,transcriber's ,note3 ,every effort has been made to replicate this text as faithfully as possible1 including inconsistencies in hyphenation4 ,it seems that the italic typeface used in this book did not have an ae ligature4 ,names of genera and higher taxonomic groups are not capitalized in the printed book3 they have bee left unchanged4 ,some changes have been made4 ,they are listed at the end of the text4 ,italic text has been marked with underscores4 ,,oe ligatures have been expanded4 ,,the ,,riddle ,,of ,,the ,,universe ,illustration3 ,,ernst ,,haeckel ,,the ,,riddle ,,of ,,the ,,universe ,,at ,,the ,,close ,,of ,,the ,,nineteenth ,,century ,,by ,,ernst ,,haeckel 7,ph4,d41 ,m4,d41 ,,ll4,d41 ,sc4,d41 and ,professor at the ,university of ,jena7 ,,author ,,of ,,the ,,history ,,of ,,creation ,,the ,,evolution ,,of ,,man ,,etc4 ,,translated ,,by ,,joseph ,mc,c,a,b,e ,illustration ,,harper ,,brothers ,,publishers ,,new ,,york ,,and ,,london #aije ,copyright1 #aijj1 by ,,harper ,,brothers4 ,all rights reserved4 ,,contents ,,page ,,author',s ,,preface v ,,translator',s ,,preface xi ,,chapter ,i ,,the ,,nature ,,of ,,the ,,problem #a ,,chapter ,,ii ,,our ,,bodily ,,frame #bb ,,chapter ,,iii ,,our ,,life #ci ,,chapter ,,iv ,,our ,,embryonic ,,development #ec ,,chapter ,v ,,the ,,history ,,of ,,our ,,species #ga ,,chapter ,,vi ,,the ,,nature ,,of ,,the ,,soul #hh ,,chapter ,,vii ,,psychic ,,gradations #ajh ,,chapter ,,viii ,,the ,,embryology ,,of ,,the ,,soul #acb ,,chapter ,,ix ,,the ,,phylogeny ,,of ,,the ,,soul #adh ,,chapter ,x ,,consciousness #agj ,,chapter ,,xi ,,the ,,immortality ,,of ,,the ,,soul #ahh ,,chapter ,,xii ,,the ,,law ,,of ,,substance #baa ,,chapter ,,xiii ,,the ,,evolution ,,of ,,the ,,world #bcc ,,chapter ,,xiv ,,the ,,unity ,,of ,,nature #bed ,,chapter ,,xv ,,god ,,and ,,the ,,world #bge ,,chapter ,,xvi ,,knowledge ,,and ,,belief #bib ,,chapter ,,xvii ,,science ,,and ,,christianity #cjh ,,chapter ,,xviii ,,our ,,monistic ,,religion #cca ,,chapter ,,xix ,,our ,,monistic ,,ethics #cdg ,,chapter ,,xx ,,solution ,,of ,,the ,,world-,,problems #cfe ,,conclusion #chj ,,index #che ,,author',s ,,preface ,the present study of the monistic philosophy is intended for thoughtful readers of every condition who are united in an honest search for the truth4 ,an intensification of this effort of man to attain a knowledge of the truth is one of the most salient features of the nineteenth century4 ,that is easily explained1 in the first place1 by the immense progress of science1 especially in its most important branch1 the history of humanity2 it is due1 in the second place1 to the open contradiction that has developed during the century between science and the traditional ,revelation2 and1 finally1 it arises from the inevitable extension and deepening of the rational demand for an elucidation of the innumerable facts that have been recently brought to light1 and for a fuller knowledge of their causes4 ,unfortunately1 this vast progress of empirical knowledge in our ,century of ,science has not been accompanied by a corresponding advancement of its theoretical interpretation--that higher knowledge of the causal nexus of individual phenomena which we call philosophy4 ,we find1 on the contrary1 that the abstract and almost wholly metaphysical science which has been taught in our universities for the last hundred years under the name of philosophy is far from assimilating our hard-earned treasures of experimental research4 ,on the other hand1 we have to admit1 with equal regret1 that most of the representatives of what is called exact science are content with the special care of their own narrow branches of observation and experiment1 and deem superfluous the deeper study of the universal connection of the phenomena they observe--that is1 philosophy4 ,while these pure empiricists do not see the wood for the trees1 the metaphysicians1 on the other hand1 are satisfied with the mere picture of the wood1 and trouble not about its individual trees4 ,the idea of a philosophy of nature1 to which both those methods of research1 the empirical and the speculative1 naturally converge1 is even yet contemptuously rejected by large numbers of representatives of both tendencies4 ,this unnatural and fatal opposition between science and philosophy1 between the results of experience and of thought1 is undoubtedly becoming more and more onerous and painful to thoughtful people4 ,that is easily proved by the increasing spread of the immense popular literature of natural philosophy which has sprung up in the course of the last half-century4 ,it is seen1 too1 in the welcome fact that1 in spite of the mutual aversion of the scientific observer and the speculative philosopher1 nevertheless eminent thinkers from both camps league themselves in a united effort to attain the solution of that highest object of inquiry which we briefly denominate the world-riddles4 ,the studies of these world-riddles which ,i offer in the present work cannot reasonably claim to give a perfect solution of them2 they merely offer to a wide circle of readers a critical inquiry into the problem1 and seek to answer the question as to how nearly we have approached that solution at the present day4 ,what stage in the attainment of truth have we actually arrived at in this closing year of the nineteenth century8 ,what progress have we really made during its course towards that immeasurably distant goal8 ,the answer which ,i give to these great questions must1 naturally1 be merely subjective and only partly correct2 for my knowledge of nature and my ability to interpret its objective reality are limited1 as are those of every man4 ,the one point that ,i can claim for it1 and which1 indeed1 ,i must ask of my strongest opponents1 is that my ,monistic ,philosophy is sincere from beginning to end--it is the complete expression of the conviction that has come to me1 after many years of ardent research into ,nature and unceasing reflection1 as to the true basis of its phenomena4 ,for fully half a century has my mind's work proceeded1 and ,i now1 in my sixty-sixth year1 may venture to claim that it is mature2 ,i am fully convinced that this ripe fruit of the tree of knowledge will receive no important addition and suffer no substantial modification during the brief spell of life that remains to me4 ,i presented all the essential and distinctive elements of my monistic and genetic philosophy thirty-three years ago1 in my ,general ,morphology of ,organisms1 a large and laborious work1 which has had but a limited circulation4 ,it was the first attempt to apply in detail the newly established theory of evolution to the whole science of organic forms4 ,in order to secure the acceptance of at least one part of the new thought which it contained1 and to kindle a wider interest in the greatest advancement of knowledge that our century has witnessed1 ,i published my ,natural ,history of ,creation two years afterwards4 ,as this less complicated work1 in spite of its great defects1 ran into nine large editions and twelve different translations1 it has contributed not a little to the spread of monistic views4 ,the same may be said of the less known ,anthropogeny#a 7#ahgd71 in which ,i set myself the difficult task of rendering the most important facts of the theory of man's descent accessible and intelligible to the general reader2 the fourth1 enlarged1 edition of that work appeared in #ahia4 ,in the paper which ,i read at the fourth ,international ,congress of ,zoology at ,cambridge1 in #ahih1 on ,our ,present ,knowledge of the ,descent of ,man#b 7a seventh edition of which appeared in #ahii71 ,i treated certain significant and particularly valuable advances which this important branch of anthropology has recently made4 ,other isolated questions of our modern natural philosophy1 which are peculiarly interesting1 have been dealt with in my ,collected ,popular ,lectures on the ,subject of ,evolution 7#ahgh74 ,finally1 ,i have briefly presented the broad principles of my monistic philosophy and its relation to the dominant faith in my ,confession of ,faith of a ,man of ,science3 ,monism as a ,connecting ,link between ,religion and ,science#c 7#ahib1 eighth edition1 #ahii74 ,the present work on ,the ,riddle of the ,universe is the continuation1 confirmation1 and integration of the views which ,i have urged for a generation in the aforesaid volumes4 ,it marks the close of my studies on the monistic conception of the universe4 ,the earlier plan1 which ,i projected many years ago1 of constructing a complete ,system of ,monistic ,philosophy on the basis of evolution will never be carried into effect now4 ,my strength is no longer equal to the task1 and many warnings of approaching age urge me to desist4 ,indeed1 ,i am wholly a child of the nineteenth century1 and with its close ,i draw the line under my life's work4 ,the vast extension of human knowledge which has taken place during the present century1 owing to a happy division of labor1 makes it impossible to-day to range over all its branches with equal thoroughness1 and to show their essential unity and connection4 ,even a genius of the highest type1 having an equal command of every branch of science1 and largely endowed with the artistic faculty of comprehensive presentation1 would be incapable of setting forth a complete view of the cosmos in the space of a moderate volume4 ,my own command of the various branches of science is uneven and defective1 so that ,i can attempt no more than to sketch the general plan of such a world-picture1 and point out the pervading unity of its parts1 however imperfect be the execution4 ,thus it is that this work on the world-enigma has something of the character of a sketch-book1 in which studies of unequal value are associated4 ,as the material of the book was partly written many years ago1 and partly produced for the first time during the last few years1 the composition is1 unfortunately1 uneven at times2 repetitions1 too1 have proved unavoidable4 ,i trust those defects will be overlooked4 ,in taking leave of my readers1 ,i venture the hope that1 through my sincere and conscientious work--in spite of its faults1 of which ,i am not unconscious--,i have contributed a little towards the solution of the great enigma4 ,amid the clash of theories1 ,i trust that ,i have indicated to many a reader who is absorbed in the zealous pursuit of purely rational knowledge that path which1 it is my firm conviction1 alone leads to the truth--the path of empirical investigation and of the ,monistic ,philosophy which is based upon it4 ,,ernst ,,haeckel4 ,,jena1 ,,germany4 ,,preface ,the hour is close upon us when we shall commence our retrospect of one of the most wonderful sections of time that was ever measured by the sweep of the earth4 ,already the expert is at work1 dissecting out and studying his particular phase of that vast world of thought and action we call the nineteenth century4 ,art1 literature1 commerce1 industry1 politics1 ethics--all have their high interpreters among us2 but in the chance of life it has fallen out that there is none to read aright for us1 in historic retrospect1 what after ages will probably regard as the most salient feature of the nineteenth century--the conflict of theology with philosophy and science4 ,the pens of our ,huxleys1 and ,tyndalls1 and ,darwins lie where they fell2 there is none left in strength among us to sum up the issues of that struggle with knowledge and sympathy4 ,in these circumstances it has been thought fitting that we should introduce to ,english readers the latest work of ,professor ,haeckel4 ,germany1 as the reader will quickly perceive1 is witnessing the same strange reaction of thought that we see about us here in ,england1 yet ,die ,weltrthsel found an immediate and very extensive circle of readers4 ,one of the most prominent zoologists of the century1 ,professor ,haeckel1 has a unique claim to pronounce with authority1 from the scientific side1 on what is known as the conflict of science and religion4 ,in the contradictory estimates that are urged on us--for the modern ecclesiastic is as emphatic in his assurance that the conflict has ended favorably to theology as the rationalist is with his counter-assertion--the last words of one of the leading combatants of the second half of the century1 still1 happily1 in full vigor of mind1 will be heard with respect and close attention4 ,a glance at the index of the work suffices to indicate its comprehensive character4 ,the judgment of the distinguished scientist cannot fail to have weight on all the topics included2 yet the reader will soon discover a vein of exceptionally interesting thought in the chapters on evolution4 ,the evolution of the human body is no longer a matter of serious dispute4 ,it has passed the first two tribunals--those of theology and of an priori philosophy--and is only challenged at the third and last--that of empirical proof--by the decorative heads of scientific bodies and a few isolated thinkers4 ,apparent rari nantes in gurgite vasto4 ,but the question of the evolution of the human mind1 or soul1 has been successfully divorced from that of the body4 ,roman ,catholic advanced theologians1 whose precise terminology demanded a clear position1 admit the latter and deny the former categorically4 ,other theologians1 and many philosophers1 have still a vague notion that the evidence for the one does not impair their sentimental objection to the other4 ,dr4 ,haeckel's work summarizes the evidence for the evolution of mind in a masterly and profoundly interesting fashion4 ,it seems impossible to follow his broad survey of the psychic world1 from protist to man1 without bearing away a conviction of the natural origin of every power and content of the human soul4 ,,translator4 ,october1 #aijj4 ,,the ,,riddle ,,of ,,the ,,universe ,,chapter ,i ,,the ,,nature ,,of ,,the ,,problem ,the ,condition of ,civilization and of ,thought at the ,close of the ,nineteenth ,century--,progress of ,our ,knowledge of ,nature1 of the ,organic and ,inorganic ,sciences--,the ,law of ,substance and the ,law of ,evolution--,progress of ,technical ,science and of ,applied ,chemistry--,stagnancy in other ,departments of ,life3 ,legal and ,political ,administration1 ,education1 and the ,church--,conflict of ,reason and ,dogma--,anthropism--,cosmological ,perspective--,cosmological ,theorems--,refutation of the ,delusion of ,man's ,importance--,number of ,world-,riddles--,criticism of the ,seven ,enigmas--,the ,way to ,solve ,them--,function of the ,senses and of the ,brain--,induction and ,deduction--,reason1 ,sentiment1 and ,revelation--,philosophy and ,science--,experience and ,speculation--,dualism and ,monism ,the close of the nineteenth century offers one of the most remarkable spectacles to the thoughtful observer4 ,all educated people are agreed that it has in many respects immeasurably outstripped its predecessors1 and has achieved tasks that were deemed impracticable at its commencement4 ,an entirely new character has been given to the whole of our modern civilization1 not only by our astounding theoretical progress in sound knowledge of nature1 but also by the remarkably fertile practical application of that knowledge in technical science1 industry1 commerce1 and so forth4 ,on the other hand1 however1 we have made little or no progress in moral and social life1 in comparison with earlier centuries2 at times there has been serious reaction4 ,and from this obvious conflict there have arisen1 not only an uneasy sense of dismemberment and falseness1 but even the danger of grave catastrophes in the political and social world4 ,it is1 then1 not merely the right1 but the sacred duty1 of every honorable and humanitarian thinker to devote himself conscientiously to the settlement of that conflict1 and to warding off the dangers that it brings in its train4 ,in our conviction this can only be done by a courageous effort to attain the truth1 and by the formation of a clear view of the world--a view that shall be based on truth and conformity to reality4 ,if we recall to mind the imperfect condition of science at the beginning of the century1 and compare this with the magnificent structure of its closing years1 we are compelled to admit that marvellous progress has been made during its course4 ,every single branch of science can boast that it has1 especially during the latter half of the century1 made numerous acquisitions of the utmost value4 ,both in our microscopic knowledge of the little and in our telescopic investigation of the great we have attained an invaluable insight that seemed inconceivable a hundred years ago4 ,improved methods of microscopic and biological research have not only revealed to us an invisible world of living things in the kingdom of the protists1 full of an infinite wealth of forms1 but they have taught us to recognize in the tiny cell the all-pervading elementary organism of whose social communities--the tissues--the body of every multicellular plant and animal1 even that of man1 is composed4 ,this anatomical knowledge is of extreme importance2 and it is supplemented by the embryological discovery that each of the higher multicellular organisms is developed out of one simple cell1 the impregnated ovum4 ,the cellular theory1 which has been founded on that discovery1 has given us the first true interpretation of the physical1 chemical1 and even the psychological processes of life--those mysterious phenomena for whose explanation it had been customary to postulate a supernatural vital force or immortal soul4 ,moreover1 the true character of disease has been made clear and intelligible to the physician for the first time by the cognate science of ,cellular ,pathology4 ,the discoveries of the nineteenth century in the inorganic world are no less important4 ,physics has made astounding progress in every section of its province--in optics and acoustics1 in magnetism and electricity1 in mechanics and thermo-dynamics2 and1 what is still more important1 it has proved the unity of the forces of the entire universe4 ,the mechanical theory of heat has shown how intimately they are connected1 and how each can1 in certain conditions1 transform itself directly into another4 ,spectral analysis has taught us that the same matter which enters into the composition of all bodies on earth1 including its living inhabitants1 builds up the rest of the planets1 the sun1 and the most distant stars4 ,astro-physics has considerably enlarged our cosmic perspective in revealing to us1 in the immeasurable depths of space1 millions of circling spheres larger than our earth1 and1 like it1 in endless transformation1 in an eternal rhythm of life and death4 ,chemistry has introduced us to a multitude of new substances1 all of which arise from the combination of a few 7about seventy7 elements that are incapable of further analysis2 some of them play a most important part in every branch of life4 ,it has been shown that one of these elements--carbon--is the remarkable substance that effects the endless variety of organic syntheses1 and thus may be considered the chemical basis of life4 ,all the particular advances1 however1 of physics and chemistry yield in theoretical importance to the discovery of the great law which brings them all to one common focus1 the ,law of ,substance4 ,as this fundamental cosmic law establishes the eternal persistence of matter and force1 their unvarying constancy throughout the entire universe1 it has become the pole-star that guides our ,monistic ,philosophy through the mighty labyrinth to a solution of the world-problem4 ,since we intend to make a general survey of the actual condition of our knowledge of nature and its progress during the present century in the following chapters1 we shall delay no longer with the review of its particular branches4 ,we would only mention one important advance1 which was contemporary with the discovery of the law of substance1 and which supplements it--the establishment of the theory of evolution4 ,it is true that there were philosophers who spoke of the evolution of things a thousand years ago2 but the recognition that such a law dominates the entire universe1 and that the world is nothing else than an eternal evolution of substance1 is a fruit of the nineteenth century4 ,it was not until the second half of this century that it attained to perfect clearness and a universal application4 ,the immortal merit of establishing the doctrine on an empirical basis1 and pointing out its world-wide application1 belongs to the great scientist ,charles ,darwin2 he it was who1 in #ahei1 supplied a solid foundation for the theory of descent1 which the able ,french naturalist ,jean ,lamarck had already sketched in its broad outlines in #ahji1 and the fundamental idea of which had been almost prophetically enunciated in #agii by ,germany's greatest poet and thinker1 ,wolfgang ,goethe4 ,in that theory we have the key to the question of all questions1 to the great enigma of the place of man in nature1 and of his natural development4 ,if we are in a position to-day to recognize the sovereignty of the law of evolution--and1 indeed1 of a monistic evolution--in every province of nature1 and to use it1 in conjunction with the law of substance1 for a simple interpretation of all natural phenomena1 we owe it chiefly to those three distinguished naturalists2 they shine as three stars of the first magnitude amid all the great men of the century4 ,this marvellous progress in a theoretical knowledge of nature has been followed by a manifold practical application in every branch of civilized life4 ,if we are to-day in the age of commerce1 if international trade and communication have attained dimensions beyond the conception of any previous age1 if we have transcended the limits of space and time by our telegraph and telephone1 we owe it1 in the first place1 to the technical advancement of physics1 especially in the application of steam and electricity4 ,if1 in photography1 we can1 with the utmost ease1 compel the sunbeam to create for us in a moment's time a correct picture of any object we like2 if we have made enormous progress in agriculture1 and in a variety of other pursuits2 if1 in surgery1 we have brought an infinite relief to human pain by our chloroform and morphia1 our antiseptics and serous therapeutics1 we owe it all to applied chemistry4 ,but it is so well known how much we have surpassed all earlier centuries through these and other scientific discoveries that we need linger over the question no longer4 ,while we look back with a just pride on the immense progress of the nineteenth century in a knowledge of nature and in its practical application1 we find1 unfortunately1 a very different and far from agreeable picture when we turn to another and not less important province of modern life4 ,to our great regret we must endorse the words of ,alfred ,wallace3 ,compared with our astounding progress in physical science and its practical application1 our system of government1 of administrative justice1 and of national education1 and our entire social and moral organization1 remain in a state of barbarism4 ,to convince ourselves of the truth of this grave indictment we need only cast an unprejudiced glance at our public life1 or look into the mirror that is daily offered to us by the press1 the organ of public sentiment4 ,we begin our review with justice1 the fundamentum regnorum4 ,no one can maintain that its condition to-day is in harmony with our advanced knowledge of man and the world4 ,not a week passes in which we do not read of judicial decisions over which every thoughtful man shakes his head in despair2 many of the decisions of our higher and lower courts are simply unintelligible4 ,we are not referring in the treatment of this particular world-problem to the fact that many modern states1 in spite of their paper constitutions1 are really governed with absolute despotism1 and that many who occupy the bench give judgment less in accordance with their sincere conviction than with wishes expressed in higher quarters4 ,we readily admit that the majority of judges and counsel decide conscientiously1 and err simply from human frailty4 ,most of their errors1 indeed1 are due to defective preparation4 ,it is popularly supposed that these are just the men of highest education1 and that on that very account they have the preference in nominations to different offices4 ,however1 this famed legal education is for the most part rather of a formal and technical character4 ,they have but a superficial acquaintance with that chief and peculiar object of their activity1 the human organism1 and its most important function1 the mind4 ,that is evident from the curious views as to the liberty of the will1 responsibility1 etc41 which we encounter daily4 ,i once told an eminent jurist that the tiny spherical ovum from which every man is developed is as truly endowed with life as the embryo of two1 or seven1 or even nine months2 he laughed incredulously4 ,most of the students of jurisprudence have no acquaintance with anthropology1 psychology1 and the doctrine of evolution--the very first requisites for a correct estimate of human nature4 ,they have no time for it2 their time is already too largely bespoken for an exhaustive study of beer and wine and for the noble art of fencing4 ,the rest of their valuable study-time is required for the purpose of learning some hundreds of paragraphs of law books1 a knowledge of which is supposed to qualify the jurist for any position whatever in our modern civilized community4 ,we shall touch but lightly on the unfortunate province of politics1 for the unsatisfactory condition of the modern political world is only too familiar4 ,in a great measure its evils are due to the fact that most of our officials are jurists--that is1 men of high technical education1 but utterly devoid of that thorough knowledge of human nature which is only obtained by the study of comparative anthropology and the monistic psychology--men without an acquaintance with those social relations of which we find the earlier types in comparative zoology and the theory of evolution1 in the cellular theory1 and the study of the protists4 ,we can only arrive at a correct knowledge of the structure and life of the social body1 the state1 through a scientific knowledge of the structure and life of the individuals who compose it1 and the cells of which they are in turn composed4 ,if our political rulers and our representatives of the people possessed this invaluable biological and anthropological knowledge1 we should not find our journals so full of the sociological blunders and political nonsense which at present are far from adorning our parliamentary reports1 and even many of our official documents4 ,worst of all is it when the modern state flings itself into the arms of the reactionary ,church1 and when the narrow-minded self-interest of parties and the infatuation of short-sighted party-leaders lend their support to the hierarchy4 ,then are witnessed such sad scenes as the ,german ,reichstag puts before our eyes even at the close of the nineteenth century4 ,we have the spectacle of the educated ,german people in the power of the ultramontane ,centre1 under the rule of the ,roman papacy1 which is its bitterest and most dangerous enemy4 ,then superstition and stupidity reign instead of right and reason4 ,never will our government improve until it casts off the fetters of the ,church and raises the views of the citizens on man and the world to a higher level by a general scientific education4 ,that does not raise the question of any special form of constitution4 ,whether a monarchy or a republic be preferable1 whether the constitution should be aristocratic or democratic1 are subordinate questions in comparison with the supreme question3 ,shall the modern civilized state be spiritual or secular8 ,shall it be theocratic--ruled by the irrational formul of faith and by clerical despotism--or nomocratic--under the sovereignty of rational laws and civic right8 ,the first task is to kindle a rational interest in our youth1 and to uplift our citizens and free them from superstition4 ,that can only be achieved by a timely reform of our schools4 ,our education of the young is no more in harmony with modern scientific progress than our legal and political world4 ,physical science1 which is so much more important than all other sciences1 and which1 properly understood1 really embraces all the so-called moral sciences1 is still regarded as a mere accessory in our schools1 if not treated as the ,cinderella of the curriculum4 ,most of our teachers still give the most prominent place to that dead learning which has come down from the cloistral schools of the ,middle ,ages4 ,in the front rank we have grammatical gymnastics and an immense waste of time over a thorough knowledge of classics and of the history of foreign nations4 ,ethics1 the most important object of practical philosophy1 is entirely neglected1 and its place is usurped by the ecclesiastical creed4 ,faith must take precedence over knowledge--not that scientific faith which leads to a monistic religion1 but the irrational superstition that lays the foundation of a perverted ,christianity4 ,the valuable teaching of modern cosmology and anthropology1 of biology and evolution1 is most inadequately imparted1 if not entirely unknown1 in our higher schools2 while the memory is burdened with a mass of philological and historical facts which are utterly useless1 either from the point of view of theoretical education or for the practical purposes of life4 ,moreover1 the antiquated arrangements and the distribution of faculties in the universities are just as little in harmony with the point we have reached in monistic science as the curriculum of the primary and secondary schools4 ,the climax of the opposition to modern education and its foundation1 advanced natural philosophy1 is reached1 of course1 in the ,church4 ,we are not speaking here of ultramontane papistry1 nor of the orthodox evangelical tendencies1 which do not fall far short of it in ignorance and in the crass superstition of their dogmas4 ,we are imagining ourselves for the moment to be in the church of a liberal ,protestant minister1 who has a good average education1 and who finds room for the rights of reason by the side of his faith4 ,there1 besides excellent moral teaching1 which is in perfect harmony with our own monistic ethics1 and humanitarian discussion of which we cordially approve1 we hear ideas on the nature of ,god1 of the world1 of man1 and of life which are directly opposed to all scientific experience4 ,it is no wonder that physicists and chemists1 doctors and philosophers1 who have made a thorough study of nature1 refuse a hearing to such preachers4 ,our theologians and our politicians are just as ignorant as our philosophers and our jurists of that elementary knowledge of nature which is based on the monistic theory of evolution1 and which is already far exceeded in the triumph of our modern learning4 ,from this opposition1 which we can only briefly point out at present1 there arise grave conflicts in our modern life which urgently demand a settlement4 ,our modern education1 the outcome of our great advance in knowledge1 has a claim upon every department of public and private life2 it would see humanity raised1 by the instrumentality of reason1 to that higher grade of culture1 and1 consequently1 to that better path towards happiness which has been opened out to us by the progress of modern science4 ,that aim1 however1 is vigorously opposed by the influential parties who would detain the mind in the exploded views of the ,middle ,ages with regard to the most important problems of life2 they linger in the fold of traditional dogma1 and would have reason prostrate itself before their higher revelation4 ,that is the condition of things1 to a very large extent1 in theology and philosophy1 in sociology and jurisprudence4 ,it is not that the motives of the latter are to be attributed1 as a rule1 to pure self-interest2 they spring partly from ignorance of the facts1 and partly from an indolent acquiescence in tradition4 ,the most dangerous of the three great enemies of reason and knowledge is not malice2 but ignorance1 or1 perhaps1 indolence4 ,the gods themselves still strive in vain against these two latter influences when they have happily vanquished the first4 ,one of the main supports of that reactionary system is still what we may call anthropism4 ,i designate by this term that powerful and world-wide group of erroneous opinions which opposes the human organism to the whole of the rest of nature1 and represents it to be the preordained end of the organic creation1 an entity essentially distinct from it1 a godlike being4 ,closer examination of this group of ideas shows it to be made up of three different dogmas1 which we may distinguish as the anthropocentric1 the anthropomorphic1 and the anthropolatrous4#d ,i4 ,the anthropocentric dogma culminates in the idea that man is the preordained centre and aim of all terrestrial life--or1 in a wider sense1 of the whole universe4 ,as this error is extremely conducive to man's interest1 and as it is intimately connected with the creation-myth of the three great ,mediterranean religions1 and with the dogmas of the ,mosaic1 ,christian1 and ,mohammedan theologies1 it still dominates the greater part of the civilized world4 ,,ii4 ,the anthropomorphic dogma is likewise connected with the creation-myth of the three aforesaid religions1 and of many others4 ,it likens the creation and control of the world by ,god to the artificial creation of a talented engineer or mechanic1 and to the administration of a wise ruler4 ,god1 as creator1 sustainer1 and ruler of the world1 is thus represented after a purely human fashion in his thought and work4 ,hence it follows1 in turn1 that man is godlike4 ,god made man to ,his own image and likeness4 ,the older1 nave mythology is pure homotheism1 attributing human shape1 flesh1 and blood to the gods4 ,it is more intelligible than the modern mystic theosophy that adores a personal ,god as an invisible--properly speaking1 gaseous--being1 yet makes him think1 speak1 and act in human fashion2 it gives us the paradoxical picture of a gaseous vertebrate4 ,,iii4 ,the anthropolatric dogma naturally results from this comparison of the activity of ,god and man2 it ends in the apotheosis of the human organism4 ,a further result is the belief in the personal immortality of the soul1 and the dualistic dogma of the twofold nature of man1 whose immortal soul is conceived as but the temporary inhabitant of the mortal frame4 ,thus these three anthropistic dogmas1 variously adapted to the respective professions of the different religions1 came at length to be vested with an extraordinary importance1 and proved the source of the most dangerous errors4 ,the anthropistic view of the world which springs from them is in irreconcilable opposition to our monistic system2 indeed1 it is at once disproved by our new cosmological perspective4 ,not only the three anthropistic dogmas1 but many other notions of the dualistic philosophy and orthodox religion1 are found to be untenable as soon as we regard them critically from the cosmological perspective of our monistic system4 ,we understand by that the comprehensive view of the universe which we have from the highest point of our monistic interpretation of nature4 ,from that stand-point we see the truth of the following cosmological theorems1 most of which1 in our opinion1 have already been amply demonstrated3 7#a7 ,the universe1 or the cosmos1 is eternal1 infinite1 and illimitable4 7#b7 ,its substance1 with its two attributes 7matter and energy71 fills infinite space1 and is in eternal motion4 7#c7 ,this motion runs on through infinite time as an unbroken development1 with a periodic change from life to death1 from evolution to devolution4 7#d7 ,the innumerable bodies which are scattered about the space-filling ether all obey the same law of substance2 while the rotating masses slowly move towards their destruction and dissolution in one part of space others are springing into new life and development in other quarters of the universe4 7#e7 ,our sun is one of these unnumbered perishable bodies1 and our earth is one of the countless transitory planets that encircle them4 7#f7 ,our earth has gone through a long process of cooling before water1 in liquid form 7the first condition of organic life71 could settle thereon4 7#g7 ,the ensuing biogenetic process1 the slow development and transformation of countless organic forms1 must have taken many millions of years--considerably over a hundred4#e 7#h7 ,among the different kinds of animals which arose in the later stages of the biogenetic process on earth the vertebrates have far outstripped all other competitors in the evolutionary race4 7#i7 ,the most important branch of the vertebrates1 the mammals1 were developed later 7during the triassic period7 from the lower amphibia and the reptilia4 7#aj7 ,the most perfect and most highly developed branch of the class mammalia is the order of primates1 which first put in an appearance1 by development from the lowest prochoriata1 at the beginning of the ,tertiary period--at least three million years ago4 7#aa7 ,the youngest and most perfect twig of the branch primates is man1 who sprang from a series of manlike apes towards the end of the ,tertiary period4 7#ab7 ,consequently1 the so-called history of the world--that is1 the brief period of a few thousand years which measures the duration of civilization--is an evanescently short episode in the long course of organic evolution1 just as this1 in turn1 is merely a small portion of the history of our planetary system2 and as our mother-earth is a mere speck in the sunbeam in the illimitable universe1 so man himself is but a tiny grain of protoplasm in the perishable framework of organic nature4 ,nothing seems to me better adapted than this magnificent cosmological perspective to give us the proper standard and the broad outlook which we need in the solution of the vast enigmas that surround us4 ,it not only clearly indicates the true place of man in nature1 but it dissipates the prevalent illusion of man's supreme importance1 and the arrogance with which he sets himself apart from the illimitable universe1 and exalts himself to the position of its most valuable element4 ,this boundless presumption of conceited man has misled him into making himself the image of ,god1 claiming an eternal life for his ephemeral personality1 and imagining that he possesses unlimited freedom of will4 ,the ridiculous imperial folly of ,caligula is but a special form of man's arrogant assumption of divinity4 ,only when we have abandoned this untenable illusion1 and taken up the correct cosmological perspective1 can we hope to reach the solution of the riddles of the universe4 ,the uneducated member of a civilized community is surrounded with countless enigmas at every step1 just as truly as the savage4 ,their number1 however1 decreases with every stride of civilization and of science2 and the monistic philosophy is ultimately confronted with but one simple and comprehensive enigma--the problem of substance4 ,still1 we may find it useful to include a certain number of problems under that title4 ,in the famous speech which ,emil du ,bois-,reymond delivered in #ahhj1 in the ,leibnitz session of the ,berlin ,academy of ,sciences1 he distinguished seven world-enigmas1 which he enumerated as follows3 7#a7 ,the nature of matter and force4 7#b7 ,the origin of motion4 7#c7 ,the origin of life4 7#d7 ,the 7apparently preordained7 orderly arrangement of nature4 7#e7 ,the origin of simple sensation and consciousness4 7#f7 ,rational thought1 and the origin of the cognate faculty1 speech4 7#g7 ,the question of the freedom of the will4 ,three of these seven enigmas are considered by the orator of the ,berlin ,academy to be entirely transcendental and insoluble--they are the first1 second1 and fifth2 three others 7the third1 fourth1 and sixth7 he considers to be capable of solution1 though extremely difficult2 as to the seventh and last world-enigma1 the freedom of the will1 which is the one of the greatest practical importance1 he remains undecided4 ,as my monism differs materially from that of the ,berlin orator1 and as his idea of the seven great enigmas has been very widely accepted1 it may be useful to indicate their true position at once4 ,in my opinion1 the three transcendental problems 7#a1 #b1 and #e7 are settled by our conception of substance 7vide chap4 xii472 the three which he considers difficult1 though soluble1 7#c1 #d1 and #f71 are decisively answered by our modern theory of evolution2 the seventh and last1 the freedom of the will1 is not an object for critical1 scientific inquiry at all1 for it is a pure dogma1 based on an illusion1 and has no real existence4 ,the means and methods we have chosen for attaining the solution of the great enigma do not differ1 on the whole1 from those of all purely scientific investigation--firstly1 experience2 secondly1 inference4 ,scientific experience comes to us by observation and experiment1 which involve the activity of our sense-organs in the first place1 and1 secondly1 of the inner sense-centres in the cortex of the brain4 ,the microscopic elementary organs of the former are the sense-cells2 of the latter1 groups of ganglionic cells4 ,the experiences which we derive from the outer world by these invaluable instruments of our mental life are then moulded into ideas by other parts of the brain1 and these1 in their turn1 are united in a chain of reasoning by association4 ,the construction of this chain may take place in two different ways1 which are1 in my opinion1 equally valuable and indispensable3 induction and deduction4 ,the higher cerebral operations1 the construction of complicated chains of reasoning1 abstraction1 the formation of concepts1 the completion of the perceptive faculty by the plastic faculty of the imagination--in a word1 consciousness1 thought1 and speculation--are functions of the ganglionic cells of the cortex of the brain1 just like the preceding simpler mental functions4 ,we unite them all in the supreme concept of reason4#f ,by reason only can we attain to a correct knowledge of the world and a solution of its great problems4 ,reason is man's highest gift1 the only prerogative that essentially distinguishes him from the lower animals4 ,nevertheless1 it has only reached this high position by the progress of culture and education1 by the development of knowledge4 ,the uneducated man and the savage are just as little 7or just as much7 rational as our nearest relatives among the mammals 7apes1 dogs1 elephants1 etc474 ,yet the opinion still obtains in many quarters that1 besides our godlike reason1 we have two further 7and even surer67 methods of receiving knowledge--emotion and revelation4 ,we must at once dispose of this dangerous error4 ,emotion has nothing whatever to do with the attainment of truth4 ,that which we prize under the name of emotion is an elaborate activity of the brain1 which consists of feelings of like and dislike1 motions of assent and dissent1 impulses of desire and aversion4 ,it may be influenced by the most diverse activities of the organism1 by the cravings of the senses and the muscles1 the stomach1 the sexual organs1 etc4 ,the interests of truth are far from promoted by these conditions and vacillations of emotion2 on the contrary1 such circumstances often disturb that reason which alone is adapted to the pursuit of truth1 and frequently mar its perceptive power4 ,no cosmic problem is solved1 or even advanced1 by the cerebral function we call emotion4 ,and the same must be said of the so-called revelation1 and of the truths of faith which it is supposed to communicate2 they are based entirely on a deception1 consciously or unconsciously1 as we shall see in the sixteenth chapter4 ,we must welcome as one of the most fortunate steps in the direction of a solution of the great cosmic problems the fact that of recent years there is a growing tendency to recognize the two paths which alone lead thereto--experience and thought1 or speculation--to be of equal value1 and mutually complementary4 ,philosophers have come to see that pure speculation--such1 for instance1 as ,plato and ,hegel employed for the construction of their idealist systems--does not lead to knowledge of reality4 ,on the other hand1 scientists have been convinced that mere experience--such as ,bacon and ,mill1 for example1 made the basis of their realist systems--is insufficient of itself for a complete philosophy4 ,for these two great paths of knowledge1 sense-experience and rational thought1 are two distinct cerebral functions2 the one is elaborated by the sense-organs and the inner sense-centres1 the other by the thought-centres1 the great centres of association in the cortex of the brain1 which lie between the sense-centres4 7,cf4 cc4 vii4 and x47 ,true knowledge is only acquired by combining the activity of the two4 ,nevertheless1 there are still many philosophers who would construct the world out of their own inner consciousness1 and who reject our empirical science precisely because they have no knowledge of the real world4 ,on the other hand1 there are many scientists who still contend that the sole object of science is the knowledge of facts1 the objective investigation of isolated phenomena2 that the age of philosophy is past1 and science has taken its place4#g ,this one-sided over-estimation of experience is as dangerous an error as the converse exaggeration of the value of speculation4 ,both channels of knowledge are mutually indispensable4 ,the greatest triumphs of modern science--the cellular theory1 the dynamic theory of heat1 the theory of evolution1 and the law of substance--are philosophic achievements2 not1 however1 the fruit of pure speculation1 but of an antecedent experience of the widest and most searching character4 ,at the commencement of the nineteenth century the great idealistic poet1 ,schiller1 gave his counsel to both groups of combatants1 the philosophers and the scientists3 ,does strife divide your efforts--no union bless your toil8 ,will truth e'er be delivered if ye your forces rend8 ,since then the situation has1 happily1 been profoundly modified2 while both schools1 in their different paths1 have pressed onward towards the same high goal1 they have recognized their common aspiration1 and they draw nearer to a knowledge of the truth in mutual covenant4 ,at the end of the nineteenth century we have returned to that monistic attitude which our greatest realistic poet1 ,goethe1 had recognized from its very commencement to be alone correct and fruitful4#h ,all the different philosophical tendencies may1 from the point of view of modern science1 be ranged in two antagonistic groups2 they represent either a dualistic or a monistic interpretation of the cosmos4 ,the former is usually bound up with teleological and idealistic dogmas1 the latter with mechanical and realistic theories4 ,dualism1 in the widest sense1 breaks up the universe into two entirely distinct substances--the material world and an immaterial ,god1 who is represented to be its creator1 sustainer1 and ruler4 ,monism1 on the contrary 7likewise taken in its widest sense71 recognizes one sole substance in the universe1 which is at once ,god and nature2 body and spirit 7or matter and energy7 it holds to be inseparable4 ,the extramundane ,god of dualism leads necessarily to theism2 and the intra-mundane ,god of the monist leads to pantheism4 ,the different ideas of monism and materialism1 and likewise the essentially distinct tendencies of theoretical and practical materialism1 are still very frequently confused4 ,as this and other similar cases of confusion of ideas are very prejudicial1 and give rise to innumerable errors1 we shall make the following brief observations1 in order to prevent misunderstanding3 ,i4 ,pure monism is identical neither with the theoretical materialism that denies the existence of spirit1 and dissolves the world into a heap of dead atoms1 nor with the theoretical spiritualism 7lately entitled energetic spiritualism by ,ostwald7 which rejects the notion of matter1 and considers the world to be a specially arranged group of energies or immaterial natural forces4 ,,ii4 ,on the contrary1 we hold1 with ,goethe1 that matter cannot exist and be operative without spirit1 nor spirit without matter4 ,we adhere firmly to the pure1 unequivocal monism of ,spinoza3 ,matter1 or infinitely extended substance1 and spirit 7or energy71 or sensitive and thinking substance1 are the two fundamental attributes or principal properties of the all-embracing divine essence of the world1 the universal substance4 7,cf4 chap4 xii47 ,,chapter ,,ii ,,our ,,bodily ,,frame ,fundamental ,importance of ,anatomy--,human ,anatomy--,hippocrates1 ,aristotle1 ,galen1 ,vesalius--,comparative ,anatomy--,georges ,cuvier--,johannes ,mller--,karl ,gegenbaur--,histology--,the ,cellular ,theory--,schleiden and ,schwann--,klliker--,virchow--,man a ,vertebrate1 a ,tetrapod1 a ,mammal1 a ,placental1 a ,primate--,prosimi and ,simi--,the ,catarrhin--,papiomorphic and ,anthropomorphic ,apes--,essential ,likeness of ,man and the ,ape in ,corporal ,structure ,all biological research1 all investigation into the forms and vital activities of organisms1 must first deal with the visible body1 in which the morphological and physiological phenomena are observed4 ,this fundamental rule holds good for man just as much as for all other living things4 ,moreover1 the inquiry must not confine itself to mere observation of the outer form2 it must penetrate to the interior1 and study both the general plan and the minute details of the structure4 ,the science which pursues this fundamental investigation in the broadest sense is anatomy4 ,the first stimulus to an inquiry into the human frame arose1 naturally1 in medicine4 ,as it was usually practised by the priests in the older civilizations1 we may assume that these highest representatives of the education of the time had already acquired a certain amount of anatomical knowledge two thousand years before ,christ1 or even earlier4 ,we do not1 however1 find more exact observations1 founded on the dissection of mammals1 and applied1 by analogy1 to the human frame1 until we come to the ,greek scientists of the sixth and fifth centuries before ,christ--,empedocles 7of ,agrigentum7 and ,democritus 7of ,abdera71 and especially the most famous physician of classic antiquity1 ,hippocrates 7of ,cos74 ,it was from these and other sources that the great ,aristotle1 the renowned father of natural history1 equally comprehensive as investigator and philosopher1 derived his first knowledge4 ,after him only one anatomist of any consequence is found in antiquity1 the ,greek physician ,claudius ,galenus 7of ,pergamus71 who developed a wealthy practice in ,rome in the second century after ,christ1 under the ,emperor ,marcus ,aurelius4 ,all these ancient anatomists acquired their knowledge1 as a rule1 not by the dissection of the human body itself--which was then sternly forbidden--but by a study of the bodies of the animals which most closely resembled man1 especially the apes2 they were all1 indeed1 comparative anatomists4 ,the triumph of ,christianity and its mystic theories meant retrogression to anatomy1 as it did to all the other sciences4 ,the popes were resolved above all things to detain humanity in ignorance2 they rightly deemed a knowledge of the human organism to be a dangerous source of enlightenment as to our true nature4 ,during the long period of thirteen centuries the writings of ,galen were almost the only source of human anatomy1 just as the works of ,aristotle were for the whole of natural history4 ,it was not until the sixteenth century1 when the spiritual tyranny of the papacy was broken by the ,reformation1 and the geocentric theory1 so intimately connected with papal doctrine1 was destroyed by the new cosmic system of ,copernicus1 that the knowledge of the human frame entered upon a new period of progress4 ,the great anatomists1 ,vesalius 7of ,brussels71 and ,eustachius and ,fallopius 7of ,modena71 advanced the knowledge of our bodily structure so much by their own thorough investigations that little remained for their numerous followers to do1 with regard to the more obvious phenomena1 except the substantiation of details4 ,andreas ,vesalius1 as courageous as he was talented and indefatigable1 was the pioneer of the movement2 he completed in his twenty-eighth year 7#aedc7 that great and systematic work ,de humani corporis fabrica2 he gave to the whole of human anatomy a new and independent scope and a more solid foundation4 ,on that account he was1 at a later date1 at ,madrid--where he was physician to ,charles ,v4 and ,philip ,,ii4--condemned to death by the ,inquisition as a magician4 ,he only escaped by undertaking a pilgrimage to ,jerusalem2 in returning he suffered shipwreck on the ,isle of ,zante1 and died there in misery and destitution4 ,the great merit of the nineteenth century1 as far as our knowledge of the human frame is concerned1 lies in the founding of two new lines of research of immense importance--comparative anatomy and histology1 or microscopic anatomy4 ,the former was intimately associated with human anatomy from the very beginning2 indeed1 it had to supply the place of the latter so long because the dissection of human corpses was a crime visited with capital punishment--that was the case even in the fifteenth century6 ,but the many anatomists of the next three centuries devoted themselves mainly to a more accurate study of the human organism4 ,the elaborate science which we now call comparative anatomy was born in the year #ahjc1 when the great ,french zoologist ,georges ,cuvier 7a native of ,mmpelgard1 in ,alsace7 published his profound ,leons sur l'anatomie compare1 and endeavored to formulate1 for the first time1 definite laws as to the organism of man and the beasts4 ,while his predecessors--among whom was ,goethe in #agij--;had mainly contented themselves with comparing the skeleton of man with those of other animals1 ,cuvier's broader vision took in the whole of the animal organization4 ,he distinguished therein four great and mutually independent types3 ,vertebrata1 ,articulata1 ,mollusca1 and ,radiata4 ,this advance was of extreme consequence for our question of all questions1 since it clearly brought out the fact that man belonged to the vertebral type1 and differed fundamentally from all the other types4 ,it is true that the keen-sighted ,linn had already1 in his ,systema ,natuae1 made a great step in advance by assigning man a definite place in the class of mammals2 he had even drawn up the three groups of half-apes1 apes1 and men 7,lemur1 simia1 and homo7 in the order of primates4 ,but his keen1 systematic mind was not furnished with that profound empirical foundation1 supplied by comparative anatomy1 which ,cuvier was the first to attain4 ,further developments were added by the great comparative anatomists of our own century--,friedrich ,meckel 7,halle71 ,johannes ,mller 7,berlin71 ,richard ,owen1 ,t4 ,huxley1 and ,karl ,gegenbaur 7,jena1 subsequently ,heidelberg74 ,the last-named1 in applying the evolutionary theory1 which ,darwin had just established1 to comparative anatomy1 raised his science to the front rank of biological studies4 ,the numerous comparative anatomical works of ,gegenbaur are1 like his well-known ,manual of ,human ,anatomy1 equally distinguished by a thorough empirical acquaintance with their immense multitudes of facts1 and by a comprehensive control of his material1 and its philosophic appreciation in the evolutionary sense4 ,his recent ,comparative ,anatomy of the ,vertebrata establishes the solid foundation on which our conviction of the vertebral character of man in every aspect is chiefly based4 ,microscopic anatomy has been developed1 in the course of the present century1 in a very different fashion from comparative anatomy4 ,at the beginning of the century 7#ahjb7 a ,french physician1 ,bichat1 made an attempt to dissect the organs of the human body into their finer constituents by the aid of the microscope1 and to show the connection of these various tissues 7hista1 or tela74 ,this first attempt led to little result1 because the scientist was ignorant of the one common element of all the different tissues4 ,this was first discovered 7#ahch7 in the shape of the cell1 in the plant world1 by ,matthias ,schleiden1 and immediately afterwards proved to be the same in the animal world by ,theodor ,schwann1 the pupil and assistant of ,johannes ,mller at ,berlin4 ,two other distinguished pupils of this great master1 who are still living1 ,albert ,klliker and ,rudolph ,virchow1 took up the cellular theory1 and the theory of tissues which is founded on it1 in the sixties1 and applied them to the human organism in all its details1 both in health and disease2 they proved that1 in man and all other animals1 every tissue is made up of the same microscopic particles1 the cells1 and these elementary organisms are the real1 self-active citizens which1 in combinations of millions1 constitute the cellular state1 our body4 ,all these cells spring from one simple cell1 the cytula1 or impregnated