recent developments in science are responsible for much of this kind of credulity4 ,but the new indulgence of possibilities1 as exhibited by the man of science1 is dependent on quite different considerations4 ,to the student of physics1 at any rate1 the work of the last two or three decades has been peculiarly disturbing4 ,he has been called upon1 not merely to revise and extend his knowledge1 but to alter his assumptions4 ,it is in this respect that the physics of our own day chiefly differs from ,victorian physics4 ,the distinctively modern epoch began with the promulgation of the ,electron ,theory4 ,that 8matter0 could be 8electrified0 was easily granted4 ,the fact that the famous question1 ,what is electricity8 could not be answered was no difficulty in admitting the fact that1 as a result of certain processes1 matter could be made to exhibit certain phenomena which could conveniently be referred to the fact that it possessed an 8electric charge40 ,and the discovery of particles very much smaller than a hydrogen atom presented no conceptual difficulties4 ,the fact that the ultimate particles of matter were smaller than had been supposed could easily be granted2 the new assumption was of the same kind as the old one4 ,and1 further1 to admit that each of these particles possessed an electric charge made no unfamiliar demands on the imagination4 ,but the next step1 that these particles consisted of nothing but an electric charge--that was a very different thing4 ,the early popularisations of the idea show something of the mental confusion it caused4 8,disembodied charges of electricity0 was a favourite descriptive phrase2 many physicists fought hard to retain even a nucleus of 8ordinary matter0 on which this charge could be supposed to be lodged4 ,that an electric charge could exist apart from matter seemed to many people as difficult to conceive as motion without anything which moved4 ,but the conception speedily became familiar2 that useful entity1 the ther1 soon made things easier4 ,for the disembodied charge1 the electron1 could be conceived as a local distortion of some kind in the ther1 and1 by endowing the ther with some sort of substantiality1 the hypothesis that matter was in some way built up out of this primitive substance could be tolerated4 ,but the general effect of the theory was to give a more philosophical tinge to science4 ,the gross1 easy assumptions of everyday thinking about 8matter0 had to be revised2 articles were written showing that matter was really immaterial1 and materialism was conjectured to have received a severe set-back4 ,the mind had barely become accustomed to the new assumptions before it was again profoundly disturbed by the publication of ,planck's ,quantum ,theory4 ,the theory1 which was invented to explain certain radiation phenomena1 asserted1 briefly1 that energy was atomic4 ,one's most intimate assumptions were disturbed4 ,men of science are not usually accustomed to philosophic exercises1 and the idea that energy1 which they regarded as necessarily continuous1 had an atomic structure seemed at first almost meaningless4 ,if we consider1 for instance1 the energy possessed by a moving body1 it seems natural to suppose that this energy can be increased or diminished in a continuous manner2 the idea that its energy can only increase or decrease by finite jumps was a very strange idea1 and led again to a scrutiny of assumptions which had appeared fundamental in science4 ,here1 again1 objections to the new theory were sometimes the outcome purely of mental inertia1 of an inability to examine and discard a way of thinking which seemed almost a necessary consequence of the structure of the mind4 ,the last great bouleversement of one's fundamental assumptions has been1 of course1 ,einstein's generalised theory of relativity4 ,here we are asked to revise our most deep-rooted assumptions--so deep-rooted that we are1 for the most part1 unconscious of them--our assumptions regarding space and time4 ,it is this thorough overhauling of primary assumptions which distinguishes the modern progress in physics from all the progress of the ,victorian age4 ,physics has not merely been extended1 it has become a radically new thing1 and there are very good reasons for supposing that it is going to change still more4 ,a certain sense of unknown possibilities is therefore natural1 even if it be the product merely of bewilderment4 ,the total effect of the new ideas is to make the universe of physics less objective2 to an unsuspected extent this indifferent universe1 with its iron laws1 is a product of our own minds4 ,to some extent this fact was always recognised1 particularly by the ,continental physicists1 but as a general persuasion it is comparatively recent4 ,we cannot escape the structure of our own minds1 it is true1 but we do not yet know what that structure is2 we do not know what barriers are breakable2 we do not know what thoughts are thinkable by man4 ,a universe in whose construction so plastic and mysterious an entity as the mind of man collaborates1 may very well hold great surprises4 ,,the ,,hope ,,of ,,science ,it is not an unfair judgment1 we think1 that decides1 on a survey of contemporary intellectual activities1 to grant science the first place4 ,whether we consider the quality of the work which is being done1 its importance to mankind1 or the spirit in which the work is done1 we think science earns that place4 ,our age is a scientific age to an extent which is certainly not generally realised4 ,contemporary scientific work is of a quality fully comparable with that of the greatest periods of its history2 it is inevitable that our age should emerge1 in the history of the future1 as an age of science4 ,it has1 indeed1 already established a perspective which leads to a revaluation of the ,victorian age4 ,there have already been many writers who have thought that age more memorable for its science than for its other achievements1 that its significance to humanity lay more in the work of ,darwin1 ,faraday1 and ,maxwell than in that of ,tennyson and ,matthew ,arnold1 or even in that of ,mr4 ,gladstone1 but the perspective we have now obtained puts the matter almost beyond doubt4 ,with most of us our outlook is the result of a decrepit tradition4 ,our orientation towards life1 so far as we are conscious of having one1 is based upon the values we attribute to the various objects of our thoughts1 and these values are determined partly by our instinctive desires and partly by the suggestions of our education--using the term 8education0 to include all converse with the minds of our fellows4 ,education1 so defined1 is the result very largely of a long and widespread tradition1 a general tradition of ,european culture4 ,it is a curious fact that1 although the history of science goes as far back as the history of the arts1 science is not an integral part of this1 nevertheless1 very catholic culture4 ,there are periods1 it is true1 when some scientific theory is sufficiently dramatic1 or appears sufficiently pertinent to man's destiny1 to secure general attention2 ,newton's theory of gravitation1 ,darwin's theory of evolution1 and ,einstein's theory of relativity have each given rise to such a period4 ,einstein's theory1 we are informed1 is now the favourite topic of enlightened conversation in ,parisian salons1 as ,newton's theory once was4 ,some of this interest1 no doubt1 is the product of disinterested curiosity1 and in that respect is vastly different from the once general interest in ,darwin's theory4 ,but we fear that many of those who are curious about ,einstein's theory would1 if they understood it1 find it uninteresting4 ,we dare not interpret this curiosity as a sign that people are beginning to be as naturally interested in science as they are in literature1 for instance4 ,nevertheless1 we believe that the old culture is moribund in the sense that its particular scale of values is undergoing revision4 ,science is becoming less an affair for specialists2 it is acquiring a 8human0 value4 ,an increasing number of people are beginning to realise that a great science1 such as ,physics1 may offer objects for contemplation which are as delicate1 as subtle1 as exquisitely harmonious as the dreams of ,plato--and much better founded4 ,and in relation to man1 his present state and possible future1 science alone1 to those who are not satisfied with less than verifiable knowledge1 speaks with the accent of authority4 ,the great constructions of science are grandiose without being chimerical2 they are beautiful but not deceiving4 ,indeed1 one sometimes has the feeling that it is only in science1 nowadays1 that one still meets with the spirit of adventure1 the sense of boundless and glorious possibilities1 with an exultant hope4 ,our poets and men of letters