ovum1 by continuous subdivision4 ,the general structure and combination of the tissues are the same in man as in the other vertebrates4 ,among these the mammals1 the youngest and most highly developed class take precedence1 in virtue of certain special features which were acquired late4 ,such are1 for instance1 the microscopic texture of the hair1 of the glands of the skin1 and of the breasts1 and the corpuscles of the blood1 which are quite peculiar to mammals1 and different from those of the other vertebrates2 man1 even in these finest histological relations1 is a true mammal4 ,the microscopic researches of ,albert ,klliker and ,franz ,leydig 7at ,wrzburg7 not only enlarged our knowledge of the finer structure of man and the beasts in every direction1 but they were especially important in the light of their connection with the evolution of the cell and the tissue2 they confirmed the great theory of ,carl ,theodor ,siebold 7#ahde7 that the lowest animals1 the ,infusoria and the ,rhizopods1 are unicellular organisms4 ,our whole frame1 both in its general plan and its detailed structure1 presents the characteristic type of the vertebrates4 ,this most important and most highly developed group in the animal world was first recognized in its natural unity in #ahja by the great ,lamarck2 he embraced under that title the four higher animal groups of ,linn--mammals1 birds1 amphibia1 and fishes4 ,to these he opposed the two lower classes1 insects and worms1 as invertebrates4 ,cuvier 7#ahab7 established the unity of the vertebrate type on a firmer basis by his comparative anatomy4 ,it is quite true that all the vertebrates1 from the fish up to man1 agree in every essential feature2 they all have a firm internal skeleton1 a framework of cartilage and bone1 consisting principally of a vertebral column and a skull2 the advanced construction of the latter presents many variations1 but1 on the whole1 all may be reduced to the same fundamental type4 ,further1 in all vertebrates the organ of the mind1 the central nervous system1 in the shape of a spinal cord and a brain1 lies at the back of this axial skeleton4 ,moreover1 what we said of its bony environment1 the skull1 is also true of the brain--the instrument of consciousness and all the higher functions of the mind2 its construction and size present very many variations in detail1 but its general characteristic structure remains always the same4 ,we meet the same phenomenon when we compare the rest of our organs with those of the other vertebrates2 everywhere1 in virtue of heredity1 the original plan and the relative distribution of the organs remain the same1 although1 through adaptation to different environments1 the size and the structure of particular sections offer considerable variation4 ,thus we find that in all cases the blood circulates in two main blood-vessels1 of which one--the aorta--passes over the intestine1 and the other--the principal vein--passes underneath1 and that by the broadening out of the latter in a very definite spot a heart has arisen2 this ventral heart is just as characteristic of all vertebrates as the dorsal heart is of the articulata and mollusca4 ,equally characteristic of all vertebrates is the early division of the intestinal tube into a head-gut 7or gill-gut71 which serves in respiration1 and a body-gut 7or liver-gut71 which co-operates with the liver in digestion2 so are1 likewise1 the ramification of the muscular system1 the peculiar structure of the urinary and sexual organs1 and so forth4 ,in all these anatomical relations man is a true vertebrate4 ,aristotle gave the name of four-footed1 or tetrapoda1 to all the higher warm-blooded animals which are distinguished by the possession of two pairs of legs4 ,the category was enlarged subsequently1 and its title changed into the ,latin quadrupeda1 when ,cuvier proved that even two-legged birds and men are really four-footed2 he showed that the internal skeleton of the four legs in all the higher land-vertebrates1 from the amphibia up to man1 was originally constructed after the same pattern out of a definite number of members4 ,the arm of man and the wing of bats and birds have the same typical skeleton as the foreleg of the animals which are conspicuously four-footed4 ,the anatomical unity of the fully developed skeleton in the four limbs of all tetrapods is very important4 ,in order to appreciate it fully one has only to compare carefully the skeleton of a salamander or a frog with that of a monkey or a man4 ,one perceives at once that the humeral zone in front and the pelvic zone behind are made up of the same principal parts as in the rest of the quadrupeds4 ,we find in all cases that the first section of the leg proper consists of one strong marrow-bone 7the humerus1 in the forearm2 the femur1 behind72 the second part1 on the contrary1 originally always consists of two bones 7the ulna and radius1 in front2 the fibula and tibia1 behind74 ,when we further compare the developed structure of the foot proper we are surprised to find that the small bones of which it is made up are also similarly arranged and distributed in every case3 in the front limb the three groups of bones of the forefoot 7or hand7 correspond in all classes of the tetrapoda3 7#a7 the carpus1 7#b7 the metacarpus1 7#c7 the five fingers 7digiti anteriores72 in the rear limb1 similarly1 we have always the same three osseous groups of the hind foot3 7#a7 the tarsus1 7#b7 the metatarsus1 and 7#c7 the five toes 7digiti posteriores74 ,it was a very difficult task to reduce all these little bones to one primitive type1 and to establish the equivalence 7or homology7 of the separate parts in all cases2 they present extreme variations of form and construction in detail1 sometimes being partly fused together and losing their individuality4 ,this great task was first successfully achieved by the most eminent comparative anatomist of our day1 ,karl ,gegenbaur4 ,he pointed out1 in his ,researches into the ,comparative ,anatomy of the ,vertebrata 7#ahfd71 how this characteristic five-toed leg of the land tetrapods originally 7not before the ,carboniferous period7 arose out of the radiating fin 7the breast-fin1 or the belly-fin7 of the ancient fishes4 ,he had also1 in his famous ,researches into the ,skull of the ,vertebrata 7#ahgb71 deduced the younger skull of the tetrapods from the oldest cranial form among the fishes1 that of the shark4 ,it is especially remarkable that the original number of the toes 7five7 on each of the four feet1 which first appeared in the old amphibia of the ,carboniferous period1 has1 in virtue of a strict heredity1 been preserved even to the present day in man4 ,also1 naturally and harmoniously1 the typical construction of the joints1 ligaments1 muscles1 and nerves of the two pairs of legs has1 in the main1 remained the same as in the rest of the four-footed4 ,in all these important relations man is a true tetrapod4 ,the mammals are the youngest and most advanced class of the vertebrates4 ,it is true they are derived from the older class of amphibia1 like birds and reptiles3 yet they are distinguished from all the other tetrapods by a number of very striking anatomical features4 ,externally1 there is the clothing of the skin with hair1 and the possession of two kinds of skin glands--the sweat glands and the sebaceous glands4 ,a local development of these glands on the abdominal skin gave rise 7probably during the ,triassic period7 to the organ which is especially characteristic of the class1 and from which it derives its name--the mammarium4 ,this important instrument of lactation is made up of milk glands 7mammae7 and the mammar-pouches 7folds of the abdominal skin72 in its development the teats appear1 through which the young mammal sucks its mother's milk4 ,in internal structure the most remarkable feature is the possession of a complete diaphragm1 a muscular wall which1 in all mammals--and only in mammals--separates the thoracic from the abdominal cavity2 in all other vertebrates there is no such separation4 ,the skull of mammals is distinguished by a number of remarkable formations1 especially in the maxillary apparatus 7the upper and lower jaws1 and the temporal bones74 ,moreover1 the brain1 the olfactory organ1 the heart1 the lungs1 the internal and external sexual organs1 the kidneys1 and other parts of the body present special peculiarities1 both in general and detailed structure1 in the mammals2 all these1 taken collectively1 point unequivocally to an early derivation of the mammals from the older groups of the reptiles and amphibia1 which must have taken place1 at the latest1 in the ,triassic period--at least twelve million years ago6 ,in all these important characteristics man is a true mammal4 ,the numerous orders 7#ab-cc7 which modern systematic zoology distinguishes in the class of mammals had been arranged in #ahaf 7by ,blainville7 in three natural groups1 which still hold good as sub-classes3 7#a7 the monotrema1 7#b7 the marsupialia1 and 7#c7 the placentalia4 ,these three sub-classes not only differ in the important respect of bodily structure and development1 but they correspond1 also1 to three different historical stages in the formation of the class1 as we shall see later on4 ,the monotremes of the ,triassic period were followed by the marsupials of the ,jurassic1 and these by the placentals of the ,cretaceous4 ,man belongs to this1 the youngest1 sub-class2 for he presents in his organization all the features which distinguish the placentals from the marsupials and the still older monotremes4 ,first of all1 there is the peculiar organ which gives a name to the placentals--the placenta4 ,it serves the purpose of nourishing the young mammal embryo for a long time during its enclosure in the mother's womb2 it consists of blood-bearing tufts which grow out of the chorion surrounding the embryo1 and penetrate corresponding cavities in the mucous membrane of the maternal uterus2 the delicate skin between the two structures is so attenuated in this spot that the nutriment in the mother's blood can pass directly into the blood of the child4 ,this excellent contrivance for nourishing the embryo1 which makes its first appearance at a somewhat late date1 gives the foetus the opportunity of a longer maintenance and a higher development in the protecting womb2 it is wanting in the implacentalia1 the two older sub-classes of the marsupials and the monotremes4 ,there are1 likewise1 other anatomical features1 particularly the higher development of the brain and the absence of the marsupial bone1 which raise the placentals above all their implacental ancestors4 ,in all these important particulars man is a true placental4 ,the very varied sub-class of the placentals has been recently subdivided into a great number of orders2 they are usually put at from ten to sixteen1 but when we include the important extinct forms which have been recently discovered the number runs up to from twenty to twenty-six4 ,in order to facilitate the study of these numerous orders1 and to obtain a deeper insight into their kindred construction1 it is very useful to form them into great natural groups1 which ,i have called legions4 ,in my latest attempt#i to arrange the advanced system of placentals in phylogenetic order ,i have substituted eight of these legions for the twenty-six orders1 and shown that these may be reduced to four main groups4 ,these1 in turn1 are traceable to one common ancestral group of all the placentals1 their fossil ancestors1 the prochoriata of the ,cretaceous period4 ,these are directly connected with the marsupial ancestors of the ,jurassic period4 ,we will only specify here1 as the most important living representatives of these four main groups1 the rodentia1 the ungulata1 the carnivora1 and the primates4 ,to the legion of the primates belong the prosimi 7half-apes71 the simi 7real apes71 and man4 ,all the members of these three orders agree in many important features1 and are at the same time distinguished by these features from the other twenty-three orders of placentals4 ,they are especially conspicuous for the length of their bones1 which were originally adapted to their arboreal manner of life4 ,their hands and feet are five-fingered1 and the long fingers are excellently suited for grasping and embracing the branches of trees2 they are provided1 either partially or completely1 with nails1 but have no claws4 ,the dentition is complete1 containing all four classes--incisors1 canine1 premolars1 and molars4 ,primates are also distinguished from all the other placentals by important features in the special construction of the skull and the brain2 and these are the more striking in proportion to their development and the lateness of their appearance in the history of the earth4 ,in all these important anatomical features our human organism agrees with that of all the other primates3 man is a true primate4 ,an impartial and thorough comparison of the bodily structure of the primates forces us to distinguish two orders in this most advanced legion of the mammalia--half-apes 7prosimiae or hemipitheci7 and apes 7simiae or pitheci74 ,the former seem in every respect to be the lower and older1 the latter to be the higher and younger order4 ,the womb of the half-ape is still double1 or two-horned1 as it is in all the other mammals4 ,in the true ape1 on the contrary1 the right and left wombs have completely amalgamated2 they blend into a pear-shaped womb1 which the human mother possesses besides the ape4 ,in the skull of the apes1 just as in that of man1 the orbits of the eyes are completely separated from the temporal cavities by an osseous partition2 in the prosimiae this is either entirely wanting or very imperfect4 ,finally1 the cerebrum of the prosimia is either quite smooth or very slightly furrowed1 and proportionately small2 that of the true ape is much larger1 and the gray bed especially1 the organ of higher psychic activity1 is much more developed2 the characteristic convolutions and furrows appear on its surface exactly in proportion as the ape approaches to man4 ,in these and other important respects1 particularly in the construction of the face and the hands1 man presents all the anatomical marks of a true ape4 ,the extensive order of apes was divided by ,geoffroi1 in #ahab1 into two sub-orders1 which are still universally accepted in systematic zoology--,new ,world and ,old ,world monkeys1 according to the hemisphere they respectively inhabit4 ,the ,american ,new ,world monkeys are called ,platyrrhinae 7flat-nosed72 their nose is flat1 and the nostrils divergent1 with a broad partition4 ,the ,old ,world monkeys1 on the contrary1 are called collectively ,catarrhinae 7narrow-nosed72 their nostrils point downward1 like man's1 and the dividing cartilage is narrow4 ,a further difference between the two groups is that the tympanum is superficial in the platyrrhinae1 but lies deeper1 inside the petrous bone1 in the catarrhinae2 in the latter a long and narrow bony passage has been formed1 while in the former it is still short and wide1 or even altogether wanting4 ,finally1 we have a much more important and decisive difference between the two groups in the circumstance that all the ,old ,world monkeys have the same teeth as man--i4 e41 twenty deciduous and thirty-two permanent teeth 7two incisors1 one canine1 two premolars1 and three molars in each half of the jaw74 ,the ,new ,world monkeys1 on the other hand1 have an additional premolar in each half-jaw1 or thirty-six teeth altogether4 ,the fact that these anatomical differences of the two simian groups are universal and conspicuous1 and that they harmonize with their geographical distribution in the two hemispheres1 fully authorizes a sharp systematic division of the two1 as well as the phylogenetic conclusion that for a very long period 7for more than a million years7 the two sub-orders have been developing quite independently of each other in the western and eastern hemispheres4 ,that is a most important point in view of the genealogy of our race2 for man bears all the marks of a true catarrhina2 he has descended from some extinct member of this sub-order in the ,old ,world4 ,the numerous types of catarrhinae which still survive in ,asia and ,africa have been formed into two sections for some time--the tailed1 doglike apes 7the cynopitheci7 and the tailless1 manlike apes 7the anthropomorpha74 ,the latter are much nearer to man than the former1 not only in the absence of a tail and in the general build of the body 7especially of the head71 but also on account of certain features which are unimportant in themselves but very significant in their constancy4 ,the sacrum of the anthropoid ape1 like that of man1 is made up of the fusion of five vertebr2 that of the cynopithecus consists of three 7more rarely four7 sacral vertebr4 ,the premolar teeth of the cynopitheci are greater in length than breadth2 those of the anthropomorpha are broader than they are long2 and the first molar has four protuberances in the former1 five in the latter4 ,furthermore1 the outer incisor of the lower jaw is broader than the inner one in the manlike apes and man2 in the doglike ape it is the smaller4 ,finally1 there is a special significance in the fact1 established by ,selenka in #ahij1 that the anthropoid apes share with man the peculiar structure of the discoid placenta1 the decidua reflexa1 and the pedicle of the allantois4 ,in fact1 even a superficial comparison of the bodily structure of the anthropomorpha which still survive makes it clear that both the ,asiatic 7the orang-outang and the gibbous ape7 and the ,african 7the gorilla and chimpanzee7 representatives of this group are nearer to man in build than any of the cynopitheci4 ,under the latter group we include the dog-faced papiomorpha1 the baboon1 and the long-tailed monkey1 at a very low stage4 ,the anatomical difference between these low papiomorpha and the most highly developed anthropoid apes is greater in every respect1 whatever organ we take for comparison1 than the difference between the latter and man4 ,this instructive fact was established with great penetration by the anatomist ,robert ,hartmann1 in his work on ,the ,anthropoid ,apes2#aj he proposed to divide the order of ,simiae in a new way--namely1 into the two great groups of primaria 7man and the anthropoid ape7 and the simiae proper1 or pitheci 7the rest of the catarrhin and all the platyrrhin74 ,in any case1 we have a clear proof of the close affinity of man and the anthropoid ape4 ,thus comparative anatomy proves to the satisfaction of every unprejudiced and critical student the significant fact that the body of man and that of the anthropoid ape are not only peculiarly similar1 but they are practically one and the same in every important respect4 ,the same two hundred bones1 in the same order and structure1 make up our inner skeleton2 the same three hundred muscles effect our movements2 the same hair clothes our skin2 the same groups of ganglionic cells build up the marvellous structure of our brain2 the same four chambered heart is the central pulsometer in our circulation2 the same thirty-two teeth are set in the same order in our jaws2 the same salivary1 hepatic1 and gastric glands compass our digestive process2 the same reproductive organs insure the maintenance of our race4 ,it is true that we find1 on close examination1 certain minor differences in point of size and shape in most of the organs of man and the ape2 but we discover the same1 or similar1 differences between the higher and lower races of men1 when we make a careful comparison--even1 in fact1 in a minute comparison of the various individuals of our own race4 ,we find no two persons who have exactly the same size and form of nose1 ears1 eyes1 and so forth4 ,one has only to compare attentively these special features in many different persons in any large company to convince one's self of the astonishing diversity of their construction and the infinite variability of specific forms4 ,not infrequently even two sisters are so much unlike as to make their origin from the same parents almost incredible4 ,yet all these individual variations do not weaken the significance of the fundamental similarity of structure2 they are traceable to certain minute differences in the growth of the individual features4 ,,chapter ,,iii ,,our ,,life ,development of ,physiology in ,antiquity and the ,middle ,ages3 ,galen--,experiment and ,vivisection--,discovery of the ,circulation of the ,blood by ,harvey--,vitalism3 ,haller--,teleological and ,vitalistic ,conception of ,life--,mechanical and ,monistic ,view of the ,physiological ,processes--,comparative ,physiology in the ,nineteenth ,century3 ,johannes ,mller--,cellular ,physiology3 ,max ,verworn--,cellular ,pathology3 ,virchow--,mammal ,physiology--,similarity of all ,vital ,activity in ,man and the ,ape ,it is only in the nineteenth century that our knowledge of human life has attained the dignity of a genuine1 independent science2 during the course of the century it has developed into one of the highest1 most interesting1 and most important branches of knowledge4 ,this science of the vital functions1 physiology1 had1 it is true1 been regarded at a much earlier date as a desirable1 if not a necessary1 condition of success in medical treatment1 and had been constantly associated with anatomy1 the science of the structure of the body4 ,but it was only much later1 and much more slowly1 than the latter that it could be thoroughly studied1 as it had to contend with much more serious difficulties4 ,the idea of life1 as the opposite of death1 naturally became the subject of speculation at a very early age4 ,in the living man1 just as in other living animals1 there were certain peculiar changes1 especially movements1 which were wanting in lifeless nature3 spontaneous locomotion1 the beat of the heart1 the drawing of the breath1 speech1 and so forth4 ,but the discrimination of such organic movements from similar phenomena in inorganic bodies was by no means easy1 and was frequently impossible2 the flowing stream1 the flickering flame1 the rushing wind1 the falling rock1 seemed to man to exhibit the same movements4 ,it was quite natural that primitive man should attribute an independent life to these dead bodies4 ,he knew no more of the real sources of movement in the one case than in the other4 ,we find the earliest scientific observations on the nature of man's vital functions 7as well as on his structure7 in the ,greek natural philosophers and physicians of the sixth and fifth centuries before ,christ4 ,the best collection of the physiological facts which were known at that time is to be found in the ,natural ,history of ,aristotle2 a great number of his assertions were probably taken from ,democritus and ,hippocrates4 ,the school of the latter had already made attempts to explain the mystery2 it postulated as the ultimate source of life in man and the beasts a volatile spirit of life 7,pneuma72 and ,erasistratus 7#bhj ,b4,c47 already drew a distinction between the lower and the higher spirit of life1 the pneuma zoticon in the heart and the pneuma psychicon in the brain4 ,the credit of gathering these scattered truths into unity1 and of making the first attempt at a systematic physiology1 belongs to the great ,greek physician ,galen2 we have already recognized in him the first great anatomist of antiquity 7cf4 p4 #bc74 ,in his researches into the organs of the body he never lost sight of the question of their vital activity1 their functions2 and even in this direction he proceeded by the same comparative method1 taking for his principal study the animals which approach nearest to man4 ,whatever he learned from these he applied directly to man4 ,he recognized the value of physiological experiment2 in his vivisection of apes1 dogs1 and swine he made a number of interesting experiments4 ,vivisection has been made the object of a violent attack in recent years1 not only by the ignorant and narrow-minded1 but by theological enemies of knowledge and by perfervid sentimentalists2 it is1 however1 one of the indispensable methods of research into the nature of life1 and has given us invaluable information on the most important questions4 ,this was recognized by ,galen seventeen hundred years ago4 ,galen reduces all the different functions of the body to three groups1 which correspond to the three forms of the pneuma1 or vital spirit4 ,the pneuma psychicon--the soul--which resides in the brain and nerves1 is the cause of thought1 sensation1 and will 7voluntary movement72 the pneuma zoticon--the heart--is responsible for the beat of the heart1 the pulse1 and the temperature2 the pneuma physicon1 seated in the liver1 is the source of the so-called vegetative functions1 digestion and assimilation1 growth and reproduction4 ,he especially emphasized the renewal of the blood in the lungs1 and expressed a hope that we should some day succeed in isolating the permanent element in the atmosphere--the pneuma1 as he calls it--which is taken into the blood in respiration4 ,more than fifteen centuries elapsed before this pneuma--oxygen--was discovered by ,lavoisier4 ,in human physiology1 as well as in anatomy1 the great system of ,galen was for thirteen centuries the ,codex aureus1 the inviolable source of all knowledge4 ,the influence of ,christianity1 so fatal to scientific culture1 raised the same insuperable obstacles in this as in every other branch of secular knowledge4 ,not a single scientist appeared from the third to the sixteenth century who dared to make independent research into man's vital activity1 and transcend the limits of the ,galenic system4 ,it was not until the sixteenth century that experiments were made in that direction by a number of distinguished physicians and anatomists 7,paracelsus1 ,servetus1 ,vesalius1 and others74 ,in #afbh ,harvey published his great discovery of the circulation of the blood1 and showed that the heart is a pump1 which drives the red stream unceasingly through the connected system of arteries and veins by a rhythmic1 unconscious contraction of its muscles4 ,not less important were ,harvey's researches into the procreation of animals1 as a result of which he formulated the well-known law3 ,every living thing comes from an egg 7omne vivum ex ovo74 ,the powerful impetus which ,harvey gave to physiological observation and experiment led to a great number of discoveries in the sixteenth and seventeenth centuries4 ,these were co-ordinated for the first time by the learned ,albrecht ,haller about the middle of the last century2 in his great work1 ,elementa ,physiologiae1 he established the inherent importance of the science1 independently of its relation to practical medicine4 ,in postulating1 however1 a special sensitive force or sensibility for neural action1 and a special irritability for muscular movement1 ,haller gave strong support to the erroneous idea of a specific vital force 7vis vitalis74 ,for more than a century afterwards1 from the middle of the eighteenth until the middle of the nineteenth century1 medicine and 7especially7 physiology were dominated by the old idea that a certain number of the vital processes may be traced to physical and chemical causes1 but that others are the outcome of a special vital force which is independent of physical agencies4 ,however much scientists differed in their conceptions of its nature and its relation to the soul1 they were all agreed as to its independence of1 and essential distinction from1 the chemico-physical forces of ordinary matter2 it was a self-contained force 7archaeus71 unknown in inorganic nature1 which compelled ordinary forces into its service4 ,not only the distinctly psychical activity1 the sensibility of the nerves and the irritability of the muscles1 but even the phenomena of sense activity1 of reproduction1 and of development seemed so wonderful and so mysterious in their sources that it was impossible to attribute them to simple physical and chemical processes4 ,as the free activity of the vital force was purposive and conscious1 it led1 in philosophy1 to a complete teleology2 especially did this seem indisputable when even the critical philosopher ,kant had acknowledged1 in his famous critique of the teleological position1 that1 though the mind's authority to give a mechanical interpretation of all phenomena is theoretically unlimited1 yet its actual capacity for such interpretation does not extend to the phenomena of organic life2 here we are compelled to have recourse to a purposive--therefore supernatural--principle4 ,this divergence of the vital phenomena from the mechanical processes of life became1 naturally1 more conspicuous as science advanced in the chemical and physical explanation of the latter4 ,the circulation of the blood and a number of other phenomena could be traced to mechanical agencies2 respiration and digestion were attributable to chemical processes like those we find in inorganic nature4 ,on the other hand1 it seemed impossible to do this with the wonderful performances of the nerves and muscles1 and with the characteristic life of the mind2 the co-ordination of all the different forces in the life of the individual seemed also beyond such a mechanical interpretation4 ,hence there arose a complete physiological dualism--an essential distinction was drawn between inorganic and organic nature1 between mechanical and vital processes1 between material force and life force1 between the body and the soul4 ,at the beginning of the nineteenth century this vitalism was firmly established in ,france by ,louis ,dumas1 and in ,germany by ,reil4 ,alexander ,humboldt had already published a poetical presentation of it in #agie1 in his narrative of the ,legend of ,rhodes2 it is repeated1 with critical notes1 in his ,views of ,nature4 ,in the first half of the seventeenth century the famous philosopher ,descartes1 starting from ,harvey's discovery of the circulation of the blood1 put forward the idea that the body of man1 like that of other animals1 is merely an intricate machine1 and that its movements take place under the same mechanical laws as the movements of an automaton of human construction4 ,it is true that ,descartes1 at the same time1 claimed for man the exclusive possession of a perfectly independent1 immaterial soul1 and held that its subjective experience1 thought1 was the only thing in the world of which we have direct and certain cognizance 7,cogito1 ergo sum74 ,yet this dualism did not prevent him from doing much to advance our knowledge of the mechanical life processes in detail4 ,borelli followed 7#affj7 with a reduction of the movements of the animal body to purely physical laws1 and ,sylvius endeavored1 about the same time1 to give a purely chemical explanation of the phenomena of digestion and respiration2 the former founded the iatromechanical1 the latter the iatrochemical1 school of medicine4 ,however1 these rational tendencies towards a natural1 mechanical explanation of the phenomena of life did not attain to a universal acceptance and application2 in the course of the eighteenth century they fell entirely away before the advance of teleological vitalism4 ,the final disproof of the latter and a return to mechanism only became possible with the happy growth of the new science of comparative physiology in the forties of the present century4 ,our knowledge of the vital functions1 like our knowledge of the structure of the human body1 was originally obtained1 for the most part1 not by direct observation of the human organism itself1 but by a study of the more closely related animals among the vertebrates1 especially the mammals4 ,in this sense the very earliest beginning of human anatomy and physiology was comparative4 ,but the distinct science of comparative physiology1 which embraces the whole sphere of life phenomena1 from the lowest animal up to man1 is a triumph of the nineteenth century4 ,its famous creator was ,johannes ,mller1 of ,berlin 7born1 the son of a shoemaker1 at ,coblentz1 in #ahja74 ,for fully twenty-five years--from #ahcc to #aheh--this most versatile and most comprehensive biologist of our age evinced an activity at the ,berlin ,university1 as professor and investigator1 which is only comparable with the associated work of ,haller and ,cuvier4 ,nearly every one of the great biologists who have taught and worked in ,germany for the last sixty years was1 directly or indirectly1 a pupil of ,johannes ,mller4 ,starting from the anatomy and physiology of man1 he soon gathered all the chief groups of the higher and lower animals within his sphere of comparison4 ,as1 moreover1 he compared the structure of extinct animals with the living1 and the healthy organism with the diseased1 endeavoring to bring together all the phenomena of life in a truly philosophic fashion1 he attained a biological knowledge far in advance of his predecessors4 ,the most valuable fruit of these comprehensive studies of ,johannes ,mller was his ,manual of ,human ,physiology4 ,this classical work contains much more than the title indicates2 it is the sketch of a comprehensive comparative biology4 ,it is still unsurpassed in respect of its contents and range of investigation4 ,in particular1 we find the methods of observation and experiment applied in it as masterfully as the philosophic processes of induction and deduction4 ,mller was originally a vitalist1 like all the physiologists of his time4 ,nevertheless1 the current idea of a vital force took a novel form in his speculations1 and gradually transformed itself into the very opposite4 ,for he attempted to explain the phenomena of life mechanically in every department of physiology4 ,his transfigured vital force was not above the physical and chemical laws of the rest of nature but entirely bound up with them4 ,it was1 in a word1 nothing more than life itself--that is1 the sum of all the movements which we perceive in the living organism4 ,he sought especially to give them the same mechanical interpretation in the life of the senses and of the mind as in the working of the muscles2 the same in the phenomena of circulation1 respiration1 and digestion as in generation and development4 ,mller's success was chiefly due to the fact that he always began with the simplest life phenomena of the lowest animals1 and followed them step by step in their gradual development up to the very highest1 to man4 ,in this his method of critical comparison proved its value both from the physiological and from the anatomical point of view4 ,johannes ,mller is1 moreover1 the only great scientist who has equally cultivated these two branches of research1 and combined them with equal brilliancy4 ,immediately after his death his vast scientific kingdom fell into four distinct provinces1 which are now nearly always represented by four or more chairs--human and comparative anatomy1 pathological anatomy1 physiology1 and the history of evolution4 ,this sudden division of ,mller's immense realm of learning in #aheh has been compared to the dissolution of the empire which ,alexander the ,great had consolidated and ruled4 ,among the many pupils of ,johannes ,mller who1 either during his lifetime or after his death1 labored hard for the advancement of the various branches of biology1 one of the most fortunate--if not the most important--was ,theodor ,schwann4 ,when the able botanist ,schleiden1 in #ahch1 indicated the cell as the common elementary organ of all plants1 and proved that all the different tissues of the plant are merely combinations of cells1 ,johannes ,mller recognized at once the extraordinary possibilities of this important discovery4 ,he himself sought to point out the same composition in various tissues of the animal body--for instance1 in the spinal cord of vertebrates--and thus led his pupil1 ,schwann1 to extend the discovery to all the animal tissues4 ,this difficult task was accomplished by ,schwann in his ,microscopic ,researches into the ,accordance in the ,structure and ,growth of ,plants and ,animals 7#ahci74 ,thus was the foundation laid of the cellular theory1 the profound importance of which1 both in physiology and anatomy1 has become clearer and more widely recognized in each subsequent year4 ,moreover1 it was shown by two other pupils of ,johannes ,mller that the activity of all organisms is1 in the ultimate analysis1 the activity of the components of their tissues1 the microscopic cells--these were the able physiologist ,ernst ,brcke1 of ,vienna1 and the distinguished histologist ,albert ,klliker1 of ,wrzburg4 ,brcke correctly denominated the cells the elementary organisms1 and showed that1 in the body of man and of all other animals1 they are the only actual1 independent factors of the life process4 ,klliker earned special distinction1 not only in the construction of the whole science of histology1 but particularly by showing that the animal ovum and its products are simple cells4 ,still1 however widely the immense importance of the cellular theory for all biological research was acknowledged1 the cellular physiology which is based on it only began an independent development very recently4 ,in this ,max ,verworn 7of ,jena7 earned a twofold distinction4 ,in his ,psycho-physiological ,studies of the ,protistae 7#ahhi7 he showed1 as a result of an ingenious series of experimental researches1 that the theory of a cell-soul which ,i put forward in #ahffaa is completely established by an accurate study of the unicellular protozoa1 and that the psychic phenomena of the protist form the bridge which unites the chemical processes of inorganic nature with the mental life of the highest animals4 ,verworn has further developed these views1 and based them on the modern theory of evolution1 in his ,general ,physiology4 ,this distinguished work returns to the comprehensive point of view of ,johannes ,mller1 in opposition to the one-sided and narrow methods of those modern physiologists who think to discover the nature of the vital phenomena by the exclusive aid of chemical and physical experiments4 ,verworn showed that it is only by ,mller's comparative method and by a profound study of the physiology of the cell that we can reach the higher stand-point which will give us a comprehensive survey of the wonderful realm of the phenomena of life4 ,only thus do we become convinced that the vital processes in man are subject to the same physical and chemical laws as those of all other animals4 ,the fundamental importance of the cellular theory for all branches of biology was made clear in the second half of the nineteenth century1 not only by the rapid progress of morphology and physiology1 but also by the entire reform of that biological science which has always been deemed most important on account of its relation to practical medicine--pathology1 or the science of disease4 ,many even of the older physicians were convinced that human diseases were natural phenomena1 like all other manifestations of life1 and should be studied scientifically1 like other vital functions4 ,particular schools of medicine--the ,iatrophysical and the ,iatrochemical--had already1 in the seventeenth century1 attempted to trace the sources of disease to certain physical and chemical changes4 ,however1 the imperfect condition of science at that period precluded any lasting results of these efforts4 ,many of the older theories1 which sought the nature of disease in supernatural and mystical causes1 were almost universally accepted down to the middle of the nineteenth century4 ,it was then that ,rudolf ,virchow1 another pupil of ,mller1 conceived the happy idea of transferring the cellular theory from the healthy to the diseased organism2 he sought in the more minute metamorphoses of the diseased cells and the tissues they composed the true source of those larger changes which1 in the form of disease1 threaten the living organism with peril and death4 ,especially during the seven years of his professorship at ,wrzburg 7#ahdi-ef7 ,virchow pursued his great task with such brilliant results that his ,cellular ,pathology 7published in #aheh7 turned1 at one stroke1 the whole of pathology and the dependent science of practical medicine into new and eminently fruitful paths4 ,this reform of medicine is significant for our present purpose in that it led us to a monistic and purely scientific conception of disease4 ,in sickness1 no less than in health1 man is subject to the same eternal iron laws of physics and chemistry as all the rest of the organic world4 ,among the numerous classes of animals which modern zoology distinguishes the mammals occupy a pre-eminent position1 not only on morphological grounds1 but also for physiological reasons4 ,as man belongs to the class of mammals 7see p4 #bg7 by every portion of his frame1 we must expect him to share his characteristic functions with the rest of the mammals4 ,such we find to be the case4 ,the circulation of the blood and respiration are accomplished in man under precisely the same laws and in the same manner as in all the other mammals--and in these alone2 they are determined by the peculiar structure of their heart and lungs4 ,in mammals only is all the arterial blood conducted from the left ventricle of the heart to the body by one1 the left1 branch of the aorta1 while in birds it passes along the right branch1 and in reptiles along both branches4 ,the blood of mammals is distinguished from that of any other vertebrate by the circumstance that its red cells have lost their nucleus 7by reversion74 ,the respiratory movements are effected largely by the diaphragm in this class of animals alone1 because only in them does it form a complete partition between the pectoral and abdominal cavities4 ,special importance1 however1 in this highest class of animals1 attaches to the production of milk in the breasts 7mammae71 and to the peculiar method of the rearing of the young1 which entails the supplying of the offspring with the mother's milk4 ,as this nutritive process reacts most powerfully on the other vital functions1 and the maternal affection of mammals must have arisen from this intimate form of rearing1 the name of the class justly reminds us of its great importance4 ,in millions of pictures1 most of them produced by painters of the highest rank1 the madonna with the child is revered as the purest and noblest type of maternal love--the instinct which is found in its extreme form in the exaggerated tenderness of the mother-ape4 ,as the apes approach nearest to man of all the mammals in point of structure1 we shall expect to hear the same of their vital functions2 and that we find to be the case4 ,everybody knows how closely the habits1 the movements1 the sense activity1 the mental life1 and the parental customs of apes resemble those of man4 ,scientific physiology proves the same significant resemblance in other less familiar processes1 particularly in the working of the heart1 the division of the breasts1 and the sexual life4 ,in the latter connection it is especially noteworthy that the mature females of many kinds of apes suffer a periodical discharge of blood from the womb1 which corresponds to the menstruation of the human female4 ,the secretion of the milk in the glands and the suctorial process also take place in the female ape in precisely the same fashion as in women4 ,finally1 it is of especial interest that the speech of apes seems on physiological comparison to be a stage in the formation of articulate human speech4 ,among living apes there is an ,indian species which is musical2 the hylobates syndactylus sings a full octave in perfectly pure1 harmonious half-tones4 ,no impartial philologist can hesitate any longer to admit that our elaborate rational language has been slowly and gradually developed out of the imperfect speech of our ,pliocene simian ancestors4 ,,chapter ,,iv ,,our ,,embryonic ,,development ,the ,older ,embryology--,the ,theory of ,preformation--,the ,theory of ,scatulation3 ,haller and ,leibnitz--,the ,theory of ,epigenesis3 ,c4 ,f4 ,wolff--,the ,theory of ,germinal ,layers3 ,carl ,ernst ,baer--,discovery of the ,human ,ovum3 ,remak1 ,klliker--,the ,egg-,cell and the ,sperm-,cell--,the ,theory of the ,gastra--,protozoa and ,metazoa--,the ,ova and the ,spermatozoa3 ,oscar ,hertwig--,conception--,embryonic ,development in ,man--,uniformity of the ,vertebrate ,embryo--,the ,germinal ,membranes in ,man--,the ,amnion1 the ,serolemma1 and the ,allantois--,the ,formation of the ,placenta and the ,after-,birth--,the ,decidua and the ,funiculus ,umbilicalis--,the ,discoid ,placenta of ,man and the ,ape ,comparative ontogeny1 or the science of the development of the individual animal1 is a child of the nineteenth century in even a truer sense than comparative anatomy and physiology4 ,how is the child formed in the mother's womb8 ,how do animals evolve from ova8 ,how does the plant come forth from the seed8 ,these pregnant questions have occupied the thoughtful mind for thousands of years4 ,yet it is only seventy years since the embryologist ,baer pointed out the correct means and methods for penetrating into the mysteries of embryonic life2 it is only forty years since ,darwin1 by his reform of the theory of descent1 gave us the key which should open the long-closed door1 and lead to a knowledge of embryonic agencies4 ,as ,i have endeavored to give a complete1 popular presentation of this very interesting but difficult study in the first section of my ,anthropogeny1 ,i will confine myself here to a brief survey and discussion of the most important phenomena4 ,let us first cast a historical glance at the older ontogeny1 and the theory of preformation which is connected with it4 ,the classical works of ,aristotle1 the many-sided father of science1 are the oldest known scientific sources of embryology1 as we found them to be for comparative anatomy4 ,not only in his great natural history1 but also in a special small work1 ,five ,books on the ,generation and ,development of ,animals1 the great philosopher gives us a host of interesting facts1 adding many observations on their significance2 it was not until our own days that many of them were fully appreciated1 and1 indeed1 we may say1 discovered afresh4 ,naturally1 many fables and errors are mixed up with them2 it was all that was known at that time of the hidden growth of the human germ4 ,yet during the long space of the next two thousand years the slumbering science made no further progress4 ,it was not until the commencement of the seventeenth century that there was a renewal of activity4 ,in #afjj the ,italian anatomist ,fabricius ab ,aquapendente published at ,padua the first pictures and descriptions of the embryos of man and some of the higher animals2 in #afhg the famous ,marcello ,malpighi1 of ,bologna1 a distinguished pioneer alike in zoology and botany1 published the first consistent exposition of the growth of the chick in the hatched egg4 ,all these older scientists were possessed with the idea that the complete body1 with all its parts1 was already contained in the ovum of animals1 only it was so minute and transparent that it could not be detected2 that1 therefore1 the whole development was nothing more than a growth1 or an unfolding1 of the parts that were already infolded 7involutae74 ,this erroneous notion1 almost universally accepted until the beginning of the present century1 is called the preformation theory2 sometimes it is called the evolution theory 7in the literal sense of unfolding72 but the latter title is accepted by modern scientists for the very different theory of transformation4 ,closely connected with the preformation theory1 and as a logical consequence of it1 there arose in the last century a further theory which keenly interested all thoughtful biologists--the curious theory of scatulation4 ,as it was thought that the outline of the entire organism1 with all its parts1 was present in the egg1 the ovary of the embryo had to be supposed to contain the ova of the following generation2 these1 again1 the ova of the next1 and so on in infinitum6 ,on that basis the distinguished physiologist ,haller calculated that ,god had created together1 #fjjj years ago--on the sixth day of his creatorial labors--the germs of #bjj1jjj1jjj1jjj men1 and ingeniously packed them all in the ovary of our venerable mother ,eve4 ,even the gifted philosopher ,leibnitz fully accepted this conclusion1 and embodied it in his monadist theory2 and as1 on his theory1 soul and body are in eternal1 inseparable companionship1 the consequence had to be accepted for the soul2 the souls of men have existed in organized bodies in their ancestors from ,adam downward--that is1 from the very beginning of things4 ,in the month of ,november1 #agei1 a young doctor of twenty-six years1 ,caspar ,friedrich ,wolff 7son of a ,berlin tailor71 published his dissertation for the degree at ,halle1 under the title1 ,theoria ,generationis4 ,supported by a series of most laborious and painstaking observations1 he proved the entire falsity of the dominant theories of preformation and scatulation4 ,in the hatched egg there is at first no trace of the coming chick and its organs2 instead of it we find on top of the yolk a small1 circular1 white disk4 ,this thin germinal disk becomes gradually round1 and then breaks up into four folds1 lying upon each other1 which are the rudiments of the four chief systems of organs--the nervous system above1 the muscular system underneath1 the vascular system 7with the heart71 and1 finally1 the alimentary canal4 ,thus1 as ,wolff justly remarked1 the embryonic development does not consist in an unfolding of the preformed organs1 but in a series of new constructions2 it is a true epigenesis4 ,one part arises after another1 and all make their appearance in a simple form1 which is very different from the later structure4 ,this only appears after a series of most remarkable formations4 ,although this great discovery--one of the most important of the eighteenth century--could be directly proved by a verification of the facts ,wolff had observed1 and although the theory of generation which was founded on it was in reality not a theory at all1 but a simple fact1 it met with no sympathy whatever for half a century4 ,it was particularly retarded by the high authority of ,haller1 who fought it strenuously with the dogmatic assertion that there is no such thing as development3 no part of the animal body is formed before another2 all were created together4 ,wolff1 who had to go to ,st4 ,petersburg1 was long in his grave before the forgotten facts he had observed were discovered afresh by ,oken at ,jena1 in #ahjf4 ,after ,wolff's epigenesis theory had been established by ,oken and ,neckel 7whose important work on the development of the alimentary canal was translated from ,latin into ,german71 a number of young ,german scientists devoted themselves eagerly to more accurate embryological research4 ,the most important and successful of these was ,carl ,ernst ,baer4 ,his principal work appeared in #ahbh1 with the title1 ,history of the ,development of ,animals3 ,observations and ,reflections4 ,not only the phenomena of the formation of the germ are clearly illustrated and fully described in it1 but it adds a number of very pregnant speculations4 ,in particular1 the form of the embryo of man and the mammals is correctly presented1 and the vastly different development of the lower invertebrate animals is also considered4 ,the two leaflike layers which appear in the round germ disk of the higher vertebrates first divide1 according to ,baer1 into two further layers1 and these four germinal layers are transformed into four tubes1 which represent the fundamental organs--the skin layer1 the muscular layer1 the vascular layer1 and the mucous layer4 ,then1 by very complicated evolutionary processes1 the later organs arise1 in substantially the same manner1 in man and all the other vertebrates4 ,the three chief groups of invertebrates1 which in their turn differ widely from each other1 have a very different development4 ,one of the most important of ,baer's many discoveries was the finding of the human ovum4 ,up to that time the little vesicles which are found in great numbers in the human ovary and in that of all other mammals had been taken for the ova4 ,baer was the first to prove1 in #ahbg1 that the real ova are enclosed in these vesicles--the ,graafian follicles--and much smaller1 being tiny spheres #a-abjth inch in diameter1 visible to the naked eye as minute specks under favorable conditions4 ,he discovered likewise that from this tiny ovum of the mammal there develops first a characteristic germ globule1 a hollow sphere with liquid contents1 the wall of which forms the slender germinal membrane1 or blastoderm4 ,ten years after ,baer had given a firm foundation to embryological science by his theory of germ layers a new task confronted it on the establishment of the cellular theory in #ahch4 ,what is the relation of the ovum and the layers which arise from it to the tissues and cells which compose the fully developed organism8 ,the correct answer to this difficult question was given about the middle of this century by two distinguished pupils of ,johannes ,mller--,robert ,remak1 of ,berlin1 and ,albert ,klliker1 of ,wrzburg4 ,they showed that the ovum is at first one simple cell1 and that the many germinal globules1 or granules1 which arise from it by repeated segmentation1 are also simple cells4 ,from this mulberry-like group of cells are constructed first the germinal layers1 and subsequently by differentiation1 or division of labor1 all the different organs4 ,klliker has the further merit of showing that the seminal fluid of male animals is also a mass of microscopic cells4 ,the active pin-shaped seed-animalcules1 or spermatozoa1 in it are merely ciliated cells1 as ,i first proved in the case of the seed-filaments of the sponge in #ahff4 ,thus it was proved that both the materials of generation1 the male sperm and the female ova1 fell in with the cellular theory4 ,that was a discovery of which the great philosophic significance was not appreciated until a much later date1 on a close study of the phenomena of conception in #ahge4 ,all the older studies in embryonic development concern man and the higher vertebrates1 especially the embryonic bird1 since hens' eggs are the largest and most convenient objects for investigation1 and are plentiful enough to facilitate experiment2 we can hatch them in the incubator1 as well as by the natural function of the hen1 and so observe from hour to hour1 during the space of three weeks1 the whole series of formations1 from the simple germ cell to the complete organism4 ,even ,baer had only been able to gather from such observations the fact that the different classes of vertebrates agreed in the characteristic form of the germ layers and the growth of particular organs4 ,in the innumerable classes of invertebrates1 on the other hand--that is1 in the great majority of animals--the embryonic development seemed to run quite a different course1 and most of them seemed to be altogether without true germinal layers4 ,it was not until about the middle of the century that such layers were found in some of the invertebrates4 ,huxley1 for instance1 found them in the medus in #ahdi1 and ,klliker in the cephalopods in #ahdd4 ,particularly important was the discovery of ,kowalewsky 7#ahhf7 that the lowest vertebrate--the lancelot1 or amphioxus--is developed in just the same manner 7and a very original fashion it is7 as an invertebrate1 apparently quite remote1 tunicate1 the sea-squirt1 or ascidian4 ,even in some of the worms1 the radiata and the articulata1 a similar formation of the germinal layers was pointed out by the same observer4 ,i myself was then 7since #ahhf7 occupied with the embryology of the sponges1 corals1 medus1 and siphonophor1 and1 as ,i found the same formation of two primary germ layers everywhere in these lowest classes of multicellular animals1 ,i came to the conclusion that this important embryonic feature is common to the entire animal world4 ,the circumstance that in the sponges and the cnidaria 7polyps1 medus1 etc47 the body consists for a long time1 sometimes throughout life1 merely of two simple layers of cells1 seemed to me especially significant4 ,huxley had already 7#ahdi7 compared these1 in the case of the medus1 with the two primary germinal layers of the vertebrates4 ,on the ground of these observations and comparisons ,i then1 in #ahgb1 in my ,philosophy of the ,calcispongiae1 published the theory of the gastra1 of which the following are the essential points3 ,i4 ,the whole animal world falls into two essentially different groups1 the unicellular primitive animals 7,protozoa7 and the multicellular animals with complex tissues 7,metazoa74 ,the entire organism of the protozoon 7the rhizopods of the infusoria7 remains throughout life a single simple cell 7or occasionally a loose colony of cells without the formation of tissue1 a coenobium74 ,the organism of the metazoon1 on the contrary1 is only unicellular at the commencement1 and is subsequently built up of a number of cells which form tissues4 ,,ii4 ,hence the method of reproduction and development is very different in each of these great categories of animals4 ,the protozoa usually multiply by non-sexual means1 by fission1 gemmation1 or spores2 they have no real ova and no sperm4 ,the metazoa1 on the contrary1 are divided into male and female sexes1 and generally propagate sexually1 by means of true ova1 which are fertilized by the male sperm4 ,,iii4 ,hence1 further1 true germinal layers1 and the tissues which are formed from them1 are found only in the metazoa2 they are entirely wanting in the protozoa4 ,,iv4 ,in all the metazoa only two primary layers appear at first1 and these have always the same essential significance2 from the outer layer the external skin and the nervous system are developed2 from the inner layer are formed the alimentary canal and all the other organs4 ,v4 ,i called the germ1 which always arises first from the impregnated ovum1 and which consists of these two primary layers1 the gut-larva1 or the gastrula2 its cup-shaped body with the two layers encloses originally a simple digestive cavity1 the primitive gut 7the progaster or archenteron71 and its simple opening is the primitive mouth 7the prostoma or blastoporus74 ,these are the earliest organs of the multicellular body1 and the two cell layers of its enclosing wall1 simple epithelia1 are its earliest tissues2 all the other organs and tissues are a later and secondary growth from these4 ,,vi4 ,from this similarity1 or homology1 of the gastrula in all classes of compound animals ,i drew the conclusion1 in virtue of the biogenetic law 7p4 #ha71 that all the metazoa come originally from one simple ancestral form1 the gastraea1 and that this ancient 7,laurentian71 long-extinct form had the structure and composition of the actual gastrula1 in which it is preserved by heredity4 ,,vii4 ,this phylogenetic conclusion1 based on the comparison of ontogenetic facts1 is confirmed by the circumstance that there are several of these gastrades still in existence 7gastraemaria1 cyemaria1 physemaria1 etc471 and also some ancient forms of other animal groups whose organization is very little higher 7the olynthus of the sponges1 the hydra1 or common fresh-water polyp1 of the cnidaria1 the convoluta and other cryptocla1 or worms of the simplest type1 of the platodes74 ,,viii4 ,in the further development of the various tissue-forming animals from the gastrula we have to distinguish two principal groups4 ,the earlier and lower types 7the coelenteria or acoelomia7 have no body cavity1 no vent1 and no blood2 such is the case with the gastrades1 sponges1 cnidaria1 and platodes4 ,the later and higher types 7the caelomaria or bilateria71 on the other hand1 have a true body cavity1 and generally blood and a vent2 to these we must refer the worms and the higher types of animals which were evolved from these later on1 the echinodermata1 mollusca1 articulata1 tunicata1 and vertebrata4 ,those are the main points of my gastra theory2 ,i have since enlarged the first sketch of it 7given in #ahgb71 and have endeavored to substantiate it in a series of ,studies on the gastra theory 7#ahgc-hd74 ,although it was almost universally rejected at first1 and fiercely combated for ten years by many authorities1 it is now 7and has been for the last fifteen years7 accepted by nearly all my colleagues4 ,let us now see what far-reaching consequences follow from it1 and from the evolution of the germ1 especially with regard to our great question1 the place of man in nature4 ,the human ovum1 like that of all other animals1 is a single cell1 and this tiny globular egg cell 7about the #abjth of an inch in diameter7 has just the same characteristic appearance as that of all other viviparous organisms4 ,the little ball of protoplasm is surrounded by a thick1 transparent1 finely reticulated membrane1 called the zona pellucida2 even the little1 globular1 germinal vesicle 7the cell-nucleus71 which is enclosed in the protoplasm 7the cell-body71 is of the same size and the same qualities as in the rest of the mammals4 ,the same applies to the active spermatozoa of the male1 the minute1 threadlike1 ciliated cells of which millions are found in every drop of the seminal fluid2 on account of their lifelike movements they were previously taken to be forms of life1 as the name indicates 7spermatozoa--sperm animals74 ,moreover1 the origin of both these important sexual cells in their respective organs is the same in man as in the other mammals2 both the ova in the ovary of the female and the spermatozoa in the spermarium of the male arise in the same fashion--they always come from cells1 which are originally derived from the coelous epithelium1 the layer of cells which clothes the cavity of the body4 ,the most important moment in the life of every man1 as in that of all other complex animals1 is the moment in which he begins his individual existence2 it is the moment when the sexual cells of both parents meet and coalesce for the formation of a single simple cell4 ,this new cell1 the impregnated egg cell1 is the individual stem cell 7the cytula71 the continued segmentation of which produces the cells of the germinal layers and the gastrula4 ,with the formation of this cytula1 hence in the process of conception itself1 the existence of the personality1 the independent individual1 commences4 ,this ontogenic fact is supremely important1 for the most far-reaching conclusions may be drawn from it4 ,in the first place1 we have a clear perception that man1 like all the other complex animals1 inherits all his personal characteristics1 bodily and mental1 from his parents2 and1 further1 we come to the momentous conclusion that the new personality which arises thus can lay no claim to immortality4 ,hence the minute processes of conception and sexual generation are of the first importance4 ,we are1 however1 only familiar with their details since #ahge1 when ,oscar ,hertwig1 my pupil and fellow-traveller at that time1 began his researches into the impregnation of the egg of the sea-urchin at ,ajaccio1 in ,corsica4 ,the beautiful capital of the island in which ,napoleon the ,great was born1 in #agfi1 was also the spot in which the mysteries of animal conception were carefully studied for the first time in their most important aspects4 ,hertwig found that the one essential element in conception is the coalescence of the two sexual cells and their nuclei4 ,only one out of the millions of male ciliated cells which press round the ovum penetrates to its nucleus4 ,the nuclei of both cells1 of the spermatozoon and of the ovum1 drawn together by a mysterious force1 which we take to be a chemical sense-activity1 related to smell1 approach each other and melt into one4 ,thus1 by the sensitive perception of the sexual nuclei1 following upon a kind of erotic chemicotropism1 a new cell is formed1 which unites in itself the inherited qualities of both parents2 the nucleus of the spermatozoon conveys the paternal features1 the nucleus of the ovum those of the mother1 to the stem cell1 from which the child is to be developed4 ,that applies both to the bodily and to the mental characteristics4 ,the formation of the germinal layers by the repeated division of the stem cell1 the growth of the gastrula and of the later germ structures which succeed it1 take place in man in just the same manner as in the other higher mammals1 under the peculiar conditions which differentiate this group from the lower vertebrates4 ,in the earlier stages of development these special characters of the placentalia are not to be detected4 ,the significant embryonic or larval form of the chordula1 which succeeds the gastrula1 has substantially the same structure in all vertebrates2 a simple straight rod1 the dorsal cord1 lies lengthways along the main axis of the shield-shaped body--the embryonic shield2 above the cord the spinal marrow develops out of the outer germinal layer1 while the gut makes its appearance underneath4 ,then1 on both sides1 to the right and left of the axial rod1 appear the segments of the pro-vertebr and the outlines of the muscular plates1 with which the formation of the members of the vertebrate body begins4 ,the gill-clefts appear on either side of the fore-gut2 they are the openings of the gullet1 through which1 in our primitive fish-ancestors1 the water which had entered at the mouth for breathing purposes made its exit at the sides of the head4 ,by a tenacious heredity these gill-clefts1 which have no meaning except for our fish-like aquatic ancestors1 are still preserved in the embryo of man and all the other vertebrates4 ,they disappear after a time4 ,even after the five vesicles of the embryonic brain appear in the head1 and the rudiments of the eyes and ears at the sides1 and after the legs sprout out at the base of the fish-like embryo1 in the form of two roundish1 flat buds1 the foetus is still so like that of other vertebrates that it is indistinguishable from them4 ,the substantial similarity in outer form and inner structure which characterizes the embryo of man and other vertebrates in this early stage of development is an embryological fact of the first importance2 from it1 by the fundamental law of biogeny1 we may draw the most momentous conclusions4 ,there is but one explanation of it--heredity from a common parent form4 ,when we see that1 at a certain stage1 the embryos of man and the ape1 the dog and the rabbit1 the pig and the sheep1 although recognizable as higher vertebrates1 cannot be distinguished from each other1 the fact can only be elucidated by assuming a common parentage4 ,and this explanation is strengthened when we follow the subsequent divergence of these embryonic forms4 ,the nearer two animals are in their bodily structure1 and1 therefore1 in the scheme of nature1 so much the longer do we find their embryos to retain this resemblance1 and so much the closer do they approach each other in the ancestral tree of their respective group1 so much the closer is their genetic relationship4 ,hence it is that the embryos of man and the anthropoid ape retain the resemblance much later1 at an advanced stage of development1 when their distinction from the embryos of other mammals can be seen at a glance4 ,i have illustrated this significant fact by a juxtaposition of corresponding stages in the development of a number of different vertebrates in my ,natural ,history of ,creation and in my ,anthropogeny4 ,the great phylogenetic significance of the resemblance we have described is seen1 not only in the comparison of the embryos of vertebrates1 but also in the comparison of their protective membranes4 ,all vertebrates of the three higher classes--reptiles1 birds1 and mammals--are distinguished from the lower classes by the possession of certain special foetal membranes1 the amnion and the serolemma4 ,the embryo is enclosed in these membranes1 or bags1 which are full of water1 and is thus protected from pressure or shock4 ,this provident arrangement probably arose during the ,permian period1 when the oldest reptiles1 the proreptilia1 the common ancestors of all the amniotes 7animals with an amnion71 completely adapted themselves to a life on land4 ,their direct ancestors1 the amphibia1 and the fishes are devoid of these foetal membranes2 they would have been superfluous to these inhabitants of the water4 ,with the inheritance of these protective coverings are closely connected two other changes in the amniotes3 firstly1 the entire disappearance of the gills 7while the gill arches and clefts continue to be inherited as rudimentary organs72 secondly1 the construction of the allantois4 ,this vesicular bag1 filled with water1 grows out of the hind-gut in the embryo of all the amniotes1 and is nothing else than an enlargement of the bladder of their amphibious ancestors4 ,from its innermost and inferior section is formed subsequently the permanent bladder of the amniotes1 while the larger outer part shrivels up4 ,usually this has an important part to play for a long time as the respiratory organ of the embryo1 a number of large blood-vessels spreading out over its inner surface4 ,the formation of the membranes1 the amnion and the serolemma1 and of the allantois1 is just the same1 and is effected by the same complicated process of growth1 in man as in all the other amniotes2 man is a true amniote4 ,the nourishment of the foetus in the maternal womb is effected1 as is well known1 by a peculiar organ1 richly supplied with blood at its surface1 called the placenta4 ,this important nutritive organ is a spongy1 round disk1 from six to eight inches in diameter1 about an inch thick1 and one or two pounds in weight2 it is separated after the birth of the child1 and issues as the after-birth4 ,the placenta consists of two very different parts1 the foetal and the maternal part4 ,the latter contains highly developed sinuses1 which retain the blood conveyed to them by the arteries of the mother4 ,on the other hand1 the foetal placenta is formed by innumerable branching tufts or villi1 which grow out of the outer surface of the allantois1 and derive their blood from the umbilical vessels4 ,the hollow1 blood-filled villi of the foetal placenta protrude into the sinuses of the maternal placenta1 and the slender membrane between the two is so attenuated that it offers no impediment to the direct interchange of material through the nutritive blood-stream 7by osmosis74 ,in the older and lower groups of the placentals the entire surface of the chorion is covered with a number of short villi2 these chorion-villi take the form of pit-like depressions of the mucous membrane of the mother1 and are easily detached at birth4 ,that happens in most of the ungulata 7the sow1 camel1 mare1 etc471 the cetacea1 and the prosimi2 these mallo-placentalia 7with a diffuse placenta7 have been denominated the indeciduata4 ,the same formation is present in man and the other placentals in the beginning4 ,it is soon modified1 however1 as the villi on one part of the chorion are withdrawn2 while on the other part they grow proportionately stronger1 and unite intimately with the mucous membrane of the womb4 ,it is in consequence of this intimate blending that a portion of the uterus is detached at birth1 and carried away with loss of blood4 ,this detachable membrane--the decidua--is a characteristic of the higher placentalia1 which have1 consequently1 been grouped under the title of deciduata2 to that category belong the carnassia1 rodentia1 simi1 and man4 ,in the carnassia and some of the ungulata 7the elephant1 for instance7 the placenta takes the form of a girdle1 hence they are known as the zonoplacentalia2 in the rodentia1 the insectivora 7the mole and the hedge-hog71 the apes1 and man1 it takes the form of a disk4 ,even ten years ago the majority of embryologists thought that man was distinguished by certain peculiarities in the form of the placenta--namely1 by the possession of what is called the decidua reflexa1 and by a special formation of the umbilical chord which unites the decidua to the foetus4 ,it was supposed that the rest of the placentals1 including the apes1 were without these special embryonic structures4 ,the funiculus umbilicalis is a smooth1 cylindrical cord1 from sixteen to twenty-three inches long1 and as thick as the little finger4 ,it forms the connecting link between the foetus and the maternal placenta1 since it conducts the nutritive vessels from the body of the foetus to the placenta2 it comprises1 besides1 the pedicle of the allantois and the yelk-sac4 ,the yelk-sac in the human case forms the greater portion of the germinal vesicle during the third week of gestation2 but it shrivels up afterwards so that it was formerly entirely missed in the mature foetus4 ,yet it remains all the time in a rudimentary condition1 and may be detected even after birth as the little umbilical vesicle4 ,moreover1 even the vesicular structure of the allantois disappears at an early stage in the human case2 with a deflection of the amnion1 it gives rise to the pedicle4 ,we cannot enter here into a discussion of the complicated anatomical and embryological relations of these structures4 ,i have described and illustrated them in my ,anthropogeny 7twenty-third chapter74 ,the opponents of evolution still appealed to these special features of human embryology1 which were supposed to distinguish man from all the other mammals1 even so late as ten years ago4 ,but in #ahij ,emil ,selenka proved that the same features are found in the anthropoid apes1 especially in the orang 7satyrus71 while the lower apes are without them4 ,thus ,huxley's pithecometra thesis was substantiated once more3 ,the differences between man and the great apes are not so great as are those between the manlike apes and the lower monkeys4 ,the supposed evidences against the near blood-relationship of man and the apes proved1 on a closer examination of the real circumstances1 to be strong reasons in favor of it4 ,every scientist who penetrates with open eyes into this dark but profoundly interesting labyrinth of our embryonic development1 and who is competent to compare it critically with that of the rest of the mammals1 will find in it a most important aid towards the elucidation of the descent of our species4 ,for the various stages of our embryonic development1 in the character of palingenetic phenomena of heredity1 cast a brilliant light on the corresponding stages of our ancestral tree1 in accordance with the great law of biogeny4 ,but even the cenogenetic phenomena of adaptation1 the formation of the temporary foetal organs--the characteristic foetal membranes1 and especially the placenta--gives us sufficiently definite indications of our close genetic relationship with the primates4 ,,chapter ,v ,,the ,,history ,,of ,,our ,,species ,origin of ,man--,mythical ,history of ,creation--,moses and ,linn--,the ,creation of ,permanent ,species--,the ,catastrophic ,theory3 ,cuvier--,transformism3 ,goethe--,theory of ,descent3 ,lamarck--,theory of ,selection3 ,darwin--,evolution 7,phylogeny7--,ancestral ,trees--,general ,morphology--,natural ,history of ,creation--,systematic ,phylogeny--,fundamental ,law of ,biogeny--,anthropogeny--,descent of ,man from the ,ape--,pithecoid ,theory--,the ,fossil ,pithecanthropus of ,dubois ,the youngest of the great branches of the living tree of biology is the science we call biological evolution1 or phylogeny4 ,it came into existence much later1 and under much more difficult circumstances1 than its natural sister1 embryonic evolution or ontogeny4 ,the object of the latter was to attain a knowledge of the mysterious processes by which the individual organism1 plant or animal1 developed from the egg4 ,phylogeny has to answer the much more obscure and difficult question3 ,what is the origin of the different organic species of plants and animals8 ,ontogeny 7embryology and metamorphism7 could follow the empirical method of direct observation in the solution of its not remote problem2 it needed but to follow1 day by day and hour by hour1 the visible changes which the foetus experiences during a brief period in the course of its development from the ovum4 ,much more difficult was the remote problem of phylogeny2 for the slow processes of gradual construction1 which effect the rise of new species of animals and plants1 go on imperceptibly during thousands and even millions of years4 ,their direct observation is possible only within very narrow limits2 the vast majority of these historical processes can only be known by direct inference--by critical reflection1 and by a comparative use of empirical sciences which belong to very different fields of thought1 palontology1 ontogeny1 and morphology4 ,to this we must add the immense opposition which was everywhere made to biological evolution on account of the close connection between questions of organic creation and supernatural myths and religious dogmas4 ,for these reasons it can easily be understood how it is that the scientific existence of a true theory of origins was only secured1 amid fierce controversy1 in the course of the last forty years4 ,every serious attempt that was made before the beginning of the nineteenth century to solve the problem of the origin of species lost its way in the mythological labyrinth of the supernatural stories of creation4 ,the efforts of a few distinguished thinkers to emancipate themselves from this tyranny and attain to a naturalistic interpretation proved unavailing4 ,a great variety of creation myths arose in connection with their religion in all the ancient civilized nations4 ,during the ,middle ,ages triumphant ,christendom naturally arrogated to itself the sole right of pronouncing on the question2 and1 the ,bible being the basis of the structure of the ,christian religion1 the whole story of creation was taken from the book of ,genesis4 ,even ,carl ,linn1 the famous ,swedish scientist1 started from that basis when1 in #agce1 in his classical ,systema ,naturae1 he made the first attempt at a systematic arrangement1 nomenclature1 and classification of the innumerable objects in nature4 ,as the best practical aid in that attempt he introduced the well-known double or binary nomenclature2 to each kind of animals and plants he gave a particular specific name1 and added to it the wider-reaching name of the genus4 ,a genus served to unite the nearest related species2 thus1 for instance1 ,linn grouped under the genus dog 7canis71 as different species1 the house-dog 7canis familiaris71 the jackal 7canis aureus71 the wolf 7canis lupus7 the fox 7canis vulpes71 etc4 ,this binary nomenclature immediately proved of such great practical assistance that it was universally accepted1 and is still always followed in zoological and botanical classification4 ,but the theoretical dogma which ,linn himself connected with his practical idea of species was fraught with the gravest peril to science4 ,the first question which forced itself on the mind of the thoughtful scientist was the question as to the nature of the concept of species1 its contents1 and its range4 ,and the creator of the idea answered this fundamental question by a nave appeal to the dominant ,mosaic legend of creation3 ,species tot sunt diversae1 quot diversas formas ab initio creavit infinitum ens--7,there are just so many distinct species as there were distinct types created in the beginning by the ,infinite74 ,this theosophic dogma cut short all attempt at a natural explanation of the origin of species4 ,linn was acquainted only with the plant and animal worlds that exist to-day2 he had no suspicion of the much more numerous extinct species which had peopled the earth with their varying forms in the earlier period of its development4 ,it was not until the beginning of the nineteenth century that we were introduced to these fossil animals by ,cuvier4 ,in his famous work on the fossil bones of the four-footed vertebrates he gave 7#ahab7 the first correct description and true interpretation of many of these fossil remains4 ,he showed1 too1 that a series of very different animal populations have succeeded each other in the various stages of the earth's history4 ,since ,cuvier held firmly to ,linn's idea of the absolute permanency of species1 he thought their origin could only be explained by the supposition that a series of great cataclysms and new creations had marked the history of the globe2 he imagined that all living creatures were destroyed at the commencement of each of these terrestrial revolutions1 and an entirely new population was created at its close4 ,although this catastrophic theory of ,cuvier's led to the most absurd consequences1 and was nothing more than a bald faith in miracles1 it obtained almost universal recognition1 and reigned triumphant until the coming of ,darwin4 ,it is easy to understand that these prevalent ideas of the absolute unchangeability and supernatural creation of organic species could not satisfy the more penetrating thinkers4 ,we find several eminent minds already1 in the second half of the last century1 busy with the attempt to find a natural explanation of the problem of creation4 ,pre-eminent among them was the great ,german poet and philosopher1 ,wolfgang ,goethe1 who1 by his long and assiduous study of morphology1 obtained1 more than a hundred years ago1 a clear insight into the intimate connection of all organic forms1 and a firm conviction of a common natural origin4 ,in his famed ,metamorphosis of ,plants 7#agij7 he derived all the different species of plants from one primitive type1 and all their different organs from one primitive organ--the leaf4 ,in his vertebral theory of the skull he endeavored to prove that the skulls of the vertebrates--including man--were all alike made up of certain groups of bones1 arranged in a definite structure1 and that these bones are nothing else than transformed vertebr4 ,it was his penetrating study of comparative osteology that led ,goethe to a firm conviction of the unity of the animal organization2 he had recognized that the human skeleton is framed on the same fundamental type as that of all other vertebrates--built on a primitive plan that only deviates more or less to one side or other in its very constant features1 and still develops and refashions itself daily4 ,this remodelling1 or transformation1 is brought about1 according to ,goethe1 by the constant interaction of two powerful constructive forces--a centripetal force within the organism1 the tendency to specification1 and a centrifugal force without1 the tendency to variation1 or the idea of metamorphosis2 the former corresponds to what we now call heredity1 the latter to the modern idea of adaptation4 ,how deeply ,goethe had penetrated into their character by these philosophic studies of the construction and reconstruction of organic natures1 and how far1 therefore1 he must be considered the most important precursor of ,darwin and ,lamarck1#ab may be gathered from the interesting passages from his works which ,i have collected in the fourth chapter of my ,natural ,history of ,creation4 ,these evolutionary ideas of ,goethe1 however1 like analogous ideas of ,kant1 ,owen1 ,treviranus1 and other philosophers of the commencement of the century 7which we have quoted in the above work71 did not amount to more than certain general conclusions4 ,they had not that great lever which the natural history of creation needed for its firm foundation on a criticism of the dogma of fixed species2 this lever was first supplied by ,lamarck4 ,the first thorough attempt at a scientific establishment of transformism was made at the beginning of the nineteenth century by the great ,french scientist ,jean ,lamarck1 the chief opponent of his colleague1 ,cuvier1 at ,paris4 ,he had already1 in #ahjb1 in his ,observations on ,living ,organisms1 expressed the new ideas as to the mutability and formation of species1 which he thoroughly established in #ahji in the two volumes of his profound work1 ,philosophie ,zoologique4 ,in this work he first gave expression to the correct idea1 in opposition to the prevalent dogma of fixed species1 that the organic species is an artificial abstraction1 a concept of only relative value1 like the wider-ranging concepts of genus1 family1 order1 and class4 ,he went on to affirm that all species are changeable1 and have arisen from older species in the course of very long periods of time4 ,the common parent forms from which they have descended were originally very simple and lowly organisms4 ,the first and oldest of them arose by abiogenesis4 ,while the type is preserved by heredity in the succession of generations1 adaptation1 on the other hand1 effects a constant modification of the species by change of habits and the exercise of the various organs4 ,even our human organism has arisen in the same natural manner1 by gradual transformation1 from a group of pithecoid mammals4 ,for all these phenomena--indeed1 for all phenomena both in nature and in the mind--,lamarck takes exclusively mechanical1 physical1 and chemical activities to be the true efficient causes4 ,his magnificent ,philosophie ,zoologique contains all the elements of a purely monistic system of nature on the basis of evolution4 ,i have fully treated these achievements of ,lamarck in the fourth chapter of my ,anthropogeny1 and in the fourth chapter of the ,natural ,history of ,creation4 ,science had now to wait until this great effort to give a scientific foundation to the theory of evolution should shatter the dominant myth of a specific creation1 and open out the path of natural development4 ,in this respect ,lamarck was not more successful in resisting the conservative authority of his great opponent1 ,cuvier1 than was his colleague and sympathizer1 ,geoffrey ,st4 ,hilaire1 twenty years later4 ,the famous controversies which he had with ,cuvier in the ,parisian ,academy in #ahcj ended with the complete triumph of the latter4 ,i have elsewhere fully described these conflicts1 in which ,goethe took so lively an interest4 ,the great expansion which the study of biology experienced at that time1 the abundance of interesting discoveries in comparative anatomy and physiology1 the establishment of the cellular theory1 and the progress of ontogeny1 gave zoologists and botanists so overwhelming a flood of welcome material to deal with that the difficult and obscure question of the origin of species was easily forgotten for a time4 ,people rested content with the old dogma of creation4 ,even when ,charles ,lyell refuted ,cuvier's extraordinary catastrophic theory in his ,principles of ,geology1 in #ahcj1 and vindicated a natural1 continuous evolution for the inorganic structure of our planet1 his simple principle of continuity found no one to apply it to the inorganic world4 ,the rudiments of a natural phylogeny which were buried in ,lamarck's works were as completely forgotten as the germ of a natural ontogeny which ,caspar ,friedrich ,wolff had given fifty years earlier in his ,theory of ,generation4 ,in both cases a full half-century elapsed before the great idea of a natural development won a fitting recognition4 ,only when ,darwin 7in #ahei7 approached the solution of the problem from a different side altogether1 and made a happy use of the rich treasures of empirical knowledge which had accumulated in the mean time1 did men begin to think once more of ,lamarck as his great precursor4 ,the unparalleled success of ,charles ,darwin is well known4 ,it shows him to-day1 at the close of the century1 to have been1 if not the greatest1 at least the most effective of its distinguished scientists4 ,no other of the many great thinkers of our time has achieved so magnificent1 so thorough1 and so far-reaching a success with a single classical work as ,darwin did in #ahei with his famous ,origin of ,species4 ,it is true that the reform of comparative anatomy and physiology by ,johannes ,mller had inaugurated a new and fertile epoch for the whole of biology1 that the establishment of the cellular theory by ,schleiden and ,schwann1 the reform of ontogeny by ,baer1 and the formulation of the law of substance by ,robert ,mayer and ,helmholtz were scientific facts of the first importance2 but no one of them has had so profound an influence on the whole structure of human knowledge as ,darwin's theory of the natural origin of species4 ,for it at once gave us the solution of the mystic problem of creation1 the great question of all questions--the problem of the true character and origin of man himself4 ,if we compare the two great founders of transformism1 we find in ,lamarck a preponderant inclination to deduction1 and to forming a completely monistic scheme of nature2 in ,darwin we have a predominant application of induction1 and a prudent concern to establish the different parts of the theory of selection as firmly as possible on a basis of observation and experiment4 ,while the ,french scientist far outran the then limits of empirical knowledge1 and rather sketched the programme of future investigation1 the ,english empiricist was mainly preoccupied about securing a unifying principle of interpretation for a mass of empirical knowledge which had hitherto accumulated without being understood4 ,we can thus understand how it was that the success of ,darwin was just as overwhelming as that of ,lamarck was evanescent4 ,darwin1 however1 had not only the signal merit of bringing all the results of the various biological sciences to a common focus in the principle of descent1 and thus giving them a harmonious interpretation1 but he also discovered1 in the principle of selection1 that direct cause of transformation which ,lamarck had missed4 ,in applying1 as a practical breeder1 the experience of artificial selection to organisms in a state of nature1 and in recognizing in the struggle for life the selective principle of natural selection1 ,darwin created his momentous theory of selection1 which is what we properly call ,darwinism4 ,one of the most pressing of the many important tasks which ,darwin proposed to modern biology was the reform of the zoological and botanical system4 ,since the innumerable species of animals and plants were not created by a supernatural miracle1 but evolved by natural processes1 their ancestral tree is their natural system4 ,the first attempt to frame a system in this sense was made by myself in #ahff1 in my ,general ,morphology of ,organisms4 ,the first volume of this work 7,general ,anatomy7 dealt with the mechanical science of the developed forms2 the second volume 7,general ,evolution7 was occupied with the science of the developing forms4 ,the systematic introduction to the latter formed a genealogical survey of the natural system of organisms4 ,until that time the term evolution had been taken to mean exclusively1 both in zoology and botany1 the development of individual organisms--embryology1 or metamorphic science4 ,i established the opposite view1 that this history of the embryo 7ontogeny7 must be completed by a second1 equally valuable1 and closely connected branch of thought--the history of the race 7phylogeny74 ,both these branches of evolutionary science are1 in my opinion1 in the closest causal connection2 this arises from the reciprocal action of the laws of heredity and adaptation2 it has a precise and comprehensive expression in my fundamental law of biogeny4 ,as the new views ,i had put forward in my ,general ,morphology met with very little notice1 and still less acceptance1 from my scientific colleagues1 in spite of their severely scientific setting1 ,i thought ,i would make the most important of them accessible to a wider circle of informed readers by a smaller work1 written in a more popular style4 ,this was done in #ahfh1 in ,the ,natural ,history of ,creation 7a series of popular scientific lectures on evolution in general1 and the systems of ,darwin1 ,goethe1 and ,lamarck in particular74 ,if the success of my ,general ,morphology was far below my reasonable anticipation1 that of ,the ,natural ,history of ,creation went far beyond it4 ,in a period of thirty years nine editions and twelve different translations of it have appeared4 ,in spite of its great defects1 the book has contributed much to the popularization of the main ideas of modern evolution4 ,still1 ,i could only give the barest outlines in it of my chief object1 the phylogenetic construction of a natural system4 ,i have1 therefore1 given the complete proof1 which is wanting in the earlier work1 of the phylogenetic system in a subsequent larger work1 my ,systematic ,phylogeny 7outlines of a natural system of organisms on the basis of their specific development74 ,the first volume of it deals with the protists and plants 7#ahid71 the second with the invertebrate animals 7#ahif71 the third with the vertebrates 7#ahie74 ,the ancestral tree of both the smaller and the larger groups is carried on in this work as far as my knowledge of the three great ancestral documents--palontology1 ontogeny1 and morphology--qualified me to extend it4 ,i had already1 in my ,general ,morphology 7at the end of the fifth book71 described the close causative connection which exists1 in my opinion1 between the two branches of organic evolution as one of the most important ideas of transformism1 and ,i had framed a precise formula for it in a number of theses on the causal nexus of biontic and phyletic development3 ,ontogenesis is a brief and rapid recapitulation of phylogenesis1 determined by the physiological functions of heredity 7generation7 and adaptation 7maintenance74 ,darwin himself had emphasized the great significance of his theory for the elucidation of embryology in #ahei1 and ,fritz ,mller had endeavored to prove it as regards the ,crustacea in the able little work1 ,facts and ,arguments for ,darwin 7#ahfd74 ,my own task has been to prove the universal application and the fundamental importance of the biogenetic law in a series of works1 especially in the ,biology of the ,calcispongiae 7#ahgb71 and in ,studies on the ,gastraea ,theory 7#ahgc-ahhd74 ,the theory of the homology of the germinal layers and of the relations of palingenesis to cenogenesis which ,i have exposed in them has been confirmed subsequently by a number of works of other zoologists4 ,that theory makes it possible to follow nature's law of unity in the innumerable variations of animal embryology2 it gives us for their ancestral history a common derivation from a simple primitive stem form4 ,the far-seeing founder of the theory of descent1 ,lamarck1 clearly recognized in #ahji that it was of universal application2 that even man himself1 the most highly developed of the mammals1 is derived from the same stem as all the other mammals2 and that this in its turn belongs to the same older branch of the ancestral tree as the rest of the vertebrates4 ,he had even indicated the agencies by which it might be possible to explain man's descent from the apes as the nearest related mammals4 ,darwin1 who was1 naturally1 of the same conviction1 purposely avoided this least acceptable consequence of his theory in his chief work in #ahei1 and put it forward for the first time in his ,descent of ,man in #ahga4 ,in the mean time 7#ahfc7 ,huxley had very ably discussed this most important consequence of evolution in his famous ,place of ,man in ,nature4 ,with the aid of comparative anatomy and ontogeny1 and the support of the facts of palontology1 ,huxley proved that the descent of man from the ape is a necessary consequence of ,darwinism1 and that no other scientific explanation of the origin of the human race is possible4 ,of the same opinion was ,karl ,gegenbaur1 the most distinguished representative of comparative anatomy1 who lifted his science to a higher level by a consistent and ingenious application of the theory of descent4 ,as a further consequence of the pithecoid theory 7the theory of the descent of man from the ape7 there now arose the difficult task of investigating1 not only the nearest related mammal ancestors of man in the ,tertiary epoch1 but also the long series of the older animal ancestors which had lived in earlier periods of the earth's history and been developed in the course of countless millions of years4 ,i had made a start with the hypothetical solution of this great historic problem in my ,general ,morphology2 a further development of it appeared in #ahgd in my ,anthropogeny 7first section1 ,origin of the ,individual2 second section1 ,origin of the ,race74 ,the fourth1 enlarged1 edition of this work 7#ahia7 contains that theory of the development of man which approaches nearest1 in my own opinion1 to the still remote truth1 in the light of our present knowledge of the documentary evidence4 ,i was especially preoccupied in its composition to use the three empirical documents--palontology1 ontogeny1 and morphology 7or comparative anatomy7--as evenly and harmoniously as possible4 ,it is true that my hypotheses were in many cases supplemented and corrected in detail by later phylogenetic research2 yet ,i am convinced that the ancestral tree of human origin which ,i have sketched therein is substantially correct4 ,for the historical succession of vertebrate fossils corresponds completely with the morphological evolutionary scale which is revealed to us by comparative anatomy and ontogeny4 ,after the ,silurian fishes come the dipnoi of the ,devonian period--the ,carboniferous amphibia1 the ,permian reptilia1 and the ,mesozoic mammals4 ,of these1 again1 the lowest forms1 the monotremes1 appear first in the ,triassic period1 the marsupials in the ,jurassic1 and then the oldest placentals in the ,cretaceous4 ,of the placentals1 in turn1 the first to appear in the oldest ,tertiary period 7the ,eocene7 are the lowest primates1 the prosimi1 which are followed by the simi in the ,miocene4 ,of the catarrhin1 the cynopitheci precede the anthropomorpha2 from one branch of the latter1 during the ,pliocene period1 arises the ape-man without speech 7the pithecanthropus alalus72 and from him descends1 finally1 speaking man4 ,the chain of our earlier invertebrate ancestors is much more difficult to investigate and much less safe than this tree of our vertebrate predecessors2 we have no fossilized relics of their soft1 boneless structures1 so palontology can give us no assistance in this case4 ,the evidence of comparative anatomy and ontogeny1 therefore1 becomes all the more important4 ,since the human embryo passes through the same chordula-stage as the germs of all other vertebrates1 since it evolves1 similarly1 out of two germinal layers of a gastrula1 we infer1 in virtue of the biogenetic law1 the early existence of corresponding ancestral forms--vermalia1 gastrada1 etc4 ,most important of all is the fact that the human embryo1 like that of all other animals1 arises originally from a single cell2 for this stem-cell 7cytula7--the impregnated egg cell--points indubitably to a corresponding unicellular ancestor1 a primitive1 ,laurentian protozoon4 ,for the purpose of our monistic philosophy1 however1 it is a matter of comparative indifference how the succession of our animal predecessors may be confirmed in detail4 ,sufficient for us1 as an incontestable historical fact1 is the important thesis that man descends immediately from the ape1 and secondarily from a long series of lower vertebrates4 ,i have laid stress on the logical proof of this pithecometra-thesis in the seventh book of the ,general ,morphology3 ,the thesis that man has been evolved from lower vertebrates1 and immediately from the simiae1 is a special inference which results with absolute necessity from the general inductive law of the theory of descent4 ,for the definitive proof and establishment of this fundamental pithecometra-thesis the palontological discoveries of the last thirty years are of the greatest importance2 in particular1 the astonishing discoveries of a number of extinct mammals of the ,tertiary period have enabled us to draw up clearly in its main outlines the evolutionary history of this most important class of animals1 from the lowest oviparous monotremes up to man4 ,the four chief groups of the placentals1 the heterogeneous legions of the carnassia1 the rodentia1 the ungulata1 and the primates1 seem to be separated by profound gulfs1 when we confine our attention to their representatives of to-day4 ,but these gulfs are completely bridged1 and the sharp distinctions of the four legions are entirely lost1 when we compare their extinct predecessors of the ,tertiary period1 and when we go back into the ,eocene twilight of history1 in the oldest part of the ,tertiary period--at least three million years ago4 ,there we find the great sub-class of the placentals1 which to-day comprises more than two thousand five hundred species1 represented by only a small number of little1 insignificant proplacentals2 and in these prochoriata the characters of the four divergent legions are so intermingled and toned down that we cannot in reason do other than consider them as the precursors of those features4 ,the oldest carnassia 7the ictopsales71 the oldest rodentia 7the esthonychales71 the oldest ungulata 7the condylarthrales7 and the oldest primates 7the lemuravales71 all have the same fundamental skeletal structure1 and the same typical dentition of the primitive placentals1 consisting of forty-four teeth 7three incisors1 one canine1 four premolars1 and three molars in each half of the jaw72 all are characterized by the small size and the imperfect structure of the brain 7especially of its chief part1 the cortex1 which does not become a true organ of thought until later on in the ,miocene and ,pliocene representatives72 they have all short legs and five-toed1 flat-soled feet 7plantigrada74 ,in many cases among these oldest placentals of the ,eocene period it was very difficult to say at first whether they should be classed with the carnassia1 rodentia1 ungulata1 or primates2 so very closely1 even to confusion1 do these four groups of the placentals1 which diverge so widely afterwards1 approach each other at that time4 ,their common origin from a single ancestral group follows incontestably4 ,these prochoriata lived in the preceding ,cretaceous period 7more than three million years ago71 and were probably developed in the ,jurassic period from a group of insectivorous marsupials 7amphitheria7 by the formation of a primitive placenta diffusa1 a placenta of the simplest type4 ,but the most important of all the recent palaeontological discoveries which have served to elucidate the origin of the placentals relate to our own stem1 the legion of primates4 ,formerly fossil remains of the primates were very scarce4 ,even ,cuvier1 the great founder of palaeontology1 maintained until his last day 7#ahcb7 that there were no fossilized primates2 he had himself1 it is true1 described the skull of an ,eocene prosimi 7adapis71 but he had wrongly classed it with the ungulata4 ,however1 during the last twenty years a fair number of well-preserved fossilized skeletons of prosimi and simi have been discovered2 in them we find all the chief intermediate members which complete the connecting chain of ancestors from the oldest prosimi to man4 ,the most famous and most interesting of these discoveries is the fossil ape-man of ,java1 the much-talked-of pithecanthropus erectus1 found by a ,dutch military doctor1 ,eugen ,dubois1 in #ahid4 ,it is in truth the much-sought missing link1 supposed to be wanting in the chain of primates1 which stretches unbroken from the lowest catarrhin to the highest-developed man4 ,i have dealt exhaustively with the significance of this discovery in the paper which ,i read on ,august #bf1 #ahih1 at the ,fourth ,international ,zoological ,congress at ,cambridge4#ac ,the palontologist1 who knows the conditions of the formation and preservation of fossils1 will think the discovery of the pithecanthropus an unusually lucky accident4 ,the apes1 being arboreal1 seldom came into the circumstances 7unless they happened to fall into the water7 which would secure the preservation and petrifaction of their skeleton4 ,thus1 by the discovery of this fossil man-monkey of ,java the descent of man from the ape has become just as clear and certain from the palontological side as it was previously from the evidence of comparative anatomy and ontogeny4 ,we now have all the principal documents which tell the history of our race4 ,,chapter ,,vi ,,the ,,nature ,,of ,,the ,,soul ,fundamental ,importance of ,psychology--,its ,definition and ,methods--,divergence of ,views ,thereon--,dualistic and ,monistic ,psychology--,relation to the ,law of ,substance--,confusion of ,ideas--,psychological ,metamorphoses3 ,kant1 ,virchow1 ,du ,bois-,reymond--,methods of ,research of ,psychic ,science--,introspective ,method 7,self-,observation7--,exact ,method 7,psycho-,physics7--,comparative ,method 7,animal ,psychology7--,psychological ,change of ,principles3 ,wundt--,folk-,psychology and ,ethnography3 ,bastian--,ontogenetic ,psychology3 ,preyer--,phylogenetic ,psychology3 ,darwin1 ,romanes ,the phenomena which are comprised under the title of the life of the soul1 or the psychic activity1 are1 on the one hand1 the most important and interesting1 on the other the most intricate and problematical1 of all the phenomena we are acquainted with4 ,as the knowledge of nature1 the object of the present philosophic study1 is itself a part of the life of the soul1 and as anthropology1 and even cosmology1 presuppose a correct knowledge of the psyche1 we may regard psychology1 the scientific study of the soul1 both as the foundation and the postulate of all other sciences4 ,from another point of view it is itself a part of philosophy1 or physiology1 or anthropology4 ,the great difficulty of establishing it on a naturalistic basis arises from the fact that psychology1 in turn1 presupposes a correct acquaintance with the human organism1 especially the brain1 the chief organ of psychic activity4 ,the great majority of psychologists have little or no acquaintance with these anatomical foundations of the soul1 and thus it happens that in no other science do we find such contradictions and untenable notions as to its proper meaning and its essential object as are current in psychology4 ,this confusion has become more and more palpable during the last thirty years1 in proportion as the immense progress of anatomy and physiology has increased our knowledge of the structure and the functions of the chief psychic organ4 ,what we call the soul is1 in my opinion1 a natural phenomenon2 ,i therefore consider psychology to be a branch of natural science--a section of physiology4 ,consequently1 ,i must emphatically assert from the commencement that we have no different methods of research for that science than for any of the others2 we have in the first place observation and experiment1 in the second place the theory of evolution1 and in the third place metaphysical speculation1 which seek to penetrate as far as possible into the cryptic nature of the phenomena by inductive and deductive reasoning4 ,however1 with a view to a thorough appreciation of the question1 we must first of all put clearly before the reader the antithesis of the dualistic and the monistic theories4 ,the prevailing conception of the psychic activity1 which we contest1 considers soul and body to be two distinct entities4 ,these two entities can exist independently of each other2 there is no intrinsic necessity for their union4 ,the organized body is a mortal1 material nature1 chemically composed of living protoplasm and its compounds 7plasma-products74 ,the soul1 on the other hand1 is an immortal1 immaterial being1 a spiritual agent1 whose mysterious activity is entirely incomprehensible to us4 ,this trivial conception is1 as such1 spiritualistic1 and its contradictory is1 in a certain sense1 materialistic4 ,it is1 at the same time1 supernatural and transcendental1 since it affirms the existence of forces which can exist and operate without a material basis2 it rests on the assumption that outside of and beyond nature there is a spiritual1 immaterial world1 of which we have no experience1 and of which we can learn nothing by natural means4 ,this hypothetical spirit world1 which is supposed to be entirely independent of the material universe1 and on the assumption of which the whole artificial structure of the dualistic system is based1 is purely a product of poetic imagination2 the same must be said of the parallel belief in the immortality of the soul1 the scientific impossibility of which we must prove more fully later on 7chap4 xi474 ,if the beliefs which prevail in these credulous circles had a sound foundation1 the phenomena they relate to could not be subject to the law of substance2 moreover1 this single exception to the highest law of the cosmos must have appeared very late in the history of the organic world1 since it only concerns the soul of man and of the higher animals4 ,the dogma of free will1 another essential element of the dualistic psychology1 is similarly irreconcilable with the universal law of substance4 ,our own naturalistic conception of the psychic activity sees in it a group of vital phenomena1 which are dependent on a definite material substratum1 like all other phenomena4 ,we shall give to this material basis of all psychic activity1 without which it is inconceivable1 the provisional name of psychoplasm2 and for this good reason--that chemical analysis proves it to be a body of the group we call protoplasmic bodies the albuminoid carbon-combinations which are at the root of all vital processes4 ,in the higher animals1 which have a nervous system and sense-organs1 neuroplasm1 the nerve-material1 has been differentiated out of psychoplasm4 ,our conception is1 in this sense1 materialistic4 ,it is at the same time empirical and naturalistic1 for our scientific experience has never yet taught us the existence of forces that can dispense with a material substratum1 or of a spiritual world over and above the realm of nature4 ,like all other natural phenomena1 the psychic processes are subject to the supreme1 all-ruling law of substance2 not even in this province is there a single exception to this highest cosmological law 7compare chap4 xii474 ,the phenomena of the lowly psychic life of the unicellular protist and the plant1 and of the lowest animal forms--their irritability1 their reflex movements1 their sensitiveness and instinct of self-preservation--are directly determined by physiological action in the protoplasm of their cells--that is1 by physical and chemical changes which are partly due to heredity and partly to adaptation4 ,and we must say just the same of the higher psychic activity of the higher animals and man1 of the formation of ideas and concepts1 of the marvellous phenomena of reason and consciousness2 for the latter have been phylogenetically evolved from the former1 and it is merely a higher degree of integration or centralization1 of association or combination of functions which were formerly isolated1 that has elevated them in this manner4 ,the first task of every science is the clear definition of the object it has to investigate4 ,in no science1 however1 is this preliminary task so difficult as in psychology2 and this circumstance is the more remarkable since logic1 the science of defining1 is itself a part of psychology4 ,when we compare all that has been said by the most distinguished philosophers and scientists of all ages on the fundamental idea of psychology1 we find ourselves in a perfect chaos of contradictory notions4 ,what1 really1 is the soul8 ,what is its relation to the mind8 ,what is the inner meaning of consciousness8 ,what is the difference between sensation and sentiment8 ,what is instinct8 ,what is the meaning of free will8 ,what is presentation8 ,what is the difference between intellect and reason8 ,what is the true nature of emotion8 ,what is the relation between all these psychic phenomena and the body8 ,the answers to these and many other cognate questions are infinitely varied2 not only are the views of the most eminent thinkers on these questions widely divergent1 but even the same scientific authority has often completely changed his views in the course of his psychological development4 ,indeed1 this psychological metamorphosis of so many thinkers has contributed not a little to the colossal confusion of ideas which prevails in psychology more than in any other branch of knowledge4 ,the most interesting example of such an entire change of objective and subjective psychological opinions is found in the case of the most influential leader of ,german philosophy1 ,immanuel ,kant4 ,the young1 severely critical ,kant came to the conclusion that the three great buttresses of mysticism--,god1 freedom1 and immortality--were untenable in the light of pure reason2 the older1 dogmatic ,kant found that these three great hallucinations were postulates of practical reason1 and were1 as such1 indispensable4 ,the more the distinguished modern school of ,neokantians urges a return to ,kant as the only possible salvation from the frightful jumble of modern metaphysics1 the more clearly do we perceive the undeniable and fatal contradiction between the fundamental opinions of the young and the older ,kant4 ,we shall return to this point later on4 ,other interesting examples of this change of views are found in two of the most famous living scientists1 ,r4 ,virchow and ,e4 du ,bois-,reymond2 the metamorphoses of their fundamental views on psychology cannot be overlooked1 as both these ,berlin biologists have played a most important part at ,germany's greatest university for more than forty years1 and have1 therefore1 directly and indirectly1 had a most profound influence on the modern mind4 ,rudolph ,virchow1 the eminent founder of cellular pathology1 was a pure monist in the best days of his scientific activity1 about the middle of the century2 he passed at that time as one of the most distinguished representatives of the newly awakened materialism1 which appeared in #ahee1 especially through two famous works1 almost contemporaneous in appearance--,ludwig ,bchner's ,matter and ,force and ,carl ,vogt's ,superstition and ,science4 ,virchow published his general biological views on the vital processes in man--which he takes to be purely mechanical natural phenomena--in a series of distinguished papers in the first volumes of the ,archiv fr pathologische ,anatomie1 which he founded4 ,the most important of these articles1 and the one in which he most clearly expresses his monistic views of that period1 is that on ,the ,tendencies ,towards ,unity in ,scientific ,medicine 7#ahdi74 ,it was certainly not without careful thought1 and a conviction of its philosophic value1 that ,virchow put this medical confession of faith at the head of his ,collected ,essays on ,scientific ,medicine in #ahef4 ,he defended in it1 clearly and definitely1 the fundamental principles of monism1 which ,i am presenting here with a view to the solution of the world-problem2 he vindicated the exclusive title of empirical science1 of which the only reliable sources are sense and brain activity2 he vigorously attacked anthropological dualism1 the alleged revelation1 and the transcendental philosophy1 with their two methods--faith and anthropomorphism4 ,above all1 he emphasized the monistic character of anthropology1 the inseparable connection of spirit and body1 of force and matter4 ,i am convinced1 he exclaims1 at the end of his preface1 that ,i shall never find myself compelled to deny the thesis of the unity of human nature4 ,unhappily1 this conviction proved to be a grave error4 ,twenty-eight years afterwards ,virchow represented the diametrically opposite view2 it is to be found in the famous speech on ,the ,liberty of ,science in ,modern ,states1 which he delivered at the ,scientific ,congress at ,munich in #ahgg1 and which contains attacks that ,i have repelled in my ,free ,science and ,free ,teaching 7#ahgh74 ,in ,emil du ,bois-,reymond we find similar contradictions with regard to the most important and fundamental theses of philosophy4 ,the more completely the distinguished orator of the ,berlin ,academy had defended the main principles of the monistic philosophy1 the more he had contributed to the refutation of vitalism and the transcendental view of life1 so much the louder was the triumphant cry of our opponents when in #ahgb1 in his famous ,ignorabimus-,speech1 he spoke of consciousness as an insoluble problem1 and opposed it to the other functions of the brain as a supernatural phenomenon4 ,i return to the point in the tenth chapter4 ,the peculiar character of many of the psychic phenomena1 especially of consciousness1 necessitates certain modifications of our ordinary scientific methods4 ,we have1 for instance1 to associate with the customary objective1 external observation1 the introspective method1 the subjective1 internal observation which scrutinizes our own personality in the mirror of consciousness4 ,the majority of psychologists have started from this certainty of the ego3 ,cogito ergo sum1 as ,descartes said--,i think1 therefore ,i am4 ,let us first cast a glance at this way of inquiry1 and then deal with the second1 complementary1 method4 ,by far the greater part of the theories of the soul which have been put forward during the last two thousand years or more are based on introspective inquiry--that is1 on self-observation1 and on the conclusions which we draw from the association and criticism of these subjective experiences4 ,introspection is the only possible method of inquiry for an important section of psychology1 especially for the study of consciousness4 ,hence this cerebral function occupies a special position1 and has been a more prolific source of philosophic error than any of the others 7cf4 chap4 x474 ,it is1 however1 most unsatisfactory1 and it leads to entirely false or incomplete notions1 to take this self-observation of the mind to be the chief1 or1 especially1 to be the only source of mental science1 as has happened in the case of many and distinguished philosophers4 ,a great number of the principal psychic phenomena1 particularly the activity of the senses and speech1 can only be studied in the same way as every other vital function of the organism--that is1 firstly1 by a thorough anatomical study of their organs1 and1 secondly1 by an exact physiological analysis of the functions which depend on them4 ,in order1 however1 to complete this external study of the mental life1 and to supplement the results of internal observation1 one needs a thorough knowledge of human anatomy1 histology1 ontogeny1 and physiology4 ,most of our so-called psychologists have little or no knowledge of these indispensable foundations of anthropology2 they are1 therefore1 incompetent to pronounce on the character even of their own soul4 ,it must be remembered1 too1 that the distinguished personality of one of these psychologists usually offers a specimen of an educated mind of the highest civilized races2 it is the last link of a long ancestral chain1 and the innumerable older and inferior links are indispensable for its proper understanding4 ,hence it is that most of the psychological literature of the day is so much waste paper4 ,the introspective method is certainly extremely valuable and indispensable2 still it needs the constant co-operation and assistance of the other methods4 ,in proportion as the various branches of the human tree of knowledge have developed during the century1 and the methods of the different sciences have been perfected1 the desire has grown to make them exact2 that is1 to make the study of phenomena as purely empirical as possible1 and to formulate the laws that result as clearly as the circumstances permit--if possible1 mathematically4 ,the latter is1 however1 only feasible in a small province of human knowledge1 especially in those sciences in which there is question of measurable quantities2 in mathematics1 in the first place1 and to a greater or less extent in astronomy1 mechanics1 and a great part of physics and chemistry4 ,hence these studies are called exact sciences in the narrower sense4 ,it is1 however1 productive only of error to call all the physical sciences exact1 and oppose them to the historical1 mental1 and moral sciences4 ,the greater part of physical science can no more be treated as an exact science than history can2 this is especially true of biology and of its subsidiary branch1 psychology4 ,as psychology is a part of physiology1 it must1 as a general rule1 follow the chief methods of that science4 ,it must establish the facts of psychic activity by empirical methods as much as possible1 by observation and experiment1 and it must then gather the laws of the mind by inductive and deductive inferences from its observations1 and formulate them with the utmost distinctness4 ,but1 for obvious reasons1 it is rarely possible to formulate them mathematically4 ,such a procedure is only profitable in one section of the physiology of the senses2 it is not practicable in the greater part of cerebral physiology4 ,one small section of physiology1 which seems amenable to the exact method of investigation1 has been carefully studied for the last twenty years and raised to the position of a separate science under the title of psycho-physics4 ,its founders1 the physiologists ,theodor ,fechner and ,ernst ,heinrich ,weber1 first of all closely investigated the dependence of sensations on the external stimuli that act on the organs of sense1 and particularly the quantitative relation between the strength of the stimulus and the intensity of the sensation4 ,they found that a certain minimum strength of stimulus is requisite for the excitement of a sensation1 and that a given stimulus must be varied to a definite amount before there is any perceptible change in the sensation4 ,for the highest sensations 7of sight1 hearing1 and pressure7 the law holds good that their variations are proportionate to the changes in the strength of the stimulus4 ,from this empirical law of ,weber ,fechner inferred1 by mathematical operations1 his fundamental law of psycho-physics1 according to which the intensity of a sensation increases in arithmetical progression1 the strength of the stimulus in geometrical progression4 ,however1 ,fechner's law and other psycho-physical laws are frequently contested1 and their exactness is called into question4 ,in any case modern psycho-physics has fallen far short of the great hopes with which it was greeted twenty years ago2 the field of its applicability is extremely limited4 ,one important result of its work is that it has proved the application of physical laws in one1 if only a small1 branch of the life of the soul--an application which was long ago postulated on principle by the materialist psychology for the whole province of mental life4 ,in this1 as in many other branches of physiology1 the exact method has proved inadequate and of little service4 ,it is the ideal to aim at everywhere1 but it is unattainable in most cases4 ,much more profitable are the comparative and genetic methods4 ,the striking resemblance of man's psychic activity to that of the higher animals--especially our nearest relatives among the mammals--is a familiar fact4 ,most uncivilized races still make no material distinction between the two sets of mental processes1 as the well-known animal fables1 the old legends1 and the idea of the transmigration of souls prove4 ,even most of the philosophers of classical antiquity shared the same conviction1 and discovered no essential qualitative difference1 but merely a quantitative one1 between the soul of man and that of the brute4 ,plato himself1 who was the first to draw a fundamental distinction between soul and body1 made one and the same soul 7or idea7 pass through a number of animal and human bodies in his theory of metempsychosis4 ,it was ,christianity1 intimately connecting faith in immortality with faith in ,god1 that emphasized the essential difference of the immortal soul of man from the mortal soul of the brute4 ,in the dualistic philosophy the idea prevailed principally through the influence of ,descartes 7#afdc72 he contended that man alone had a true soul1 and1 consequently1 sensation and free will1 and that the animals were mere automata1 or machines1 without will or sensibility4 ,ever since the majority of psychologists--including even ,kant--have entirely neglected the mental life of the brute1 and restricted psychological research to man3 human psychology1 mainly introspective1 dispensed with the fruitful comparative method1 and so remained at that lower point of view which human morphology took before ,cuvier raised it to the position of a philosophic science by the foundation of comparative anatomy4 ,scientific interest in the psychic activity of the brute was revived in the second half of the last century1 in connection with the advance of systematic zoology and physiology4 ,a strong impulse was given to it by the work of ,reimarus3 ,general observations on the instincts of animals 7,hamburg1 #agfj74 ,at the same time a deeper scientific investigation had been facilitated by the thorough reform of physiology by ,johannes ,mller4 ,this distinguished biologist1 having a comprehensive knowledge of the whole field of organic nature1 of morphology1 and of physiology1 introduced the exact methods of observation and experiment into the whole province of physiology1 and1 with consummate skill1 combined them with the comparative methods4 ,he applied them1 not only to mental life in the broader sense 7to speech1 senses1 and brain-action71 but to all the other phenomena of life4 ,the sixth book of his ,manual of ,human ,physiology treats specially of the life of the soul1 and contains eighty pages of important psychological observations4 ,during the last forty years a great number of works on comparative animal psychology have appeared1 principally occasioned by the great impulse which ,darwin gave in #ahei by his work on ,the ,origin of ,species1 and by the application of the idea of evolution to the province of psychology4 ,the more important of these works we owe to ,romanes and ,sir ,j4 ,lubbock1 in ,england2 to ,w4 ,wundt1 ,l4 ,bchner1 ,g4 ,schneider1 ,fritz ,schultze1 and ,karl ,groos1 in ,germany2 to ,alfred ,espinas and ,e4 ,jourdan1 in ,france2 and to ,tito ,vignoli1 in ,italy4 ,in ,germany1 ,wilhelm ,wundt1 of ,leipzig1 is considered to be the ablest living psychologist2 he has the inestimable advantage over most other philosophers of a thorough zoological1 anatomical1 and physiological education4 ,formerly assistant and pupil of ,helmholtz1 ,wundt had early accustomed himself to follow the application of the laws of physics and chemistry through the whole field of physiology1 and1 consequently1 in the sense of ,johannes ,mller1 in psychology1 as a subsection of the latter4 ,starting from this point of view1 ,wundt published his valuable ,lectures on human and animal psychology in #ahfc4 ,he proved1 as he himself tells us in the preface1 that the theatre of the most important psychic processes is in the unconscious soul1 and he affords us a view of the mechanism which1 in the unconscious background of the soul1 manipulates the impressions which arise from the external stimuli4 ,what seems to me1 however1 of special importance and value in ,wundt's work is that he extends the law of the persistence of force for the first time to the psychic world1 and makes use of a series of facts of electro-physiology by way of demonstration4 ,thirty years afterwards 7#ahib7 ,wundt published a second1 much abridged and entirely modified1 edition of his work4 ,the important principles of the first edition are entirely abandoned in the second1 and the monistic is exchanged for a purely dualistic stand-point4 ,wundt himself says in the preface to the second edition that he has emancipated himself from the fundamental errors of the first1 and that he learned many years ago to consider the work a sin of his youth2 it weighed on him as a kind of crime1 from which he longed to free himself as soon as possible4 ,in fact1 the most important systems of psychology are completely opposed to each other in the two editions of ,wundt's famous ,observations4 ,in the first edition he is purely monistic and materialistic1 in the second edition purely dualistic and spiritualistic4 ,in the one psychology is treated as a physical science1 on the same laws as the whole of physiology1 of which it is only a part2 thirty years afterwards he finds psychology to be a spiritual science1 with principles and objects entirely different from those of physical science4 ,this conversion is most clearly expressed in his principle of psycho-physical parallelism1 according to which every psychic event has a corresponding physical change2 but the two are completely independent1 and are not in any natural causal connection4 ,this complete dualism of body and soul1 of nature and mind1 naturally gave the liveliest satisfaction to the prevailing school-philosophy1 and was acclaimed by it as an important advance1 especially seeing that it came from a distinguished scientist who had previously adhered to the opposite system of monism4 ,as ,i myself continue1 after more than forty years' study1 in this narrow position1 and have not been able to free myself from it in spite of all my efforts1 ,i must naturally consider the youthful sin of the young physiologist ,wundt to be a correct knowledge of nature1 and energetically defend it against the antagonistic view of the old philosopher ,wundt4 ,this entire change of philosophical principles1 which we find in ,wundt1 as we found it in ,kant1 ,virchow1 ,du ,bois-,reymond1 ,karl ,ernst ,baer1 and others1 is very interesting4 ,in their youth these able and talented scientists embrace the whole field of biological research in a broad survey1 and make strenuous efforts to find a unifying1 natural basis for their knowledge2 in their later years they have found that this is not completely attainable1 and so they entirely abandon the idea4 ,in extenuation of these psychological metamorphoses they can1 naturally1 plead that in their youth they overlooked the difficulties of the great task1 and misconceived the true goal2 with the maturer judgment of age and the accumulation of experience they were convinced of their errors1 and discovered the true path to the source of truth4 ,on the other hand1 it is possible to think that great scientists approach their task with less prejudice and more energy in their earlier years--that their vision is clearer and their judgment purer2 the experiences of later years sometimes have the effect1 not of enriching1 but of disturbing1 the mind1 and with old age there comes a gradual decay of the brain1 just as happens in all other organs4 ,in any case1 this change of views is in itself an instructive psychological fact2 because1 like many other forms of change of opinion1 it shows that the highest psychic functions are subject to profound individual changes in the course of life1 like all the other vital processes4 ,for the profitable construction of comparative psychology it is extremely important not to confine the critical comparison to man and the brute in general1 but to put side by side the innumerable gradations of their mental activity4 ,only thus can we attain a clear knowledge of the long scale of psychic development which runs unbroken from the lowest1 unicellular forms of life up to the mammals1 and to man at their head4 ,but even within the limits of our own race such gradations are very noticeable1 and the ramifications of the psychic ancestral tree are very numerous4 ,the psychic difference between the crudest savage of the lowest grade and the most perfect specimen of the highest civilization is colossal--much greater than is commonly supposed4 ,by the due appreciation of this fact1 especially in the latter half of the century1 the ,anthropology of the uncivilized races 7,waitz7 has received a strong support1 and comparative ethnography has come to be considered extremely important for psychological purposes4 ,unfortunately1 the enormous quantity of raw material of this science has not yet been treated in a satisfactory critical manner4 ,what confused and mystic ideas still prevail in this department may be seen1 for instance1 in the ,vlkergedanke of the famous traveller1 ,adolf ,bastian1 who1 though a prolific writer1 merely turns out a hopeless mass of uncritical compilation and confused speculation4 ,the most neglected of all psychological methods1 even up to the present day1 is the evolution of the soul2 yet this little-frequented path is precisely the one that leads us most quickly and securely through the gloomy primeval forest of psychological prejudices1 dogmas1 and errors1 to a clear insight into many of the chief psychic problems4 ,as ,i did in the other branch of organic evolution1 ,i again put before the reader the two great branches of the science which ,i differentiated in #ahff--ontogeny and phylogeny4 ,the ontogeny1 or embryonic development1 of the soul1 individual or biontic psychogeny1 investigates the gradual and hierarchic development of the soul in the individual1 and seeks to learn the laws by which it is controlled4 ,for a great part of the life of the mind a good deal has been done in this direction for centuries2 rational pedagogy must have set itself the task at an early date of the theoretical study of the gradual development and formative capacity of the young mind that was committed to it for education and formation4 ,most pedagogues1 however1 were idealistic or dualistic philosophers1 and so they went to work with all the prejudices of the spiritualistic psychology4 ,it is only in the last few decades that this dogmatic tendency has been largely superseded even in the school by scientific methods2 we now find a greater concern to apply the chief laws of evolution even in the discussion of the soul of the child4 ,the raw material of the child's soul is already qualitatively determined by heredity from parents and ancestors2 education has the noble task of bringing it to a perfect maturity by intellectual instruction and moral training--that is1 by adaptation4 ,wilhelm ,preyer was the first to lay the foundation of our knowledge of the early psychic development in his interesting work on ,the ,mind of the ,child4 ,much is still to be done in the study of the later stages and metamorphoses of the individual soul1 and once more the correct1 critical application of the biogenetic law is proving a guiding star to the scientific mind4 ,a new and fertile epoch of higher development dawned for psychology and all other biological sciences when ,charles ,darwin applied the principles of evolution to them forty years ago4 ,the seventh chapter of his epoch-making work on ,the ,origin of ,species is devoted to instinct4 ,it contains the valuable proof that the instincts of animals are subject1 like all other vital processes1 to the general laws of historic development4 ,the special instincts of particular species were formed by adaptation1 and the modifications thus acquired were handed on to posterity by heredity2 in their formation and preservation natural selection plays the same part as in the transformation of every other physiological function4 ,darwin afterwards developed this fundamental thought in a number of works1 showing that the same laws of mental evolution hold good throughout the entire organic world1 not less in man than in the brute1 and even in the plant4 ,hence the unity of the organic world1 which is revealed by the common origin of its members1 applies also to the entire province of psychic life1 from the simplest unicellular organism up to man4 ,to ,george ,romanes we owe the further development of ,darwin's psychology and its special application to the different sections of psychic activity4 ,unfortunately1 his premature decease prevented the completion of the great work which was to reconstruct every section of comparative psychology on the lines of monistic evolution4 ,the two volumes of this work which were completed are among the most valuable productions of psychological literature4 ,for1 conformably to the principles of our modern monistic research1 his first care was to collect and arrange all the important facts which have been empirically established in the field of comparative psychology in the course of centuries2 in the second place1 these facts are tested with an objective criticism1 and systematically distributed2 finally1 such rational conclusions are drawn from them on the chief general questions of psychology as are in harmony with the fundamental principles of modern monism4 ,the first volume of ,romanes's work bears the title of ,mental ,evolution in the ,animal ,world2 it presents1 in natural connection1 the entire length of the chain of psychic evolution in the animal world1 from the simplest sensations and instincts of the lowest animals to the elaborate phenomena of consciousness and reason in the highest4 ,it contains also a number of extracts from a manuscript which ,darwin left on instinct1 and a complete collection of all that he wrote in the province of psychology4 ,the second and more important volume of ,romanes's work treats of ,mental evolution in man and the origin of human faculties4 ,the distinguished psychologist gives a convincing proof in it that the psychological barrier between man and the brute has been overcome4 ,man's power of conceptual thought and of abstraction has been gradually evolved from the non-conceptual stages of thought and ideation in the nearest related mammals4 ,man's highest mental powers--reason1 speech1 and conscience--have arisen from the lower stages of the same faculties in our primate ancestors 7the simi and prosimi74 ,man has no single mental faculty which is his exclusive prerogative4 ,his whole psychic life differs from that of the nearest related mammals only in degree1 and not in kind2 quantitatively1 not qualitatively4 ,i recommend those of my readers who are interested in these momentous questions of psychology to study the profound work of ,romanes4 ,i am completely at one with him and ,darwin in almost all their views and convictions4 ,wherever an apparent discrepancy is found between these authors and my earlier productions1 it is either a case of imperfect expression on my part or an unimportant difference in application of principle4 ,for the rest1 it is characteristic of this science of ideas that the most eminent philosophers hold entirely antagonistic views on its fundamental notions4 ,,chapter ,,vii ,,psychic ,,gradations ,psychological ,unity of ,organic ,nature--,material ,basis of the ,soul3 ,psychoplasm--,scale of ,sensation--,scale of ,movement--,scale of ,reflex ,action--,simple and ,compound ,reflex ,action--,reflex ,action and ,consciousness--,scale of ,perception--,unconscious and ,conscious ,perception--,scale of ,memory--,unconscious and ,conscious ,memory--,association of ,perceptions--,instinct--,primary and ,secondary ,instincts--,scale of ,reason--,language--,emotion and ,passion--,the ,will--,freedom of the ,will ,the great progress which psychology has made1 with the assistance of evolution1 in the latter half of the century culminates in the recognition of the psychological unity of the organic world4 ,comparative psychology1 in co-operation with the ontogeny and phylogeny of the psyche1 has enforced the conviction that organic life in all its stages1 from the simplest unicellular protozoon up to man1 springs from the same elementary forces of nature1 from the physiological functions of sensation and movement4 ,the future task of scientific psychology1 therefore1 is not1 as it once was1 the exclusively subjective and introspective analysis of the highly developed mind of a philosopher1 but the objective1 comparative study of the long gradation by which man has slowly arisen through a vast series of lower animal conditions4 ,this great task of separating the different steps in the psychological ladder1 and proving their unbroken phylogenetic connection1 has only been seriously attempted during the last ten years1 especially in the splendid work of ,romanes4 ,we must confine ourselves here to a brief discussion of a few of the general questions which that gradation has suggested4 ,all the phenomena of the psychic life are1 without exception1 bound up with certain material changes in the living substance of the body1 the protoplasm4 ,we have given to that part of the protoplasm which seems to be the indispensable substratum of psychic life the name of psychoplasm 7the soul-substance1 in the monistic sense72 in other words1 we do not attribute any peculiar essence to it1 but we consider the psyche to be merely a collective idea of all the psychic functions of protoplasm4 ,in this sense the soul is merely a physiological abstraction like assimilation or generation4 ,in man and the higher animals1 in accordance with the division of labor of the organs and tissues1 the psychoplasm is a differentiated part of the nervous system1 the neuroplasm of the ganglionic cells and their fibres4 ,in the lower animals1 however1 which have no special nerves and organs of sense1 and in the plants1 the psychoplasm has not yet reached an independent differentiation4 ,finally1 in the unicellular protists1 the psychoplasm is identified either with the whole of the living protoplasm of the simple cell or with a portion of it4 ,in all cases1 in the lowest as well as the highest stages of the psychological hierarchy1 a certain chemical composition and a certain physical activity of the psychoplasm are indispensable before the soul can function or act4 ,that is equally true of the elementary psychic function of the plasmatic sensation and movement of the protozoa1 and of the complex functions of the sense-organs and the brain in the higher animals and man4 ,the activity of the psychoplasm1 which we call the soul1 is always connected with metabolism4 ,all living organisms1 without exception1 are sensitive2 they are influenced by the condition of their environment1 and react thereon by certain modifications in their own structure4 ,light and heat1 gravity and electricity1 mechanical processes and chemical action in the environment1 act as stimuli on the sensitive psychoplasm1 and effect changes in its molecular composition4 ,we may distinguish the following five chief stages of this sensibility3 ,i4 ,at the lowest stage of organization the whole psychoplasm1 as such1 is sensitive1 and reacts on the stimuli from without2 that is the case with the lowest protists1 with many plants1 and with some of the most rudimentary animals4 ,,ii4 ,at the second stage very simple and undiscriminating sense-organs begin to appear on the surface of the organism1 in the form of protoplasmic filaments and pigment spots1 the forerunners of the nerves of touch and the eyes2 these are found in some of the higher protists and in many of the lower animals and plants4 ,,iii4 ,at the third stage specific organs of sense1 each with a peculiar adaptation1 have arisen by differentiation out of these rudimentary processes3 there are the chemical instruments of smell and taste1 and the physical organs of touch1 temperature1 hearing1 and sight4 ,the specific energy of these sense-organs is not an original inherent property of theirs1 but has been gained by functional adaptation and progressive heredity4 ,,iv4 ,the fourth stage is characterized by the centralization or integration of the nervous system1 and1 consequently1 of sensation2 by the association of the previously isolated or localized sensations presentations arise1 though they still remain unconscious4 ,that is the condition of many both of the lower and the higher animals4 ,v4 ,finally1 at the fifth stage1 the highest psychic function1 conscious perception1 is developed by the mirroring of the sensations in a central part of the nervous system1 as we find in man and the higher vertebrates1 and probably in some of the higher invertebrates1 notably the articulata4 ,all living organisms without exception have the faculty of spontaneous movement1 in contradistinction to the rigidity and inertia of unorganized substances 7e4g41 crystals72 in other words1 certain changes of place of the particles occur in the living psychoplasm from internal causes1 which have their source in its own chemical composition4 ,these active vital movements are partly discovered by direct observation and partly only known indirectly1 by inference from their effects4 ,we may distinguish five stages of them4 ,i4 ,at the lowest stage of organic life1 in the chromacea1 and many protophyta and lower metaphyta1 we perceive only those movements of growth which are common to all organisms4 ,they are usually so slow that they cannot be directly observed2 they have to be inferred from their results--from the change in size and form of the growing organism4 ,,ii4 ,many protists1 particularly unicellular alg of the groups of diatomacea and desmidiacea1 accomplish a kind of creeping or swimming motion by secretion1 by ejecting a slimy substance at one side4 ,,iii4 ,other organisms which float in water--for instance1 many of the radiolaria1 siphonophora1 ktenophora1 and others--ascend and descend by altering their specific gravity1 sometimes by osmosis1 sometimes by the separation or squeezing-out of air4 ,,iv4 ,many plants1 especially the sensitive plants 7mimosa7 and other papilionacea1 effect movements of their leaves or other organs by change of pressure--that is1 they alter the strain of the protoplasm1 and1 consequently1 its pressure on the enclosing elastic walls of the cells4 ,v4 ,the most important of all organic movements are the phenomena of contraction--i4e41 changes of form at the surface of the organism1 which are dependent on a twofold displacement of their elements2 they always involve two different conditions or phases of motion--contraction and expansion4 ,four different forms of this plasmatic contraction may be enumerated3 7a7 ,amoeboid movement 7in rhizopods1 blood-cells1 pigment-cells1 etc474 7b7 ,a similar flow of protoplasm within enclosed cells4 7c7 ,vibratory motion 7ciliary movements7 in infusoria1 spermatozoa1 ciliated epithelial cells4 7d7 ,muscular movement 7in most animals74 ,the elementary psychic activity that arises from the combination of sensation and movement is called reflex 7in the widest sense71 reflective function1 or reflex action4 ,the movement--no matter what kind it is--seems in this case to be the immediate result of the stimulus which evoked the sensation2 it has1 on that account1 been called stimulated motion in its simplest form 7in the protists74 ,all living protoplasm has this feature of irritability4 ,any physical or chemical change in the environment may1 in certain circumstances1 act as a stimulus on the psychoplasm1 and elicit or release a movement4 ,we shall see later on how this important physical concept of releasing directly connects the simplest organic reflex actions with similar mechanical phenomena of movement in the inorganic world 7for instance1 in the explosion of powder by a spark1 or of dynamite by a blow74 ,we may distinguish the following seven stages in the scale of reflex action3 ,i4 ,at the lowest stage of organization1 in the lowest protists1 the stimuli of the outer world 7heat1 light1 electricity1 etc47 cause in the indifferent protoplasm only those indispensable movements of growth and nutrition which are common to all organisms1 and are absolutely necessary for their preservation4 ,that is also the case in most of the plants4 ,,ii4 ,in the case of many freely moving protists 7especially the amoeba1 the heliozoon1 and the rhizopod7 the stimuli from without produce on every spot of the unprotected surface of the unicellular organism external movements which take the form of changes of shape1 and sometimes changes of place 7amoeboid movement1 pseudopod formation1 the extension and withdrawal of what look like feet72 these indefinite1 variable processes of the protoplasm are not yet permanent organs4 ,in the same way1 general organic irritability takes the form of indeterminate reflex action in the sensitive plants and the lowest metazoa2 in many multicellular organisms the stimuli may be conducted from one cell to another1 as all the cells are connected by fine fibres4 ,,iii4 ,many protists1 especially the more highly developed protozoa1 produce on their unicellular body two little organs of the simplest character--an organ of touch and an organ of movement4 ,both these instruments are direct external projections of protoplasm2 the stimulus1 which alights on the first1 is immediately conducted to the other by the psychoplasm of the unicellular body1 and causes it to contract4 ,this phenomenon is particularly easy to observe1 and even produce experimentally1 in many of the stationary infusoria 7for instance1 the poteriodendron among the flagellata1 and the vorticella among the ciliata74 ,the faintest stimulus that touches the extremely sensitive hairs1 or cilia1 at the free end of the cells1 immediately causes a contraction of a thread-like stalk at the other1 fixed end4 ,this phenomenon is known as a simple reflex arch4 ,,iv4 ,these phenomena of the unicellular organism of the infusoria lead on to the interesting mechanism of the neuro-muscular cells1 which we find in the multicellular body of many of the lower metazoa1 especially in the cnidaria 7polyps and corals74 ,each single neuro-muscular cell is a unicellular reflex organ2 it has on its surface a sensitive spot1 and a motor muscular fibre inside at the opposite end2 the latter contracts as soon as the former is stimulated4 ,v4 ,in other cnidaria1 notably in the free swimming medus--which are closely related to the stationary polyps--the simple neuro-muscular cell becomes two different cells1 connected by a filament2 an external sense-cell 7in the outer skin7 and an internal muscular cell 7under the skin74 ,in this bicellular reflex organ the one cell is the rudimentary organ of sensation1 the other of movement2 the connecting bridge of the psychoplasmic filament conducts the stimulus from one to the other4 ,,vi4 ,the most important step in the gradual construction of the reflex mechanism is the division into three cells2 in the place of the simple connecting bridge we spoke of there appears a third independent cell1 the soul-cell1 or ganglionic cell2 with it appears also a new psychic function1 unconscious presentation1 which has its seat in this cell4 ,the stimulus is first conducted from the sensitive cell to this intermediate presentative or psychic cell1 and then issued from this to the motor muscular cell as a mandate of movement4 ,these tricellular reflex organs are preponderantly developed in the great majority of the invertebrates4 ,,vii4 ,instead of this arrangement we find in most of the vertebrates a quadricellular reflex organ1 two distinct soul-cells1 instead of one1 being inserted between the sensitive cell and the motor cell4 ,the external stimulus1 in this case1 is first conducted centripetally to the sensitive cell 7the sensible psychic cell71 from this to the will-cell 7the motor psychic cell71 and from this1 finally1 to the contractile muscular cell4 ,when many such reflex organs combine and new psychic cells are interposed we have the intricate reflex mechanism of man and the higher vertebrates4 ,the important distinction which we make1 in morphology and physiology1 between unicellular and multicellular organisms holds good for their elementary psychic activity1 reflex action4 ,in the unicellular protists 7both the plasmodomous primitive plants1 or protophyta1 and the plasmophagous primitive animals1 or protozoa7 the whole physical process of reflex action takes place in the protoplasm of one single cell2 their cell-soul seems to be a unifying function of the psychoplasm of which the various phases only begin to be seen separately when the differentiation of special organs sets in4 ,the second stage of psychic activity1 compound reflex action1 begins with the cenobitic protists 7v4g41 the volvox and the carchesium74 ,the innumerable social cells1 which make up this cell-community or coenobium1 are always more or less connected1 often directly connected by filamentous bridges of protoplasm4 ,a stimulus that alights on one or more cells of the community is communicated to the rest by means of the connecting fibres1 and may produce a general contraction4 ,this connection is found1 also1 in the tissues of the multicellular animals and plants4 ,it was erroneously believed at one time that the cells of vegetal tissue were completely isolated from each other1 but we have now discovered fine filaments of protoplasm throughout1 which penetrate the thick membranes of the cells1 and maintain a material and psychological communication between their living plasmic contents4 ,that is the explanation of the mimosa3 when the tread of the passer-by shakes the root of the plant1 the stimulus is immediately conveyed to all the cells1 and causes a general contraction of its tender leaves and a drooping of the stems4 ,an important and universal feature of all reflex phenomena is the absence of consciousness4 ,for reasons which we shall give in the tenth chapter we only admit the presence of consciousness in man and the higher animals1 not in plants1 the lower animals1 and the protists2 consequently all stimulated movements in the latter must be regarded as reflex--that is1 all movements which are not spontaneous1 not the outcome of internal causes 7impulsive and automatic movements74#ad ,it is different with the higher animals which have developed a centralized nervous system and elaborate sense-organs4 ,in these cases consciousness has been gradually evolved from the psychic reflex activity1 and now conscious1 voluntary action appears1 in opposition to the still continuing reflex action below4 ,however1 we must distinguish two different processes1 as we did in the question of instinct--primary and secondary reflex action4 ,primary reflex actions are those which have never reached the stage of consciousness in phyletic development1 and thus preserve the primitive character 7by heredity from lower animal forms74 ,secondary reflex actions are those which were conscious1 voluntary actions in our ancestors1 but which afterwards became unconscious from habit or the lapse of consciousness4 ,it is impossible to draw a hard and fast line in such cases between conscious and unconscious psychic function4 ,older psychologists 7,herbart1 for instance7 considered presentation to be the fundamental psychic phenomenon1 from which all the others are derived4 ,modern comparative psychology endorses this view in so far as it relates to the idea of unconscious presentation2 but it considers conscious presentation to be a secondary phenomenon of mental life1 which is entirely wanting in plants and the lower animals1 and is only developed in the higher animals4 ,among the many contradictory definitions which psychologists have given of presentation1 we think the best is that which makes it consist in an internal picture of the external object which is given us in sensation--an idea1 in the broader sense4 ,we may distinguish the following four stages in the rising scale of presentative function3 ,i4 ,cellular presentation4--,at the lowest stages we find presentation to be a general physiological property of psychoplasm2 even in the simplest unicellular protist sensations may leave a permanent trace in the psychoplasm1 and these may be reproduced by memory4 ,in more than four thousand kinds of radiolaria1 which ,i have described1 every single species is distinguished by special1 hereditary skeletal structure4 ,the construction of this specific1 and often highly elaborate1 skeleton by a cell of the simplest description 7generally globular7 is only intelligible when we attribute the faculty of presentation1 and1 indeed1 of a special reproduction of the plastic feeling of distance1 to the constructive protoplasm--as ,i have pointed out in my ,psychology of the ,radiolaria4#ae ,,ii4 ,histionic presentation4--,in the coenobia or cell-colonies of the social protists1 and still better in the tissues of plants and lower1 nerveless animals 7sponges1 polyps1 etc471 we find the second stage of unconscious presentation1 which consists of the common psychic activity of a number of closely connected cells4 ,if a single stimulus may1 instead of simply spending itself in the reflex movement of an organ 7the leaf of a plant1 for instance1 or the arm of a polyp71 leave a permanent impression1 which can be spontaneously reproduced later on1 we are bound to assume1 in explaining the phenomenon1 a histionic presentation1 dependent on the psychoplasm of the associated tissue-cells4 ,,iii4 ,unconscious presentation in the ganglionic cells4--,this third and higher stage of presentation is the commonest form the function takes in the animal world2 it seems to be a localization of presentation in definite soul-cells4 ,in its simplest form it appears at the sixth stage of reflex action1 when the tricellular reflex organ arises3 the seat of presentation is then the intermediate psychic cell1 which is interposed between the sensitive cell and the muscular cell4 ,with the increasing development of the animal nervous system and its progressive differentiation and integration1 this unconscious presentation also rises to higher stages4 ,,iv4 ,conscious presentation in the cerebral cells4--,with the highest stage of development of the animal organization consciousness arises1 as a special function of a certain central organ of the nervous system4 ,as the presentations are conscious1 and as special parts of the brain arise for the association of these conscious presentations1 the organism is qualified for those highest psychic functions which we call thought and reflection1 intellect and reason4 ,although the tracing of the phyletic barrier between the older1 unconscious1 and the younger1 conscious1 presentation is extremely difficult1 we can affirm1 with some degree of probability1 that the evolution of the latter from the former was polyphyletic2 because we find conscious and rational thought1 not only in the highest forms of the vertebrate stem 7man1 mammals1 birds1 and a part of the lower vertebrates71 but also in the most highly developed representatives of other animal groups 7ants and other insects1 spiders and the higher crabs among the articulata1 cephalopods among the mollusca74 ,the evolutionary scale of memory is closely connected with that of presentation2 this extremely important function of the psychoplasm--the condition of all further psychic development--consists essentially in the reproduction of presentations4 ,the impressions in the bioplasm1 which the stimulus produced as sensations1 and which became presentations in remaining1 are revived by memory2 they pass from potentiality to actuality4 ,the latent potential energy of the psychoplasm is transformed into kinetic energy4 ,we may distinguish four stages in the upward development of memory1 corresponding to the four stages of presentation4 ,i4 ,cellular memory4--,thirty years ago ,ewald ,hering showed memory to be a general property of organized matter in a thoughtful work1 and indicated the great significance of this function1 to which we owe almost all that we are and have4 ,six years later1 in my work on ,the ,perigenesis of the ,plastidule1 or the ,undulatory ,origin of the ,parts of ,life3 an ,experiment in the ,mechanical ,explanation of ,elementary ,evolutionary ,processes1 ,i developed these ideas1 and endeavored to base them on the principles of evolution4 ,i have attempted to show in that work that unconscious memory is a universal and very important function of all plastidules2 that is1 of those hypothetical molecules1 or groups of molecules1 which ,naegeli has called micellae1 others bioplasts1 and so forth4 ,only living plastidules1 as individual molecules of the active protoplasm1 are reproductive1 and so gifted with memory2 that is the chief difference between the organic and inorganic worlds4 ,it might be stated thus3 ,heredity is the memory of the plastidule1 while variability is its comprehension4 ,the elementary memory of the unicellular protist is made up of the molecular memory of the plastidules or micellae1 of which its living cell-body is constructed4 ,as regards the extraordinary performances of unconscious memory in these unicellular protists1 nothing could be more instructive than the infinitely varied and regular formation of their defensive apparatus1 their shells and skeletons2 in particular1 the diatomes and cosmaria among the protophytes1 and the radiolaria and thalamophora among the protozoa1 afford an abundance of most interesting illustrations4 ,in many thousand species of these protists the specific form which is inherited is relatively constant1 and proves the fidelity of their unconscious cellular memory4 ,,ii4 ,histionic memory4--,equally interesting examples of the second stage of memory1 the unconscious memory of tissues1 are found in the heredity of the individual organs of plants and the lower1 nerveless animals 7sponges1 etc474 ,this second stage seems to be a reproduction of the histionic presentations1 that association of cellular presentations which sets in with the formation of coenobia in the social protists4 ,,iii4 ,in the same way we must regard the third stage1 the unconscious memory of those animals which have a nervous system1 as a reproduction of the corresponding unconscious presentations which are stored up in certain ganglionic cells4 ,in most of the lower animals all memory is unconscious4 ,moreover1 even in man and the higher animals1 to whom we must ascribe consciousness1 the daily acts of unconscious memory are much more numerous and varied than those of the conscious faculty2 we shall easily convince ourselves of that if we make an impartial study of a thousand unconscious acts we perform daily out of habit1 and without thinking of them1 in walking1 speaking1 writing1 eating1 and so forth4 ,,iv4 ,conscious memory1 which is the work of certain brain-cells in man and the higher animals1 is an internal mirroring of very late development1 the highest outcome of the same psychic reproduction of presentations which were mere unconscious processes in the ganglionic cells of our lower animal ancestors4 ,the concatenation of presentations--usually called the association of ideas--also runs through a long scale1 from the lowest to the highest stages4 ,this1 too1 is originally and predominantly unconscious 7instinct72 only in the higher classes of animals does it gradually become conscious 7reason74 ,the psychic results of this association of ideas are extremely varied2 still1 a very long1 unbroken line of gradual development connects the simplest unconscious association of the lowest protist with the elaborate conscious chain of ideas of the civilized man4 ,the unity of consciousness in man is given as its highest consequence 7,hume1 ,condillac74 ,all higher mental activity becomes more perfect in proportion as the normal association extends to more numerous presentations1 and in proportion to the order which is imposed on them by the criticism of pure reason4 ,in dreams1 where this criticism is absent1 the association of the reproduced impressions often takes the wildest forms4 ,even in the work of the poetic imagination1 which constructs new groups of images by varying the association of the impressions received1 and in hallucinations1 etc41 they are often most unnaturally arranged1 and seem to the prosaic observer to be perfectly irrational4 ,this is especially true of supernatural forms of belief1 the apparitions of spiritism1 and the fantastic notions of the transcendental dualist philosophy2 though it is precisely these abnormal associations of faith and of revelation that have often been deemed the greatest treasures of the human mind 7cf4 chap4 xvi474 ,the antiquated psychology of the ,middle ,ages 7which1 however1 still numbers many adherents7 considered the mental life of man and that of the brute to be two entirely different phenomena2 the one it attributed to reason1 the other to instinct4 ,in harmony with the traditional story of creation1 it was assumed that each animal species had received a definite1 unconscious psychic force from the ,creator at its formation1 and that this instinct of each species was just as unchangeable as its bodily structure4 ,lamarck proved the untenableness of this error in #ahji by establishing the theory of ,descent1 and ,darwin completely demolished it in #ahei4 ,he proved the following important theses with the aid of his theory of selection3 #a4 ,the instincts of species show individual differences1 and are just as subject to modification under the law of adaptation as the morphological features of their bodily structure4 #b4 ,these modifications 7generally arising from a change of habits7 are partly transmitted to offspring by heredity1 and thus accumulate and are accentuated in the course of generations4 #c4 ,selection1 both artificial and natural1 singles out certain of these inherited modifications of the psychic activity2 it preserves the most useful and rejects the least adaptive4 #d4 ,the divergence of psychic character which thus arises leads1 in the course of generations1 to the formation of new instincts1 just as the divergence of morphological character gives rise to new species4 ,darwin's theory of instinct is now accepted by most biologists2 ,romanes has treated it so ably1 and so greatly expanded it in his distinguished work on ,mental ,evolution in the ,animal ,world1 that ,i need merely refer to it here4 ,i will only venture the brief statement that1 in my opinion1 there are instincts in all organisms--in all the protists and plants as well as in all the animals and in man2 though in the latter they tend to disappear in proportion as reason makes progress at their expense4 ,the two chief classes of instincts to be differentiated are the primary and secondary4 ,primary instincts are the common lower impulses which are unconscious and inherent in the psychoplasm from the commencement of organic life2 especially the impulses to self-preservation 7by defence and maintenance7 and to the preservation of the species 7by generation and the care of the young74 ,both these fundamental instincts of organic life1 hunger and love1 sprang up originally in perfect unconsciousness1 without any co-operation of the intellect or reason4 ,it is otherwise with the secondary instincts4 ,these were due originally to an intelligent adaptation1 to rational thought and resolution1 and to purposive conscious action4 ,gradually1 however1 they became so automatic that this other nature acted unconsciously1 and1 even through the action of heredity1 seemed to be innate in subsequent generations4 ,the consciousness and deliberation which originally accompanied these particular instincts of the higher animals and man have died away in the course of the life of the plastidules 7as in abridged heredity74 ,the unconscious purposive actions of the higher animals 7for instance1 their mechanical instincts7 thus come to appear in the light of innate impulses4 ,we have to explain in the same way the origin of the priori ideas of man2 they were originally formed empirically by his predecessors4#af ,in the superficial psychological treatises which ignore the mental activity of animals and attribute to man only a true soul1 we find him credited also with the exclusive possession of reason and consciousness4 ,this is another trivial error 7still to be found in many a manual1 nevertheless7 which the comparative psychology of the last forty years has entirely dissipated4 ,the higher vertebrates 7especially those mammals which are most nearly related to man7 have just as good a title to reason as man himself1 and within the limits of the animal world there is the same long chain of the gradual development of reason as in the case of humanity4 ,the difference between the reason of a ,goethe1 a ,kant1 a ,lamarck1 or a ,darwin1 and that of the lowest savage1 a ,veddah1 an ,akka1 a native ,australian1 or a ,patagonian1 is much greater than the graduated difference between the reason of the latter and that of the most rational mammals1 the anthropoid apes1 or even the papiomorpha1 the dog1 or the elephant4 ,this important thesis has been convincingly proved by the thoroughly critical comparative work of ,romanes and others4 ,we shall not1 therefore1 attempt to cover that ground here1 nor to enlarge on the distinction between the reason and the intellect2 as to the meaning and limits of these concepts philosophic experts give the most contradictory definitions1 as they do on so many other fundamental questions of psychology4 ,in general it may be said that the process of the formation of concepts1 which is common to both these cerebral functions1 is confined to the narrower circle of concrete1 proximate associations in the intellect1 but reaches out to the wider circle of abstract1 more comprehensive groups of associations in the work of reason4 ,in the long gradation which connects the reflex actions and the instincts of the lower animals with the reason of the highest1 intellect precedes the latter4 ,and there is the fact1 of great importance to our whole psychological treatise1 that even these highest of our mental faculties are just as much subject to the laws of heredity and adaptation as are their respective organs2 ,flechsig pointed out in #ahid that the organs of thought1 in man and the higher mammals1 are those parts of the cortex of the brain which lie between the four inner sense-centres 7cf4 chapters x4 and xi474 ,the higher grade of development of ideas1 of intellect and reason1 which raises man so much above the brute1 is intimately connected with the rise of language4 ,still here also we have to recognize a long chain of evolution which stretches unbroken from the lowest to the highest stages4 ,speech is no more an exclusive prerogative of man than reason4 ,in the wider sense1 it is a common feature of all the higher gregarious animals1 at least of all the articulata and the vertebrates1 which live in communities or herds2 they need it for the purpose of understanding each other and communicating their impressions4 ,this is effected either by touch or by signs1 or by sounds having a definite meaning4 ,the song of the bird or of the anthropoid ape 7hylobates71 the bark of the dog1 the neigh of the horse1 the chirp of the cricket1 the cry of the cicada1 are all specimens of animal speech4 ,only in man1 however1 has that articulate conceptual speech developed which has enabled his reason to attain such high achievements4 ,comparative philology1 one of the most interesting sciences that has arisen during the century1 has shown that the numerous elaborate languages of the different nations have been slowly and gradually evolved from a few simple primitive tongues 7,wilhelm ,humboldt1 ,bopp1 ,schleicher1 ,steinthal1 and others74 ,august ,schleicher1 of ,jena1 in particular1 has proved that the historical development of language takes place under the same phylogenetic laws as the evolution of other physiological faculties and their organs4 ,romanes 7#ahic7 has expanded this proof1 and amply demonstrated that human speech1 also1 differs from that of the brute only in degree of development1 not in essence and kind4 ,the important group of psychic activities which we embrace under the name of emotion plays a conspicuous part both in theoretical and practical psychology4 ,from our point of view they have a peculiar importance from the fact that we clearly see in them the direct connection of cerebral functions with other physiological functions 7the beat of the heart1 sense-action1 muscular movement1 etc472 they1 therefore1 prove the unnatural and untenable character of the philosophy which would essentially dissociate psychology from physiology4 ,all the external expressions of emotional life which we find in man are also present in the higher animals 7especially in the