generally are extraordinarily tame and disillusioned creatures compared with our romantic and daring men of science4 ,it is refreshing to turn from the lamentations of our literary men to such a book as the ,space1 ,time1 ,matter of ,hermann ,weyl1 if only for the fervour1 the immense enthusiasm with which that highly accomplished mathematician writes4 ,einstein is his ,columbus1 with the difference that his ,america has indicated the existence of yet vaster continents4 ,and this enthusiasm is justified by its fruits2 it has inspired ,herr ,weyl to make what is unquestionably the greatest advance on ,einstein's own work which has yet been made4 ,it is not in ,physics alone that we find this note4 ,to the biologists1 also1 the world has become young again4 ,should our ignorant and unimaginative politicians1 and our still more ignorant and unimaginative business men1 succeed in turning the whole heroic effort and age-long struggle which has produced our present culture to a mockery1 they will put an end to a curiously interesting and promising transition age1 to an age which is at once fin de sicle and at the morning of a glorious renaissance4 ,but if they do not succeed1 if the ordinary man shows himself even a little worthy of the immense travail of his species1 then we prophesy that science will become an integral part of the culture of the future4 ,the new physics1 the new biology1 the new psychology1 will be too obviously pertinent to all man's chief preoccupations for us to be able to pretend that the present narrowly conceived humaniora furnish a liberal education4 ,we even believe that if the old arts are to become youthful again1 it must be by a transfusion of blood4 ,it will not be sufficient that the philosophy and literature of the future should 8accommodate0 themselves to the scientific outlook2 they must be inspired by it4 ,meanwhile1 scientific men must be charitable2 they must believe the best4 ,if science is to become an integral part of culture1 scientific men must help to make this possible4 ,we believe that much of the present interest in science is genuine2 that it springs from a serious attempt on the part of many people to find out what science can tell them about themselves and the ,universe they live in4 ,science is not hunted purely for its dividend-earning capacities or for its power of providing new thrills4 ,einstein1 we understand1 is suspicious of the popular interest his theory has evoked2 8a mere fashion10 he says4 ,and doubtless his suspicion is largely justified4 ,but we believe there is more in it than that--that there are many who1 besides valuing the delightful dreams of the poets and philosophers1 have an affection for knowledge4 ,and when they find that the constructions of science are not one whit less delightful than the dreams of the poets1 this affection may give rise to a permanent attachment4 ,and with these new objects of interest will come a change in values4 ,men will learn to differentiate in their beliefs between those which are mere indulgences of emotion and those which correspond to objective truth4 ,this is the path by which the mind becomes mature4 ,it may not be1 in all stages1 a pleasant process1 but it leads to increased freedom and increased power4 ,the impossible will no longer be attempted1 but the region of the possible will be seen to be vastly greater4 ,man will see in what directions he can shape his destiny1 and he will be able to enter on the task with a rational hope4 ,all his courage and endurance will have a chance of victorious achievement2 he will know that he is not engaged in a forlorn hope2 the world will become young again4 ,,the ,,return ,,of ,,mystery 8,it is a universal condition of the enjoyable that the mind must believe in the existence of a law and yet have a mystery to move about in40--,,james ,,clerk ,,maxwell4 ,that our thinking1 and with it our feeling1 is largely conditioned by assumptions which have no logical necessity1 is a commonplace of philosophy1 and is indeed apparent to the slightest introspection4 ,characteristic of any age is a body of beliefs1 resting on more or less good evidence1 and a group of feelings associated with those beliefs4 ,the ,german language1 so rich in indefinite but valuable general terms1 afforded the word ,zeitgeist for this complex1 a word we have directly translated into the ,spirit of the ,age4 ,the name is a good one2 it indicates that we are dealing with something which is widely diffused and also subject to change4 ,it is subject to change1 but it plays a dominating rle in the age to which it belongs4 ,the ,spirit of the ,age is something that practically all the intellectual life of the age has in common4 ,it is not manifested only in philosophical treatises or in works of art2 it is often manifested even more strikingly in statesmen's speeches and a country's domestic and foreign policy4 ,it is a kind of intellectual and emotional atmosphere of which everybody is aware1 but which probably nobody could define4 ,we see1 however1 that a very important part of it consists of a sense of probability1 of a tendency to accept certain kinds of explanation and to reject others4 ,for the last few decades1 at any rate1 ,science has been the chief factor in forming this omnipresent sense of probability4 ,as a matter of fact1 it is probable that the influence of ,science in forming the ,spirit of the ,age can be traced a very long way back1 as far back as ,copernicus4 ,not that we assert the existence of a close connection between the ,science and the other intellectual activities of ,copernicus's own age4 ,the influence of which we speak is likely to manifest itself gradually2 in particular1 it may take a long time to affect the arts4 ,and by the time it has percolated so far its origin may be forgotten2 it may appear as a subconscious rather than as a conscious group of assumptions4 ,by the time a scientific discovery becomes part of the mental furniture of an age1 many of what were originally its possible implications will have become an integral part of it4 ,the original discovery will then be merely the nucleus of a rich intellectual and1 possibly1 emotional complex1 of which the parts are no longer envisaged separately4 ,the work of ,newton1 for example1 and the great body of exact investigations he made possible1 influenced the outlook of the nineteenth century chiefly in the direction of making determinism plausible4 ,such lecturers as ,tyndall could confidently appeal to this mental predisposition on the part of their audience1 although they had no need to postulate any direct acquaintance with the work of ,newton and of his successors4 ,the fact that ,newton successfully formulated exact laws for the description of natural phenomena is the important aspect of his work from our present point of view4 ,the influence of ,copernicus was rather different4 ,from the point of view of the history of ,science his importance is that he made ,newton possible2 from our present point of view his importance is that he made ,darwin possible4 ,copernicus' destruction of the isolated position of man's planet in the solar system prepares the mind for ,darwin's destruction of the isolated position of man in the animal kingdom4 ,they each shocked the same set of prepossessions4 ,the 8materialistic philosophy0 which was so marked a feature of the latter part of the nineteenth century1 and which still forms1 we believe1 the prevalent intellectual complexion1 owed the whole of its plausibility to its supposed scientific backing4 ,its basis was not merely biological2 physics played quite as great a part as biology4 ,the notion of determinism derived its strength1 as we have said1 chiefly from physics2 biology was not in a position to demonstrate the exact correspondences required4 ,the ultimate grandiose vision of the purely natural and inevitable march of evolution from the atoms of the primitive nebula to the ,british ,association for the ,advancement of ,science1 as outlined by ,tyndall in his ,belfast ,address1 assumed the results of physics and astronomy as much as ,darwin's ,origin of ,species4 ,it was because biology was not the only science involved that it was possible to found a 8materialistic0 philosophy on ,darwinism4 ,one primary assumption of that philosophy1 that life arises from 8dead0 matter1 not only had no biological support1 but had been decisively refuted by the experiments of ,pasteur4 ,but1 as related to the general movement of ,science1 the hypothesis had the necessary plausibility4 ,considering the then existing evidence1 this hypothesis1 together with the hypothesis that mental states are produced by atomic movements in a strictly determinist manner1 are1 indeed1 striking instances of the way in which the ,zeitgeist1 as much as the evidence1 determines the