anthropoid ape and the dog72 however varied their development may be1 they are all derived from the two elementary functions of the psyche1 sensation and motion1 and from their combination in reflex action and presentation4 ,to the province of sensation1 in a wide sense1 we must attribute the feeling of like and dislike which determines the emotion2 while the corresponding desire and aversion 7love and hatred71 the effort to attain what is liked and avoid what is disliked1 belong to the category of movement4 ,attraction and repulsion seem to be the sources of will1 that momentous element of the soul which determines the character of the individual4 ,the passions1 which play so important a part in the psychic life of man1 are but intensifications of emotion4 ,romanes has recently shown that these also are common to man and the brute4 ,even at the lowest stage of organic life we find in all the protists those elementary feelings of like and dislike1 revealing themselves in what are called their tropisms1 in the striving after light and darkness1 heat or cold1 and in their different relations to positive and negative electricity4 ,on the other hand1 we find at the highest stage of psychic life1 in civilized man1 those finer shades of emotion1 of delight and disgust1 of love and hatred1 which are the mainsprings of civilization and the inexhaustible sources of poetry4 ,yet a connecting chain of all conceivable gradations unites the most primitive elements of feeling in the psychoplasm of the unicellular protist with the highest forms of passion that rule in the ganglionic cells of the cortex of the human brain4 ,that the latter are absolutely amenable to physical laws was proved long ago by the great ,spinoza in his famous ,statics of ,emotion4 ,the notion of will has as many different meanings and definitions as most other psychological notions--presentation1 soul1 mind1 and so forth4 ,sometimes will is taken in the widest sense as a cosmic attribute1 as in the ,world as will and presentation of ,schopenhauer2 sometimes it is taken in its narrowest sense as an anthropological attribute1 the exclusive prerogative of man--as ,descartes taught1 for instance1 who considered the brute to be a mere machine1 without will or sensation4 ,in the ordinary use of the term1 will is derived from the phenomenon of voluntary movement1 and is thus regarded as a psychic attribute of most animals4 ,but when we examine the will in the light of comparative physiology and evolution1 we find--as we do in the case of sensation--that it is a universal property of living psychoplasm4 ,the automatic and the reflex movements which we observe everywhere1 even in the unicellular protists1 seem to be the outcome of inclinations which are inseparably connected with the very idea of life4 ,even in the plants and lowest animals these inclinations1 or tropisms1 seem to be the joint outcome of the inclinations of all the combined individual cells4 ,but when the tricellular reflex organ arises 7page #aae71 and a third independent cell--the psychic1 or ganglionic1 cell--is interposed between the sense-cell and the motor cell1 we have an independent elementary organ of will4 ,in the lower animals1 however1 this will remains unconscious4 ,it is only when consciousness arises in the higher animals1 as the subjective mirror of the objective1 though internal1 processes in the neuroplasm of the psychic cells1 that the will reaches that highest stage which likens it in character to the human will1 and which1 in the case of man1 assumes in common parlance the predicate of liberty4 ,its free dominion and action become more and more deceptive as the muscular system and the sense-organs develop with a free and rapid locomotion1 entailing a correlative evolution of the brain and the organs of thought4 ,the question of the liberty of the will is the one which has more than any other cosmic problem occupied the time of thoughtful humanity1 the more so that in this case the great philosophic interest of the question was enhanced by the association of most momentous consequences for practical philosophy--for ethics1 education1 law1 and so forth4 ,emil du ,bois-,reymond1 who treats it as the seventh and last of his seven cosmic problems1 rightly says of the question3 ,affecting everybody1 apparently accessible to everybody1 intimately involved in the fundamental conditions of human society1 vitally connected with religious belief1 this question has been of immeasurable importance in the history of civilization4 ,there is probably no other object of thought on which the modern library contains so many dusty folios that will never again be opened4 ,the importance of the question is also seen in the fact that ,kant put it in the same category with the questions of the immortality of the soul and belief in ,god4 ,he called these three great questions the indispensable postulates of practical reason1 though he had already clearly shown them to have no reality whatever in the light of pure reason4 ,the most remarkable fact in connection with this fierce and confused struggle over the freedom of the will is1 perhaps1 that it has been theoretically rejected1 not only by the greatest critical philosophers1 but even by their extreme opponents1 and yet it is still affirmed to be self-evident by the majority of people4 ,some of the first teachers of the ,christian ,churches--such as ,st4 ,augustine and ,calvin--rejected the freedom of the will as decisively as the famous leaders of pure materialism1 ,holbach in the eighteenth and ,bchner in the nineteenth century4 ,christian theologians deny it1 because it is irreconcilable with their belief in the omnipotence of ,god and in predestination4 ,god1 omnipotent and omniscient1 saw and willed all things from eternity--he must1 consequently1 have predetermined the conduct of man4 ,if man1 with his free will1 were to act otherwise than ,god had ordained1 ,god would not be all-mighty and all-knowing4 ,in the same sense ,leibnitz1 too1 was an unconditional determinist4 ,the monistic scientists of the last century1 especially ,laplace1 defended determinism as a consequence of their mechanical view of life4 ,the great struggle between the determinist and the indeterminist1 between the opponent and the sustainer of the freedom of the will1 has ended to-day1 after more than two thousand years1 completely in favor of the determinist4 ,the human will has no more freedom than that of the higher animals1 from which it differs only in degree1 not in kind4 ,in the last century the dogma of liberty was fought with general philosophic and cosmological arguments4 ,the nineteenth century has given us very different weapons for its definitive destruction--the powerful weapons which we find in the arsenal of comparative physiology and evolution4 ,we now know that each act of the will is as fatally determined by the organization of the individual and as dependent on the momentary condition of his environment as every other psychic activity4 ,the character of the inclination was determined long ago by heredity from parents and ancestors2 the determination to each particular act is an instance of adaptation to the circumstances of the moment wherein the strongest motive prevails1 according to the laws which govern the statics of emotion4 ,ontogeny teaches us to understand the evolution of the will in the individual child4 ,phylogeny reveals to us the historical development of the will within the ranks of our vertebrate ancestors4 ,,chapter ,,viii ,,the ,,embryology ,,of ,,the ,,soul ,importance of ,ontogeny to ,psychology--,development of the ,child-,soul--,commencement of ,existence of the ,individual ,soul--,the ,storing of the ,soul--,mythology of the ,origin of the ,soul--,physiology of the ,origin of the ,soul--,elementary ,processes in ,conception--,coalescence of the ,ovum and the ,spermatozoon--,cell-,love--,heredity of the ,soul from ,parents and ,ancestors--,its ,physiological ,nature as the ,mechanics of the ,protoplasm--,blending of ,souls 7,psychic ,amphigony7--,reversion1 ,psychological ,atavism--,the ,biogenetic ,law in ,psychology--,palingenetic ,repetition and ,cenogenetic ,modification--,embryonic and ,post-,embryonic ,psychogeny ,the human soul--whatever we may hold as to its nature--undergoes a continual development throughout the life of the individual4 ,this ontogenetic fact is of fundamental importance in our monistic psychology1 though the professional psychologists pay little or no attention to it4 ,since the embryology of the individual is1 on ,baer's principle--and in accordance with the universal belief of modern biologists--the true torch-bearer for all research into the organic body1 it will afford us a reliable light on the momentous problems of its psychic activity4 ,although1 however1 this embryology of the soul is so important and interesting1 it has hitherto met with the consideration it deserves only within a very narrow circle4 ,until recently teachers were almost the only ones to occupy themselves with a part of the problem2 since their avocation compelled them to assist and supervise the formation of the psychic activity in the child1 they were bound to take a theoretical interest1 also1 in the psychogenetic facts that came under their notice4 ,however1 these teachers1 for the most part1 both in recent and in earlier times1 were dominated by the current dualistic psychology--in so far as they reflected at all2 and they were totally ignorant of the important facts of comparative psychology1 and unacquainted with the structure and function of the brain4 ,moreover1 their observations only extended to children in their school-days1 or in the years immediately preceding4 ,the remarkable phenomena which the individual psychogeny of the child offers in its earliest years1 and which are the joy and admiration of all thoughtful parents1 were scarcely ever made the subject of serious scientific research4 ,wilhelm ,preyer was the pioneer of this study in his interesting work on ,the ,mind of the ,child 7#ahha74 ,to obtain a perfectly clear knowledge of the matter1 however1 we must go further back still2 we must commence at the first appearance of the soul in the impregnated ovum4 ,the origin of the human individual--body and soul--was still wrapped in complete mystery at the beginning of the nineteenth century4 ,caspar ,friedrich ,wolff had1 it is true1 discovered the true character of embryonic development in #agei1 in his theoria generationis1 and proved with the confidence of a critical observer that there is a true epigenesis--i4e41 a series of very remarkable formative processes--in the evolution of the foetus from the simple ovum4 ,but the physiologists of the time1 with the famous ,albert ,haller at their head1 flatly refused to entertain these empirical truths1 which may be directly proved by microscopic observation1 and clung to the old dogma of preformation4 ,this theory assumed that in the human ovum--and in the egg of all other animals--the organism was already present1 or preformed1 in all its parts2 the evolution of the embryo consisted literally in an unfolding 7evolutio7 of the folded organs4 ,one curious consequence of this error was the theory of scatulation1 which we have mentioned on p4 #ee2 since the ovary had to be admitted to be present in the embryo of the woman1 it was also necessary to suppose that the germs of the next generation were already formed in it1 and so on in infinitum4 ,opposed to this dogma of the ,ovulists was the equally erroneous notion of the ,animalculists2 the latter held that the germ was not really in the female ovum1 but in the paternal element1 and that the store of succeeding generations was to be sought in the spermatozoa4 ,leibnitz consistently applied this theory of scatulation to the human soul2 he denied that either soul or body had a real development 7epigenesis71 and said in his ,theodicy3 ,thus ,i consider that the souls which are destined one day to become human exist in the seed1 like those of other species2 that they have existed in our ancestors as far back as ,adam--that is1 since the beginning of the world--in the forms of organized bodies4 ,similar notions prevailed in biology and philosophy until the third decade of the present century1 when the reform of embryology by ,baer gave them their death blow4 ,in the province of psychology1 however1 they still find many adherents2 they form one group of the many curious mystical ideas which give us a living illustration of the ontogeny of the soul4 ,the more accurate knowledge which we have recently obtained1 through comparative ethnology1 of the various forms of myths of ancient and modern uncivilized races1 is also of great interest in psychogeny4 ,still1 it would take us too far from our purpose if we were to enter into it with any fulness here2 we must refer the reader to ,adalbert ,svoboda's excellent work on ,forms of ,faith 7#ahig74 ,in respect of their scientific and poetical contents1 we may arrange all pertinent psychogenetic myths in the following five groups3 ,i4 ,the myth of transmigration4--,the soul lived formerly in the body of another animal1 and passed from this into a human body4 ,the ,egyptian priests1 for instance1 taught that the human soul wandered through all the species of animals after the death of the body1 returning to a human frame after three thousand years of transmigration4 ,,ii4 ,the myth of the in-planting of the soul4--,the soul existed independently in another place--a psychogenetic store1 as it were 7in a kind of embryonic slumber or latent life72 it was taken out by a bird 7sometimes represented as an eagle1 generally as a white stork71 and implanted in the human body4 ,,iii4 ,the myth of the creation of the soul4--,god creates the souls1 and keeps them stored--sometimes in a pond 7living in the form of plankton71 according to other myths in a tree 7where they are conceived as the fruit of a phanerogam72 the ,creator takes them from the pond or tree1 and inserts them in the human germ during the act of conception4 ,,iv4 ,the myth of the scatulation of the soul 7the theory of ,leibnitz which we have given above74 ,v4 ,the myth of the division of the soul 7the theory of ,rudolph ,wagner #ahee and of other physiologists74--,in the act of procreation a portion is detached from both the 7immaterial7 souls of the parents2 the maternal contribution passes in the ovum1 the paternal in the spermatozoa2 when these two germinal cells coalesce1 the two psychic fragments that accompany them also combine to form a new 7immaterial7 soul4 ,although the poetic fancies we have mentioned as to the origin of the individual human soul are still widely accepted1 their purely mythological character is now firmly established4 ,the deeply interesting and remarkable research which has been made in the course of the last twenty-five years into the more minute processes of the impregnation and germination of the ovum has made it clear that these mysterious phenomena belong entirely to the province of cellular physiology 7cf4 p4 #dh74 ,both the female element1 the ovum1 and the male fertilizing body1 the sperma or spermatozoa1 are simple cells4 ,these living cells possess a certain sum of physiological properties to which we give the title of the cell-soul1 just as we do in the permanently unicellular protist 7see p4 #dh74 ,both germinal cells have the faculty of movement and sensation4 ,the young ovum1 or egg-cell1 moves after the manner of an amoeba2 the minute spermatozoa1 of which there are millions in every drop of the seminal fluid1 are ciliated cells1 and swim about as freely in the sperm1 by means of their lashes or cilia1 as the ordinary ciliated infusoria 7the flagellata74 ,when the two cells meet as a result of copulation1 or when they are brought into contact through artificial fertilization 7in the fishes1 for instance71 they attract each other and become firmly attached4 ,the main cause of this cellular attraction is a chemical sensitive action of the protoplasm1 allied to smell or taste1 which we call erotic chemicotropism2 it may also be correctly 7both in the chemical and the romantic sense7 termed cellular affinity or sexual cell-love4 ,a number of the ciliated cells in the sperm swim rapidly towards the stationary egg-cell and seek to penetrate into it4 ,as ,hertwig showed in #ahge1 as a rule only one of the suitors is fortunate enough to reach the desired goal4 ,as soon as this favored spermatozoon has pierced into the body of the ovum with its head 7the nucleus of the cell71 a thin mucous layer is detached from the ovum which prevents the further entrance of spermatozoa4 ,the formation of this protective membrane was only prevented when ,hertwig kept the ovum stiff with cold by lowering the temperature1 or benumbed it with narcotics 7chloroform1 morphia1 nicotine1 etc472 then there was super-impregnation or poly-spermy--a number of sperm-threads pierced into the body of the unconscious ovum4 ,this remarkable fact proved that there is a low degree of cellular instinct 7or1 at least1 of specific1 lively sensation7 in the sexual cells just as effectively as do the important phenomena that immediately follow in their interior4 ,both nuclei--that of the ovum and of the spermatozoon--attract each other1 approach1 and1 on contact1 completely fuse together4 ,thus from the impregnated ovum arises the important new cell which we call the stem-cell 7cytula71 from the repeated segmentation of which the whole polycellular organism is evolved4 ,the psychological information which is afforded by these remarkable facts of impregnation1 which have only been properly observed during the last twenty-five years1 is supremely important2 its vast significance has hitherto been very far from appreciated4 ,we shall condense the main conclusions of research in the following five theses3 ,i4 ,each human individual1 like every other higher animal1 is a single simple cell at the commencement of his existence4 ,,ii4 ,this stem-cell 7cytula7 is formed in the same manner in all cases--that is1 by the blending or copulation of two separate cells of diverse origin1 the female ovum and the male spermatozoon4 ,,iii4 ,each of these sexual cells has its own cell-soul--that is1 each is distinguished by a peculiar form of sensation and movement4 ,,iv4 ,at the moment of conception or impregnation1 not only the protoplasm and the nuclei of the two sexual cells coalesce1 but also their cell-souls2 in other words1 the potential energies which are latent in both1 and inseparable from the matter of the protoplasm1 unite for the formation of a new potential energy1 the germ-soul of the newly constructed stem-cell4 ,v4 ,consequently each personality owes his bodily and spiritual qualities to both parents2 by heredity the nucleus of the ovum contributes a portion of the maternal features1 while the nucleus of the spermatozoon brings a part of the father's characteristics4 ,by these empirical facts of conception1 moreover1 the further fact of extreme importance is established1 that every man1 like every other animal1 has a beginning of existence2 the complete copulation of the two sexual cell-nuclei marks the precise moment when not only the body1 but also the soul1 of the new stem-cell makes its appearance4 ,this fact suffices of itself to destroy the myth of the immortality of the soul1 to which we shall return later on4 ,it suffices1 too1 for the destruction of the still prevalent superstition that man owes his personal existence to the favor of ,god4 ,its origin is rather to be attributed solely to the eros of his parents1 to that powerful impulse that is common to all polycellular animals and plants1 and leads to their nuptial union4 ,but the essential point in this physiological process is not the embrace1 as was formerly supposed1 or the amorousness connected therewith2 it is simply the introduction of the spermatozoa into the vagina4 ,this is the sole means1 in the land-dwelling animals1 by which the fertilizing element can reach the released ova 7which usually takes place in the uterus in man74 ,in the case of the lower aquatic animals 7fishes1 mussels1 medus1 etc47 the mature sexual elements on both sides are simply discharged into the water1 and their union is let to chance2 they have no real copulation1 and so they show none of those higher psychic erotic functions which play so conspicuous a part in the life of the higher animals4 ,hence it is1 also1 that all the lower1 non-copulating animals are wanting in those interesting organs which ,darwin has called secondary sexual characters1 and which are the outcome of sexual selection3 such are the beard of man1 the antlers of the stag1 the beautiful plumage of the bird of paradise and of so many other birds1 together with other distinctions of the male which are absent in the female4 ,among the above theses as to the physiology of conception the inheritance of the psychic qualities of the two parents is of particular importance for psychological purposes4 ,it is well known that every child inherits from both his parents peculiarities of character1 temperament1 talent1 acuteness of sense1 and strength of will4 ,it is equally well known that even psychic qualities are often 7if not always7 transmitted from grandparents by heredity--often1 in fact1 a man resembles his grandparents more than his parents in certain respects2 and that is true both of bodily and mental features4 ,all the chief laws of heredity which ,i first formulated in my ,general ,morphology1 and popularized in my ,natural ,history of ,creation1 are just as valid and universal in their application to psychic phenomena as to bodily structure--in fact1 they are frequently more striking and conspicuous in the former than in the latter4 ,however1 the great province of heredity1 to the inestimable importance of which ,darwin first opened our eyes in #ahei1 is thickly beset with obscure problems and physiological difficulties4 ,we dare not claim1 even after forty years of research1 that all its aspects are clear to us4 ,yet we have done so much that we can confidently speak of heredity as a physiological function of the organism1 which is directly connected with the faculty of generation2 and we must reduce it1 like all other vital phenomena1 to exclusively physical and chemical processes1 to the mechanics of the protoplasm4 ,we now know accurately enough the process of impregnation itself2 we know that in it the nucleus of the spermatozoon contributes the qualities of the male parent1 and the nucleus of the ovum gives the qualities of the mother1 to the newly born stem-cell4 ,the blending of the two nuclei is the physiological moment of heredity2 by it the personal features of both body and soul are transmitted to the new individual4 ,these facts of ontogeny are beyond the explanation of the dualistic and mystic psychology which still prevails in the schools2 whereas they find a perfectly simple interpretation in our monistic philosophy4 ,the physiological fact which is most material for a correct appreciation of individual psychogeny is the continuity of the psyche through the rise and fall of generations4 ,a new individual comes into existence at the moment of conception2 yet it is not an independent entity1 either in respect of its mental or its bodily features1 but merely the product of the blending of the two parental factors1 the maternal egg-cell and paternal sperm-cell4 ,the cell-souls of these two sexual cells combine in the act of conception for the formation of a new cell-soul1 just as truly as the two cell-nuclei1 which are the material vehicles of this psychic potential energy1 unite to form a new nucleus4 ,as we now see that the individuals of one and the same species--even sisters born of the same parents--always show certain differences1 however slight1 we must assume that these variations were already present in the chemical plasmatic constitution of the generative cells themselves4#ag ,these facts alone would suffice to explain the infinite variety of individual features1 of soul and of bodily form1 that we find in the organic world4 ,as an extreme1 but one-sided1 consequence of them1 there is the theory of ,weismann1 which considers the amphimixis1 or the blending of the germ-plasm in sexual generation1 to be the universal and the sole cause of individual variability4 ,this exclusive theory1 which is connected with his theory of the continuity of the germ-plasm1 is1 in my opinion1 an exaggeration4 ,i am convinced1 on the contrary1 that the great laws of progressive heredity and of the correlative functional adaptation apply to the soul as well as to the body4 ,the new characteristics which the individual has acquired during life may react to some extent on the molecular texture of the germ-plasm in the egg-cell and sperm-cell1 and may thus be transferred to the next generation by heredity in certain conditions 7naturally1 only in the form of latent energy74 ,although in the soul-blending at the moment of conception only the latent forces of the two parent souls are transmitted by the coalescence of the erotic cell-nuclei1 still it is possible that the hereditary psychic influence of earlier1 and sometimes very much older1 generations may be communicated at the same time4 ,for the laws of latent heredity or atavism apply to the soul just as validly as to the anatomical organization4 ,we find these remarkable phenomena of reversion in a very simple and instructive form in the alternation of generations of the polyps and medus4 ,here we see two very different generations alternate so regularly that the first resembles the third1 fifth1 and so on2 while the second 7very different from the preceding7 is like the fourth1 sixth1 etc4 7,natural ,history of ,creation74 ,we do not find such alternation of generations in man and the higher animals and plants1 in which1 owing to continuous heredity1 each generation resembles the next2 nevertheless1 even in these cases we often meet with phenomena of reversion1 which must be reduced to the same law of latent heredity4 ,eminent men often take more after their grandparents than their parents even in the finer shades of psychic activity--in the possession of certain artistic talents or inclinations1 in force of character1 and in warmth of temperament2 not infrequently there is a striking feature which neither parents nor grandparents possessed1 but which may be traced a long way back to an older branch of the family4 ,even in these remarkable cases of atavism the same laws of heredity apply to the psyche and to the physiognomy1 to the personal quality of the sense-organs1 muscles1 skeleton1 and other parts of the body4 ,we can trace them most clearly in the reigning dynasties and in old families of the nobility1 whose conspicuous share in the life of the ,state has given occasion to a more careful historical picture of the individuals in the chain of generations--for instance1 in the ,hohenzollerns1 the princes of ,orange1 the ,bourbons1 etc41 and in the ,roman ,csars4 ,the causal-nexus of biontic 7individual7 and phyletic 7historical7 evolution1 which ,i gave in my ,general ,morphology as the supreme law at the root of all biogenetic research1 has a universal application to psychology no less than to morphology4 ,i have fully treated the special importance which it has with regard to man1 in both respects1 in the first chapter of my ,anthropogeny4 ,in man1 as in all other organisms1 the embryonic development is an epitome of the historical development of the species4 ,this condensed and abbreviated recapitulation is the more complete in proportion as the original epitomized development 7palingenesis7 is preserved by a constant heredity2 on the other hand1 it falls off from completeness in proportion as the later disturbing development 7cenogenesis7 is accentuated by varying adaptation4 ,while we apply this law to the evolution of the soul1 we must lay special stress on the injunction to keep both sides of it critically before us4 ,for1 in the case of man1 just as in all the higher animals and plants1 such appreciable perturbations of type 7or cenogeneses7 have taken place during the millions of years of development that the original simple idea of palingenesis1 or epitome of history1 has been greatly disturbed and altered4 ,while1 on the one side1 the palingenetic recapitulation is preserved by the laws of like-time and like-place heredity1 it is subject to an essential cenogenetic change1 on the other hand1 by the laws of abbreviated and simplified heredity4 ,that is clearly seen in the embryonic evolution of the psychic organs1 the nervous system1 the muscles1 and the sense-organs4 ,but it applies in just the same manner to the psychic functions1 which are absolutely dependent on the normal construction of these organs4 ,their evolution is subject to great cenogenetic modification in man and all other viviparous animals1 precisely because the complete development of the embryo occupies a longer time within the body of the mother4 ,but we have to distinguish two periods of individual psychogeny3 7#a7 the embryonic1 and 7#b7 the post-embryonic development of the soul4 ,i4 ,embryonic ,psychogeny4--,the human foetus1 or embryo1 normally takes nine months 7or two hundred and seventy days7 to develop in the uterus4 ,during this time it is entirely cut off from the outer world1 and protected1 not only by the thick muscular wall of the womb1 but also by the special foetal membranes 7embryolemmata7 which are common to all the three higher classes of vertebrates--reptiles1 birds1 and mammals4 ,in all the classes of amniotes these membranes 7the amnion and the serolemma7 develop in just the same fashion4 ,they represent the protective arrangements which were acquired by the earliest reptiles 7proreptilia71 the common parents of all the amniotes1 in the ,permian period 7towards the end of the palozoic age71 when these higher vertebrates accustomed themselves to live on land and breathe the atmosphere4 ,their ancestors1 the amphibia of the ,carboniferous period1 still lived and breathed in the water1 like their earlier predecessors1 the fishes4 ,in the case of these older and lower vertebrates that lived in the water1 the embryonic development had the palingenetic character in a still higher degree1 as is the case in most of the fishes and amphibia of the present day4 ,the familiar tadpole and the larva of the salamander or the frog still preserve the structure of their fish-ancestors in the first part of their life in the water2 they resemble them1 likewise1 in their habits of life1 in breathing by gills1 in the action of their sense-organs1 and in other psychic organs4 ,then1 when the interesting metamorphosis of the swimming tadpole takes place1 and when it adapts itself to a land-life1 the fish-like body changes into that of a four-footed1 crawling amphibium2 instead of the gill-breathing in the water comes an exclusive breathing of the atmosphere by means of lungs1 and1 with the changed habits of life1 even the psychic apparatus1 the nervous system1 and the sense-organs reach a higher degree of construction4 ,if we could completely follow the psychogeny of the tadpole from beginning to end1 we should be able to apply the biogenetic law in many ways to its psychic evolution4 ,for it develops in direct communication with the changing conditions of the outer world1 and so must quickly adapt its sensation and movement to these4 ,the swimming tadpole has not only the structure but the habits of life of a fish1 and only acquires those of a frog in its metamorphosis4 ,it is different with man and all the other amniotes2 their embryo is entirely withdrawn from the direct influence of the outer world1 and cut off from any reciprocal action therewith1 by enclosure in its protective membranes4 ,besides1 the special care of the young on the part of the amniotes gives their embryo much more favorable conditions for the cenogenetic abbreviation of the palingenetic evolution4 ,there is1 in the first place1 the excellent arrangement for the nourishment of the embryo2 in the reptiles1 birds1 and monotremes 7the oviparous mammals7 it is effected by the great yellow nutritive yelk1 which is associated with the egg2 in the rest of the mammals 7the marsupials and placentals7 it is effected by the mother's blood1 which is conducted to the foetus by the blood-vessels of the yelk-sac and the allantois4 ,in the case of the most highly developed placentals this elaborate nutritive arrangement has reached the highest degree of perfection by the construction of a placenta2 hence in these classes the embryo is fully developed before birth4 ,but its soul remains during all this time in a state of embryonic slumber1 a state of repose which ,preyer has justly compared to the hibernation of animals4 ,we have a similar long sleep in the chrysalis stage of those insects which undergo a complete metamorphosis--butterflies1 bees1 flies1 beetles1 and so forth4 ,this sleep of the pupa1 during which the most important formations of organs and tissues take place1 is the more interesting from the fact that the preceding condition of the free larva 7caterpillar1 grub1 or maggot7 included a highly developed psychic activity1 and that this is1 significantly1 lower than the stage which is seen afterwards 7when the chrysalis sleep is over7 in the perfect1 winged1 sexually mature insect4 ,man's psychic activity1 like that of most of the higher animals1 runs through a long series of stages of development during the individual life4 ,we may single out the five following as the most important of them3 ,i4 ,the soul of the new-born infant up to the birth of self-consciousness and the learning of speech4 ,,ii4 ,the soul of the boy or girl up to puberty 7i4e41 until the awakening of the sexual instinct74 ,,iii4 ,the soul of the youth or maiden up to the time of sexual intercourse 7the idealist period74 ,,iv4 ,the soul of the grown man and the mature woman 7the period of full maturity and of the founding of families1 lasting until about the sixtieth year for the man and the fiftieth for the woman--until involution sets in74 ,v4 ,the soul of the old man or woman 7the period of degeneration74 ,man's psychic life runs the same evolution--upward progress1 full maturity1 and downward degeneration--as every other vital activity in his organization4 ,,chapter ,,ix ,,the ,,phylogeny ,,of ,,the ,,soul ,gradual ,historical ,evolution of the ,human ,soul from the ,animal ,soul--,methods of ,phylogenetic ,psychology--,four ,chief ,stages in the ,phylogeny of the ,soul3 ,i4 ,the ,cell-,soul 7,cytopsyche7 of the ,protist 7,infusoria1 ,ova1 etc473 ,cellular ,psychology2 ,,ii4 ,the ,soul of a ,colony of ,cells1 or the ,cenobitic ,soul 7,coenopsyche73 ,psychology of the ,morula and ,blastula2 ,,iii4 ,the ,soul of the ,tissue 7,histopsyche73 ,its ,twofold ,nature3 ,the ,soul of the ,plant3 ,the ,soul of the ,lower1 ,nerveless ,animal3 ,double ,soul of the ,siphonophora 7,personal and ,kormal ,soul72 ,,iv4 ,the ,nerve-,soul 7,neuropsyche7 of the ,higher ,animal--,three ,sections of its ,psychic ,apparatus3 ,sense-,organs1 ,muscles1 and ,nerves--,typical ,formation of the ,nerve-,centre in the ,various ,groups of ,animals--,psychic ,organ of the ,vertebrate3 the ,brain and the ,spinal ,cord--,phylogeny of the ,mammal ,soul ,the theory of descent1 combined with anthropological research1 has convinced us of the descent of our human organism from a long series of animal ancestors by a slow and gradual transformation occupying many millions of years4 ,since1 then1 we cannot dissever man's psychic life from the rest of his vital functions--we are rather forced to a conviction of the natural evolution of our whole body and mind--it becomes one of the main tasks of the modern monistic psychology to trace the stages of the historical development of the soul of man from the soul of the brute4 ,our phylogeny of the soul seeks to attain this object2 it may also1 as a branch of general psychology1 be called phylogenetic psychology1 or1 in contradistinction to biontic 7individual71 phyletic psychogeny4 ,and1 although this new science has scarcely been taken up in earnest yet1 and most of the professional psychologists deny its very right to existence1 we must claim for it the utmost importance and the deepest interest4 ,for1 in our opinion1 it is its special province to solve for us the great enigma of the nature and origin of the human soul4 ,the methods and paths which will lead us to the remote goal of a complete phylogenetic psychology--a goal that is still buried in the mists of the future1 and almost imperceptible to many--do not differ from those of other branches of evolutionary research4 ,comparative anatomy1 physiology1 and ontogeny are of the first importance4 ,much support is given also by palontology1 for the order in which the fossil remains of the various classes of vertebrates succeed each other in the course of organic evolution reveals to us1 to some extent1 the gradual growth of their psychic power as well as their phyletic connection4 ,we must admit that we are here1 as we are in every branch of phylogenetic research1 driven to the construction of a number of hypotheses in order to fill up the considerable lacun of empirical phylogeny4 ,yet these hypotheses cast so clear and significant a light on the chief stages of historical development that we are afforded a most gratifying insight into their entire course4 ,the comparative psychology of man and the higher animals enables us to learn from the highest group of the placentals1 the primates1 the long strides by which the human soul has advanced beyond the psyche of the anthropoid ape4 ,the phylogeny of the mammals and of the lower vertebrates acquaints us with the long series of the earlier ancestors of the primates which have arisen within this stem since the ,silurian age4 ,all these vertebrates agree in the structure and development of their characteristic psychic organ--the spinal cord4 ,we learn from the comparative anatomy of the vermalia that this spinal cord has been evolved from a dorsal acroganglion1 or vertical brain1 of an invertebrate ancestor4 ,we learn1 further1 from comparative ontogeny that this simple psychic organ has been evolved from the stratum of cells in the outer germinal layer1 the ectoderm1 of the platodes4 ,in these earliest flat-worms1 which have no specialized nervous system1 the outer skin-covering serves as a general sensitive and psychic organ4 ,finally1 comparative embryology teaches us that these simple metazoa have arisen by gastrulation from blastades1 from hollow spheres1 the wall of which is merely one simple layer of cells1 the blastoderm2 and the same science1 with the aid of the biogenetic law1 explains how these protozoic coenobia originally sprang from the simplest unicellular organisms4 ,on a critical study of these different embryonic formations1 the evolution of which from each other we can directly observe under the microscope1 we arrive1 by means of the great law of biogeny1 at a series of most important conclusions as to the chief stages in the development of our psychic life4 ,we may distinguish eight of these to begin with3 ,i4 ,unicellular protozoa with a simple cell-soul3 the infusoria4 ,,ii4 ,multicellular protozoa with a communal soul3 the catallacta4 ,,iii4 ,the earliest metazoa with an epithelial soul3 the platodes4 ,,iv4 ,invertebrate ancestors with a simple vertical brain3 the vermalia4 ,v4 ,vertebrates without skull or brain1 with a simple spinal cord3 the acrania4 ,,vi4 ,animals with skull and brain 7of five vesicles73 the craniota4 ,,vii4 ,mammals with predominant development of the cortex of the brain3 the placentals4 ,,viii4 ,the higher anthropoid apes and man1 with organs of thought 7in the cerebrum73 the anthropomorpha4 ,among these eight stages in the development of the human soul we may further distinguish more or less clearly a number of subordinate stages4 ,naturally1 however1 in reconstructing them we have to fall back on the same defective evidence of empirical psychology which the comparative anatomy and physiology of the actual fauna affords us4 ,as the craniote animals of the sixth stage--and these are true fishes--are already found fossilized in the ,silurian system1 we are forced to assume that the five preceding series of ancestors 7which were incapable of fossilization7 were evolved in an earlier1 pre-,silurian age4 ,i4 ,the cell-soul 7or cytopsyche73 first stage of phyletic psychogenesis4--,the earliest ancestors of man and all other animals were unicellular protozoa4 ,this fundamental hypothesis of rational phylogeny is based1 in virtue of the phylogenetic law1 on the familiar embryological fact that every man1 like every other metazoon 7i4e41 every multicellular organism with tissues71 begins his personal existence as a simple cell1 the stem-cell 7cytula71 or the impregnated egg-cell 7see p4 #fc74 ,as this cell has a soul from the commencement1 so had also the corresponding unicellular ancestral forms1 which were represented in the oldest series of man's ancestors by a number of different protozoa4 ,we learn the character of the psychic activity of these unicellular organisms from the comparative physiology of the protists of to-day4 ,close observation and careful experiment have opened out to us in this respect1 in the second half of the nineteenth century1 a new world of the most interesting phenomena4 ,the best description of them was given by ,max ,verworn in his thoughtful work1 based on original research1 ,psycho-physiological ,studies of the ,protists4 ,the work includes also the few earlier observations of the psychic life of the protist4 ,verworn came to the firm conclusion that the psychic processes are unconscious in all the protists1 that the phenomena of sensation and movement coincide with the molecular vital processes in their protoplasm1 and that their ultimate causes are to be sought in the properties of the protoplasmic molecules 7the plastidules74 ,hence the psychic phenomena of the protists form a bridge that connects the chemical processes of the inorganic world with the psychic life of the highest animals2 they represent the germ of the highest psychic phenomena of the metazoa and of man4 ,the careful observations and many experiments of ,verworn1 together with those of ,wilhelm ,engelmann1 ,wilhelm ,preyer1 ,richard ,hertwig1 and other more recent students of the protists1 afford conclusive evidence for my theory of the cell-soul 7#ahff74 ,on the strength of several years of study of different kinds of protists1 especially rhizopods and infusoria1 ,i published a theory thirty-three years ago to the effect that every living cell has psychic properties1 and that the psychic life of the multicellular animals and plants is merely the sum total of the psychic functions of the cells which build up their structure4 ,in the lower groups 7in alg and sponges1 for instance7 all the cells of the body have an equal share in it 7or with very slight differences72 in the higher groups1 in harmony with the law of the division of labor1 only a select portion of them are involved--the soul-cells4 ,the important consequences of this cellular psychology were partly treated in my work on ,the ,perigenesis of the ,plastidule 7#ahgf71 and partly in my speech at ,munich1 in #ahgg1 on ,modern ,evolution in ,relation to the ,whole of ,science4 ,a more popular presentation of them is to be found in my two ,vienna papers 7#ahgh7 on ,the ,origin and ,development of the ,sense-,organs and on ,cell-,souls and ,soul-,cells4 ,moreover1 the cell-soul1 even within the limits of the protist world1 presents a long series of stages of development1 from the most simple and primitive to a comparatively elaborate activity4 ,in the earliest and simplest protists the faculty of sensation and movement is equally distributed over the entire protoplasm of the homogeneous morsel2 in the higher forms certain cell-instruments1 or organella1 appear1 as their physiological organs4 ,motor cell-parts of that character are found in the pseudopodia of the rhizopods1 and the vibrating hairs1 lashes1 or cilia of the infusoria4 ,the cell-nucleus1 which is wanting in the earlier and lower protists1 is considered to be an internal central organ of the cell-life4 ,it is especially noteworthy1 from a physiologico-chemical point of view1 that the very earliest protists were plasmodomous1 with plant-like nutrition--hence protophyta1 or primitive plants2 from these came as a secondary stage1 by metasitism1 the first plasmophagi1 with animal nutrition--the protozoa1 or primitive animals4#ah ,this metasitism1 or circulation of nutritive matter1 implies an important psychological advance2 with it began the development of those characteristic properties of the animal soul which are wanting in the plant4 ,we find the highest development of the animal cell-soul in the class of ciliata1 or ciliated infusoria4 ,when we compare their activity with the corresponding psychic life of the higher1 multicellular animals1 we find scarcely any psychological difference2 the sensitive and motor organella of these protozoa seem to accomplish the same as the sense-organs1 nerves1 and muscles of the metazoa4 ,indeed1 we have found in the great cell-nucleus 7meganucleus7 of the infusoria a central organ of psychic activity1 which plays much the same part in their unicellular organism as the brain does in the psychic life of higher animals4 ,however1 it is very difficult to determine how far this comparison is justified2 the views of experts diverge considerably over the matter4 ,some take all spontaneous bodily movement in them to be automatic1 or impulsive1 and all stimulated movement to be reflex2 others are convinced that such movements are partly voluntary and intentional4 ,the latter would attribute to the infusoria a certain degree of consciousness1 and even self-consciousness2 but this is rejected by the others4 ,however that very difficult question may be settled1 it does not alter the fact that these unicellular protozoa give proof of the possession of a highly developed cell-soul1 which is of great interest for a correct decision as to the psyche of our earliest unicellular ancestors4 ,,ii4 ,the communal or cenobitic soul 7coenopsyche73 second stage of phyletic psychogenesis4--,individual development begins1 in man and in all other multicellular animals1 with the repeated segmentation of one simple cell4 ,this stem-cell1 the impregnated ovum1 divides first into two daughter cells1 by a process of ordinary indirect segmentation2 as the process is repeated there arise 7by equal division of the egg7 successively four1 eight1 sixteen1 thirty-two1 sixty-four such new cells1 or blastomeres4 ,usually 7that is1 in the case of the majority of animals7 an irregular enlargement sooner or later takes the place of this original regular division of cells4 ,but the result is the same in all cases--the formation of a 7generally spherical7 cluster of heterogeneous 7originally homogeneous7 cells4 ,this stage is called the morula 7mulberry1 which it somewhat resembles in shape74 ,then1 as a rule1 a fluid gathers in the interior of this aggregate of cells2 it changes into a spherical vesicle2 all the cells go to its surface1 and arrange themselves in one simple layer--the blastoderm4 ,the hollow sphere which is thus formed is the important stage of the germinal vesicle1 the blastula1 or blastosphere4 ,the psychological phenomena which we directly observe in the formation of the blastula are partly sensations1 partly movements1 of this community of cells4 ,the movements may be divided into two groups3 7#a7 the inner movements1 which are always repeated in substantially the same manner in the process of ordinary 7indirect7 segmentation of cells 7formation of the axis of the nucleus1 mitosis1 karyokinesis1 etc472 7#b7 the outer movements1 which are seen in the regular change of position of the social cells and their grouping for the construction of the blastoderm4 ,we assume that these movements are hereditary and unconscious1 because they are always determined in the same fashion by heredity from the earlier protist ancestors4 ,the sensations also fall into two groups3 7#a7 the sensations of the individual cells1 which reveal themselves in the assertion of their individual independence and their relation to neighboring cells 7with which they are in contact1 and partly in direct combination1 by means of protoplasmic fibres72 7#b7 the common sensation of the entire community of cells1 which is seen in the individual formation of the blastula as a hollow vesicle4 ,the causal interpretation of the formation of the blastula is given us by the biogenetic law1 which explains the phenomena we directly observe to be the outcome of heredity1 and relates them to corresponding historical processes which took place long ago in the origin of the earliest protist-coenobia1 the blastads4 ,but we get a physiological and psychological insight into these important phenomena of the earliest cell-communities by observation and experiment on their modern representatives4 ,such permanent cell-communities or colonies are still found in great numbers both among the plasmodomous primitive plants 7for instance1 the paulotomacea1 diatomacea1 volvocin1 etc47 and the plasmophagous primitive animals 7the infusoria and rhizopods74 ,in all these coenobia we can easily distinguish two different grades of psychic activity3 7#a7 the cell-soul of the individual cells 7the elementary organisms7 and 7#b7 the communal soul of the entire colony4 ,,iii4 ,the tissue-soul 7histopsyche73 third stage of phyletic psychogenesis4--,in all multicellular1 tissue-forming plants 7metaphyta7 and in the lowest1 nerveless classes of tissue-forming animals 7metazoa7 we have to distinguish two different forms of psychic activity--namely3 7#a7 the psyche of the individual cells which compose the tissue1 and 7#b7 the psyche of the tissue itself1 or of the cell-state which is made up of the tissues4 ,this tissue-soul is the higher psychological function which gives physiological individuality to the compound multicellular organism as a true cell-commonwealth4 ,it controls all the separate cell-souls of the social cells--the mutually dependent citizens which constitute the community4 ,this fundamental twofold character of the psyche in the metaphyta and the lower1 nerveless metazoa is very important4 ,it may be verified by unprejudiced observation and suitable experiment4 ,in the first place1 each single cell has its own sensation and movement1 and1 in addition1 each tissue and each organ1 composed of a number of homogeneous cells1 has its special irritability and psychic unity 7e4g41 the pollen and stamens74 ,a4 ,the plant-soul 7phytopsyche7 is1 in our view1 the summary of the entire psychic activity of the tissue-forming1 multicellular plant 7the metaphyton1 as distinct from the unicellular protophyton72 it is1 however1 the subject of the most diverse opinions even at the present day4 ,it was once customary to draw an essential distinction between the plant and the animal1 on the ground that the latter had a soul and the plant had none4 ,however1 an unprejudiced comparison of the irritability and movements of various higher plants and lower animals convinced many observers1 even at the beginning of the century1 that there must be a soul on both sides4 ,at a later date ,fechner1 ,leitgeb1 and others strongly contended for the plant-soul4 ,but a profounder knowledge of the subject was obtained when the similarity of the elementary structure of the plant and of the animal was proved by the cellular theory1 and especially when the similarity of conduct of the active1 living protoplasm in both was shown in the plasma theory of ,max ,schultze 7#ahei74 ,modern comparative physiology has shown that the physiological attitude towards various stimuli 7light1 heat1 electricity1 gravity1 friction1 chemical action1 etc47 of the sensitive portions of many plants and animals is exactly the same1 and that the reflex movements which the stimuli elicit take place in precisely the same manner on both sides4 ,hence1 if it was necessary to attribute this activity to a soul in the lower1 nerveless metazoa 7sponges1 polyps1 etc471 it was also necessary in the case of many 7if not all7 metaphyta1 at least in the very sensitive mimosa1 the fly-traps 7dionaea and drosera71 and the numerous kinds of climbing plants4 ,it is true that modern vegetal physiology has given a purely physical explanation of many of these stimulated movements1 or tropisms1 by special features of growth1 variations of pressure1 etc4 ,yet these mechanical causes are neither more nor less psychophysical than the similar reflex movements of the sponges1 polyps1 and other nerveless metazoa1 even though their mechanism is entirely different4 ,the character of the tissue-soul reveals itself in the same way in both cases--the cells of the tissue 7the regular1 orderly structure of cells7 transmit the stimuli they have received in one part1 and thus provoke movements of other parts1 or of the whole organ4 ,this transmission of stimuli has as much title to be called psychic activity as its more complete form in the higher animals with nerves2 the anatomic explanation of it is that the social cells of the tissue1 or cell-community1 are not isolated from each other 7as was formerly supposed71 but are connected throughout by fine threads or bridges of protoplasm4 ,when the sensitive mimosa closes its graceful leaves and droops its stalk at contact1 or on being shaken2 when the irritable fly-trap 7the diona7 swiftly clasps its leaves together at a touch1 and captures a fly2 the sensation seems to be keener1 the transmission of the stimulus more rapid1 and the movement more energetic than in the reflex action of the stimulated bath-sponge and many other sponges4 ,b4 ,the soul of the nerveless metazoa4--,of very special interest for comparative psychology in general1 and for the phylogeny of the animal soul in particular1 is the psychic activity of those lower metazoa which have tissues1 and sometimes differentiated organs1 but no nerves or specific organs of sense4 ,to this category belong four different groups of the earliest coelenterates3 7a7 the gastrads1 7b7 the platodaria1 7c7 the sponges1 and 7d7 the hydropolyps1 the lowest form of cnidaria4 ,the gastraeads 7or animals with a primitive gut7 form a small group of the lowest coelenterates1 which is of great importance as the common ancestral group of all the metazoa4 ,the body of these little swimming animals looks like a tiny 7generally oval7 vesicle1 which has a simple cavity with one opening--the primitive gut and the primitive mouth4 ,the wall of the digestive cavity is formed of two simple layers of cells1 or epithelium1 the inner of which--the gut-layer--is responsible for the vegetal activity of nourishment1 while the outer1 or skin-layer1 discharges the animal functions of movement and sensation4 ,the homogeneous sensitive cells of the skin-layer bear long1 slender hairs or lashes 7cilia71 by the vibration of which the swimming motion is effected4 ,the few surviving forms of gastrads1 the gastrmaria 7trichoplacidae7 and cyemaria 7orthonectidae71 are extremely interesting1 from the fact that they remain throughout life at a stage of structure which is passed by all the other metazoa 7from the sponge to man7 at the commencement of their embryonic development4 ,as ,i have shown in my ,theory of the ,gastraea 7#ahgb71 a very characteristic embryonic form1 the gastrula1 is immediately developed from the blastula in all the tissue animals4 ,the germinal membrane 7blastoderm71 which represents the wall of the hollow vesicle1 forms a depression at one side1 and this soon sinks in so deep that the inner cavity of the vesicle disappears4 ,the half of the membrane which bends in is thus laid on1 and inside1 the other half2 the latter forms the skin-layer1 or outer germinal layer 7ectoderm or epiblast71 and the former becomes the gut-layer1 or inner germinal layer 7endoderm or hypoblast74 ,the new cavity of the cup-shaped body is the digestive stomach cavity 7the progaste71 and its opening is the primitive mouth 7or prostoma74#ai ,the skin-layer1 or ectoderm1 is the primitive psychic organ in the metazoa2 from it1 in all the nerve animals1 not only the external skin and the organs of sense1 but also the nervous system1 are developed4 ,in the gastrads1 which have no nerves1 all the cells which compose the simple epithelium of the ectoderm are equally organs of sensation and of movement2 we have here the tissue-soul in its simplest form4 ,the platodaria1 the earliest and simplest form of the platodes1 seem to be of the same primitive construction4 ,some of these cryptocoela--the convoluta1 etc4--have no specific nervous system1 while their nearest relatives1 the turbellaria1 have already differentiated one1 and even developed a vertical brain4 ,the sponges form a peculiar group in the animal world1 which differs widely in organization from all the other metazoa4 ,the innumerable kinds of sponges grow1 as a rule1 at the bottom of the sea4 ,the simplest form of sponge1 the olynthus1 is in reality nothing more than a gastraea1 the body-wall of which is perforated like a sieve1 with fine pores1 in order to permit the entrance of the nourishing stream of water4 ,in the majority of sponges--even in the most familiar one1 the bath-sponge--the