direction of our thinking4 ,the importance of such conceptions cannot be over-estimated4 ,directly or indirectly they influence the whole life1 if not of their time1 then of an age which succeeds them4 ,the philosophy in question had existed for centuries1 of course2 what made it influential was the scientific backing it received1 for1 in these matters1 ,science has for some time past played the dominant rle4 ,neither religion nor philosophy has been able successfully to oppose it2 nowadays1 indeed1 they seem concerned only to agree with it4 ,and if1 here and there1 a few artists have felt themselves outraged by what were supposed to be the teachings of ,science1 their influence has not been sufficient to deflect the stream4 ,such isolated protestants have had nothing but their feelings to oppose to what were considered to be facts1 and the world1 with what may have been a stupid honesty1 has followed after the supposed facts4 ,but the influence of ,science on the arts would require a separate investigation4 ,a certain stability is given to some serious art by its own tradition1 and this may lessen its sensitiveness regarded merely as an indication of the spirit of its age4 ,it is1 nevertheless1 very sensitive4 ,in a history of modern literature1 for example1 it is impossible to exclude direct references to ,darwin2 it is usual1 indeed1 to devote some space to such 8influences40 ,and the artist who is not at home in his age may be reduced to impotence by it4 ,dostoevsky is a magnificent example of a writer who1 extremely sensitive to the spirit of his age1 and profoundly understanding it1 strove to transcend it4 ,a smaller ,dostoevsky might well have been nothing4 ,and is a post-,darwinian ,beethoven1 or a post-,darwinian ,dante1 really conceivable8 ,now it is unfortunate that1 so far as scientific discoveries form the ,spirit of the ,age1 they do so at second-hand4 ,the ,origin of ,species happens to be easy to read1 but even so that body of thought known as 8,darwinism0 owes its influence chiefly to such expositors as ,huxley and ,tyndall4 ,the thing becomes set2 it assumes hard1 bold outlines2 the issue has to be presented with something of the simplicity of an election cry4 ,the universe of ,science becomes finally a universe from which all mystery is banished and where the only ultimates are small1 incompressible spheres whose movements and combinations produce--everything4 ,the chasm separating this conclusion from the actual scientific evidence is not realised4 ,very tentative and almost fantastic hypotheses become dogmas1 and it is as dogmas that they become influences4 ,as a matter of fact the scientific evidence1 even of ,darwin's day1 suggested quite other possibilities than those popularised as a 8materialistic0 philosophy4 ,james ,clerk ,maxwell1 who had a profounder insight into physical reality than any other man of his time1 in a very little known essay1 draws attention to the 8singularities0 characteristic of certain natural phenomena1 and suggests that there are more singular points the higher the rank of the existence4 8,at these points1 influences whose physical magnitude is too small to be taken account of by a finite being1 may produce results of the greatest importance10 and he warns his readers against 8that prejudice in favour of determinism which seems to arise from assuming that the physical science of the future is a mere magnified image of that of the past40 ,maxwell's remark is now seen to have been prophetic4 ,the extraordinarily profound and far-reaching philosophical implications of the theory of relativity have hardly yet begun to be investigated1 but we have already a general sense of their direction4 ,hermann ,weyl's ,raum1 ,zeit1 ,materie1 for instance1 the most thorough mathematical exposition of the whole theory which has yet appeared1 hints not obscurely at the philosophical bearing of the new investigations4 ,now that1 by ,weyl's own work1 ,maxwell's electromagnetic equations are included by the theory1 it seems to be scientifically complete4 ,it presents us with a picture of the universe which is wholly unlike the picture of the early physics4 ,in particular1 an altogether different rle is assigned to the human mind4 ,so far as the exterior universe and the laws of nature are concerned1 we see that the primary entity is the mind itself4 ,it is the mind which has created1 not only space and time1 but the matter it has put within that framework4 ,the mind has not created the universe out of nothing1 it is true4 ,but it is almost impossible to say anything intelligible in the old sense about the fundamental entities to which ,einstein's theory leads us4 ,professor ,eddington suggests that they may be 8the very stuff of our consciousness10 a somewhat mystical remark which nevertheless shows the trend of the new speculations4 ,and1 as a striking confirmation of ,maxwell's view of the possible development of physical science1 we may quote one of the last sentences of ,weyl's profound discussion3 8,it must be emphatically stated that the present state of physics lends no support whatever to the belief that there is a causality of physical nature which is founded on rigorously exact laws40 ,unfortunately not all men are mathematicians4 ,the great and wonderful vista now opened up by ,science--greater and more significant1 we believe1 than has existed at any previous time in the history of thought--is at present a consequence of highly abstruse investigations4 ,the sheer technical difficulty of these inquiries will long hinder them from exerting their due influence on philosophy and1 through philosophy1 on the whole of the intellectual life of the age4 ,but the new conceptions exist1 and they derive their unshakable strength from the fact that they are the result of the severest ,science4 ,and surely no one can fail to see that they promise not only fascinating regions for thought1 but a new liberation of the human spirit4 ,mystery1 but more wonderful and full of promise than ever1 has been restored to the universe4 ,,mathematics ,,and ,,music ,it is possible that the old heading 8,arts and ,sciences0 has been responsible for some of the barrenness which is so conspicuous a feature of sthetic theory4 ,for the heading seems usually to have suggested1 not only that there is a difference between the arts and the sciences1 but that the difference is of a fundamental kind4 ,for the purposes of sthetic theory the various arts are assumed to have more in common than any one of them has with any of the sciences4 ,we find the writer on sthetics expounding his principles in chapters headed ,painting1 ,sculpture1 ,poetry1 ,music2 but it is rare indeed to find the argument extended to mathematics and physics4 ,yet there is no evidence that such omissions are due to deliberate reflection2 the philosopher has not decided1 after examination1 that the sciences are unsthetic objects2 we must assume that accidents of taste and education have prevented him from paying attention to what may conceivably be useful data for the formulation of a theory of sthetic4 ,within the last two or three generations scientific men have been thinking and writing a good deal about the philosophic basis and implications of their study1 and it is significant that this inquiry has led many of them to insist on the sthetic character of the satisfactions that science affords4 ,the late ,henri ,poincar1 in particular1 has shown that scientific theories are akin to works of art1 and in this country1 ,dr4 ,norman ,campbell has asserted his belief that great men of science are essentially great artists4 ,the point of view is an interesting one1 and suggests that fresh light may be thrown upon sthetic problems by a new grouping of their subject-matter4 ,instead of putting the arts and the sciences on opposite sides of the fence1 it may be helpful to see whether certain members of these two groups have not a natural affinity with one another1 and so gain hints for a different and more comprehensive classification4 ,it is noteworthy1 in this respect1 that music has always occupied an exceptional position among the arts4 ,pater tried to relate it to other arts by saying it was the art to which all others aspire3 ,the arts may be represented as continually struggling after the law or principle of music1 to a condition which music alone completely realises2 and one of the chief functions of sthetic criticism1 dealing with the products of art1 new or old1 is to estimate the degree in which each of these products approaches1 in this sense1 to musical law4 ,it is characteristic of ,pater's criticism1 and of much of the criticism of his school1 that it exists1 as it were1 within a world of its own4 ,the meanings to be attached to his most important terms are always suggested or insinuated2 they are never defined4 ,the method is useful1 perhaps even necessary1 in dealing with a complex and elusive object1 and where appeal is made to perceptions which lie on the fringe of consciousness4 ,but it runs the grave danger of becoming altogether too tenuous to be intelligible when we make direct reference to the object it is supposed to illuminate4 ,when1 for instance1 ,pater says of the best music1 8the end is not distinct from the means1 the form from the matter1 the subject from the expression10 we become acutely aware of the absence of definition in each of these primary terms directly we think of any actual composition4 ,we feel1 indeed1 that the terminology is not natural2 in contemplating a poem the mind may be naturally impelled to distinguish between subject and expression as a kind of first effort in analysis2 it is doubtful whether1 in listening to music1 this direction for analysis ever presents itself4 ,so that to say that in music subject and expression are identical is not to say anything useful about music1 but merely to declare that that kind of analysis is irrelevant4 ,it is very probable that nothing is to be gained by first making distinctions which have a meaning for other arts and then bringing music into the scheme by saying that for music such distinctions become meaningless4 ,but if we are to maintain that this kind of criticism is irrelevant1 then music becomes not only an isolated art but the art of which we know least4 ,if it cannot be accommodated as an example within the general body of sthetic criticism1 the criticism that uses such terms as ,pater uses1 then whatever general conclusions the multifarious writings of the last two centuries on the 8beautiful0 may be considered to have reached are not applicable to music4 ,in this extremity it is natural1 nowadays1 to become 8scientific40 ,comparative studies are undertaken3 the music of ,java is compared with the music of ,bach3 the evolution of musical devices is made clear2 the psychological condition of the patient under music is examined3 the time taken for the right degree of hypnosis to be induced is determined4 ,that such methods may one day stumble upon important facts it would be rash to deny1 but nothing has yet been reached which illuminates the particular problem that music presents4 ,we are frankly of the opinion that1 so far1 the difficult utterances of certain mystical or semi-mystical writers throw more light on the real nature of music than do those of common sense4 ,among such writers on music ,schopenhauer is notorious2 and it is worth while to dwell a little on his speculations1 fantastic as they may seem1 since they contain an element common to all such interpretations1 which does serve to isolate the essential problem of music4 ,in ,schopenhauer's sthetic the object of all arts1 except music1 is to lead1 by the description of objects1 to the recognition of the ,ideas 7,platonic7 whose appearance in multiplicity constitutes the world4 ,all arts1 therefore1 have a transcendental function2 their aim is to reveal to us the ,platonic world of eternal essences or ,ideas4 ,but they have to raise us to this region via the objects of experience2 in that sense they are also1 therefore1 concerned with the world of appearance and are dependent upon it4 ,the case is different with music4 ,music is not concerned with the external world either as a symbol or as a reality4 ,it is not even1 in ,schopenhauer's language1 concerned with the ,ideas1 but refers directly to that 8,will0 which1 in ,schopenhauer's philosophy1 underlies the ,ideas themselves4 ,the essence of his theory is given in the following passage3 444 so ist die ,musik1 da sie die ,ideen bergeht1 auch von der erscheinenden ,welt ganz unabhngig1 ignoriert sie schlechthin1 knnte gewissermaassen1 auch wenn die ,welt gar nicht wre1 doch bestehen3 was von den anderen ,knsten sich nicht sagen lsst4 ,die ,musik ist nmlich eine so unmittelbare ,objektivation und ,abbild des ganzen ,willens1 wie die ,welt selbst es ist1 ja wie die ,ideen es sind1 deren vervielfltigte ,erscheinung die ,welt der einzelnen ,dinge ausmacht4 ,or1 as he says a little later on1 the world may be regarded as embodied music4 ,it is not likely that anyone will take ,schopenhauer's philosophy of music seriously2 and even those who are sympathetic to his general view are not likely to find their sense of the ludicrous undisturbed by his identification of bass notes with the planets1 tenor notes with the vegetable world1 and so on4 ,the intensity of his response to music and his humourless courage have led him to what are perhaps the most fantastic statements in all his writings4 ,but what is worth noting is that so imaginative and fertile a speculator1 because he was genuinely sensitive to music1 had to give it a profoundly isolated position in his sthetic4 ,in so doing we think he recognised one very important difference between music and the other arts4 ,it is true that music is independent of the world of experience in a way that other arts are not4 ,it is true that there is a sense in which ,schopenhauer is right when he says that music would exist even if the world did not4 ,we can see what is meant if we compare the development of a 8dramatic0 piece of music1 such as the first movement of ,beethoven's ,c minor ,symphony1 with a great tragedy4 ,the tragedy1 as a condition of success1 must make reference to our experience of life4 ,the ostensible matter of the tragedy1 the characters and incidents1 must not violate our conception of reality if they are to be accepted4 ,the tragedy must be plausible4 ,such considerations obviously do not apply to music4 ,it is meaningless to say that the development of a composition must satisfy our sense of probability4 ,yet there is a meaning in saying that its development seems either arbitrary or inevitable4 ,the analogy that immediately presents itself is a chain of logical reasoning1 as in the sustained development of a mathematical theorem4 ,such development is independent of all experience2 the mind is obeying none but its own laws1 and is paying no attention to any alien elements4 ,and it is this characteristic of mathematics which seems responsible for the fascination the study possesses for its devotees4 ,remote from human passions1 remote even from the pitiful facts of nature1 the generations have gradually created an ordered cosmos1 where pure thought can dwell as in its natural home1 and where one1 at least1 of our nobler impulses can escape from the dreary exile of the actual world1 says ,mr4 ,bertrand ,russell in a typical passage4 ,a strain of romantic eloquence seems1 indeed1 to be inseparable from the writings of mathematicians on their subject4 ,but the analogy can be pressed more closely4 ,there are elegant and inelegant mathematical demonstrations1 those which merely 8command assent10 as ,lord ,rayleigh said1 and those which provide a very high degree of sthetic satisfaction4 ,in these latter demonstrations the mind seems to be moving with more swiftness and freedom2 the whole demonstration seems to flower in a natural and spontaneous way2 we have the impression of inevitability4 ,mathematical elegance1 as ,poincar has put it1 8n'est autre chose que la satisfaction due je ne sais quelle adaptation entre la solution que l'on vient de dcouvrir et les besoins de notre esprit40 ,it is as if there were a mode of living natural to the human spirit1 an unadapted life1 a life free from the necessity of accommodating itself to the elements1 so largely alien1 of the actual world4 ,mathematics is the expression of this life so far as the intellect is concerned4 ,is it too much to say that music is a fuller embodiment of this free life8 ,if we are to say this we must acknowledge that more than the intellect is capable of this free life1 that there is a logic of the emotions as well as of the mind4 ,this assumption is not difficult to make2 indeed1 if we reflect on our experience of some compositions1 such as1 to take the same example1 the first movement of the ,c minor ,symphony1 it is difficult to avoid making it4 ,and1 in considering the matter from this point of view1 we may gain some results useful for musical criticism in general4 ,the theme of the movement in question is characteristic of many of ,beethoven's themes in that it does not serve merely as a kind of structural skeleton on which a composition is to be built4 ,in this respect it differs from1 for instance1 many of ,bach's themes4 ,the theme immediately1 in its ominous and arresting quality1 throws the mind into a certain state of expectancy1 a state where a large number of happenings1 but only the happenings belonging to a certain class1 can logically follow4 ,as an analogous vague yet restricted initial preparation we may instance the entry of the witches at the