bulbous organism constructs a kind of stem or tree1 which is made up of thousands of these gastrads1 and permeated by a nutritive system of canals4 ,sensation and movement are only developed in the faintest degree in the sponges2 they have no nerves1 muscles1 or organs of sense4 ,it was therefore quite natural that such stationary1 shapeless1 insensitive animals should have been commonly taken to be plants in earlier years4 ,their psychic life--for which no special organs have been differentiated--is far inferior to that of the mimosa and other sensitive plants4 ,the soul of the cnidaria is of the utmost importance in comparative and phylogenetic psychology2 for in this numerous group of the coelenterates the historical evolution of the nerve-soul out of the tissue-soul is repeated before our eyes4 ,to this group belong the innumerable classes of stationary polyps and corals1 and of swimming medus and siphonophora4 ,as the common ancestor of all the cnidaria we can safely assign a very simple polyp1 which is substantially the same in structure as the common1 still surviving1 fresh-water polyp--the hydra4 ,yet the hydr1 and the stationary1 closely related hydropolyps1 have no nerves or higher sense-organs1 although they are extremely sensitive4 ,on the other hand1 the free-swimming medus1 which are developed from them--and are still connected with them by alternation of generations--have an independent nervous system and specific sense-organs4 ,here1 also1 we may directly observe the ontogenetic evolution of the nerve-soul 7neuropsyche7 out of the tissue-soul 7histopsyche71 and thus learn its phylogenetic origin4 ,this is the more interesting as such phenomena are polyphyletic--that is1 they have occurred several times--more than once1 at least--quite independently4 ,as ,i have shown elsewhere1 the hydromedus have arisen from the hydropolyps in a different manner from that of the evolution of the scyphomedus from the scyphopolyps2 the gemmation is terminal in the case of the latter1 and lateral with the former4 ,in addition1 both groups have characteristic hereditary differences in the more minute structure of their psychic organs4 ,the class of siphonophora is also very interesting to the psychologist4 ,in these pretty1 free-swimming organisms1 which come from the hydromedus we can observe a double soul3 the personal soul of the numerous individualities which compose them1 and the common1 harmoniously acting psyche of the entire colony4 ,,iv4 ,the nerve-soul 7neuropsyche73 fourth stage of phyletic psychogeny4--,the psychic life of all the higher animals is conducted1 as in man1 by means of a more or less complicated psychic apparatus4 ,this apparatus is always composed of three chief sections3 the organs of sense are responsible for the various sensations2 the muscles effect the movements2 the nerves form the connection between the two by means of a special central organ1 the brain or ganglion4 ,the arrangement and action of this psychic mechanism have been frequently compared with those of a telegraphic system3 the nerves are the wires1 the brain the central1 and the sense-organs subordinate stations4 ,the motor nerves conduct the commands of the will centrifugally from the nerve-centre to the muscles1 by the contraction of which they produce the movements3 the sensitive nerves transmit the various sensations centripetally--that is1 from the peripheral sense-organs to the brain1 and thus render an account of the impressions they receive from the outer world4 ,the ganglionic cells1 or psychic cells1 which compose the central nervous organ1 are the most perfect of all organic elements2 they not only conduct the commerce between the muscles and the organs of sense1 but they also effect the highest performances of the animal soul1 the formation of ideas and thoughts1 and especially consciousness4 ,the great progress of anatomy1 physiology1 histology1 and ontogeny has recently added a wealth of interesting discoveries to our knowledge of the mechanism of the soul4 ,if speculative philosophy assimilated only the most important of these significant results of empirical biology1 it would have a very different character from that it unfortunately presents4 ,as ,i have not space for an exhaustive treatment of them here1 ,i will confine myself to a relation of the chief facts4 ,each of the higher animal species has a characteristic psychic organ2 the central nervous system of each has certain peculiarities of shape1 position1 and composition4 ,the medus1 among the radiating cnidaria1 have a ring of nervous matter at the border of the fringe1 generally provided with four or eight ganglia4 ,the mouth of the five-rayed cnidarion is girt with a nerve-ring1 from which proceed five branches4 ,the bi-symmetrical platodes and the vermalia have a vertical brain1 or acroganglion1 composed of two dorsal ganglia1 lying above the mouth2 from these upper ganglia two branch nerves proceed to the skin and the muscles4 ,in some of the vermalia and in the mollusca a pair of ventral lower ganglia are added1 which are connected with the former by a ring round the gullet4 ,this ring is found also in the articulata2 but in these it is continued on the belly side of the long body as a ventral medulla1 a double fibre like a rope-ladder1 which expands into a double ganglion in each member4 ,the vertebrates have an entirely different formation of the psychic organ2 they have always a spinal medulla developed at the back of the body2 and from an expansion of its fore part there arises subsequently the characteristic vesicular brain4#bj ,although the psychic organs of the higher species of animals differ very materially in position1 form1 and composition1 nevertheless comparative anatomy is in a position to prove a common origin for most of them--namely1 from the vertical brain of the platodes and vermalia2 they have all1 moreover1 had their origin in the outermost layer of the embryo1 the ectoderm1 or outer skin-layer4 ,hence we find the same typical structure in all varieties of the central nervous organ--a combination of ganglionic cells1 or psychic cells 7the real active elementary organs of the soul71 and of nerve-fibres1 which effect the connection and transmission of the action4 ,the first fact we meet in the comparative psychology of the vertebrates1 and which should be the empirical starting-point of all scientific human psychology1 is the characteristic structure of the central nervous system4 ,this central psychic organ has a particular position1 shape1 and texture in the vertebrate as it has in all the higher species4 ,in every case we find a spinal medulla1 a strong cylindrical nervous cord1 which runs down the middle of the back1 in the upper part of the vertebral column 7or the cord which represents it74 ,in every case a number of nerves branch off from this medulla in regular division1 one pair to each segment or vertebra4 ,in every case this medullary cord arises in the same way in the foetus2 a fine groove appears in the middle axis of the skin at the back2 then the parallel borders of this medullary groove are lifted up a little1 bend over towards each other1 and form into a kind of tube4 ,the long dorsal cylindrical medullary tube which is thus formed is thoroughly characteristic of the vertebrates2 it is always the same in the early embryonic sketch of the organism1 and it is always the chief feature of the different kinds of psychic organ which evolve from it in time4 ,only one single group of invertebrates has a similar structure3 the rare1 marine tunicata1 copelata1 ascidia1 and thalidi4 ,these animals have other important peculiarities of structure 7especially in the chorda and the gut7 which show a striking divergence from the other invertebrates and resemblance to the vertebrates4 ,the inference we draw is that both these groups1 the vertebrates and the tunicates1 have arisen from a common ancestral group of the vermalia1 the prochordonia4#ba ,still1 there is a great difference between the two classes in the fact that the body of the tunicate does not articulate1 or form members1 and has a very simple organization 7most of them subsequently attach themselves to the bottom of the sea and degenerate74 ,the vertebrate1 on the other hand1 is characterized by an early development of internal members1 and the formation of pro-vertebr 7vertebratio74 ,this prepares the way for the much higher development of their organism1 which finally attains perfection in man4 ,this is easily seen in the finer structure of his spinal cord1 and in the development of a number of segmental pairs of nerves1 the spinal nerves1 which proceed to the various parts of the body4 ,the long ancestral history of our vertebrate soul commences with the formation of the most rudimentary spinal cord in the earliest acrania2 slowly and gradually1 through a period of many millions of years1 it conducts to that marvellous structure of the human brain which seems to entitle the highest primate form to quite an exceptional position in nature4 ,since a clear conception of this slow and steady progress of our phyletic psychogeny is indispensable for a true psychology1 we must divide that vast period into a number of stages or sections3 in each of them the perfecting of the structure of the nervous centre has been accompanied by a corresponding evolution of its function1 the psyche4 ,i distinguish eight of these periods in the phylogeny of the spinal cord1 which are characterized by eight different groups of vertebrates3 7#a7 the acrania2 7#b7 the cyclostomata2 7#c7 the fishes2 7#d7 the amphibia2 7#e7 the implacental mammals 7monotremes and marsupials72 7#f7 the earlier placental mammals1 especially the prosimi2 7#g7 the younger primates1 the simi2 and 7#h7 the anthropoid apes and man4 ,i4 ,first stage--the acrania3 their only modern representative is the lancelot or amphioxus2 the psychic organ remains a simple medullary tube1 and contains a regularly segmented spinal cord1 without brain4 ,,ii4 ,second stage--the cyclostomata3 the oldest group of the craniota1 now only represented by the petromyzontes and myxinoides3 the fore-termination of the cord expands into a vesicle1 which then subdivides into five successive parts--the great-brain1 intermediate-brain1 middle-brain1 little-brain1 and hind-brain3 these five cerebral vesicles form the common type from which the brain of all craniota has evolved1 from the lamprey to man4 ,,iii4 ,third stage--the primitive fishes 7selachii73 similar to the modern shark3 in these oldest fishes1 from which all the gnathostomata descend1 the more pronounced division of the five cerebral vesicles sets in4 ,,iv4 ,fourth stage--the amphibia4 ,these earliest land animals1 making their first appearance in the ,carboniferous period1 represent the commencement of the characteristic structure of the tetrapod and a corresponding development of the fish-brain3 it advances still further in their ,permian successors1 the reptiles1 the earliest representatives of which1 the tocosauria1 are the common ancestors of all the amniota 7reptiles and birds on one side1 mammals on the other74 ,v4-,,viii4 ,fifth to the eighth stages--the mammals4 ,i have exhaustively treated1 and illustrated with a number of plates1 in my ,anthropogeny1 the evolution of our nervous system and the correlative question of the development of the soul4 ,i have now1 therefore1 merely to refer the reader to that work4 ,it only remains for me to add a few remarks on the last and most interesting class of facts pertaining to this--to the evolution of the soul and its organs within the limits of the class mammalia4 ,in doing so1 ,i must remind the reader that the monophyletic origin of this class--that is1 the descent of all the mammals from one common ancestral form 7of the ,triassic period7--is now fully established4 ,the most important consequence of the monophyletic origin of the mammals is the necessity of deriving the human soul from a long evolutionary series of other mammal souls4 ,a deep anatomical and physiological gulf separated the brain structure and the dependent psychic activity of the higher mammals from those of the lower3 this gulf1 however1 is completely bridged over by a long series of intermediate stages4 ,the period of at least fourteen 7more than a hundred1 on other estimates7 million years1 which has elapsed since the commencement of the ,triassic period1 is amply sufficient to allow even the greatest psychological advance4 ,the following is a summary of the results of investigation in this quarter1 which has recently been very penetrating3 ,i4 ,the brain of the mammal is differentiated from that of the other vertebrates by certain features1 which are found in all branches of the class2 especially by a preponderant development of the first and fourth vesicles1 the cerebrum and cerebellum1 while the third vesicle1 the middle brain1 disappears altogether4 ,,ii4 ,the brain development of the lowest and earliest mammals 7the monotremes1 marsupials1 and prochoriates7 is closely allied to that of their palozoic ancestors1 the ,carboniferous amphibia 7the stegocephala7 and the ,permian reptiles 7the tocosauria74 ,,iii4 ,during the ,tertiary period commences the typical development of the cerebrum1 which distinguishes the younger mammals so strikingly from the older4 ,,iv4 ,the special development 7quantitatively and qualitatively7 of the cerebrum which is so prominent a feature in man1 and which is the root of his pre-eminent psychic achievements1 is only found1 outside humanity1 in a small section of the most highly developed mammals of the earlier ,tertiary epoch1 especially in the anthropoid apes4 ,v4 ,the differences of brain structure and psychic faculty which separate man from the anthropoid ape are slighter than the corresponding interval between the anthropoid apes and the lower primates 7the earliest simi and prosimi74 ,,vi4 ,consequently1 the historical1 gradual evolution of the human soul from a long chain of higher and lower mammal souls must1 by application of the universally valid phyletic laws of the theory of descent1 be regarded as a fact which has been scientifically proved4 ,,chapter ,x ,,consciousness ,consciousness as a ,natural ,phenomenon--,its ,definition--,difficulties of the ,problem--,its ,relation to the ,life of the ,soul--,our ,human ,consciousness--,various ,theories3 ,i4 ,anthropistic ,theory 7,descartes72 ,,ii4 ,neurological ,theory 7,darwin72 ,,iii4 ,animal ,theory 7,schopenhauer72 ,,iv4 ,biological ,theory 7,fechner72 ,v4 ,cellular ,theory 7,fritz ,schultze72 ,,vi4 ,atomistic ,theory--,monistic and ,dualistic ,theories--,transcendental ,character of ,consciousness--,the ,ignorabimus ,verdict of ,du ,bois-,reymond--,physiology of ,consciousness--,discovery of the ,organs of ,thought by ,flechsig--,pathology--,double and ,intermittent ,consciousness--,ontogeny of ,consciousness3 ,modifications at ,different ,ages--,phylogeny of ,consciousness--,formation of ,concepts ,no phenomenon of the life of the soul is so wonderful and so variously interpreted as consciousness4 ,the most contradictory views are current to-day1 as they were two thousand years ago1 not only with regard to the nature of this psychic function and its relation to the body1 but even as to its diffusion in the organic world and its origin and development4 ,it is more responsible than any other psychic faculty for the erroneous idea of an immaterial soul and the belief in personal immortality2 many of the gravest errors that still dominate even our modern civilization may be traced to it4 ,hence it is that ,i have entitled consciousness the central mystery of psychology2 it is the strong citadel of all mystic and dualistic errors1 before whose ramparts the best-equipped efforts of reason threaten to miscarry4 ,this fact would suffice of itself to induce us to make a special critical study of consciousness from our monistic point of view4 ,we shall see that consciousness is simply a natural phenomenon like any other psychic quality1 and that it is subject to the law of substance like all other natural phenomena4 ,even as to the elementary idea of consciousness1 its contents and extension1 the views of the most distinguished philosophers and scientists are widely divergent4 ,perhaps the meaning of consciousness is best conceived as an internal perception1 and compared with the action of a mirror4 ,as its two chief departments we distinguish objective and subjective consciousness--consciousness of the world1 the non-ego1 and of the ego4 ,by far the greater part of our conscious activity1 as ,schopenhauer justly remarked1 belongs to the consciousness of the outer world1 or the non-ego3 this world-consciousness embraces all possible phenomena of the outer world which are in any sense accessible to our minds4 ,much more contracted is the sphere of self-consciousness1 the internal mirror of all our own psychic activity1 all our presentations1 sensations1 and volitions4 ,many distinguished thinkers1 especially on the physiological side 7,wundt and ,ziehen1 for instance7 take the ideas of consciousness and psychic function to be identical--all psychic action is conscious2 the province of psychic life1 they say1 is coextensive with that of consciousness4 ,in our opinion1 such a definition gives an undue extension to the meaning of consciousness1 and occasions many errors and misunderstandings4 ,we share1 rather1 the view of other philosophers 7,romanes1 ,fritz ,schultze1 and ,paulsen71 that even our unconscious presentations1 sensations1 and volitions pertain to our psychic life2 indeed1 the province of these unconscious psychic actions 7reflex action1 and so forth7 is far more extensive than that of consciousness4 ,moreover1 the two provinces are intimately connected1 and are separated by no sharp line of demarcation4 ,an unconscious presentation may become conscious at any moment2 let our attention be withdrawn from it by some other object1 and forthwith it disappears from consciousness once more4 ,the only source of our knowledge of consciousness is that faculty itself2 that is the chief cause of the extraordinary difficulty of subjecting it to scientific research4 ,subject and object are one and the same in it3 the perceptive subject mirrors itself in its own inner nature1 which is to be the object of our inquiry4 ,thus we can never have a complete objective certainty of the consciousness of others2 we can only proceed by a comparison of their psychic condition with our own4 ,as long as this comparison is restricted to normal people we are justified in drawing certain conclusions as to their consciousness1 the validity of which is unchallenged4 ,but when we pass on to consider abnormal individuals 7the genius1 the eccentric1 the stupid1 or the insane7 our conclusions from analogy are either unsafe or entirely erroneous4 ,the same must be said with even greater truth when we attempt to compare human consciousness with that of the animals 7even the higher1 but especially the lower74 ,in that case such grave difficulties arise that the views of physiologists and philosophers diverge as widely as the poles on the subject4 ,we shall briefly enumerate the most important of these views4 ,i4 ,the anthropistic theory of consciousness4--,it is peculiar to man4 ,to ,descartes we must trace the widespread notion that consciousness and thought are man's exclusive prerogative1 and that he alone is blessed with an immortal soul4 ,this famous ,french philosopher and mathematician 7educated in a ,jesuit ,college7 established a rigid partition between the psychic activity of man and that of the brute4 ,in his opinion the human soul1 a thinking1 immaterial being1 is completely separated from the body1 which is extended and material4 ,yet it is united to the body at a certain point in the brain 7the glandula pinealis7 for the purpose of receiving impressions from the outer world and effecting muscular movements4 ,the animals1 not being endowed with thought1 have no soul3 they are mere automata1 or cleverly constructed machines1 whose sensations1 presentations1 and volitions are purely mechanical1 and take place according to the ordinary laws of physics4 ,hence ,descartes was a dualist in human psychology1 and a monist in the psychology of the brute4 ,this open contradiction in so clear and acute a thinker is very striking2 in explaining it1 it is not unnatural to suppose that he concealed his real opinion1 and left the discovery of it to independent scholars4 ,as a pupil of the ,jesuits1 ,descartes had been taught to deny the truth in the face of his better insight2 and perhaps he dreaded the power and the fires of the ,church4 ,besides1 his sceptical principle1 that every sincere effort to attain the truth must start with a doubt of the traditional dogma had already drawn upon him fanatical accusations of scepticism and atheism4 ,the great influence which ,descartes had on subsequent philosophy was very remarkable1 and entirely in harmony with his book-keeping by double entry4 ,the materialists of the seventeenth and eighteenth centuries appealed to the ,cartesian theory of the animal soul and its purely mechanical activity in support of their monistic psychology4 ,the spiritualists1 on the other hand1 asserted that their dogma of the immortality of the soul and its independence of the body was firmly established by ,descartes' theory of the human soul4 ,this view is still prevalent in the camp of the theologians and dualistic metaphysicians4 ,the scientific conception of nature1 however1 which has been built up in the nineteenth century1 has1 with the aid of empirical progress1 in physiological and comparative psychology1 completely falsified it4 ,,ii4 ,neurological theory of consciousness4--,it is present only in man and those higher animals which have a centralized nervous system and organs of sense4 ,the conviction that a large number of animals--at least the higher mammals--are not less endowed than man with a thinking soul and consciousness prevails in modern zoology1 exact physiology1 and the monistic psychology4 ,the immense progress we have made in the various branches of biology has contributed to bring about a recognition of this important truth4 ,we confine ourselves for the present to the higher vertebrates1 and especially the mammals4 ,that these most intelligent specimens of these highly developed vertebrates--apes and dogs1 in particular--have a strong resemblance to man in their whole psychic life has been recognized and speculated on for thousands of years4 ,their faculty of presentation and sensation1 of feeling and desire1 is so like that of man that we need adduce no proof of our thesis4 ,but even the higher associational activity of the brain1 the formation of judgments and their connection into chains of reasoning1 thought1 and consciousness in the narrower sense1 are developed in them after the same fashion as in man3 they differ only in degree1 not in kind4 ,moreover1 we learn from comparative anatomy and histology that the intricate structure of the brain 7both in general and in detail7 is substantially the same in the mammals as it is in man4 ,the same lesson is enforced by comparative ontogeny with regard to the origin of these psychic organs4 ,comparative physiology teaches us that the various states of consciousness are just the same in these highest placentals as in man2 and we learn by experiment that there is the same reaction to external stimuli4 ,the higher animals can be narcotized by alcohol1 chloroform1 ether1 etc41 and may be hypnotized by the usual methods1 just as in the case of man4 ,it is1 however1 impossible to determine mathematically at what stage of animal life consciousness is to be first recognized as such4 ,some zoologists draw the line very high in the scale1 others very low4 ,darwin1 who most accurately distinguishes the various stages of consciousness1 intelligence1 and emotion in the higher animals1 and explains them by progressive evolution1 points out how difficult1 or even impossible1 it is to determine the first beginning of this supreme psychic faculty in the lower animals4 ,personally1 out of the many contradictory theories1 ,i take that to be most probable which holds the centralization of the nervous system to be a condition of consciousness2 and that is wanting in the lower classes of animals4 ,the presence of a central nervous organ1 of highly developed sense-organs1 and an elaborate association of groups of presentations1 seem to me to be required before the unity of consciousness is possible4 ,,iii4 ,animal theory of consciousness4--,all animals1 and they alone1 have consciousness4 ,this theory would draw a sharp distinction between the psychic life of the animal and of the plant4 ,such a distinction was urged by many of the older writers1 and was clearly formulated by ,linn in his celebrated ,systema ,naturae2 the two great kingdoms of the organic world are1 in his opinion1 divided by the fact that animals have sensation and consciousness1 and the plants are devoid of them4 ,later on ,schopenhauer laid stress on the same distinction3 ,consciousness is only known to us as a feature of animal nature4 ,even though it extend upwards through the whole animal kingdom1 even to man and his reason1 the unconsciousness of the plant1 from which it started1 remains as the basic feature4 ,in the lowest animals we have but the dawn of it4 ,the inaccuracy of this view was obvious by about the middle of the present century1 when a deeper study was made of the psychic activity of the lower animal forms1 especially the coelenterates 7sponges and cnidaria73 they are undoubtedly animals1 yet there is no more trace of a definite consciousness in them than in most of the plants4 ,the distinction between the two kingdoms was still further obliterated when more careful research was made into their unicellular forms4 ,there is no psychological difference between the plasmophagous protozoa and the plasmodomous protophyta1 even in respect of their consciousness4 ,,iv4 ,biological theory of consciousness4--,it is found in all organisms1 animal or vegetal1 but not in lifeless bodies 7such as crystals74 ,this opinion is usually associated with the idea that all organisms 7as distinguished from inorganic substances7 have souls3 the three ideas--life1 soul1 and consciousness--are then taken to be coextensive4 ,another modification of this view holds that1 though these fundamental phenomena of organic life are inseparably connected1 yet consciousness is only a part of the activity of the soul1 and of the vital activity4 ,fechner1 in particular1 has endeavored to prove that the plant has a soul1 in the same sense as an animal is said to have one2 and many credit the vegetal soul with a consciousness similar to that of the animal soul4 ,in truth1 the remarkable stimulated movements of the leaves of the sensitive plants 7the mimosa1 drosera1 and diona71 the automatic movements of other plants 7the clover and wood-sorrel1 and especially the hedysarum71 the movements of the sleeping plants 7particularly the papilionacea71 etc41 are strikingly similar to the movements of the lower animal forms3 whoever ascribes consciousness to the latter cannot refuse it to such vegetal forms4 ,v4 ,cellular theory of consciousness4--,it is a vital property of every cell4 ,the application of the cellular theory to every branch of biology involved its extension to psychology4 ,just as we take the living cell to be the elementary organism in anatomy and physiology1 and derive the whole system of the multicellular animal or plant from it1 so1 with equal right1 we may consider the cell-soul to be the psychological unit1 and the complex psychic activity of the higher organism to be the result of the combination of the psychic activity of the cells which compose it4 ,i gave the outlines of this cellular psychology in my ,general ,morphology in #ahff1 and entered more fully into the subject in my paper on ,cell-,souls and ,soul-,cells4 ,i was led to a deeper study of this elementary psychology by my protracted research into the unicellular forms of life4 ,many of these tiny 7generally microscopic7 protists show similar expressions of sensation and will1 and similar instincts and movements1 to those of higher animals2 that is especially true of the very sensitive and lively infusoria4 ,in the relation of these sensitive cell-organisms to their environment1 and in many other of their vital expressions 7for instance1 in the wonderful architecture of the rhizopods1 the thalamophor1 and the infusoria71 we seemed to have clear indications of conscious psychic action4 ,if1 then1 we accept the biological theory of consciousness 7,no4 ,,iv471 and credit every psychic function with a share of that faculty1 we shall be compelled to ascribe it to each independent protist cell4 ,in that case its material basis would be either the entire protoplasm of the cell1 or its nucleus1 or a portion of it4 ,in the psychade theory of ,fritz ,schultze the elementary consciousness of the psychade would have the same relation to the individual cells as personal consciousness has to the multicellular organism of the personality in the higher animals and man4 ,it is impossible definitively to disprove this theory1 which ,i held at one time4 ,still1 ,i now feel compelled to agree with ,max ,verworn1 in his belief that none of the protists have a developed self-consciousness1 but that their sensations and movements are of an unconscious character4 ,,vi4 ,atomistic theory of consciousness4--,it is an elementary property of all atoms4 ,this atomistic hypothesis goes furthest of all the different views as to the extension of consciousness4 ,it certainly escapes the difficulty which so many philosophers and biologists experience in solving the problem of the first origin of consciousness4 ,it is a phenomenon of so peculiar a character that a derivation of it from other psychic functions seems extremely hazardous4 ,it seemed1 therefore1 the easiest way out of the difficulty to conceive it as an inherent property of all matter1 like gravitation or chemical affinity4 ,on that hypothesis there would be as many forms of this original consciousness as there are chemical elements2 each atom of hydrogen would have its hydrogenic consciousness1 each atom of carbon its carbonic consciousness1 and so forth4 ,there are philosophers1 even1 who ascribe consciousness to the four elements of ,empedocles1 the union of which1 by love and hate1 produces the totality of things4 ,personally1 ,i have never subscribed to this hypothesis of atomic consciousness4 ,i emphasize the point because ,emil du ,bois-,reymond has attributed it to me4 ,in the controversy ,i had with him 7#ahhj7 he violently attacked my pernicious and false philosophy1 and contended that ,i had1 in my paper on ,the ,perigenesis of the ,plastidule1 laid it down as a metaphysical axiom that every atom has its individual consciousness4 ,on the contrary1 ,i explicitly stated that ,i conceive the elementary psychic qualities of sensation and will1 which may be attributed to atoms1 to be unconscious--just as unconscious as the elementary memory which ,i1 in company with that distinguished physiologist1 ,ewald ,hering1 consider to be a common function of all organized matter--or1 more correctly1 living substance4 ,du ,bois-,reymond curiously confuses soul and consciousness2 whether from oversight or not ,i cannot say4 ,since he considers consciousness to be a transcendental phenomenon 7as we shall see presently71 while denying that character to other psychic functions--the action of the senses1 for example--,i must infer that he recognizes the difference of the two ideas4 ,other parts of his eloquent speeches contain quite the opposite view1 for the famous orator not infrequently contradicts himself on important questions of principle4 ,however1 ,i repeat that1 in my opinion1 consciousness is only part of the psychic phenomena which we find in man and the higher animals2 the great majority of them are unconscious4 ,however divergent are the different views as to the nature and origin of consciousness1 they may1 nevertheless1 on a clear and logical examination1 all be reduced to two fundamental theories--the transcendental 7or dualistic7 and the physiological 7or monistic74 ,i have myself always held the latter view1 in the light of my evolutionary principles1 and it is now shared by a great number of distinguished scientists1 though it is by no means generally accepted4 ,the transcendental theory is the older and much more common2 it has recently come once more into prominence1 principally through ,du ,bois-,reymond1 and it has acquired a great importance in modern discussions of cosmic problems through his famous ,ignorabimus speech4 ,on account of the extreme importance of this fundamental question we must touch briefly on its main features4 ,in the celebrated discourse on ,the ,limits of ,natural ,science1 which ,e4 du ,bois-,reymond gave on ,august #ad1 #ahgb1 at the ,scientific ,congress at ,leipzig1 he spoke of two absolute limits to our possible knowledge of nature which the human mind will never transcend in its most advanced science--never1 as the oft-quoted termination of the address1 ,ignorabimus1 emphatically pronounces4 ,the first absolutely insoluble world-enigma is the connection of matter and force1 and the distinctive character of these fundamental natural phenomena2 we shall go more fully into this problem of substance in the twelfth chapter4 ,the second insuperable difficulty of philosophy is given as the problem of consciousness--the question how our mental activity is to be explained by material conditions1 especially movements1 how substance the substance which underlies matter and force comes1 under certain conditions1 to feel1 to desire1 and to think4 ,for brevity1 and in order to give a characteristic name to the ,leipzig discourse1 ,i have called it the ,ignorabimus speech2 this is the more permissible1 as ,e4 du ,bois-,reymond himself1 with a just pride1 eight years afterwards1 speaking of the extraordinary consequences of his discourse1 said3 ,criticism sounded every possible note1 from friendly praise to the severest censure1 and the word ',ignorabimus1' which was the culmination of my inquiry1 was at once transformed into a kind of scientific shibboleth4 ,it is quite true that loud praise and approbation resounded in the halls of the dualistic and spiritualistic philosophy1 and especially in the camp of the ,church militant2 even the spiritists and the host of believers1 who thought the immortality of their precious souls was saved by the ,ignorabimus1 joined in the chorus4 ,the severest censure came at first only from a few scientists and philosophers--from the few who had sufficient scientific knowledge and moral courage to oppose the dogmatism of the all-powerful secretary and dictator of the ,berlin ,academy of ,science4 ,towards the end1 however1 the author of the ,ignorabimus speech briefly alluded to the question whether these two great world-enigmas1 the general problem of substance and the special problem of consciousness1 are not two aspects of one and the same problem4 ,this idea1 he said1 is certainly the simplest1 and preferable to the one which makes the world doubly incomprehensible4 ,such1 however1 is the nature of things that even here we can obtain no clear knowledge1 and it is useless to speak further of the question4 ,the latter sentiment ,i have always stoutly contested1 and have endeavored to prove that the two great questions are not two distinct problems4 ,the neurological problem of consciousness is but a particular aspect of the all-pervading cosmological problem of substance4 ,the peculiar phenomenon of consciousness is not1 as ,du ,bois-,reymond and the dualistic school would have us believe1 a completely transcendental problem2 it is1 as ,i showed thirty-three years ago1 a physiological problem1 and1 as such1 must be reduced to the phenomena of physics and chemistry4 ,i subsequently gave it the more definite title of a neurological problem1 as ,i share the view that true consciousness 7thought and reason7 is only present in those higher animals which have a centralized nervous system and organs of sense of a certain degree of development4 ,those conditions are certainly found in the higher vertebrates1 especially in the placental mammals1 the class from which man has sprung4 ,the consciousness of the highest apes1 dogs1 elephants1 etc41 differs from that of man in degree only1 not in kind1 and the graduated interval between the consciousness of these rational placentals and that of the lowest races of men 7the ,veddahs1 etc47 is less than the corresponding interval between these uncivilized races and the highest specimens of thoughtful humanity 7,spinoza1 ,goethe1 ,lamarck1 ,darwin1 etc474 ,consciousness is but a part of the higher activity of the soul1 and as such it is dependent on the normal structure of the corresponding psychic organ1 the brain4 ,physiological observation and experiment determined twenty years ago that the particular portion of the mammal-brain which we call the seat 7preferably the organ7 of consciousness is a part of the cerebrum1 an area in the late-developed gray bed1 or cortex1 which is evolved out of the convex dorsal portion of the primary cerebral vesicle1 the fore-brain4 ,now1 the morphological proof of this physiological thesis has been successfully given by the remarkable progress of the microscopic anatomy of the brain1 which we owe to the perfect methods of research of modern science 7,klliker1 ,flechsig1 ,golgi1 ,edinger1 ,weigert1 and others74 ,the most important development is the discovery of the organs of thought by ,paul ,flechsig1 of ,leipzig2 he proved that in the gray bed of the brain are found the four seats of the central sense-organs1 or four inner spheres of sensation--the sphere of touch in the vertical lobe1 the sphere of smell in the frontal lobe1 the sphere of sight in the occipital lobe1 and the sphere of hearing in the temporal lobe4 ,between these four sense-centres lie the four great thought-centres1 or centres of association1 the real organs of mental life2 they are those highest instruments of psychic activity that produce thought and consciousness4 ,in front we have the frontal brain or centre of association2 behind1 on top there is the vertical brain1 or parietal centre of association1 and underneath the principal brain1 or the great occipito-temporal centre of association 7the most important of all72 lower down1 and internally1 the insular brain or the insula of ,reil1 the insular centre of association4 ,these four thought-centres1 distinguished from the intermediate sense-centres by a peculiar and elaborate nerve-structure1 are the true and sole organs of thought and consciousness4 ,flechsig has recently pointed out that1 in the case of man1 very specific structures are found in one part of them2 these structures are wanting in the other mammals1 and they1 therefore1 afford an explanation of the superiority of man's mental powers4 ,the momentous announcement of modern physiology1 that the cerebrum is the organ of consciousness and mental action in man and the higher mammals1 is illustrated and confirmed by the pathological study of its diseases4 ,when parts of the cortex are destroyed by disease their respective functions are affected1 and thus we are enabled1 to some extent1 to localize the activities of the brain2 when certain parts of the area are diseased1 that portion of thought and consciousness disappears which depends on those particular sections4 ,pathological experiment yields the same result2 the decay of some known area 7for instance1 the centre of speech7 extinguishes its function 7speech74 ,in fact1 there is proof enough in the most familiar phenomena of consciousness of their complete dependence on chemical changes in the substance of the brain4 ,many beverages 7such as coffee and tea7 stimulate our powers of thought2 others 7such as wine and beer7 intensify feeling2 musk and camphor reanimate the fainting consciousness2 ether and chloroform deaden it1 and so forth4 ,how would that be possible if consciousness were an immaterial entity1 independent of these anatomical organs8 ,and what becomes of the consciousness of the immortal soul when it no longer has the use of these organs8 ,these and other familiar facts prove that man's consciousness--and that of the nearest mammals--is changeable1 and that its activity is always open to modification from inner 7alimentation1 circulation1 etc47 and outer causes 7lesion of the brain1 stimulation1 etc474 ,very instructive1 too1 are the facts of double and intermittent consciousness1 which remind us of alternate generations of presentations4 ,the same individual has an entirely different consciousness on different days1 with a change of circumstances2 he does not know to-day what he did yesterday3 yesterday he could say1 ,i am ,i2 to-day he must say1 ,i am another being4 ,such intermittence of consciousness may last not only days1 but months1 and even years2 the change may even become permanent4 ,as everybody knows1 the new-born infant has no consciousness4 ,preyer has shown that it is only developed after the child has begun to speak2 for a long time it speaks of itself in the third person4 ,in the important moment when it first pronounces the word ,i1 when the feeling of self becomes clear1 we have the beginning of self-consciousness1 and of the antithesis to the non-ego4 ,the rapid and solid progress in knowledge which the child makes in its first ten years1 under the care of parents and teachers1 and the slower progress of the second decade1 until it reaches complete maturity of mind1 are intimately connected with a great advancement in the growth and development of consciousness and of its organ1 the brain4 ,but even when the pupil has got his certificate of maturity his consciousness is still far from mature2 it is then that his world-consciousness first begins to develop1 in his manifold relations with the outer world4 ,then1 in the third decade1 we have the full maturity of rational thought and consciousness1 which1 in cases of normal development1 yield their ripe fruits during the next three decades4 ,the slow1 gradual degeneration of the higher mental powers1 which characterizes senility1 usually sets in at the commencement of the seventh decade--sometimes earlier1 sometimes later4 ,memory1 receptiveness1 and interest in particular objects gradually decay2 though productivity1 mature consciousness1 and philosophic interest in general truths often remain for many years longer4 ,the individual development of consciousness in earlier youth proves the universal validity of the biogenetic law2 and1 indeed1 it is still recognizable in many ways during the later years4 ,in any case1 the ontogenesis of consciousness makes it perfectly clear that it is not an immaterial entity1 but a physiological function of the brain1 and that it is1 consequently1 no exception to the general law of substance4 ,from the fact that consciousness1 like all other psychic functions1 is dependent on the normal development of certain organs1 and that it gradually unfolds in the child in proportion to the development of those organs1 we may already conclude that it has arisen in the animal kingdom by a gradual historical development4 ,still1 however certain we are of the fact of this natural evolution of consciousness1 we are1 unfortunately1 not yet in a position to enter more deeply into the question and construct special hypotheses in elucidation of it4 ,palontology1 it is true1 gives us a few facts which are not without significance4 ,for instance1 the quantitative and qualitative development of the brain of the placental mammals during the ,tertiary period is very remarkable4 ,the cavity of many of the fossil skulls of the period has been carefully examined1 and has given us a good deal of reliable information as to the size1 and1 to some extent1 as to the structure1 of the brain they enclosed4 ,we find1 within the limits of one and the same group 7the ungulates1 the rodents1 or the primates71 a marked advance in the later miocene and pliocene specimens as compared with the earlier eocene and oligocene representatives of the same stem2 in the former the brain 7in proportion to the size of the organism7 is six to eight times as large as in the latter4 ,moreover1 that highest stage of consciousness1 which is reached by man alone1 has been evolved step by step--even by the very progress of civilization--from a lower condition1 as we find illustrated to-day in the case of uncivilized races4 ,that is easily proved by a comparison of their languages1 which is closely connected with the comparison of their ideas4 ,the higher the conceptual faculty advances in thoughtful civilized man1 the more qualified he is to detect common features amid a multitude of details1 and embody them in general concepts1 and so much the clearer and deeper does his consciousness become4 ,,chapter ,,xi ,,the ,,immortality ,,of ,,the ,,soul ,the ,citadel of ,superstition--,athanatism and ,thanatism--,individual ,character of ,death--,immortality of the ,unicellular ,organisms 7,protists7--,cosmic and ,personal ,immortality--,primary ,thanatism 7of ,uncivilized ,peoples7--,secondary ,thanatism 7of ,ancient and ,recent ,philosophers7--,athanatism and ,religion--,origin of the ,belief in ,immortality--,christian ,athanatism--,eternal ,life--,the ,day of ,judgment--,metaphysical ,athanatism--,substance of the ,soul--,ether ,souls and ,air ,souls2 ,fluid ,souls and ,solid ,souls--,immortality of the ,animal ,soul--,arguments for and ,against ,athanatism--,athanatist ,illusions ,when we turn from the genetic study of the soul to the great question of its immortality1 we come to that highest point of superstition which is regarded as the impregnable citadel of all mystical and dualistic notions4 ,for in this crucial question1 more than in any other problem1 philosophic thought is complicated by the selfish interest of the human personality1 who is determined to have a guarantee of his existence beyond the grave at any price4 ,this higher necessity of feeling is so powerful that it sweeps aside all the logical arguments of critical reason4 ,consciously or unconsciously1 most men are influenced in all their general views1 and1 therefore1 in their theory of life1 by the dogma of personal immortality2 and to this theoretical error must be added practical consequences of the most far-reaching character4 ,it is our task1 therefore1 to submit every aspect of this important dogma to a critical examination1 and to prove its untenability in the light of the empirical data of modern biology4 ,in order to have a short and convenient expression for the two opposed opinions on the question1 we shall call the belief in man's personal immortality athanatism 7from athanes or athanatos immortal74 ,on the other hand1 we give the name of thanatism 7from thanatos death7 to the opinion which holds that at a man's death not only all the other physiological functions are arrested1 but his soul also disappears--that is1 that sum of cerebral functions which psychic dualism regards as a peculiar entity1 independent of the other vital processes in the living body4 ,in approaching this physiological problem of death we must point out the individual character of this organic phenomenon4 ,by death we understand simply the definitive cessation of the vital activity of the individual organism1 no matter to which category or stage of individuality the organism in question belongs4 ,man is dead when his own personality ceases to exist1 whether he has left offspring that they may continue to propagate for many generations or not4 ,in a certain sense we often say that the minds of great men 7in a dynasty of eminent rulers1 for instance1 or a family of talented artists7 live for many generations2 and in the same way we speak of the soul of a noble woman living in her children and children's children4 ,but in these cases we are dealing with intricate phenomena of heredity1 in which a microscopic cell 7the sperm-cell of the father or the egg-cell of the mother7 transmits certain features to offspring4 ,the particular personalities who produce those sexual cells in thousands are mortal beings1 and at their death their personal psychic activity is extinguished like every other physiological function4 ,a number of eminent zoologists--,weismann being particularly prominent--have recently defended the opinion that only the lowest unicellular organisms1 the protists1 are immortal1 in contradistinction to the multicellular plants and animals1 whose bodies are formed of tissues4 ,this curious theory is especially based on the fact that most of the protists multiply without sexual means1 by division or the formation of spores4 ,in such processes the whole body of the unicellular organism breaks up into two or more equal parts 7daughter cells71 and each of these portions completes itself by further growth until it has the size and form of the mother cell4 ,however1 by the very process of division the individuality of the unicellular creature has been destroyed2 both its physiological and its morphological unity have gone4 ,the view of ,weismann is logically inconsistent with the very notion of individual--an indivisible entity2 for it implies a unity which cannot be divided without destroying its nature4 ,in this sense the unicellular protophyta and protozoa are throughout life physiological individuals1 just as much as the multicellular tissue-plants and animals4 ,a sexual propagation by simple division is found in many of the multicellular species 7for instance1 in many cnidaria1 corals1 medus1 etc472 the mother animal1 the division of which gives birth to the two daughter animals1 ceases to exist with the segmentation4 ,the protozoa1 says ,weismann1 have no individuals and no generations in the metazoic sense4 ,i must entirely dissent from his thesis4 ,as ,i was the first to introduce the title of metazoa1 and oppose these multicellular1 tissue-forming animals to the unicellular protozoa 7infusoria1 rhizopods1 etc471 and as ,i was the first to point out the essential difference in the development of the two 7the former from germinal layers1 and the latter not71 ,i must protest that ,i consider the protozoa to be just as mortal in the physiological 7and psychological7 sense as the metazoa2 neither body nor soul is immortal in either group4 ,the other erroneous consequences of ,weismann's notion have been refuted by ,moebius 7#ahhd71 who justly remarks that every event in the world is periodic1 and that there is no source from which immortal organic individuals might have sprung4 ,when we take the idea of immortality in the widest sense1 and extend it to the totality of the knowable universe1 it has a scientific significance2 it is then not merely acceptable1 but self-evident1 to the monistic philosopher4 ,in that sense the thesis of the indestructibility and eternal duration of all that exists is equivalent to our supreme law of nature1 the law of substance 7see chap4 xii74 ,as we intend to discuss this immortality of the cosmos fully later on1 in establishing the theory of the persistence of matter and force1 we shall not dilate on it at present4 ,we pass on immediately to the criticism of that belief in immortality which is the only sense usually attached to the word1 the immortality of the individual soul4 ,we shall first inquire into the extent and the origin of this mystic and dualistic notion1 and point out1 in particular1 the wide acceptance of the contradictory thesis1 our monistic1 empirically established thanatism4 ,i must distinguish two essentially different forms of thanatism--primary and secondary2 primary thanatism is the original absence of the dogma of immortality 7in the primitive uncivilized races72 secondary thanatism is the later outcome of a rational knowledge of nature in the civilized intelligence4 ,we still find it asserted in philosophic1 and especially in theological1 works that belief in the personal immortality of the human soul was originally shared by all men--or1 at least1 by all rational men4 ,that is not the case4 ,this dogma is not an original idea of the human mind1 nor has it ever found universal acceptance4 ,it has been absolutely proved by modern comparative ethnology that many uncivilized races of the earliest and most primitive stage had no notion either of immortality or of ,god4 ,that is true1 for instance1 of the ,veddahs of ,ceylon1 those primitive pygmies whom1 on the authority of the able studies of the ,sarasins1 we consider to be a relic of the earliest inhabitants of ,india2#bb it is also the case in several of the earliest groups of the nearly related ,dravidas1 the ,indian ,seelongs1 and some native ,australian races4 ,similarly1 several of the primitive branches of the ,american race1 in the interior of ,brazil1 on the upper ,amazon1 etc41 have no knowledge either of gods or immortality4 ,this primary absence of belief in immortality and deity is an extremely important fact2 it is1 obviously1 easy to distinguish from the secondary absence of such belief1 which has come about in the highest civilized races as the result of laborious critico-philosophical study4 ,differently from the primary thanatism which originally characterized primitive man1 and has always been widely spread1 the secondary absence of belief in immortality is only found at a late stage of history3 it is the ripe fruit of profound reflection on life and death1 the outcome of bold and independent philosophical speculation4 ,we first meet it in some of the ,ionic philosophers of the sixth century ,b4,c41 then in the founders of the old materialistic philosophy1 ,democritus and ,empedocles1 and also in ,simonides and ,epicurus1 ,seneca and ,plinius1 and in an elaborate form in ,lucretius ,carus4 ,with the spread of ,christianity at the decay of classical antiquity1 athanatism1 one of its chief articles of faith1 dominated the world1 and so1 amid other forms of superstition1 the myth of personal immortality came to be invested with a high importance4 ,naturally1 through the long night of the ,dark ,ages it was rarely that a brave free-thinker ventured to express an opinion to the contrary3 the examples of ,galileo1 ,giordano ,bruno1 and other independent philosophers1 effectually destroyed all freedom of utterance4 ,heresy only became possible when the ,reformation and the ,renaissance had broken the power of the papacy4 ,the history of modern philosophy tells of the manifold methods by which the matured mind of man sought to rid itself of the superstition of immortality4 ,still1 the intimate connection of the belief with the ,christian dogma invested it with such power1 even in the more emancipated sphere of ,protestantism1 that the majority of convinced free-thinkers kept their sentiments to themselves4 ,from time to time some distinguished scholar ventured to make a frank declaration of his belief in the impossibility of the continued life of the soul after death4 ,this was done in ,france in the second half of the eighteenth century by ,voltaire1 ,danton1 ,mirabeau1 and others1 and by the leaders of the materialistic school of those days1 ,holbach1 ,lamettrie1 etc4 ,the same opinion was defended by the able friend of the ,materialists1 the greatest of the ,hohenzollerns1 the monistic philosopher of ,sans-souci4 ,what would ,frederick the ,great1 the crowned thanatist and atheist1 say1 could he compare his monistic views with those of his successor of to-day8 ,among thoughtful physicians the conviction that the existence of the soul came to an end at death has been common for centuries3 generally1 however1 they refrained from giving it expression4 ,moreover1 the empirical science of the brain remained so imperfect during the last century that the soul could continue to be regarded as its mysterious inhabitant4 ,it was the gigantic progress of biology in the present century1 and especially in the latter half of the century1 that finally destroyed the myth4 ,the establishment of the theory of descent and the cellular theory1 the astounding discoveries of ontogeny and experimental physiology--above all1 the marvellous progress of the microscopic anatomy of the brain1 gradually deprived athanatism of every basis2 now1 indeed1 it is rarely that an informed and honorable biologist is found to defend the immortality of the soul4 ,all the monistic philosophers of the century 7,strauss1 ,feuerbach1 ,bchner1 ,spencer1 etc47 are thanatists4 ,the dogma of personal immortality owes its great popularity and its high importance to its intimate connection with the teaching of ,christianity4 ,this circumstance gave rise to the erroneous and still prevalent belief that the myth is a fundamental element of all the higher religions4 ,that is by no means the case4 ,the higher ,oriental religions include no belief whatever in the immortality of the soul2 it is not found in ,buddhism1 the religion that dominates thirty per cent4 of the entire human race2 it is not found in the ancient popular religion of the ,chinese1 nor in the reformed religion of ,confucius which succeeded it2 and1 what is still more significant1 it is not found in the earlier and purer religion of the ,jews4 ,neither in the five ,mosaic books1 nor in any of the writings of the ,old ,testament which were written before the ,babylonian ,exile1 is there any trace of the notion of individual persistence after death4 ,the mystic notion that the human soul will live forever after death has had a polyphyletic origin4 ,it was unknown to the earliest speaking man 7the hypothetical homo primigenius of ,asia71 to his predecessors1 of course1 the pithecanthropus and prothylobates1 and to the least developed of his modern successors1 the ,veddahs of ,ceylon1 the ,seelongs of ,india1 and other distant races4 ,with the development of reason and deeper reflection on life and death1 sleep and dreams1 mystic ideas of a dualistic composition of our nature were evolved--independently of each other--in a number of the earlier races4 ,very different influences were at work in these polyphyletic creations--worship of ancestors1 love of relatives1 love of life and desire of its prolongation1 hope of better conditions of life beyond the grave1 hope of the reward of good and punishment of evil deeds1 and so forth4 ,comparative psychology has recently brought to our knowledge a great variety of myths and legends of that character2 they are1 for the most part1 closely associated with the oldest forms of theistic and religious belief4 ,in most of the modern religions athanatism is intimately connected with theism2 the majority of believers transfer their materialistic idea of a personal ,god to their immortal soul4 ,that is particularly true of the dominant religion of modern civilized states1 ,christianity4 ,as everybody knows1 the dogma of the immortality of the soul has long since assumed in the ,christian religion that rigid form which it has in the articles of faith3 ,i believe in the resurrection of the body and in an eternal life4 ,man will arise on the last day1 as ,christ is alleged to have done on ,easter morn1 and receive a reward according to the tenor of his earthly life4 ,this typically ,christian idea is thoroughly materialistic and anthropomorphic2 it is very little superior to the corresponding crude legends of uncivilized peoples4 ,the impossibility of the resurrection of the body is clear to every man who has some knowledge of anatomy and physiology4 ,the resurrection of ,christ1 which is celebrated every ,easter by millions of ,christians1 is as purely mythical as the awakening of the dead1 which he is alleged to have taught4 ,these mystic articles of faith are just as untenable in the light of pure reason as the cognate hypothesis of eternal life4 ,the fantastic notions which the ,christian ,church disseminates as to the eternal life of the immortal soul after the dissolution of the body are just as materialistic as the dogma of the resurrection of the body4 ,in his interesting work on ,religion in the ,light of the ,darwinian ,theory1 ,savage justly remarks3 ,it is one of the standing charges of the ,church against science that it is materialistic4 ,i must say1 in passing1 that the whole ecclesiastical doctrine of a future life has always been1 and still is1 materialism of the purest type4 ,it teaches that the material body shall rise1 and dwell in a material heaven4 ,to prove this one has only to read impartially some of the sermons and ornate discourses in which the glory of the future life is extolled as the highest good of the ,christian1 and belief in it is laid down to be the foundation of morality4 ,according to them1 all the joys of the most advanced modern civilization await the pious believer in ,paradise1 while the ,all-loving ,father reserves his eternal fires for the godless materialist4 ,in opposition to the materialist athanatism1 which is dominant in the ,christian and ,mohammedan ,churches1 we have1 apparently1 a purer and higher form of faith in the metaphysical athanatism1 as taught by most of our dualist and spiritualist philosophers4 ,plato must be considered its chief creator3 in the fourth century before ,christ he taught that complete dualism of body and soul which afterwards became one of the most important1 theoretically1 and one of the most influential1 practically1 of the ,christian articles of faith4 ,the body is mortal1 material1 physical2 the soul is immortal1 immaterial1 metaphysical4 ,they are only temporarily associated1 for the course of the individual life4 ,as ,plato postulated an eternal life before as well as after this temporary association1 he must be classed as an adherent of metempsychosis1 or transmigration of souls2 the soul existed as such1 or as an eternal idea1 before it entered into a human body4 ,when it quits one body it seeks such other as is most suited to its character for its habitation4 ,the souls of bloody tyrants pass into the bodies of wolves and vultures1 those of virtuous toilers migrate into the bodies of bees and ants1 and so forth4 ,the childish navety of this ,platonic morality is obvious2 on closer examination his views are found to be absolutely incompatible with the scientific truth which we owe to modern anatomy1 physiology1 histology1 and ontogeny2 we mention them only because1 in spite of their absurdity1 they have had a profound influence on thought and culture4 ,on the one hand1 the mysticism of the ,neo-,platonists1 which penetrated into ,christianity1 attaches itself to the psychology of ,plato2 on the other hand1 it became subsequently one of the chief supports of spiritualistic and idealistic philosophy4 ,the ,platonic idea gave way in time to the notion of psychic substance2 this is just as incomprehensible and metaphysical1 though it often assumed a physical appearance4 ,the conception of the soul as a substance is far from clear in many psychologists2 sometimes it is regarded as an immaterial entity of a peculiar character in an abstract and idealistic sense1 sometimes in a concrete and realistic sense1 and sometimes as a confused tertium quid between the two4 ,if we adhere to the monistic idea of substance1 which we develop in chap4 xii41 and which takes it to be the simplest element of our whole world-system1 we find energy and matter inseparably associated in it4 ,we must1 therefore1 distinguish in the substance of the soul the characteristic psychic energy which is all we perceive 7sensation1 presentation1 volition1 etc471 and the psychic matter1 which is the inseparable basis of its activity--that is1 the living protoplasm4 ,thus1 in the higher animals the matter of the soul is a part of the nervous system2 in the lower nerveless animals and plants it is a part of their multicellular protoplasmic body2 and in the unicellular protists it is a part of their protoplasmic cell-body4 ,in this way we are brought once more to the psychic organs1 and to an appreciation of the fact that these material organs are indispensable for the action of the soul2 but the soul itself is actual--it is the sum-total of their physiological functions4 ,however1 the idea of a specific soul-substance found in the dualistic philosophers who admit such a thing is very different from this4 ,they conceive the immortal soul to be material1 yet invisible1 and essentially different from the visible body which it inhabits4 ,thus invisibility comes to be regarded as a most important attribute of the soul4 ,some1 in fact1 compare the soul with ether1 and regard it1 like ether1 as an extremely subtle1 light1 and highly elastic material1 an imponderable agency1 that fills the intervals between the ponderable particles of the living organism1 others compare the soul with the wind1 and so give it a gaseous nature2 and it is this simile which first found favor with primitive peoples1 and led in time to the familiar dualistic conception4 ,when a man died1 the body remained as a lifeless corpse1 but the immortal soul flew out of it with the last breath4 ,the comparison of the human soul with physical ether as a qualitatively similar idea has assumed a more concrete shape in recent times through the great progress of optics and electricity 7especially in the last decade72 for these sciences have taught us a good deal about the energy of ether1 and enabled us to formulate certain conclusions as to the material character of this all-pervading agency4 ,as ,i intend to describe these important discoveries later on 7in chap4 xii471 ,i shall do no more at present than briefly point out that they render the notion of an etheric soul absolutely untenable4 ,such an etheric soul--that is a psychic substance--which is similar to physical ether1 and which1 like ether1 passes between the ponderable elements of the living protoplasm or the molecules of the brain1 cannot possibly account for the individual life of the soul4 ,neither the mystic notions of that kind which were warmly discussed about the middle of the century1 nor the attempts of modern ,neovitalists to put their mystical vital force on a line with physical ether1 call for refutation any longer4 ,much more widespread1 and still much respected1 is the view which ascribes a gaseous nature to the substance of the soul4 ,the comparison of human breath with the wind is a very old one2 they were originally considered to be identical1 and were both given the same name4 ,the anemos and psyche of the ,greeks1 and the anima and spiritus of the ,romans1 were originally all names for a breath of wind2 they were transferred from this to the breath of man4 ,after a time this living breath was identified with the vital force1 and finally it came to be regarded as the soul itself1 or1 in a narrower sense1 as its highest manifestation1 the spirit4 ,from that the imagination went on to derive the mystic notion of individual spirits2 these1 also1 are still usually conceived as ariform beings--though they are credited with the physiological functions of an organism1 and they have been photographed in certain well-known spiritist circles4 ,experimental physics has succeeded1 during the last decade of the century1 in reducing all gaseous bodies to a liquid--most of them1 also1 to a solid--condition4 ,nothing more is needed than special apparatus1 which exerts a violent pressure on the gases at a very low temperature4 ,by this process not only the atmospheric elements1 oxygen1 hydrogen1 and nitrogen1 but even compound gases 7such as carbonic-acid gas7 and gaseous aggregates 7like the atmosphere7 have been changed from gaseous to liquid form4 ,in this way the invisible substances have become visible to all1 and in a certain sense tangible4 ,with this transformation the mystic nimbus which formerly veiled the character of the gas in popular estimation--as an invisible body that wrought visible effects--has entirely disappeared4 ,if1 then1 the substance of the soul were really gaseous1 it should be possible to liquefy it by the application of a high pressure at a low temperature4 ,we could then catch the soul as it is breathed out at the moment of death1 condense it1 and exhibit it in a bottle as immortal fluid 7,fluidum animae immortale74 ,by a further lowering of temperature and increase of pressure it might be possible to solidify it--to produce soul-snow4 ,the experiment has not yet succeeded4 ,if athanatism were true1 if1 indeed1 the human soul were to live for all eternity1 we should have to grant the same privilege to the souls of the higher animals1 at least to those of the nearest related mammals 7apes1 dogs1 etc474 ,for man is not distinguished from them by a special kind of soul1 or by any peculiar and exclusive psychic function1 but only by a higher degree of psychic activity1 a superior stage of development4 ,in particular1 consciousness--the function of the association of ideas1 thought1 and reason--has reached a higher level in many men 7by no means in all7 than in most of the animals4 ,yet this difference is far from being so great as is popularly supposed2 and it is much slighter in every respect than the corresponding difference between the higher and the lower animal souls1 or even the difference between the highest and the lowest stages of the human soul itself4 ,if we ascribe personal immortality to man1 we are bound to grant it also to the higher animals4 ,it is1 therefore1 quite natural that we should find this belief in the immortality of the animal soul among many ancient and modern peoples2 we even meet it sometimes to-day in many thoughtful men who postulate an immortal life for themselves1 and have1 at the same time1 a thorough empirical knowledge of the psychic life of the animals4 ,i once knew an old head-forester1 who1 being left a widower and without children at an early age1 had lived alone for more than thirty years in a noble forest of ,east ,prussia4 ,his only companions were one or two servants1 with whom he exchanged merely a few necessary words1 and a great pack of different kinds of dogs1 with which he lived in perfect psychic communion4 ,through many years of training this keen observer and friend of nature had penetrated deep into the individual souls of his dogs1 and he was as convinced of their personal immortality as he was of his own4 ,some of his most intelligent dogs were1 in his impartial and objective estimation1 at a higher stage of psychic development than his old1 stupid maid and the rough1 wrinkled manservant4 ,any unprejudiced observer1 who will study the conscious and intelligent psychic activity of a fine dog for a year1 and follow attentively the physiological processes of its thought1 judgment1 and reason1 will have to admit that it has just as valid a claim to immortality as man himself4 ,the proofs of the immortality of the soul1 which have been adduced for the last two thousand years1 and are1 indeed1 still credited with some validity1 have their origin1 for the most part1 not in an effort to discover the truth1 but in an alleged necessity of emotion--that is1 in imagination and poetic conceit4 ,as ,kant puts it1 the immortality of the soul is not an object of pure reason1 but a postulate of practical reason4 ,but we must set practical reason entirely aside1 together with all the exigencies of emotion1 or of moral education1 etc41 when we enter upon an honest and impartial pursuit of truth2 for we shall only attain it by the work of pure reason1 starting from empirical data and capable of logical analysis4 ,we have to say the same of athanatism as of theism2 both are creations of poetic mysticism and of transcendental faith1 not of rational science4 ,when we come to analyze all the different proofs that have been urged for the immortality of the soul1 we find that not a single one of them is of a scientific character2 not a single one is consistent with the truths we have learned in the last few decades from physiological psychology and the theory of descent4 ,the theological proof--that a personal creator has breathed an immortal soul 7generally regarded as a portion of the divine soul7 into man--is a pure myth4 ,the cosmological proof--that the moral order of the world demands the eternal duration of the human soul--is a baseless dogma4 ,the teleological proof--that the higher destiny of man involves the perfecting of his defective1 earthly soul beyond the grave--rests on a false anthropism4 ,the moral proof--that the defects and the unsatisfied desires of earthly existence must be fulfilled by compensative justice on the other side of eternity--is nothing more than a pious wish4 ,the ethnological proof--that the belief in immortality1 like the belief in ,god1 is an innate truth1 common to all humanity--is an error in fact4 ,the ontological proof--that the soul1 being a simple1 immaterial1 and indivisible entity1 cannot be involved in the corruption of death--is based on an entirely erroneous view of the psychic phenomena2 it is a spiritualistic fallacy4 ,all these and similar proofs of athanatism are in a parlous condition2 they are definitely annulled by the scientific criticism of the last few decades4 ,the extreme importance of the subject leads us to oppose to these untenable proofs of immortality a brief exposition of the sound scientific arguments against it4 ,the physiological argument shows that the human soul is not an independent1 immaterial substance1 but1 like the soul of all the higher animals1 merely a collective title for the sum-total of man's cerebral functions2 and these are just as much determined by physical and chemical processes as any of the other vital functions1 and just as amenable to the law of substance4 ,the histological argument is based on the extremely complicated microscopic structure of the brain2 it shows us the true elementary organs of the soul in the ganglionic cells4 ,the experimental argument proves that the various functions of the soul are bound up with certain special parts of the brain1 and cannot be exercised unless these are in a normal condition2 if the areas are destroyed1 their function is extinguished2 and this is especially applicable to the organs of thought1 the four central instruments of mental activity4 ,the pathological argument is the complement of the physiological2 when certain parts of the brain 7the centres of speech1 sight1 hearing1 etc47 are destroyed by sickness1 their activity 7speech1 vision1 hearing1 etc47 disappears2 in this way nature herself makes the decisive physiological experiment4 ,the ontogenetic argument puts before us the facts of the development of the soul in the individual2 we see how the child-soul gradually unfolds its various powers2 the youth presents them in full bloom1 the mature man shows their ripe fruit2 in old age we see the gradual decay of the psychic powers1 corresponding to the senile degeneration of the brain4 ,the phylogenetic argument derives its strength from palontology1 and the comparative anatomy and physiology of the brain2 co-operating with and completing each other1 these sciences prove to the hilt that the human brain 7and1 consequently1 its function--the soul7 has been evolved step by step from that of the mammal1 and1 still further back1 from that of the lower vertebrate4 ,these inquiries1 which might be supplemented by many other results of modern science1 prove the old dogma of the immortality of the soul to be absolutely untenable2 in the twentieth century it will not be regarded as a subject of serious scientific research1 but will be left wholly to transcendental faith4 ,the critique of pure reason shows this treasured faith to be a mere superstition1 like the belief in a personal ,god which generally accompanies it4 ,yet even to-day millions of believers--not only of the lower1 uneducated masses1 but even of the most cultured classes--look on this superstition as their dearest possession and their most priceless treasure4 ,it is1 therefore1 necessary to enter more deeply into the subject1 and--assuming it to be true--to make a critical inquiry into its practical value4 ,it soon becomes apparent to the impartial critic that this value rests1 for the most part1 on fancy1 on the want of clear judgment and consecutive thought4 ,it is my firm and honest conviction that a definitive abandonment of these athanatist illusions would involve no painful loss1 but an inestimable positive gain for humanity4 ,man's emotional craving clings to the belief on immortality for two main reasons3 firstly1 in the hope of better conditions of life beyond the grave2 and1 secondly1 in the hope of seeing once more the dear and loved ones whom death has torn from us4 ,as for the first hope1 it corresponds to a natural feeling of the justice of compensation1 which is quite correct subjectively1 but has no objective validity whatever4 ,we make our claim for an indemnity for the unnumbered defects and sorrows of our earthly existence1 without the slightest real prospect or guarantee of receiving it4 ,we long for an eternal life in which we shall meet no sadness and no pain1 but an unbounded peace and joy4 ,the pictures that most men form of this blissful existence are extremely curious2 the immaterial soul is placed in the midst of grossly material pleasures4 ,the imagination of each believer paints the enduring splendor according to his personal taste4 ,the ,american ,indian1 whose athanatism ,schiller has so well depicted1 trusts to find in his ,paradise the finest hunting-grounds with innumerable hordes of buffaloes and bears2 the ,eskimo looks forward to sun-tipped icebergs with an inexhaustible supply of bears1 seals1 and other polar animals2 the effeminate ,cingalese frames his ,paradise on the wonderful island-paradise of ,ceylon with its noble gardens and forests--adding that there will be unlimited supplies of rice and curry1 of cocoanuts and other fruit1 always at hand2 the ,mohammedan ,arab believes it will be a place of shady gardens of flowers1 watered by cool springs1 and filled with lovely maidens2 the ,catholic fisherman of ,sicily looks forward to a daily superabundance of the most valuable fishes and the finest macaroni1 and eternal absolution for all his sins1 which he can go on committing in his eternal home2 the evangelical of ,north ,europe longs for an immense ,gothic cathedral1 in which he can chant the praises of the ,lord of ,hosts for all eternity4 ,in a word1 each believer really expects his eternal life to be a direct continuation of his individual life on earth1 only in a much improved and enlarged edition4 ,we must lay special stress on the thoroughly materialistic character of ,christian athanatism1 which is closely connected with the absurd dogma of the resurrection of the body4 ,as thousands of paintings of famous masters inform us1 the bodies that have risen again1 with the souls that have been born again1 walk about in heaven just as they did in this vale of tears2 they see ,god with their eyes1 they hear ,his voice with their ears1 they sing hymns to ,his praise with their larynx1 and so forth4 ,in fine1 the modern inhabitants of the ,christian ,paradise have the same dual character of body and soul1 the same organs of an earthly body1 as our ancient ancestors had in ,odin's ,hall in ,walhalla1 as the immortal ,turks and ,arabs have in ,mohammed's lovely gardens1 as the old ,greek demi-gods and heroes had in the enjoyment of nectar and ambrosia at the table of ,zeus4 ,but1 however gloriously we may depict this eternal life in ,paradise1 it remains endless in duration4 ,do we realize what eternity means8--the uninterrupted continuance of our individual life forever6 ,the profound legend of the wandering ,jew1 the fruitless search for rest of the unhappy ,ahasuerus1 should teach us to appreciate such an eternal life at its true value4 ,the best we can desire after a courageous life1 spent in doing good according to our light1 is the eternal peace of the grave4 ,lord1 give them an eternal rest4 ,any impartial scholar who is acquainted with geological calculations of time1 and has reflected on the long series of millions of years the organic history of the earth has occupied1 must admit that the crude notion of an eternal life is not a comfort1 but a fearful menace1 to the best of men4 ,only want of clear judgment and consecutive thought can dispute it4 ,the best and most plausible ground for athanatism is found in the hope that immortality will reunite us to the beloved friends who have been prematurely taken from us by some grim mischance4 ,but even this supposed good fortune proves to be an illusion on closer inquiry2 and in any case it would be greatly marred by the prospect of meeting the less agreeable acquaintances and the enemies who have troubled our existence here below4 ,even the closest family ties would involve many a difficulty4 ,there are plenty of men who would gladly sacrifice all the glories of ,paradise if it meant the eternal companionship of their better half and their mother-in-law4 ,it is more than questionable whether ,henry ,,viii4 would like the prospect of living eternally with his six wives2 or ,augustus the ,strong of ,poland1 who had a hundred mistresses and three hundred and fifty-two children4 ,as he was on good terms with the ,vicar of ,christ1 he must be assumed to be in ,paradise1 in spite of his sins1 and in spite of the fact that his mad military ventures cost the lives of more than a hundred thousand ,saxons4 ,another insoluble difficulty faces the athanatist when he asks in what stage of their individual development the disembodied souls will spend their eternal life4 ,will the new-born infant develop its psychic powers in heaven under the same hard conditions of the struggle for life which educate man here on earth8 ,will the talented youth who has fallen in the wholesale murder of war unfold his rich1 unused mental powers in ,walhalla8 ,will the feeble1 childish old man1 who has filled the world with the fame of his deeds in the ripeness of his age1 live forever in mental decay8 ,or will he return to an earlier stage of development8 ,if the immortal souls in ,olympus are to live in a condition of rejuvenescence and perfectness1 then both the stimulus to the formation of1 and the interest in1 personality disappear for them4 ,not less impossible1 in the light of pure reason1 do we find the anthropistic myth of the last judgment1 and the separation of the souls of men into two great groups1 of which one is destined for the eternal joys of ,paradise and the other for the eternal torments of hell--and that from a personal ,god who is called the ,father of ,love6 ,and it is this ,universal ,father who has himself created the conditions of heredity and adaptation1 in virtue of which the elect1 on the one side1 were bound to pursue the path towards eternal bliss1 and the luckless poor and miserable1 on the other hand1 were driven into the paths of the damned8 ,a critical comparison of the countless and manifold fantasies which belief in immortality has produced during the last few thousand years in the different races and religions yields a most remarkable picture4 ,an intensely interesting presentation of it1 based on most extensive original research1 may be found in ,adalbert ,svoboda's distinguished works1 ,the ,illusion of the ,soul and ,forms of ,faith4 ,however absurd and inconsistent with modern knowledge most of these myths seem to be1 they still play an important part1 and1 as postulates of practical reason1 they exercise a powerful influence on the opinions of individuals and on the destiny of races4 ,the idealist and spiritualist philosophy of the day will freely grant that these prevalent materialistic forms of belief in immortality are untenable2 it will say that the refined idea of an immaterial soul1 a ,platonic idea or a transcendental psychic substance1 must be substituted for them4 ,but modern realism can have nothing whatever to do with these incomprehensible notions2 they satisfy neither the mind's feeling of causality nor the yearning of our emotions4 ,if we take a comprehensive glance at all that modern anthropology1 psychology1 and cosmology teach with regard to athanatism1 we are forced to this definite conclusion3 ,the belief in the immortality of the human soul is a dogma which is in hopeless contradiction with the most solid empirical truths of modern science4 ,,chapter ,,xii ,,the ,,law ,,of ,,substance ,the ,fundamental ,chemical ,law of the ,constancy of ,matter--,the ,fundamental ,physical ,law of the ,conservation of ,energy--,combination of ,both ,laws in the ,law of ,substance--,the ,kinetic1 ,pyknotic1 and ,dualistic ,ideas of ,substance--,monism of ,matter--,ponderable ,matter--,atoms and ,elements--,affinity of the ,elements--,the ,soul of the ,atom 7,feeling and ,inclination7--,existence and ,character of ,ether--,ether and ,ponderable ,matter--,force and ,energy--,potential and ,actual ,force--,unity of ,natural ,forces--,supremacy of the ,law of ,substance ,the supreme and all-pervading law of nature1 the true and only cosmological law1 is1 in my opinion1 the law of substance2 its discovery and establishment is the greatest intellectual triumph of the nineteenth century1 in the sense that all other known laws of nature are subordinate to it4 ,under the name of law of substance we embrace two supreme laws of different origin and age--the older is the chemical law of the conservation of matter1 and the younger is the physical law of the conservation of energy4#bc ,it will be self-evident to many readers1 and it is acknowledged by most of the scientific men of the day1 that these two great laws are essentially inseparable4 ,this fundamental thesis1 however1 is still much contested in some quarters1 and we must proceed to furnish the proof of it4 ,but we must first devote a few words to each of the two laws4 ,the law of the persistence or indestructibility of matter1 established by ,lavoisier in #aghi1 may be formulated thus3 ,the sum of matter1 which fills infinite space1 is unchangeable4 ,a body has merely changed its form1 when it seems to have disappeared4 ,when coal burns1 it is changed into carbonic-acid gas by combination with the oxygen of the atmosphere2 when a piece of sugar melts in water1 it merely passes from the solid to the fluid condition4 ,in the same way1 it is merely a question of change of form in the cases where a new body seems to be produced4 ,a shower of rain is the moisture of the atmosphere cast down in the form of drops of water2 when a piece of iron rusts1 the surface layer of the metal has combined with water and with atmospheric oxygen1 and formed a rust1 or oxyhydrate of iron4 ,nowhere in nature do we find an example of the production1 or creation1 of new matter2 nowhere does a particle of existing matter pass entirely away4 ,this empirical truth is now the unquestionable foundation of chemistry2 it may be directly verified at any moment by means of the balance4 ,to the great ,french chemist ,lavoisier belongs the high merit of first making this experiment with the balance4 ,at the present day the scientist1 who is occupied from one end of the year to the other with the study of natural phenomena1 is so firmly convinced of the absolute constancy of matter that he is no longer able to imagine the contrary state of things4 ,we may formulate the law of the persistence of force or conservation of energy thus3 ,the sum of force1 which is at work in infinite space and produces all phenomena1 is unchangeable4 ,when the locomotive rushes along the line1 the potential energy of the steam is transformed into the kinetic or actual energy of the mechanical movement2 when we hear its shrill whistle1 as it speeds along1 the sound-waves of the vibrating atmosphere are conveyed through the tympanum and the three bones of the ear into the inner labyrinth1 and thence transferred by the auditory nerve to the acoustic ganglionic cells which form the centre of hearing in the temporal lobe of the gray bed of the brain4 ,the whole marvellous panorama of life that spreads over the surface of our globe is1 in the last analysis1 transformed sunlight4 ,it is well known how the remarkable progress of technical science has made it possible for us to convert the different physical forces from one form to another2 heat may be changed into molar movement1 or movement of mass2 this in turn into light or sound1 and then into electricity1 and so forth4 ,accurate measurement of the quantity of force which is used in this metamorphosis has shown that it is constant or unchanged4 ,no particle of living energy is ever extinguished2 no particle is ever created anew4 ,friedrich ,mohr1 of ,bonn1 was very near to the discovery of this great fact in #ahcg1 but the discovery was actually made by the able ,swabian physician1 ,robert ,mayer1 of ,heilbronn1 in #ahdb4 ,independently of ,mayer1 however1 the principle was reached almost at the same time by the famous physiologist1 ,hermann ,helmholtz2 five years afterwards he pointed out its general application to1 and fertility in1 every branch of physics4 ,we ought to say to-day that it rules also in the entire province of physiology--that is1 of organic physics2 but on that point we meet a strenuous opposition from the vitalistic biologists and the dualist and spiritualist philosophers4 ,for these the peculiar spiritual forces of human nature are a group of free forces1 not subject to the law of energy2 the idea is closely connected with the dogma of the freedom of the will4 ,we have1 however1 already seen 7p4 #bjd7 that the dogma is untenable4 ,modern physics draws a distinction between force and energy1 but our general observations so far have not needed a reference to it4 ,the conviction that these two great cosmic theorems1 the chemical law of the persistence of matter and the physical law of the persistence of force1 are fundamentally one1 is of the utmost importance in our monistic system4 ,the two theories are just as intimately united as their objects--matter and force or energy4 ,indeed1 this fundamental unity of the two laws is self-evident to many monistic scientists and philosophers1 since they merely relate to two different aspects of one and the same object1 the cosmos4 ,but1 however natural the thought may be1 it is still very far from being generally accepted4 ,it is stoutly contested by the entire dualistic philosophy1 vitalistic biology1 and parallelistic psychology2 even1 in fact1 by a few 7inconsistent7 monists1 who think they find a check to it in consciousness1 in the higher mental activity of man1 or in other phenomena of our free mental life4 ,for my part1 ,i am convinced of the profound importance of the unifying law of substance1 as an expression of the inseparable connection in reality of two laws which are only separated in conception4 ,that they were not originally taken together and their unity recognized from the beginning is merely an accident of the date of their respective discoveries4 ,the earlier and more accessible chemical law of the persistence of matter was detected by ,lavoisier in #aghi1 and1 after a general application of the balance1 became the basis of exact chemistry4 ,on the other hand1 the more recondite law of the persistence of force was only discovered by ,mayer in #ahdb1 and only laid down as the basis of exact physics by ,helmholtz4 ,the unity of the two laws--still much disputed--is expressed by many scientists who are convinced of it in the formula3 ,law of the persistence of matter and force4 ,in order to have a briefer and more convenient expression for this fundamental thought1 ,i proposed some time ago to call it the law of substance or the fundamental cosmic law2 it might also be called the universal law1 or the law of constancy1 or the axiom of the constancy of the universe4 ,in the ultimate analysis it is found to be a necessary consequence of the principle of causality4#bd ,the first thinker to introduce the purely monistic conception of substance into science and appreciate its profound importance was the great philosopher ,baruch ,spinoza2 his chief work appeared shortly after his premature death in #afgg1 just one hundred years before ,lavoisier gave empirical proof of the constancy of matter by means of the chemist's principal instrument1 the balance4 ,in his stately pantheistic system the notion of the world 7the universe1 or the cosmos7 is identical with the all-pervading notion of ,god2 it is at one and the same time the purest and most rational monism and the clearest and most abstract monotheism4 ,this universal substance1 this divine nature of the world1 shows us two different aspects of its being1 or two fundamental attributes--matter 7infinitely extended substance7 and spirit 7the all-embracing energy of thought74 ,all the changes which have since come over the idea of substance are reduced1 on a logical analysis1 to this supreme thought of ,spinoza's2 with ,goethe ,i take it to be the loftiest1 profoundest1 and truest thought of all ages4 ,every single object in the world which comes within the sphere of our cognizance1 all individual forms of existence1 are but special transitory forms--accidents or modes--of substance4 ,these modes are material things when we regard them under the attribute of extension 7or occupation of space71 but forces or ideas when we consider them under the attribute of thought 7or energy74 ,to this profound thought of ,spinoza our purified monism returns after a lapse of two hundred years2 for us1 too1 matter 7space-filling substance7 and energy 7moving force7 are but two inseparable attributes of the one underlying substance4 ,among the various modifications which the fundamental idea of substance has undergone in modern physics1 in association with the prevalent atomism1 we shall select only two of the most divergent theories for a brief discussion1 the kinetic and the pyknotic4 ,both theories agree that we have succeeded in reducing all the different forces of nature to one common original force2 gravity and chemical action1 electricity and magnetism1 light and heat1 etc41 are only different manifestations1 forms1 or dynamodes1 of a single primitive force 7prodynamis74 ,this fundamental force is generally conceived as a vibratory motion of the smallest particles of matter--a vibration of atoms4 ,the atoms themselves1 according to the usual kinetic theory of substance1 are dead1 separate particles of matter1 which dance to and fro in empty space and act at a distance4 ,the real founder and most distinguished representative of the kinetic theory is ,newton1 the famous discoverer of the law of gravitation4 ,in his great work1 the ,philosophiae ,naturalis ,principia ,mathematica 7#afhg71 he showed that throughout the universe the same law of attraction controls the unvarying constancy of gravitation2 the attraction of two particles being in direct proportion to their mass and in inverse proportion to the square of their distance4 ,this universal force of gravity is at work in the fall of an apple and the tidal wave no less than in the course of the planets round the sun and the movements of all the heavenly bodies4 ,newton had the immortal merit of establishing the law of gravitation and embodying it in an indisputable mathematical formula4 ,yet this dead mathematical formula1 on which most scientists lay great stress1 as so frequently happens1 gives us merely the quantitative demonstration of the theory2 it gives us no insight whatever into the qualitative nature of the phenomena4 ,the action at a distance without a medium1 which ,newton deduced from his law of gravitation1 and which became one of the most serious and most dangerous dogmas of later physics1 does not afford the slightest explanation of the real causes of attraction2 indeed1 it long obstructed our way to the real discovery of them4 ,i cannot but suspect that his speculations on this mysterious action at a distance contributed not a little to the leading of the great ,english mathematician into the obscure labyrinth of mystic dreams and theistic superstition in which he passed the last thirty-four years of his life2 we find him1 at the end1 giving metaphysical hypotheses on the predictions of ,daniel and on the paradoxical fantasies of ,st4 ,john4 ,in fundamental opposition to the theory of vibration1 or the kinetic theory of substance1 we have the modern theory of condensation1 or the pyknotic theory of substance4 ,it is most ably established in the suggestive work of ,j4 ,c4 ,vogt on ,the ,nature of ,electricity and ,magnetism on the ,basis of a ,simplified ,conception of ,substance 7#ahia74 ,vogt assumes the primitive force of the world1 the universal prodynamis1 to be1 not the vibration or oscillation of particles in empty space1 but the condensation of a simple primitive substance1 which fills the infinity of space in an unbroken continuity4 ,its sole inherent mechanical form of activity consists in a tendency to condensation or contraction1 which produces infinitesimal centres of condensation2 these may change their degree of thickness1 and1 therefore1 their volume1 but are constant as such4 ,these minute parts of the universal substance1 the centres of condensation1 which might be called pyknatoms1 correspond in general to the ultimate separate atoms of the kinetic theory2 they differ1 however1 very considerably in that they are credited with sensation and inclination 7or will-movement of the simplest form71 with souls1 in a certain sense--in harmony with the old theory of ,empedocles of the love and hatred of the elements4 ,moreover1 these atoms with souls do not float in empty space1 but in the continuous1 extremely attenuated intermediate substance1 which represents the uncondensed portion of the primitive matter4 ,by means of certain constellations1 centres of perturbation1 or systems of deformation1 great masses of centres of condensation quickly unite in immense proportions1 and so obtain a preponderance over the surrounding masses4 ,by that process the primitive substance1 which in its original state of quiescence had the same mean consistency throughout1 divides or differentiates into two kinds4 ,the centres of disturbance1 which positively exceed the mean consistency in virtue of the pyknosis or condensation1 form the ponderable matter of bodies2 the finer1 intermediate substance1 which occupies the space between them1 and negatively falls below the mean consistency1 forms the ether1 or imponderable matter4 ,as a consequence of this division into mass and ether there ensues a ceaseless struggle between the two antagonistic elements1 and this struggle is the source of all physical processes4 ,the positive ponderable matter1 the element with the feeling of like or desire1 is continually striving to complete the process of condensation1 and thus collecting an enormous amount of potential energy2 the negative1 imponderable matter1 on the other hand1 offers a perpetual and equal resistance to the further increase of its strain and of the feeling of dislike connected therewith1 and thus gathers the utmost amount of actual energy4 ,we cannot go any further here into the details of the brilliant theory of ,j4 ,c4 ,vogt4 ,the interested reader cannot do better than have recourse to the second volume of the above work for a clear1 popular exposition of the difficult problem4 ,i am myself too little informed in physics and mathematics to enter into a critical discussion of its lights and shades2 still1 ,i think that this pyknotic theory of substance will prove more acceptable to every biologist who is convinced of the unity of nature than the kinetic theory which prevails in physics to-day4 ,a misunderstanding may easily arise from the fact that ,vogt puts his process of condensation in explicit contradiction with the general phenomenon of motion2 but it must be remembered that he is speaking of vibratory movement in the sense of the physicist4 ,his hypothetical condensation is just as much determined by a movement of substance as is the hypothetical vibration2 only the kind of movement and the relation of the moving elements are very different in the two hypotheses4 ,moreover1 it is not the whole theory of vibration1 but only an important section of it1 that is contradicted by the theory of condensation4 ,modern physics1 for the most part1 still firmly adheres to the older theory of vibration1 to the idea of an actio in distans and the eternal vibration of dead atoms in empty space2 it rejects the pyknotic theory4 ,although ,vogt's theory may be still far from perfect1 and his original speculations may be marred by many errors1 yet ,i think he has rendered a very good service in eliminating the untenable principles of the kinetic theory of substance4 ,as to my own opinion--and that of many other scientists--,i must lay down the following theses1 which are involved in ,vogt's pyknotic theory1 as indispensable for a truly monistic view of substance1 and one that covers the whole field of organic and inorganic nature3 ,i4 ,the two fundamental forms of substance1 ponderable matter and ether1 are not dead and only moved by extrinsic force1 but they are endowed with sensation and will 7though1 naturally1 of the lowest grade72 they experience an inclination for condensation1 a dislike of strain2 they strive after the one and struggle against the other4 ,,ii4 ,there is no such thing as empty space2 that part of space which is not occupied with ponderable atoms is filled with ether4 ,,iii4 ,there is no such thing as an action at a distance through perfectly empty space2 all action of bodies upon each other is either determined by immediate contact or is effected by the mediation of ether4 ,both the theories of substance which we have just contrasted are monistic in principle1 since the opposition between the two conditions of substance--mass and ether--is not original2 moreover1 they involve a continuous immediate contact and reciprocal action of the two elements4 ,it is otherwise with the dualistic theories of substance which still obtain in the idealist and spiritualist philosophy1 and which have the support of a powerful theology1 in so far as theology indulges in such metaphysical speculations4 ,these theories draw a distinction between two entirely different kinds of substance1 material and immaterial4 ,material substance enters into the composition of the bodies which are the object of physics and chemistry2 the law of the persistence of matter and force is confined to this world 7apart from a belief in its creation from nothing and other miracles74 ,immaterial substance is found in the spiritual world to which the law does not extend2 in this province the laws of physics and chemistry are either entirely inapplicable or they are subordinated to a vital force1 or a free will1 or a divine omnipotence1 or some other phantom which is beyond the ken of critical science4 ,in truth1 these profound errors need no further refutation to-day1 for experience has never yet discovered for us a single immaterial substance1 a single force which is not dependent on matter1 or a single form of energy which is not exerted by material movement1 whether it be of mass1 or of ether1 or of both4 ,even the most elaborate and most perfect forms of energy that we know--the psychic life of the higher animals1 the thought and reason of man--depend on material processes1 or changes in the neuroplasm of the ganglionic cells2 they are inconceivable apart from such modifications4 ,i have already shown 7chap4 xi47 that the physiological hypothesis of a special1 immaterial soul-substance is untenable4 ,the study of ponderable matter is primarily the concern of chemistry4 ,few are ignorant of the astonishing theoretical progress which this science has made in the course of the century and the immense practical influence it has had on every aspect of modern life4 ,we shall confine ourselves here to a few remarks on the more important questions which concern the nature of ponderable matter4 ,it is well known that analytical chemistry has succeeded in resolving the immense variety of bodies in nature into a small number of simple elements--that is1 simple bodies which are incapable of further analysis4 ,the number of these elements is about seventy4 ,only fourteen of them are widely distributed on the earth and of much practical importance2 the majority are rare elements 7principally metals7 of little practical moment4 ,the affinity of these groups of elements1 and the remarkable proportions of their atomic weights1 which ,lothar ,meyer and ,mendelejeff have proved in their ,periodic ,system of the ,elements1 make it extremely probable that they are not absolute species of ponderable matter--that is1 not eternally unchangeable particles4 ,the seventy elements have in that system been distributed into eight leading groups1 and arranged in them according to their atomic weight1 so that the elements which have a chemical affinity are formed into families4 ,the relations of the various groups in such a natural system of the elements recall1 on the one hand1 similar relations of the innumerable compounds of carbon1 and1 again1 the relations of parallel groups in the natural arrangement of the animal and plant species4 ,since in the latter cases the affinity of the related forms is based on descent from a common parent form1 it seems very probable that the same holds good of the families and orders of the chemical elements4 ,we may1 therefore1 conclude that the empirical elements we now know are not really simple1 ultimate1 and unchangeable forms of matter1 but compounds of homogeneous1 simple1 primitive atoms1 variously distributed as to number and grouping4 ,the recent speculations of ,gustav ,wendt1 ,wilhelm ,preyer1 ,sir ,w4 ,crookes1 and others1 have pointed out how we may conceive the evolution of the elements from a simple primitive material1 the prothyl4 ,the modern atomistic theory1 which is regarded as an indispensable instrument in chemistry to-day1 must be carefully distinguished from the old philosophic atomism which was taught more than two thousand years ago by a group of distinguished thinkers of antiquity--,leucippus1 ,democritus1 and ,epicurus3 it was considerably developed and modified later on by ,descartes1 ,hobbes1 ,leibnitz1 and other famous philosophers4 ,but it was not until #ahjh that modern atomism assumed a definite and acceptable form1 and was furnished with an empirical basis by ,dalton1 who formulated the law of simple and multiple proportions in the formation of chemical combinations4 ,he first determined the atomic weight of the different elements1 and thus created the solid and exact foundation on which more recent chemical theories are based2 these are all atomistic1 in the sense that they assume the elements to be made up of homogeneous1 infinitesimal1 distinct particles1 which are incapable of further analysis4 ,that does not touch the question of the real nature of the atoms--their form1 size1 psychology1 etc4 ,these atomic qualities are merely hypothetical2 while the chemistry of the atoms1 their chemical affinity--that is1 the constant proportion in which they combine with the atoms of other elements--is empirical4#be ,the different relation of the various elements towards each other1 which chemistry calls affinity1 is one of the most important properties of ponderable matter2 it is manifested in the different relative quantities or proportions of their combination in the intensity of its consummation4 ,every shade of inclination1 from complete indifference to the fiercest passion1 is exemplified in the chemical relation of the various elements towards each other1 just as we find in the psychology of man1 and especially in the life of the sexes4 ,goethe1 in his classical romance1 ,affinities1 compared the relations of pairs of lovers with the phenomenon of the same name in the formation of chemical combinations4 ,the irresistible passion that draws ,edward to the sympathetic ,ottilia1 or ,paris to ,helen1 and leaps over all bounds of reason and morality1 is the same powerful unconscious attractive force which impels the living spermatozoon to force an entrance into the ovum in the fertilization of the egg of the animal or plant--the same impetuous movement which unites two atoms of hydrogen to one atom of oxygen for the formation of a molecule of water4 ,this fundamental unity of affinity in the whole of nature1 from the simplest chemical process to the most complicated love story1 was recognized by the great ,greek scientist1 ,empedocles1 in the fifth century ,b4,c41 in his theory of the love and hatred of the elements4 ,it receives empirical confirmation from the interesting progress of cellular psychology1 the great significance of which we have only learned to appreciate in the last thirty years4 ,on those phenomena we base our conviction that even the atom is not without a rudimentary form of sensation and will1 or as it is better expressed1 of feeling 7aesthesis7 and inclination 7tropesis7--that is1 a universal soul of the simplest character4 ,the same must be said of the molecules which are composed of two or more atoms4 ,further combinations of different kinds of these molecules give rise to simple and1 subsequently1 complex chemical compounds1 in the activity of which the same phenomena are repeated in a more complicated form4 ,the study of ether1 or imponderable matter1 pertains principally to physics4 ,the existence of an extremely attenuated medium1 filling the whole of space outside of ponderable matter1 was known and applied to the elucidation of various phenomena 7especially light7 a long time ago2 but it was not until the second half of the nineteenth century that we became more closely acquainted with this remarkable substance1 in connection with our astonishing empirical discoveries in the province of electricity1 with their experimental detection1 their theoretical interpretation1 and their practical application4 ,the path was opened in particular by the famous researches of ,heinrich ,hertz1 of ,bonn1 in #ahhh4 ,the premature death of a brilliant young physicist of so much promise cannot be sufficiently deplored4 ,like the premature death of ,spinoza1 ,raphael1 ,schubert1 and many other great men1 it is one of those brutal facts of human history which are enough of themselves to destroy the untenable myth of a wise ,providence and an ,all-loving ,father in heaven4 ,the existence of ether 7or cosmic ether7 as a real element is a positive fact1 and has been known as such for the last twelve years4 ,we sometimes read even to-day that ether is a pure hypothesis2 this erroneous assertion comes not only from uninformed philosophers and popular writers1 but even from certain prudent and exact physicists4 ,but there would be just as much reason to deny the existence of ponderable matter4 ,as a matter of fact1 there are metaphysicians who accomplish even this feat1 and whose highest wisdom lies in denying or calling into question the existence of an external universe2 according to them only one real entity exists--their own precious personality1 or1 to be more correct1 their immortal soul4 ,several modern physiologists have embraced this ultra-idealist view1 which is to be found in ,descartes1 ,berkeley1 ,fichte1 and others4 ,their psycho-monism affirms3 ,one thing only exists1 and that is my own mind4 ,this audacious spiritualism seems to us to rest on an erroneous inference from ,kant's correct critical theory1 that we can know the outer world only in the phenomenal aspect which is accessible to our human organs of thought--the brain and the organs of sense4 ,if by those means we can attain only an imperfect and limited knowledge of the material world1 that is no reason for denying its existence altogether4 ,in my opinion1 the existence of ether is as certain as that of ponderable matter--as certain as my own existence1 as ,i reflect and write on it4 ,as we assure ourselves of the existence of ponderable matter by its mass and weight1 by chemical and mechanical experiments1 so we prove that of ether by the experiences and experiments of optics and electricity4 ,although1 however1 the existence of ether is now regarded as a positive fact by nearly all physicists1 and although many effects of this remarkable substance are familiar to us through an extensive experience1 especially in the way of optical and electrical experiments1 yet we are still far from being clear and confident as to its real character4 ,the views of the most eminent physicists1 who have made a special study of it1 are extremely divergent2 they frequently contradict each other on the most important points4 ,one is1 therefore1 free to choose among the contradictory hypotheses according to one's knowledge and judgment4 ,i will put in the following eight theses the view which has approved itself to me after mature reflection on the subject1 though ,i am no expert in this department3 ,i4 ,ether fills the whole of space1 in so far as it is not occupied by ponderable matter1 as a continuous substance2 it fully occupies the space between the atoms of ponderable matter4 ,,ii4 ,ether has probably no chemical quality1 and is not composed of atoms4 ,if it be supposed that it consists of minute homogeneous atoms 7for instance1 indivisible etheric particles of a uniform size71 it must be further supposed that there is something else between these atoms1 either empty space or a third1 completely unknown medium1 a purely hypothetical interether2 the question as to the nature of this brings us back to the original difficulty1 and so on in infinitum4 ,,iii4 ,as the idea of an empty space and an action at a distance is scarcely possible in the present condition of our knowledge 7at least it does not help to a clear monistic view71 ,i postulate for ether a special structure which is not atomistic1 like that of ponderable matter1 and which may provisionally be called 7without further determination7 etheric or dynamic structure4 ,,iv4 ,the consistency of ether is also peculiar1 on our hypothesis1 and different from that of ponderable matter4 ,it is neither gaseous1 as some conceive1 nor solid1 as others suppose2 the best idea of it can be formed by comparison with an extremely attenuated1 elastic1 and light jelly4 ,v4 ,ether may be called imponderable matter in the sense that we have no means of determining its weight experimentally4 ,if it really has weight1 as is very probable1 it must be so slight as to be far below the capacity of our most delicate balance4 ,some physicists have attempted to determine its weight by the energy of the light-waves1 and have discovered that it is some fifteen trillion times lighter than atmospheric air2 on that hypothesis a sphere of ether of the size of our earth would weigh at least two hundred and fifty pounds7874 ,,vi4 ,the etheric consistency may probably 7in accordance with the pyknotic theory7 pass into the gaseous