beginning of ,macbeth4 ,as the music proceeds this rich1 but more or less definite1 state in the hearer becomes more and more precise1 more and more subtle4 ,it is1 as it were1 explored and shown in all its height and depth4 ,what was pregnant in the theme is exhibited to us in all its extent1 its definiteness1 and its force4 ,the theme was the entrance to a world4 ,and we have the consciousness of logic1 of inevitability1 because at no point are we constrained4 ,we exult because we are free2 this is how we1 too1 would move but for our fetters1 our alien1 arbitrary fetters from which1 for this time1 we have been freed4 ,and in none of this1 unless we have incurably literary minds1 are we ever reminded of experience4 ,this life is no life that we have lived or that1 on this planet1 we could live4 ,music is as independent of the world as mathematics1 but it cannot1 like a system of geometry1 even be applied to the real world as an hypothesis4 ,it is even doubtful how far the emotions it expresses1 when it is merely expressing emotion1 correspond to those of real life4 ,the sorrow of the bereaved father is not the same thing as the sorrow of the bereaved lover1 but music can express sorrow with thousands of nuances4 ,it is customary to say that the emotions of music are generalised emotions2 that its sorrow1 for instance1 is a kind of common denominator of all sorrows4 ,but the exact opposite seems to be the case4 ,the situations of real life1 like the resources of language1 are probably too limited to afford correspondences to the immense variety of emotions expressible in music4 ,the musician is as free as the non-,euclidean geometer to create worlds which have no objective counterpart4 ,it is natural1 therefore1 in comparing the arts1 that we should class mathematics and music together1 since they resemble one another by their most intimate characteristics and differ1 in these respects1 from all other arts4 ,it is worth noting1 in this connection1 that it is only in mathematics and music that we have the creative infant prodigy4 ,experience and learning1 compared with what we vaguely call 8instinct0 or 8gift10 play a comparatively insignificant rle2 the boy mathematician or musician1 unlike other artists1 is not utilising a store of impressions1 emotional or other1 drawn from experience or learning2 he is utilising inner resources so obviously independent of experience that1 like ,plato's slave1 he seems to have brought them with him from some anterior life4 ,and the artistic progress of a musician1 if it be a true progress1 means primarily that he is making ever more accessible the riches of this inner life4 ,it is difficult to avoid mysticism1 or at least ,platonism1 at this point4 ,but here again it seems to us that ,schopenhauer understood something essential4 ,when he says that music1 like the ,platonic ideas1 is an embodiment of the 8,will0 that underlies all things1 he does at least say that what is revealed to us by a composition is something other than the 8personality0 of the composer4 ,the function of music is not1 like that of literature1 to illuminate this world1 but there is a world it illuminates--a world at least as vast and independent of this one as that mathematical 8cosmos0 described by ,mr4 ,bertrand ,russell4 ,there is much music1 of course1 which suggests no such mystical fancies4 ,with most of ,wagner's music1 for instance1 there is no hint of other worlds1 but rather a gorgeous colouring of this one--or of those aspects of this one which excite romantic poets with strong bodily appetites who can assume the background of the vigorous material prosperity of the nineteenth century4 ,such music is fully comparable with a certain kind of literature2 all it lacks is the definiteness of statement1 and hence the intellectual clarity1 which the use of language affords4 ,it may be even more powerful and subtle than literature can be--,tristan und ,isolde expresses certain emotions with immense adequacy4 ,but it is not doing something which music alone can do2 and1 for that reason1 it throws very little light on the peculiar problem of music4 ,for the peculiar problem of music consists in its independence1 in its power of transporting us to a world which is not otherwise revealed4 ,to ,schopenhauer1 to whom both the world and music were embodiments of the same ,will1 there was a musical equivalent for every experience2 and1 it would seem to follow1 for every musical utterance there is a corresponding experience4 ,the two worlds are independent1 but there exists between them1 as a mathematician would say1 a one-to-one correspondence4 ,yet he very strangely goes on to accept the theory that a musical utterance is a kind of generalisation of a number of distinct experiences4 ,he points out that the musical setting of a poem1 for instance1 will serve for a number of similar poems4 ,it is the 8kernal0 of all these poems which is given directly by the music4 ,but it is equally true that the same poem will serve for several musical settings4 ,when ,beethoven1 as one of sixty-three composers1 composed his setting of ,carpani's poem 8,in questa tomba oscura10 he probably composed the best setting1 since it is the only one that has survived2 but among the other sixty-two there must have been many which1 in ,schopenhauer's phrase1 were expressions of the 8kernal0 of the poem4 ,the fact seems to be that1 unless music is deliberately illustrative1 it is not concerned with what is otherwise expressible4 ,that is why musicians are always dissatisfied with 8literary0 descriptions of music4 ,however good in their own kind they may be1 they are always felt to be irrelevant and even1 in some way1 a degradation of the actual musical utterance4 ,it is felt that they exhibit a certain insensitiveness or lack of taste1 as in that curiously popular image which likens twin hills to a woman's breasts4 ,as compared with literature1 music is abstract4 ,it is independent1 as literature is not1 of the facts of life4 ,but just as there is some music which approaches to the condition of literature1 so there is some literature which approaches to the condition of music4 ,such literature1 while it is concerned with the world of experience1 as literature must be1 is concerned with that world as symbol and not as reality4 ,such literature1 we might say1 is not concerned to illuminate the world of what we here call experience1 but to reveal something about the soul of man itself--or1 if we prefer scientific jargon to mystical1 to deal with the normally subconscious rather than with the normally conscious4 ,both kinds of literature have been called realistic1 but they are realistic from entirely different points of view4 ,dostoevsky1 for instance1 regarded the realism of such writers as ,zola as trivial4 ,and can ,macbeth be regarded as a realistic work1 on the basis of the ,french conception of realism8 ,macbeth is1 indeed1 a striking example of the extent to which literature can approach the condition of music4 ,the whole apparatus of the play1 the witches1 the characters1 the incidents1 are so obviously not presented for their own sakes1 but as symbols through which an overwhelming perception was to be conveyed4 ,here the fact that the literary artist must accommodate himself to the laws of the real world1 that he must satisfy our sense of probability1 seems hardly a hindrance4 ,our sense of probability is1 indeed1 purposely lulled by the entrance of the witches at the beginning4 ,we are made aware that not the real world alone is concerned4 ,in this respect the supernatural 8machinery0 of ,macbeth performs an altogether different function from that in ,hamlet4 ,the whole of ,hamlet is perfectly realistic in the tight sense4 ,but the fact that literature must always use symbols differentiates it utterly from music4 ,and just as we have seen that real life may present no analogies to what is revealed in music1 so it may happen that the literary artist who has access to a wide and deep inner life may find no symbols1 such as are essential to literary art1 to convey his perceptions4 ,mr4 ,t4 ,s4 ,eliot has stated that ,hamlet is an artistic failure because the whole play1 considered as presentation in terms of symbols1 does not adequately convey the emotions or perceptions we confusedly feel ,shakespeare is trying to express4 ,whether or not ,mr4 ,eliot is correct in his instance1 his general thesis is perfectly sound4 ,even if ,hamlet could be re-written so as to satisfy ,mr4 ,eliot1 it is still true that there are some perceptions1 states of mind1 emotions1 or whatever one likes to call them1 which it is very difficult to believe are expressible in literature at all4 ,santayana gives a neat but somewhat trivial instance in one of his essays where he says that there is no human incident or group of incidents which can serve as a fitting symbol for pure radiant joy--a sort of prolonged1 exultant1 celestial state of joy4 ,a shadow1 to the mature mind1 lies over the brightest and most delightful of life's happenings4 ,he suggests that a poet who should try to imitate music in this respect could do little but write the word 8,joy60 with exclamation marks4 ,he could write nothing else that was unambiguous4 ,and1 indeed1 a symbol is always ambiguous unless1 like the symbols of the mathematician1 its meaning is completely exhausted by its symbolic intent4 ,the symbol distracts2 it brings with it a crowd of irrelevant associations1 and for that reason1 even when the symbols are most superbly handled1 as in ,macbeth1 the resultant communication is less definite than with music4 ,but the very great1 the immense1 importance of literature lies in the fact that it can1 partially at least1 shape the facts of life so as to make them consonant with the nature of man4 ,if experience can furnish symbols which express the deepest needs and aspirations of the soul1 then life can be1 at least partially1 illuminated4 ,for man can understand nothing which is not consonant with his own nature4 ,the literature which truly illuminates life is the literature which interprets life most fully in terms of our own emotions and aspirations4 ,in this sense not only all literature1 but all science1 is anthropomorphic4 ,science is only possible in so far as it is logical4 ,that is to say1 the universe can only be understood in so far as its happenings are obedient to the laws of man's own mind4 ,in its relation to mathematics1 where the mind pays no attention to the arbitrary conditions of experience1 physics plays something of the same part as is played by literature in its relation to music4 ,both physics and literature1 in their universal function1 are concerned with a world which need not obey the laws native to the spirit of man4 ,such illumination as they can give is dependent upon1 as it were1 what correspondences they can find4 ,the revelation of life afforded by ,the ,brothers ,karamazov1 for instance1 consists in relating the phenomena of life to the deepest impulses of the spirit of man4 ,only so does life become in any measure truly comprehended2 and it is in this respect that such works differ from those reports on life where we may recognise and assent to everything1 but where our comprehension of anything is not deepened4 ,such works as ,the ,brothers ,karamazov may be called philosophic1 if we use the word to include something other than purely intellectual understanding4 ,we have suggested that1 if mathematics may be taken as the intellectual analogue of music1 then it is not perhaps too far-fetched to say that such a science as physics may be taken as the intellectual analogue of literature1 since both are concerned to interpret what we call the real in terms of what we call the ideal1 while the two former arts are not concerned with the real4 ,and the question arises whether the arts1 mathematics1 and music1 which are not concerned to illuminate experience1 are worthy of serious attention4 ,in the case of mathematics the answer is not doubtful1 since it has repeatedly shown itself applicable to real happenings1 however little notions of utility may have played a part1 or need have played a part1 in its creation4 ,even the most remote mathematical theorems are not certainly immune from practical application4 ,but no such claim can be made for music1 and it is for that reason that to some philosophers music is a pleasing but essentially trivial art4 ,to such philosophers music1 while it may suggest spiritual profundities1 is1 after all1 saying nothing of any possible significance4 ,the adventures of the soul that it depicts are less significant even than a stage fight4 ,its one justification is the pleasure it affords2 it takes us out of ourselves in a way no other art can do1 and after this refreshing interregnum we return to the things that matter4 ,it may be so2 we can give no proof that it is not so2 we can only say we find the point of view incredible4 ,on this point1 again1 we certainly find the mystical view of ,schopenhauer1 if less intelligible1 at least more convincing than that of common sense4 ,,human ,,testimony ,everybody normally acts on the assumption that the value of human testimony is an extremely variable quantity4 ,the rules by which we assess the value of testimony1 in the ordinary affairs of life1 are of that thoroughly habitual kind that hardly involve conscious processes2 they repose on two judgments1 which we are always making4 ,our belief in direct testimony to an event is conditioned by the nature of the event and by our estimate of the 8personal equation0 of the witness4 ,these two factors are not quite independent2 it is very seldom1 for instance1 that we attribute 8general untrustworthiness0 to anybody who is known to us4 ,our experience usually teaches us that there are certain classes of statements--e4g4 his breaks at billiards1 the number of miles his motor-car runs on a gallon of petrol--for which that particular witness's credibility is at a minimum4 ,for some other classes of statements we may have learnt to take his word without hesitation4 ,what the mathematicians call the 8credibility0 of a witness is not1 in the case of any witness of whom we have personal knowledge1 a constant figure4 ,it varies with the event1 often in an extremely complicated way4 ,when ,brown is listening to ,jones talking about the enormities of ,smith the extremely delicate and rapid weighing of probabilities being performed by ,brown beggars any mathematical description4 ,when the witness is personally unknown to us the matter becomes simpler4 ,our conclusions1 one way or another1 will be held with less confidence1 but they will be more simply arrived at4 ,we may1 on the evidence supplied by the testimony itself--the tone of the letter1 the man's manner in the dock--class the witness as a man of a certain type4 ,corresponding to each type we have a rough scale of credibility for different types of events4 ,in cases where we know nothing of the witness beyond his bare statement that he witnessed the occurrence of the event our estimate of his credibility is based on very general and usually rather vague considerations4 ,we are guided by two things3 the initial credibility of the event and our estimate of the general value of human testimony4 ,both of these criteria1 and in particular the second1 are excessively ill-defined4 ,in the first place1 what do we mean by the initial credibility of an event8 ,there are very few cases where this notion can be precisely defined4 ,the simple instances dealt with in the elements of mathematical probability do1 it is true1 permit of precise definition4 ,the chance that a white ball will be drawn from an urn containing five black balls and one white ball can be exactly estimated1 for we are in possession of all the very simple relevant factors4 ,but the probability that ,romulus founded ,rome obviously belongs to a very different category4 ,and what is the initial credibility of a miracle8 ,hume1 as is well known1 thought that the a priori incredibility of a miracle was so great that its occurrence could not be established by human testimony4 ,he is here trying to establish a ratio between the initial credibility of a class of events and the initial credibility of human testimony to such events4 ,he is taking some kind of average in both cases1 but it is difficult to see how such an average can be arrived at4 ,vague considerations of this kind are of no value in forming conclusions on matters of real interest to us1 although they may be sufficient to warrant a lazy scepticism regarding what ,william ,james calls 8dead hypotheses10 or may form the basis for amusing and ingenious mathematical exercises4 ,but we have no notion of an average initial credibility which is of any use in practice2 each case must be judged on its own merits4 ,and if1 to take the second point1 we reached some average for the value of human testimony in general1 we should never1 in practice1 apply it4 ,the utmost we can hope to do is to establish a more or less constant relation between the testimony of classes of witnesses and classes of events4 ,we have to divide witnesses into types1 and for each given type estimate the value of its testimony to different classes of events4 ,we must investigate the difference it makes when the witness is taken as isolated and when he is taken as a member of a group of witnesses4 ,in this way we may hope to reach results which are of value in judicial procedure1 in the study of history1 and in various particular investigations1 including those modern substitutes for miracles1 the phenomena of spiritualism4 ,we are1 in fact1 to investigate man in his capacity as a truth-recording instrument4 ,the result of such researches as have been made may be said1 briefly1 to show that human testimony has much less value than is normally assigned to it and1 in particular1 much less value than it is held to possess in a ,court of ,law4 ,the experimental results obtained in this field are1 indeed1 often startling4 ,it is hardly too much to say that one's first impulse1 on becoming acquainted with the results hitherto reached1 is to fall back on a general and dismayed scepticism regarding the value of human testimony to anything whatever4 ,but a closer examination of the results show us that this attitude is unwarranted1 and reinforces the common-sense assumption that the value of human testimony is a matter of degree1 varying from complete worthlessness to a very fair presumption that the event occurred as stated4 ,the investigation is useful chiefly in showing us what factors influence this value4 ,it is convenient to separate out these factors according to the scheme recently employed by ,dr4 ,edmond ,locard1 in his analysis of police records over a number of years4 ,the statements made by a witness repose1 in the first place1 on sensations which he has experienced4 ,it might be thought too obvious to be worth mentioning that we require the witness who heard a sound1 for instance1 to have reasonably good hearing1 and yet there are many cases where simple preliminary considerations of this kind are not taken into account4 ,professor ,zllner's famous book ,transcendental ,physics1 for instance1 alleged marvels that occurred in the presence of ,slade1 the medium2 and these alleged marvels1 of great influence in spreading a belief in spiritualism1 were witnessed to by four professors1 ,zllner1 ,fechner1 ,scheibner and ,weber4 ,but a member of the ,seybert ,commission1 ,mr4 ,george ,s4 ,fullerton1 as a result of personal interviews1 found that two of these professors1 ,fechner and ,scheibner1 were partially blind at the time4 ,their sensations1 therefore1 in this respect1 were untrustworthy4 ,but defects of this kind may usually be determined and this factor conditioning the witnesses' credibility allowed for4 ,where a witness makes appeal to a sensation which may be checked the check should always be imposed4 ,thus ,dr4 ,locard gives an instance where a witness stated that an event occurred in a mill at a certain hour4 ,how did he know the hour8 ,by hearing a clock strike at the time the event occurred4 ,a test was made1 and it was found that the noise of the mill made the striking of the clock quite inaudible4 ,the witness then remembered that he did not hear the clock strike until he had left the mill4 ,similarly1 witnesses have testified that they saw a man leave a doorway1 their post of observation being one from which the doorway could not be seen4 ,sensations may often be checked1 however1 and1 to a careful inquirer1 they need not be a grave source of error4 ,but the next stage is concerned with the witness's perceptions4 ,of his sensations he will single some out for attention and neglect the rest4 ,he singles out those which1 for some reason or another1 interest him most4 ,it may quite easily happen1 therefore1 that the sensations most relevant to the inquiry in hand have been neglected4 ,they have been filtered1 as it were1 through the medium of the witness's interest2 and it is often the case that his interest has not been excited by the sensations most pertinent to the subsequent inquiry4 ,it is on this fact that conjurers very largely depend for their success4 ,the attention of the audience is distracted2 they are invited to dismiss certain sensations as being of no importance1 and1 in general1 it is remarkably easy to ensure this distraction of attention4 ,dr4 ,hodgson's case of the ,english officer and the ,hindu juggler well illustrates this point3 ,referring to the movements of the coins1 he said that he had taken a coin from his own pocket and placed it on the ground himself1 yet that this coin had indulged in the same freaks as the other coins4 ,his wife ventured to suggest that the juggler had taken the coin and placed it on the ground1 but the officer was emphatic in repeating his statement1 and appealed to me for confirmation4 ,he was1 however1 mistaken4 ,i had watched the transaction with special curiosity1 as ,i knew what was necessary for the performance of the trick4 ,the officer had apparently intended to place the coin upon the ground himself1 but as he was doing so the juggler leant slightly forward1 dexterously and in a most unobtrusive manner received the coin from the fingers of the officer1 as the latter was stooping down1 and laid it close to the others4 ,if the juggler had not thus taken the coin1 but had allowed the officer himself to place it on the ground1 the trick1 as actually performed1 would have been frustrated4 ,now ,i think it highly improbable that the movement of the juggler entirely escaped the perception of the officer2 highly improbable1 that is to say1 that the officer was absolutely unaware of the juggler's action at the moment of its happening2 but ,i suppose that1 although an impression was made on his consciousness1 it was so slight as to be speedily effaced by the officer's imagination of himself as stooping and placing the coin upon the ground4 ,we have here an instance of erroneous testimony by a witness to his own actions2 testimony to the actions of other people is usually much less trustworthy4 ,in this matter of direct perception we may discriminate still further4 ,tactile perceptions are of almost no value whatever4 ,if a witness be blindfolded and asked to determine1 by touch alone1 the nature1 the volume and the material of an object1 it will be found that the responses are very inaccurate4 ,experience of tactile sensations is relatively small and deductions therefrom are practically valueless4 ,thus the shock of a bullet entering the body may be interpreted as a slight blow1 several dagger thrusts in the back as one thrust1 and so on4 ,a piece of ice drawn across the neck of a blindfolded man and warm water simultaneously poured on his chest have been stated to cause death by fright1 the man having previously been informed that he was going to have his throat cut4 ,perceptions of odour or of taste are even less trustworthy2 and here the difficulty of expression in precise terms1 in the lack of a precise vocabulary1 is complicated by the fact that the witness primarily perceives odours and tastes as pleasant or unpleasant1 and pays attention only to that aspect of them4 ,in cases of poisoning1 therefore1 evidence of this kind should be given very little value4 ,it is only when we come to the senses of hearing and of sight that we enter the region where perceptions may have evidential value4 ,in the case of hearing1 however1 we must still proceed very warily4 ,experiment has shown that estimates of direction1 for example1 are quite valueless1 since the different estimates made by different observers obey the laws of pure chance4 ,training can do a little1 but very little1 to render these perceptions more trustworthy2 in general1 however1 evidence as to the direction of a sound may be neglected4 ,estimates of the distance of a sound1 also1 are of very small value4 ,the intensity of a heard sound depends on the intensity of the source1 and also on its distance2 and these two factors may be apportioned by the observer in the most arbitrary manner4 ,in the case where the sound is articulate1 as in overhearing a conversation1 we are in the presence of still other sources of error1 due to illegitimate inference and the association of ideas4 ,for words which are not heard will be supplied by the witness in all good faith4 ,he will have a theory of the purport of the conversation1 and will arrange the sounds he heard to fit it4 ,edgar ,allen ,poe's example1 in ,the ,murders in the ,rue ,morgue1 of the cries of an ape which were interpreted as remarks in different languages by different observers1 is judged by ,dr4 ,locard to be not at all fantastic4 ,the same general source of error applies to visual perceptions4 ,not everything is observed1 and the lacun are filled in by the witness in what seems to him the most probable manner4 ,oversights in proof-reading furnish a familiar example of this kind of error4 ,but psychological experiments have produced much more striking examples4 ,claparde arranged for a man1 wearing the mask of a clown1 to enter his lecture room while a lecture was in progress4 ,the students were afterwards asked to pick out this mask from a series of ten1 and out of twenty-three who attempted the task five only were successful--and even these successes were probably due1 largely or wholly1 to chance4 ,the appreciation of distances1 measured by the eye1 is also very likely to be erroneous1 the rule being that large distances are under-estimated and small ones over-estimated4 ,a similar rule holds good of estimations of intervals of time4 ,errors of this kind are not pure errors of perception2 they are due chiefly to lack of experience4 ,a carpenter or builder would usually make a much more accurate estimate of the dimensions of1 say1 the side of a house than would the ordinary person2 and astronomers who work with transit instruments have1 as a class1 very accurate perceptions of small intervals of time4 ,it is chiefly lack of experience1 also1 which is responsible for the absurdly different estimates different observers will make of the number of people in a crowd4 ,dr4 ,locard states that1 on questioning the policemen employed to keep order during a procession as to the number of people they estimated to be taking part in the procession1 he obtained the figures five thousand1 ten thousand1 twenty-four thousand4 ,the actual number1 he states1 was three thousand4 ,and during another procession two middle-aged1 intelligent1 educated ,paris journalists gave as their estimates for the number of people engaged1 the one thirty thousand and the other three hundred thousand4 ,but now let us suppose that our witness1 through the medium of his imperfect senses and his partial attention1 has received a certain image4 ,what deformations may it suffer before it is produced as his evidence8 ,if his memory of the incident has 8lapsed0 the image will undergo comparatively little alteration1 but if it has often been called to mind it will probably suffer a very considerable change4 ,each time the image is recalled it will suggest others2 the creative imagination gets to work1 altering the emphasis1 adding particulars1 obliterating others1 and the result will be as much a work of art as the reproduction of a fact4 ,this tendency is particularly to be noticed with women1 and with certain 8excitable0 types2 it may be almost a national characteristic1 as with ,gascons and ,sicilians4 ,but all witnesses are prone to this kind of inaccuracy4 ,where the event has often been narrated by the witness the deformations become even more serious4 ,for he is here exposed not only to the suggestions of his own creative imagination1 but to the suggestions of other people4 ,every one wishes to make a success of the story he is telling1 and the perception of what points to stress and what details to add is wonderfully ready and alert4 ,it has often happened that a witness of perfect good faith has changed from the simple spectator of a drama to a prominent actor in it under the influence of repeated narration4 ,finally1 we reach the point when the witness has to bear his formal testimony4 ,his observations were imperfect1 he has imperfectly remembered them1 his imagination has distorted them1 and he is now to express them4 ,a very considerable additional source of inaccuracy is likely to enter here4 ,the witness probably cannot express his complete image--words may not be sufficiently precise to render the fine shades of his remembered perceptions4 ,the nature of a sound1 the kind of emotion expressed by a voice1--he may have no words for such things4 ,and1 in any case1 the witness will not express his complete image4 ,he will select--in accordance with his own estimate of what is pertinent and what trivial4 ,he will do this even if he be allowed to talk to his heart's content2 but the method of question and answer as pursued in our ,law ,courts leads to even more imperfect expression4 ,for he is forced to be precise where his recollection is vague1 and he will either give a false precision to his answer or else profess complete ignorance4 ,more often still the witness sins by exaggeration1 and these exaggerations1 in a thousand subtle ways1 usually tend to add to his own importance4 ,and it is important to notice that1 besides tending to import fictitious details1 the witness will tend to exaggerate his degree of conviction4 ,where he was originally doubtful he is now perfectly sure4 ,so far we have been considering the witness in isolation1 and we have not considered the reaction upon his testimony of the emotional state produced in him by the event4 ,yet the emotions accompanying the event have a great bearing upon the value of the witness's testimony4 ,during the war it was noticed that the evidence of soldiers freshly wounded was often of the most fantastic description4 ,they would testify to the details of catastrophes which had never occurred2 they would assert that so-and-so had been decapitated in front of their eyes1 and so-and-so buried by an explosion1 when1 as a matter of fact1 nothing remotely resembling these events had taken place4 ,and1 under the influence of the comparatively slighter emotions of a spiritualistic sance1 people will identify the same 8materialised0 mask as the features of their husbands1 wives1 sons1 daughters4 ,under the influence of such emotions it may be taken as a general rule that perceptions deteriorate1 and illegitimate inference1 8unconscious reasoning10 becomes more marked4 ,unconscious reasoning1 indeed1 plays a very great part in nearly all cases of mal-observation4 ,it is well exemplified in the statement of the man sitting in a dark wood3 8,that dog's bark is not really a grasshopper1 it is the squeaking of a cart40 ,and ,dr4 ,locard tells of one experiment he made1 while in the ,army1 with a barometer which bore a remote resemblance to a clock4 ,his suggestion that it was a clock was invariably accepted1 even by the most eminent people1 and several of them acquired their knowledge of the time of day from its indications1 even when the hour so indicated was highly improbable4 ,the testimony of great and commanding figures1 even to the time of day1 may therefore be open to suspicion4 ,but the immense part played by unconscious reasoning is best seen in the psychology of conjuring1 under which head it is fair to group the great majority of alleged spiritualistic phenomena4 ,in this latter case we have further to recognise what ,freud calls the 8pleasure-pain principle10 as distinguished from the 8reality-principle40 ,in other words1 the witnesses are seldom disinterested2 they strongly desire to witness certain events rather than others1 and in such cases the slightest suggestion is sufficient to produce conviction4 ,when the witness is not isolated1 but is a member of a group1 the defects we have before noted1 due to the creative imagination1 are likely to be accentuated4 ,the event will have been discussed and a uniform version gradually prepared4 ,it is almost impossible1 from the unanimous testimony of a number of witnesses who have been in consultation1 to extract the original perceptions4 ,the phenomenon of mimtisme testimonial makes its appearance1 and may assume abnormal dimensions4 ,a kind of collective hysteria may be induced1 and there can be little doubt that some of the collective denunciations of witches which took place in the ,middle ,ages were manifestations of this form of mimicry4 ,such are some of the results that have been reached by the modern investigations of the value of human testimony4 ,they tell us little we did not know before1 for mankind has had an immense experience of human testimony2 but they make our knowledge more precise and enable us to see what kinds of testimony are most open to suspicion4 ,the effect of these researches on judicial procedure should be considerable1 and their influence on the study of history not less marked4 ,on this latter subject their influence can only be indirect1 and in the direction1 probably1 of throwing still more doubt on the accuracy of historical records4 ,the 8credibility0 of a witness still remains a vague quantity1 but the chances are that it is something less than the value hitherto assigned to it4 ,the investigation can claim no such precise results as those enunciated by ,craig in #afii in his ,theologi ,christian ,principia mathematica1 where1 after proving that the suspicions of any history vary in the duplicate ratio of the times taken from the beginning of the history1 he shows that faith in the ,gospel1 so far as it depended on oral tradition1 expired about the year #hhj1 and1 so far as it depended on written tradition1 would expire in the year #caej4 ,the new investigations of the value of human testimony start from humbler1 but surer1 foundations4 ,printed in ,great ,britain by ,butler ,tanner1 ,frome and ,london ,,transcriber',s ,,notes ,simple typographical errors have been silently corrected2 unbalanced quotation marks were remedied when the change was obvious1 and otherwise left unbalanced4 ,punctuation1 hyphenation1 and spelling were made consistent when a predominant preference was found in the original book2 otherwise they were not changed4