state under certain conditions by progressive condensation1 just as a gas may be converted into a fluid1 and ultimately into a solid1 by lowering its temperature4 ,,vii4 ,consequently1 these three conditions of matter may be arranged 7and it is a point of great importance in our monistic cosmogony7 in a genetic1 continuous order4 ,we may distinguish five stages in it3 7#a7 the etheric1 7#b7 the gaseous1 7#c7 the fluid1 7#d7 the viscous 7in the living protoplasm71 and 7#e7 the solid state4 ,,viii4 ,ether is boundless and immeasurable1 like the space it occupies4 ,it is in eternal motion2 and this specific movement of ether 7it is immaterial whether we conceive it as vibration1 strain1 condensation1 etc471 in reciprocal action with mass-movement 7or gravitation71 is the ultimate cause of all phenomena4 ,the great question of the nature of ether1 as ,hertz justly calls it1 includes the question of its relation to ponderable matter2 for these two forms of matter are not only always in the closest external contact1 but also in eternal1 dynamic1 reciprocal action4 ,we may divide the most general phenomena of nature1 which are distinguished by physics as natural forces or functions of matter1 into two groups2 the first of them may be regarded mainly 7though not exclusively7 as a function of ether1 and the second a function of ponderable matter--as in the following scheme which ,i take from my ,monism3 ,,the ,,world 7,,nature1 ,,or ,,the ,,cosmos7 ---------------------------------------- ------------------------------ ,,ether--,imponderable4 ,,mass--,ponderable4 ---------------------------------------- ------------------------------ #a4 ,consistency3 #a4 ,consistency3 ,etheric 7i4e41 neither ,not etheric 7but gaseous1 fluid1 gaseous nor fluid1 nor solid74 or solid74 #b4 ,structure3 #b4 ,structure3 ,not atomistic1 not made up of ,atomistic1 made up of infinitesimal1 separate particles 7atoms71 but distinct particles 7atoms7 continuous4 discontinuous4 #c4 ,chief ,functions3 #c4 ,chief ,functions3 ,light1 radiant heat1 electricity1 ,gravity1 inertia1 molecular heat1 and magnetism4 and chemical affinity4 ---------------------------------------- ------------------------------ ,the two groups of functions of matter1 which we have opposed in this table1 may1 to some extent1 be regarded as the outcome of the first division of labor in the development of matter1 the primary ergonomy of matter4 ,but this distinction must not be supposed to involve an absolute separation of the two antithetic groups2 they always retain their connection1 and are in constant reciprocal action4 ,it is well known that the optical and electrical phenomena of ether are closely connected with mechanical and chemical changes in ponderable elements2 the radiant heat of ether may be directly converted into the mechanical heat of the mass2 gravitation is impossible unless the ether effects the mutual attraction of the separated atoms1 because we cannot admit the idea of an actio in distans4 ,in like manner1 the conversion of one form of energy into another1 as indicated in the law of the persistence of force1 illustrates the constant reciprocity of the two chief types of substance1 ether and mass4 ,the great law of nature1 which1 under the title of the law of substance1 we put at the head of all physical considerations1 was conceived as the law of the persistence of force by ,robert ,meyer1 who first formulated it1 and ,helmholtz1 who continued the work4 ,another ,german scientist1 ,friedrich ,mohr1 of ,bonn1 had clearly outlined it in its main features ten years earlier 7#ahcg74 ,the old idea of force was1 after a time1 differentiated by modern physics from that of energy1 which was at first synonymous with it4 ,hence the law is now usually called the law of the persistence of energy4 ,however1 this finer distinction need not enter into the general consideration1 to which ,i must confine myself here1 and into the question of the great principle of the persistence of substance4 ,the interested reader will find a very clear treatment of the question in ,tyndall's excellent paper on ,the ,fundamental ,law of ,nature1 in his ,fragments of ,science4 ,it fully explains the broad significance of this profound cosmic law1 and points out its application to the main problems of very different branches of science4 ,we shall confine our attention to the important fact that the principle of energy and the correlative idea of the unity of natural forces1 on the basis of a common origin1 are now accepted by all competent physicists1 and are regarded as the greatest advance of physics in the nineteenth century4 ,we now know that heat1 sound1 light1 chemical action1 electricity1 and magnetism are all modes of motion4 ,we can1 by a certain apparatus1 convert any one of these forces into another1 and prove by an accurate measurement that not a single particle of energy is lost in the process4 ,the sum-total of force or energy in the universe remains constant1 no matter what changes take place around us2 it is eternal and infinite1 like the matter on which it is inseparably dependent4 ,the whole drama of nature apparently consists in an alternation of movement and repose2 yet the bodies at rest have an inalienable quantity of force1 just as truly as those that are in motion4 ,it is in this movement that the potential energy of the former is converted into the kinetic energy of the latter4 ,as the principle of the persistence of force takes into account repulsion as well as attraction1 it affirms that the mechanical value of the potential energy and the kinetic energy in the material world is a constant quantity4 ,to put it briefly1 the force of the universe is divided into two parts1 which may be mutually converted1 according to a fixed relation of value4 ,the diminution of the one involves the increase of the other2 the total value remains unchanged in the universe4 ,the potential energy and the actual1 or kinetic1 energy are being continually transformed from one condition to the other2 but the infinite sum of force in the world at large never suffers the slightest curtailment4 ,once modern physics had established the law of substance as far as the simpler relations of inorganic bodies are concerned1 physiology took up the story1 and proved its application to the entire province of the organic world4 ,it showed that all the vital activities of the organism--without exception--are based on a constant reciprocity of force and a correlative change of material1 or metabolism1 just as much as the simplest processes in lifeless bodies4 ,not only the growth and the nutrition of plants and animals1 but even their functions of sensation and movement1 their sense-action and psychic life1 depend on the conversion of potential into kinetic energy1 and vice vers4 ,this supreme law dominates also those elaborate performances of the nervous system which we call1 in the higher animals and man1 the action of the mind4 ,our monistic view1 that the great cosmic law applies throughout the whole of nature1 is of the highest moment4 ,for it not only involves1 on its positive side1 the essential unity of the cosmos and the causal connection of all phenomena that come within our cognizance1 but it also1 in a negative way1 marks the highest intellectual progress1 in that it definitely rules out the three central dogmas of metaphysics--,god1 freedom1 and immortality4 ,in assigning mechanical causes to phenomena everywhere1 the law of substance comes into line with the universal law of causality4 ,,chapter ,,xiii ,,the ,,evolution ,,of ,,the ,,world ,the ,notion of ,creation--,miracles--,creation of the ,whole ,universe and of its ,various ,parts--,creation of ,substance 7,cosmological ,creation7--,deism3 ,one ,creative ,day--,creation of ,separate ,entities--,five ,forms of ,ontological ,creationism--,theory of ,evolution--,i4 ,monistic ,cosmogony--,beginning and ,end of the ,world--,the ,infinity and ,eternity of the ,universe--,space and ,time--,universum perpetuum mobile--,entropy of the ,universe--,,ii4 ,monistic ,geogeny--,history of the ,inorganic and ,organic ,worlds--,,iii4 ,monistic ,biogeny--,transformism and the ,theory of ,descent3 ,lamarck and ,darwin--,,iv4 ,monistic ,anthropogeny--,origin of ,man ,the greatest1 vastest1 and most difficult of all cosmic problems is that of the origin and development of the world--the question of creation1 in a word4 ,even to the solution of this most difficult world-riddle the nineteenth century has contributed more than all its predecessors2 in a certain sense1 indeed1 it has found the solution4 ,we have at least attained to a clear view of the fact that all the partial questions of creation are indivisibly connected1 that they represent one single1 comprehensive cosmic problem1 and that the key to this problem is found in the one magic word--evolution4 ,the great questions of the creation of man1 the creation of the animals and plants1 the creation of the earth and the sun1 etc41 are all parts of the general question1 ,what is the origin of the whole world8 ,has it been created by supernatural power1 or has it been evolved by a natural process8 ,what are the causes and the manner of this evolution8 ,if we succeed in finding the correct answer to one of these questions1 we have1 according to our monistic conception of the world1 cast a brilliant light on the solution of them all1 and on the entire cosmic problem4 ,the current opinion as to the origin of the world in earlier ages was almost a universal belief in creation4 ,this belief has been expressed in thousands of interesting1 more or less fabulous1 legends1 poems1 cosmogonies1 and myths4 ,a few great philosophers were devoid of it1 especially those remarkable free-thinkers of classical antiquity who first conceived the idea of natural evolution4 ,all the creation-myths1 on the contrary1 were of a supernatural1 miraculous1 and transcendental character4 ,incompetent1 as it was1 to investigate for itself the nature of the world and its origin by natural causes1 the undeveloped mind naturally had recourse to the idea of miracle4 ,in most of these creation-myths anthropism was blended with the belief in the miraculous4 ,the creator was supposed to have constructed the world on a definite plan1 just as man accomplishes his artificial constructions2 the conception of the creator was generally completely anthropomorphic1 a palpable anthropistic creationism4 ,the all-mighty maker of heaven and earth1 as he is called in ,genesis and the ,catechism1 is just as humanly conceived as the modern creator of ,agassiz and ,reinke1 or the intelligent engineer of other recent biologists4 ,entering more fully into the notion of creation1 we can distinguish as two entirely different acts the production of the universe as a whole and the partial production of its various parts1 in harmony with ,spinoza's idea of substance 7the universe7 and accidents 7or modes1 the individual phenomena of substance74 ,this distinction is of great importance1 because there are many eminent philosophers who admit the one and reject the other4 ,according to this creationist theory1 then1 ,god has made the world out of nothing4 ,it is supposed that ,god 7a rational1 but immaterial1 being7 existed by himself for an eternity before he resolved to create the world4 ,some supporters of the theory restrict ,god's creative function to one single act2 they believe that this extramundane ,god 7the rest of whose life is shrouded in mystery7 created the substance of the world in a single moment1 endowed it with the faculty of the most extensive evolution1 and troubled no further about it4 ,this view may be found1 for instance1 in the ,english ,deists in many forms4 ,it approaches very close to our monistic theory of evolution1 only abandoning it in the one instant in which ,god accomplished the creation4 ,other creationists contend that ,god did not confine himself to the mere creation of matter1 but that he continues to be operative as the sustainer and ruler of the world4 ,different modifications of this belief are found1 some approaching very close to pantheism and others to complete theism4 ,all these and similar forms of belief in creation are incompatible with the law of the persistence of matter and force2 that law knows nothing of a beginning4 ,it is interesting to note that ,e4 du ,bois-,reymond has identified himself with this cosmological creationism in his latest speech 7on ,neovitalism1 #ahid74 ,it is more consonant with the divine omnipotence1 he says1 to assume that it created the whole material of the world in one creative act unthinkable ages ago in such wise that it should be endowed with inviolable laws to control the origin and the progress of living things--that1 for instance1 here on earth rudimentary organisms should arise from which1 without further assistance1 the whole of living nature could be evolved1 from a primitive bacillus to the graceful palm-wood1 from a primitive micrococcus to ,solomon's lovely wives or to the brain of ,newton4 ,thus we are content with one creative day1 and we derive organic nature mechanically1 without the aid of either old or new vitalism4 ,du ,bois-,reymond here shows1 as in the question of consciousness1 the shallow and illogical character of his monistic thought4 ,according to another still prevalent theory1 which may be called ontological creationism1 ,god not only created the world at large1 but also its separate contents4 ,in the ,christian world the old ,semitic legend of creation1 taken from ,genesis1 is still very widely accepted2 even among modern scientists it finds an adherent here and there4 ,i have fully entered into the criticism of it in the first chapter of my ,natural ,history of ,creation4 ,the following theories may be enumerated as the most interesting modifications of this ontological creationism3 ,i4 ,dualistic creation4--,god restricted his interference to two creative acts4 ,first he created the inorganic world1 mere dead substance1 to which alone the law of energy applies1 working blindly and aimlessly in the mechanism of material things and the building of the mountains2 then ,god attained intelligence and communicated it to the purposive intelligent forces which initiate and control organic evolution4#bf ,,ii4 ,trialistic creation4--,god made the world in three creative acts3 7a7 the creation of the heavens--the extra-terrestrial world1 7b7 the creation of the earth 7as the centre of the world7 and of its living inhabitants1 and 7c7 the creation of man 7in the image and likeness of ,god74 ,this dogma is still widely prevalent among theologians and other educated people2 it is taught as the truth in many of our schools4 ,,iii4 ,heptameral creation2 a creation in seven days 7teste ,moses74--,although few educated people really believe in this ,mosaic myth now1 it is still firmly impressed on our children in the biblical lessons of their earliest years4 ,the numerous attempts that have been made1 especially in ,england1 to harmonize it with the modern theory of evolution have entirely failed4 ,it obtained some importance in science when ,linn adopted it in the establishment of his system1 and based his definition of organic species 7which he considered to be unchangeable7 on it3 ,there are as many different species of animals and plants as there were different forms created in the beginning by the ,infinite4 ,this dogma was pretty generally held until the time of ,darwin 7#ahei71 although ,lamarck had already proved its untenability in #ahji4 ,,iv4 ,periodic creation4--,at the beginning of each period of the earth's history the whole population of animals and plants was created anew1 and destroyed by a general catastrophe at its close2 there were as many general creative acts as there are distinct geological periods 7the catastrophic theory of ,cuvier #ahah and ,louis ,agassiz #aheh74 ,palontology1 which seemed to support this theory in its more imperfect stage1 has since completely refuted it4 ,v4 ,individual creation4--,every single man--and every individual animal and plant--does not arise by a natural process of growth1 but is created by the favor of ,god4 ,this view of creation is still often met with in journals1 especially in the births column4 ,the special talents and features of our children are often gratefully acknowledged to be gifts of ,god2 their hereditary defects fit into another theory4 ,the error of these creation-legends and the cognate belief in miracles must have been apparent to thoughtful minds at an early period2 more than two thousand years ago we find that many attempts were made to replace them by a rational theory1 and to explain the origin of the world by natural causes4 ,in the front rank1 once more1 we must place the leaders of the ,ionic school1 with ,democritus1 ,heraclitus1 ,empedocles1 ,aristotle1 ,lucretius1 and other ancient philosophers4 ,the first imperfect attempts which they made astonish us1 in a measure1 by the flashes of mental light in which they anticipate modern ideas4 ,it must be remembered that classical antiquity had not that solid groundwork for scientific speculation which has been provided by the countless observations and experiments of modern scientists4 ,during the ,middle ,ages--especially during the domination of the papacy--scientific work in this direction entirely ceased4 ,the torture and the stake of the ,inquisition insured that an unconditional belief in the ,hebrew mythology should be the final answer to all the questions of creation4 ,even the phenomena which led directly to the observation of the facts of evolution--the embryology of the plant and the animal1 and of man--remained unnoticed1 or only excited the interest of an occasional keen observer2 but their discoveries were ignored or forgotten4 ,moreover1 the path to a correct knowledge of natural development was barred by the dominant theory of preformation1 the dogma which held that the characteristic form and structure of each animal and plant were already sketched in miniature in the germ 7cf4 p4 #ed74 ,the science which we now call the science of evolution 7in the broadest sense7 is1 both in its general outline and in its separate parts1 a child of the nineteenth century2 it is one of its most momentous and most brilliant achievements4 ,almost unknown in the preceding century1 this theory has now become the sure foundation of our whole world-system4 ,i have treated it exhaustively in my ,general ,morphology 7#ahff71 more popularly in my ,natural ,history of ,creation 7#ahfh71 and in its special application to man in my ,anthropogeny 7#ahgd74 ,here ,i shall restrict myself to a brief survey of the chief advances which the science has made in the course of the century4 ,it falls into four sections1 according to the nature of its object2 that is1 it deals with the natural origin of 7#a7 the cosmos1 7#b7 the earth1 7#c7 terrestrial forms of life1 and 7#d7 man4 ,i4--,,monistic ,,cosmogony ,the first attempt to explain the constitution and the mechanical origin of the world in a simple manner by ,newtonian laws--that is1 by mathematical and physical laws--was made by ,immanuel ,kant in the famous work of his youth 7#agee71 ,general ,history of the ,earth and ,theory of the ,heavens4 ,unfortunately1 this distinguished and daring work remained almost unknown for ninety years2 it was only disinterred in #ahde by ,alexander ,humboldt in the first volume of his ,cosmos4 ,in the mean time the great ,french mathematician1 ,pierre ,laplace1 had arrived independently at similar views to those of ,kant1 and he gave them a mathematical foundation in his ,exposition du ,systme du ,monde 7#agif74 ,his chief work1 the ,mcanique ,cleste1 appeared a hundred years ago4 ,the analogous features of the cosmogony of ,kant and ,laplace consist1 as is well known1 in a mechanical explanation of the movements of the planets1 and the conclusion which is drawn therefrom1 that all the cosmic bodies were formed originally by a condensation of rotating nebulous spheres4 ,this nebular hypothesis has been much improved and supplemented since1 but it is still the best of all the attempts to explain the origin of the world on monistic and mechanical lines4 ,it has recently been strongly confirmed and enlarged by the theory that this cosmogonic process did not simply take place once1 but is periodically repeated4 ,while new cosmic bodies arise and develop out of rotating masses of nebula in some parts of the universe1 in other parts old1 extinct1 frigid suns come into collision1 and are once more reduced by the heat generated to the condition of nebul4 ,nearly all the older and the more recent cosmogonies1 including most of those which were inspired by ,kant and ,laplace1 started from the popular idea that the world had had a beginning4 ,hence1 according to a widespread version of the nebular hypothesis1 in the beginning was made a vast nebula of infinitely attenuated and light material1 and at a certain moment 7countless ages ago7 a movement of rotation was imparted to this mass4 ,given this first beginning of the cosmogonic movement1 it is easy1 on mechanical principles1 to deduce and mathematically establish the further phenomena of the formation of the cosmic bodies1 the separation of the planets1 and so forth4 ,this first origin of movement is ,du ,bois-,reymond's second world-enigma2 he regards it as transcendental4 ,many other scientists and philosophers are equally helpless before this difficulty2 they resign themselves to the notion that we have here a primary supernatural impetus to the scheme of things1 a miracle4 ,in our opinion1 this second world-enigma is solved by the recognition that movement is as innate and original a property of substance as is sensation4 ,the proof of this monistic assumption is found1 first1 in the law of substance1 and1 secondly1 in the discoveries which astronomy and physics have made in the latter half of the century4 ,by the spectral analysis of ,bunsen and ,kirchhoff 7#ahfj7 we have found1 not only that the millions of bodies1 which fill the infinity of space1 are of the same material as our own sun and earth1 but also that they are in various stages of evolution2 we have obtained by its aid information as to the movements and distances of the stars1 which the telescope would never have given us4 ,moreover1 the telescope itself has been vastly improved1 and has1 in alliance with photography1 made a host of scientific discoveries of which no one dreamed at the beginning of the century4 ,in particular1 a closer acquaintance with comets1 meteorites1 star-clusters1 and nebul has helped us to realize the great significance of the smaller bodies which are found in millions in the space between the stars4 ,we now know that the paths of the millions of heavenly bodies are changeable1 and to some extent irregular1 whereas the planetary system was formerly thought to be constant1 and the rotating spheres were described as pursuing their orbits in eternal regularity4 ,astro-physics owes much of its triumph to the immense progress of other branches of physics1 of optics1 and electricity1 and especially of the theory of ether4 ,and here1 again1 our supreme law of substance is found to be one of the most valuable achievements of modern science4 ,we now know that it rules unconditionally in the most distant reaches of space1 just as it does in our planetary system1 in the most minute particle of the earth as well as in the smallest cell of our human frame4 ,we are1 moreover1 justified in concluding1 if we are not logically compelled to conclude1 that the persistence of matter and force has held good throughout all time as it does to-day4 ,through all eternity the infinite universe has been1 and is1 subject to the law of substance4 ,from this great progress of astronomy and physics1 which mutually elucidate and supplement each other1 we draw a series of most important conclusions with regard to the constitution and evolution of the cosmos1 and the persistence and transformation of substance4 ,let us put them briefly in the following theses3 ,i4 ,the extent of the universe is infinite and unbounded2 it is empty in no part1 but everywhere filled with substance4 ,,ii4 ,the duration of the world is equally infinite and unbounded2 it has no beginning and no end3 it is eternity4 ,,iii4 ,substance is everywhere and always in uninterrupted movement and transformation3 nowhere is there perfect repose and rigidity2 yet the infinite quantity of matter and of eternally changing force remains constant4 ,,iv4 ,this universal movement of substance in space takes the form of an eternal cycle or of a periodical process of evolution4 ,v4 ,the phases of this evolution consist in a periodic change of consistency1 of which the first outcome is the primary division into mass and ether--the ergonomy of ponderable and imponderable matter4 ,,vi4 ,this division is effected by a progressive condensation of matter as the formation of countless infinitesimal centres of condensation1 in which the inherent primitive properties of substance--feeling and inclination--are the active causes4 ,,vii4 ,while minute and then larger bodies are being formed by this pyknotic process in one part of space1 and the intermediate ether increases its strain1 the opposite process--the destruction of cosmic bodies by collision--is taking place in another quarter4 ,,viii4 ,the immense quantity of heat which is generated in this mechanical process of the collision of swiftly moving bodies represents the new kinetic energy which effects the movement of the resultant nebul and the construction of new rotating bodies4 ,the eternal drama begins afresh4 ,even our mother earth1 which was formed of part of the gyrating solar system millions of ages ago1 will grow cold and lifeless after the lapse of further millions1 and1 gradually narrowing its orbit1 will fall eventually into the sun4 ,it seems to me that these modern discoveries as to the periodic decay and re-birth of cosmic bodies1 which we owe to the most recent advance of physics and astronomy1 associated with the law of substance1 are especially important in giving us a clear insight into the universal cosmic process of evolution4 ,in their light our earth shrinks into the slender proportions of a mote in the sunbeam1 of which unnumbered millions chase each other through the vast depths of space4 ,our own human nature1 which exalted itself into an image of ,god in its anthropistic illusion1 sinks to the level of a placental mammal1 which has no more value for the universe at large than the ant1 the fly of a summer's day1 the microscopic infusorium1 or the smallest bacillus4 ,humanity is but a transitory phase of the evolution of an eternal substance1 a particular phenomenal form of matter and energy1 the true proportion of which we soon perceive when we set it on the background of infinite space and eternal time4 ,since ,kant explained space and time to be merely forms of perception--space the form of external1 time of internal1 sensitivity--there has been a keen controversy1 which still continues1 over this important problem4 ,a large section of modern metaphysicians have persuaded themselves that this critical fact possesses a great importance as the starting-point of a purely idealist theory of knowledge1 and that1 consequently1 the natural opinion of the ordinary healthy mind as to the reality of time and space is swept aside4 ,this narrow and ultra-idealist conception of time and space has become a prolific source of error4 ,it overlooks the fact that ,kant only touched one side of the problem1 the subjective side1 in that theory1 and recognized the equal validity of its objective side4 ,time and space1 he said1 have empirical reality1 but transcendental ideality4 ,our modern monism is quite compatible with this thesis of ,kant's1 but not with the one-sided exaggeration of the subjective aspect of the problem2 the latter leads logically to the absurd idealism that culminates in ,berkeley's thesis1 ,bodies are but ideas2 their essence is in their perception4 ,the thesis should be read thus3 ,bodies are only ideas for my personal consciousness2 their existence is just as real as that of my organs of thought1 the ganglionic cells in the gray bed of my brain1 which receive the impress of bodies on my sense-organs and form those ideas by association of the impressions4 ,it is just as easy to doubt or to deny the reality of my own consciousness as to doubt that of time and space4 ,in the delirium of fever1 in hallucinations1 in dreams1 and in double-consciousness1 ,i take ideas to be true which are merely fancies4 ,i mistake my own personality for another 7vide p4 #ahe72 ,descartes' famous ,cogito ergo sum applies no longer4 ,on the other hand1 the reality of time and space is now fully established by that expansion of our philosophy which we owe to the law of substance and to our monistic cosmogony4 ,when we have happily got rid of the untenable idea of empty space1 there remains as the infinite space-filling-medium matter1 in its two forms of ether and mass4 ,so also we find a time-filling event in the eternal movement1 or genetic energy1 which reveals itself in the uninterrupted evolution of substance1 in the perpetuum mobile of the universe4 ,as a body which has been set in motion continues to move as long as no external agency interferes with it1 the idea was conceived long ago of constructing an apparatus which should illustrate perpetual motion4 ,the fact was overlooked that every movement meets with external impediments and gradually ceases1 unless a new impetus is given to it from without and a new force is introduced to counteract the impediments4 ,thus1 for instance1 a pendulum would swing backward and forward for an eternity at the same speed if the resistance of the atmosphere and the friction at the point it hangs from did not gradually deprive it of the mechanical kinetic energy of its motion and convert it into heat4 ,we have to furnish it with fresh mechanical energy by a spring 7or1 as in the pendulum-clock1 by the drag of a weight74 ,hence it is impossible to construct a machine that would produce1 without external aid1 a surplus of energy by which it could keep itself going4 ,every attempt to make such a perpetuum mobile must necessarily fail2 the discovery of the law of substance showed1 in addition1 the theoretical impossibility of it4 ,the case is different1 however1 when we turn to the world at large1 the boundless universe that is in eternal movement4 ,the infinite matter1 which fills it objectively1 is what we call space in our subjective impression of it2 time is our subjective conception of its eternal movement1 which is1 objectively1 a periodic1 cyclic evolution4 ,these two forms of perception teach us the infinity and eternity of the universe4 ,that is1 moreover1 equal to saying that the universe itself is a perpetuum mobile4 ,this infinite and eternal machine of the universe sustains itself in eternal and uninterrupted movement1 because every impediment is compensated by an equivalence of energy1 and the unlimited sum of kinetic and potential energy remains always the same4 ,the law of the persistence of force proves also that the idea of a perpetuum mobile is just as applicable to1 and as significant for1 the cosmos as a whole as it is impossible for the isolated action of any part of it4 ,hence the theory of entropy is likewise untenable4 ,the able founder of the mechanical theory of heat 7#ahej71 ,clausius1 embodied the momentous contents of this important theory in two theses4 ,the first runs3 ,the energy of the universe is constant--that is one-half of our law of substance1 the principle of energy 7vide p4 #bcj74 ,the second thesis is3 ,the energy of the universe tends towards a maximum4 ,in my opinion this second assertion is just as erroneous as the first is true4 ,in the theory of ,clausius the entire energy of the universe is of two kinds1 one of which 7heat of the higher degree1 mechanical1 electrical1 chemical energy1 etc47 is partly convertible into work1 but the other is not2 the latter energy1 already converted into heat and distributed in the cooler masses1 is irrevocably lost as far as any further work is concerned4 ,clausius calls this unconsumed energy1 which is no longer available for mechanical work1 entropy 7that is1 force that is directed inward72 it is continually increasing at the cost of the other half4 ,as1 therefore1 the mechanical energy of the universe is daily being transformed into heat1 and this cannot be reconverted into mechanical force1 the sum of heat and energy in the universe must continually tend to be reduced and dissipated4 ,all difference of temperature must ultimately disappear1 and the completely latent heat must be equally distributed through one inert mass of motionless matter4 ,all organic life and movement must cease when this maximum of entropy has been reached4 ,that would be a real end of the world4 ,if this theory of entropy were true1 we should have a beginning corresponding to this assumed end of the world--a minimum of entropy1 in which the differences in temperature of the various parts of the cosmos would be at a maximum4 ,both ideas are quite untenable in the light of our monistic and consistent theory of the eternal cosmogenetic process2 both contradict the law of substance4 ,there is neither beginning nor end of the world4 ,the universe is infinite1 and eternally in motion2 the conversion of kinetic into potential energy1 and vicissim1 goes on uninterruptedly2 and the sum of this actual and potential energy remains constant4 ,the second thesis of the mechanical theory of heat contradicts the first1 and so must be rejected4 ,the representatives of the theory of entropy are quite correct as long as they confine themselves to distinct processes1 in which1 under certain conditions1 the latent heat cannot be reconverted into work4 ,thus1 for instance1 in the steam-engine the heat can only be converted into mechanical work when it passes from a warmer body 7steam7 into a cooler 7water72 the process cannot be reversed4 ,in the world at large1 however1 quite other conditions obtain--conditions which permit the reconversion of latent heat into mechanical work4 ,for instance1 in the collision of two heavenly bodies1 which rush towards each other at inconceivable speed1 enormous quantities of heat are liberated1 while the pulverized masses are hurled and scattered about space4 ,the eternal drama begins afresh--the rotating mass1 the condensation of its parts1 the formation of new meteorites1 their combination into larger bodies1 and so on4 ,,ii4--,,monistic ,,geogeny ,the history of the earth1 of which we are now going to make a brief survey1 is only a minute section of the history of the cosmos4 ,like the latter1 it has been the object of philosophic speculation and mythological fantasy for many thousand years4 ,its true scientific study1 however1 is much younger2 it belongs1 for the most part1 to the nineteenth century4 ,the fact that the earth is a planet revolving round the sun was determined by the system of ,copernicus 7#aedc72 ,galilei1 ,kepler1 and other great astronomers1 mathematically determined its distance from the sun1 the laws of its motion1 and so forth4 ,kant and ,laplace indicated1 in their cosmogony1 the way in which the earth had been developed from the parent sun4 ,but the later history of the earth1 the formation of its crust1 the origin of its seas and continents1 its mountains and deserts1 was rarely made the subject of serious scientific research in the eighteenth century1 and in the first two decades of the nineteenth4 ,as a rule1 men were satisfied with unreliable conjectures or with the traditional story of creation2 once more the ,mosaic legend barred the way to an independent investigation4 ,in #ahbb an important work appeared1 which followed the same method in the scientific investigation of the history of the earth that had already proved the most fertile--the ontological method1 or the principle of actualism4 ,it consists in a careful study and manipulation of actual phenomena with a view to the elucidation of the analogous historical processes of the past4 ,the ,society of ,science at ,gttingen had offered a prize in #ahah for the most searching and comprehensive inquiry into the changes in the earth's crust which are historically demonstrable1 and the application which may be made of a knowledge of them in the investigation of the terrestrial revolutions which lie beyond the range of history4 ,this prize was obtained by ,karl ,hoff1 of ,gotha1 for his distinguished work1 ,history of the ,natural ,changes in the ,crust of the ,earth in the ,light of ,tradition 7#ahbb-cd74 ,sir ,charles ,lyell then applied this ontological or actualistic method with great success to the whole province of geology2 his ,principles of ,geology 7#ahcj7 laid the firm foundation on which the fabric of the history of the earth was so happily erected4 ,the important geogenetic research of ,alexander ,humboldt1 ,leopold ,buch1 ,gustav ,bischof1 ,edward ,sss1 and other geologists1 were wholly based on the empirical foundation and the speculative principles of ,karl ,hoff and ,charles ,lyell4 ,they cleared the way for purely rational science in the field of geology2 they removed the obstacles that had been put in the path by mythological fancy and religious tradition1 especially by the ,bible and its legends4 ,i have already discussed the merits of ,lyell1 and his relations with his friend ,charles ,darwin1 in the sixteenth and seventeenth chapters of my ,natural ,history of ,creation1 and must refer the reader to the standard works on geology for a further acquaintance with the history of the earth and the great progress which dynamical and historical geology have made during the century4 ,the first division of the history of the earth must be a separation of inorganic and organic geogeny2 the latter begins with the first appearance of living things on our planet4 ,the earlier section1 the inorganic history of the earth1 ran much the same course as that of the other planets of our system4 ,they were all cast off as rings of nebula at the equator of the rotating solar mass1 and gradually condensed into independent bodies4 ,after cooling down a little1 the glowing ball of the earth was formed out of the gaseous mass1 and eventually1 as the heat continued to radiate out into space1 there was formed at its surface the thin solid crust on which we live4 ,when the temperature at the surface had gone down to a certain point1 the water descended upon it from the environing clouds of steam1 and thus the first condition was secured for the rise of organic life4 ,many million years--certainly more than a hundred--have passed since this important process of the formation of water took place1 introducing the third section of cosmogony1 which we call biogeny4 ,,iii4--,,monistic ,,biogeny ,the third phase of the evolution of the world opens with the advent of organisms on our planet1 and continues uninterrupted from that point until the present day4 ,the great problems which this most interesting part of the earth's history suggests to us were still thought insoluble at the beginning of the nineteenth century1 or1 at least1 so difficult that their solution seemed to be extremely remote4 ,now1 at the close of the century1 we can affirm with legitimate pride that they have been substantially solved by modern biology and its theory of transformism2 indeed1 many of the phenomena of the organic world are now interpreted on physical principles as completely as the familiar physical phenomena of inorganic nature4 ,the merit of making the first important step in this difficult path and of pointing out the way to the monistic solution of all the problems of biology must be accorded to the great ,french scientist1 ,jean ,lamarck2 it was in #ahji1 the year of the birth of ,charles ,darwin1 that he published his famous ,philosophie ,zoologique4 ,in this original work not only is a splendid effort made to interpret all the phenomena of organic life from a monistic and physical point of view1 but the path is opened which alone leads to the solution of the greatest enigma of this branch of science--the problem of the natural origin of organic species4 ,lamarck1 who had an equally extensive empirical acquaintance with zoology and botany1 drew the first sketch of the theory of descent2 he showed that all the countless members of the plant and animal kingdoms have arisen by slow transformation from simple1 common ancestral types1 and that it is the gradual modification of forms by adaptation1 in reciprocal action with heredity1 which has brought about this secular metamorphosis4 ,i have fully appreciated the merit of ,lamarck in the fifth chapter1 and of ,darwin in the sixth and seventh chapters1 of the ,natural ,history of ,creation4 ,darwin1 fifty years afterwards1 not only gave a solid foundation to all the essential parts of the theory of descent1 but he filled up the lacunae of ,lamarck's work by his theory of selection4 ,darwin reaped abundantly the success that ,lamarck had never seen1 with all his merit4 ,his epoch-making work on ,the ,origin of ,species by ,natural ,selection has transformed modern biology from its very foundations1 in the course of the last forty years1 and has raised it to a stage of development that yields to no other science in existence4 ,darwin is the ,copernicus of the organic world1 as ,i said in #ahfh1 and ,e4 du ,bois-,reymond repeated fifteen years afterwards4#bg ,,iv4--,,monistic ,,anthropogeny ,the fourth and last phase of the world's history must be for us men that latest period of time which has witnessed the development of our own race4 ,lamarck 7#ahji7 had already recognized that this evolution is only rationally conceivable as the outcome of a natural process1 by descent from the apes1 our next of kin among the mammals4 ,huxley then proved1 in his famous essay on ,the ,place of ,man in ,nature1 that this momentous thesis is an inevitable consequence of the theory of descent1 and is thoroughly established by the facts of anatomy1 embryology1 and palontology4 ,he considered this question of all questions to be substantially answered4 ,darwin followed with a brilliant discussion of the question under many aspects in his ,descent of ,man 7#ahga74 ,i had myself devoted a special chapter to this important problem of the science of evolution in my ,general ,morphology 7#ahff74 ,in #ahgd ,i published my ,anthropogeny1 which contains the first attempt to trace the descent of man through the entire chain of his ancestry right up to the earliest archigonous monera2 the attempt was based equally on the three great documents of evolutionary science--anatomy1 embryology1 and palontology4 ,the progress we have made in anthropogenetic research during the last few years is described in the paper which ,i read on ,our ,present ,knowledge of the ,origin of ,man at the ,international ,congress of ,zoologists at ,cambridge in #ahih4bh ,,chapter ,,xiv ,,the ,,unity ,,of ,,nature ,the ,monism of the ,cosmos--,essential ,unity of ,organic and ,inorganic ,nature--,carbon-,theory--,the ,hypothesis of ,abiogenesis--,mechanical and ,purposive ,causes--,mechanicism and ,teleology in ,kant's ,works--,design in the ,organic and ,inorganic ,worlds--,vitalism--,neovitalism--,dyste leology 7the ,moral of the ,rudimentary ,organs7--,absence of ,design in1 and ,imperfection of1 ,nature--,telic ,action in ,organized ,bodies--,its ,absence in ,ontogeny and ,phylogeny--,the ,platonist ,ideas--,no ,moral ,order ,discoverable in the ,history of the ,organic ,world1 of the ,vertebrates1 or of the ,human ,race--,prevision--,design and ,chance ,one of the first things to be proved by the law of substance is the basic fact that any natural force can be directly or indirectly converted into any other4 ,mechanical and chemical energy1 sound and heat1 light and electricity1 are mutually convertible2 they seem to be but different modes of one and the same fundamental force or energy4 ,thence follows the important thesis of the unity of all natural forces1 or1 as it may also be expressed1 the monism of energy4 ,this fundamental principle is now generally recognized in the entire province of physics and chemistry1 as far as it applies to inorganic substances4 ,it seems to be otherwise with the organic world and its wealth of color and form4 ,it is1 of course1 obvious that a great part of the phenomena of life may be immediately traced to mechanical and chemical energy1 and to the effects of electricity and light4 ,for other vital processes1 however1 especially for psychic activity and consciousness1 such an interpretation is vigorously contested4 ,yet the modern science of evolution has achieved the task of constructing a bridge between these two apparently irreconcilable provinces4 ,we are now certain that all the phenomena of organic life are subject to the universal law of substance no less than the phenomena of the inorganic universe4 ,the unity of nature which necessarily follows1 and the demolition of the earlier dualism1 are certainly among the most valuable results of modern evolution4 ,thirty-three years ago ,i made an exhaustive effort to establish this monism of the cosmos and the essential unity of organic and inorganic nature by a thorough1 critical demonstration1 and a comparison of the accordance of these two great divisions of nature with regard to matter1 form1 and force4#bi ,a short epitome of the result is given in the fifteenth chapter of my ,natural ,history of ,creation4 ,the views ,i put forward are accepted by the majority of modern scientists1 but an attempt has been made in many quarters lately to dispute them and to maintain the old antithesis of the two divisions of nature4 ,the ablest of these is to be found in the recent ,welt als ,that of the botanist ,reinke4 ,it defends pure cosmological dualism with admirable lucidity and consistency1 and only goes to prove how utterly untenable the teleological system is that is connected therewith4 ,according to the author1 physical and chemical forces alone are at work in the entire field of inorganic nature1 while in the organic world we find intelligent forces1 regulative or dominant forces4 ,the law of substance is supposed to apply to the one1 but not to the other4 ,on the whole1 it is a question of the old antithesis of a mechanical and a teleological system4 ,but before we go more fully into it1 let us glance briefly at two other theories1 which seem to me to be of great importance in the decision of that controversy--the carbon-theory and the theory of spontaneous generation4 ,physiological chemistry has1 after countless analyses1 established the following five facts during the last forty years3 ,i4 ,no other elements are found in organic bodies than those of the inorganic world4 ,,ii4 ,the combinations of elements which are peculiar to organisms1 and which are responsible for their vital phenomena1 are compound protoplasmic substances1 of the group of albuminates4 ,,iii4 ,organic life itself is a chemico-physical process1 based on the metabolism 7or interchange of material7 of these albuminates4 ,,iv4 ,the only element which is capable of building up these compound albuminates1 in combination with other elements 7oxygen1 hydrogen1 nitrogen1 and sulphur71 is carbon4 ,v4 ,these protoplasmic compounds of carbon are distinguished from most other chemical combinations by their very intricate molecular structure1 their instability1 and their jelly-like consistency4 ,on the basis of these five fundamental facts the following carbon-theory was erected thirty-three years ago3 ,the peculiar chemico-physical properties of carbon--especially the fluidity and the facility of decomposition of the most elaborate albuminoid compounds of carbon--are the sole and the mechanical causes of the specific phenomena of movement1 which distinguish organic from inorganic substances1 and which are called life1 in the usual sense of the word 7see ,the ,natural ,history of ,creation74 ,although this carbon-theory is warmly disputed in some quarters1 no better monistic theory has yet appeared to replace it4 ,we have now a much better and more thorough knowledge of the physiological relations of cell-life1 and of the chemistry and physics of the living protoplasm1 than we had thirty-three years ago1 and so it is possible to make a more confident and effective defence of the carbon-theory4 ,the old idea of spontaneous generation is now taken in many different senses4 ,it is owing to this indistinctness of the idea1 and its application to so many different hypotheses1 that the problem is one of the most contentious and confused of the science of the day4 ,i restrict the idea of spontaneous generation--also called abiogenesis or archigony--to the first development of living protoplasm out of inorganic carbonates1 and distinguish two phases in this beginning of biogenesis3 7#a7 autogony1 or the rise of the simplest protoplasmic substances in a formative fluid1 and 7#b7 plasmogony1 the differentiation of individual primitive organisms out of these protoplasmic compounds1 in the form of monera4 ,i have treated this important1 though difficult1 problem so exhaustively in the fifteenth chapter of my ,natural ,history of ,creation that ,i may content myself here with referring to it4 ,there is also a very searching and severely scientific inquiry into it in my ,general ,morphology 7#ahff74 ,naegeli has also treated the hypothesis in quite the same sense in his mechanico-physiological theory of descent 7#ahhd71 and has represented it to be an indispensable thesis in any natural theory of evolution4 ,i entirely agree with his assertion that to reject abiogenesis is to admit a miracle4 ,the hypothesis of spontaneous generation and the allied carbon-theory are of great importance in deciding the long-standing conflict between the teleological 7dualistic7 and the mechanical 7monistic7 interpretation of phenomena4 ,since ,darwin gave us the key to the monistic explanation of organization in his theory of selection forty years ago1 it has become possible for us to trace the splendid variety of orderly tendencies of the organic world to mechanical1 natural causes1 just as we could formerly in the inorganic world alone4 ,hence the supernatural and telic forces1 to which the scientist had had recourse1 have been rendered superfluous4 ,modern metaphysics1 however1 continues to regard the latter as indispensable and the former as inadequate4 ,no philosopher has done more than ,immanuel ,kant in defining the profound distinction between efficient and final causes1 with relation to the interpretation of the whole cosmos4 ,in his well-known earlier work on ,the ,general ,natural ,history and ,theory of the ,heavens he made a bold attempt to treat the constitution and the mechanical origin of the entire fabric of the universe according to ,newtonian laws4 ,this cosmological nebular theory was based entirely on the mechanical phenomena of gravitation4 ,it was expanded and mathematically established later on by ,laplace4 ,when the famous ,french astronomer was asked by ,napoleon ,i4 where ,god1 the creator and sustainer of all things1 came in in his system1 he clearly and honestly replied3 ,sire1 ,i have managed without that hypothesis4 ,that indicated the atheistic character which this mechanical cosmogony shares with all the other inorganic sciences4 ,this is the more noteworthy because the theory of ,kant and ,laplace is now almost universally accepted2 every attempt to supersede it has failed4 ,when atheism is denounced as a grave reproach1 as it so often is1 it is well to remember that the reproach extends to the whole of modern science1 in so far as it gives a purely mechanical interpretation of the inorganic world4 ,mechanicism 7in the ,kantian sense7 alone can give us a true explanation of natural phenomena1 for it traces them to their real efficient causes1 to blind and unconscious agencies1 which are determined in their action only by the material constitution of the bodies we are investigating4 ,kant himself emphatically affirms that there can be no science without this mechanicism of nature1 and that the capacity of human reason to give a mechanical interpretation of phenomena is unlimited4 ,but when he came subsequently to give an elucidation of the complex phenomena of organic nature in his critique of the teleological system1 he declared that these mechanical causes were inadequate2 that in this we must call final causes to our assistance4 ,it is true1 he said1 that even here we must recognize the theoretical faculty of the mind to give a mechanical interpretation1 but its actual competence to do so is restricted4 ,he grants it this capacity to some extent2 but for the majority of the vital processes 7and especially for man's psychic activity7 he thinks we are bound to postulate final causes4 ,the remarkable #gi of the critique of judgment bears the characteristic heading3 ,on the ,necessity for the ,subordination of the ,mechanical ,principle to the ,teleological in the ,explanation of a ,thing as a ,natural ,end4 ,it seemed to ,kant so impossible to explain the orderly processes in the living organism without postulating supernatural final causes 7that is1 a purposive creative force7 that he said3 ,it is quite certain that we cannot even satisfactorily understand1 much less elucidate1 the nature of an organism and its internal faculty on purely mechanical natural principles2 it is so certain1 indeed1 that we may confidently say1 ',it is absurd for a man to conceive the idea even that some day a ,newton will arise who can explain the origin of a single blade of grass by natural laws which are uncontrolled by design'--such a hope is entirely forbidden us4 ,seventy years afterwards this impossible ,newton of the organic world appeared in the person of ,charles ,darwin1 and achieved the great task that ,kant had deemed impracticable4 ,since ,newton 7#afhb7 formulated the law of gravitation1 and ,kant 7#agee7 established the constitution and mechanical origin of the entire fabric of the world on ,newtonian laws1 and ,laplace 7#agif7 provided a mathematical foundation for this law of cosmic mechanicism1 the whole of the inorganic sciences have become purely mechanical1 and at the same time purely atheistic4 ,astronomy1 cosmogony1 geology1 meteorology1 and inorganic physics and chemistry are now absolutely ruled by mechanical laws on a mathematical foundation4 ,the idea of design has wholly disappeared from this vast province of science4 ,at the close of the nineteenth century1 now that this monistic view has fought its way to general recognition1 no scientist ever asks seriously of the purpose of any single phenomenon in the whole of this great field4 ,is any astronomer likely to inquire seriously to-day into the purpose of planetary motion1 or a mineralogist to seek design in the structure of a crystal8 ,does the physicist investigate the purpose of electric force1 or the chemist that of atomic weight8 ,we may confidently answer in the negative--certainly not1 in the sense that ,god1 or a purposive natural force1 had at some time created these fundamental laws of the mechanism of the universe with a definite design1 and causes them to work daily in accordance with his rational will4 ,the anthropomorphic notion of a deliberate architect and ruler of the world has gone forever from this field2 the eternal1 iron laws of nature have taken his place4 ,but the idea of design has a very great significance and application in the organic world4 ,we do undeniably perceive a purpose in the structure and in the life of an organism4 ,the plant and the animal seem to be controlled by a definite design in the combination of their several parts1 just as clearly as we see in the machines which man invents and constructs2 as long as life continues the functions of the several organs are directed to definite ends1 just as is the operation of the various parts of a machine4 ,hence it was quite natural that the older nave study of nature1 in explaining the origin and activity of the living being1 should postulate a creator who had arranged all things with wisdom and understanding1 and had constructed each plant and animal according to the special purpose of its life4 ,the conception of this almighty creator of heaven and earth was usually quite anthropomorphic2 he created everything after its kind4 ,as long as the creator seemed to man to be of human shape1 to think with his brain1 see with his eyes1 and fashion with his hands1 it was possible to form a definite picture of this divine engineer and his artistic work in the great workshop of creation4 ,this was not so easy when the idea of ,god became refined1 and man saw in his invisible ,god a creator without organs--a gaseous being4 ,still more unintelligible did these anthropomorphic ideas become when physiology substituted for the conscious1 divine architect an unconscious1 creative vital force--a mysterious1 purposive1 natural force1 which differed from the familiar forces of physics and chemistry1 and only took these in part1 during life1 into its service4 ,this vitalism prevailed until about the middle of the nineteenth century4 ,johannes ,mller1 the great ,berlin physiologist1 was the first to menace it with a destructive dose of facts4 ,it is true that the distinguished biologist had himself 7like all others in the first half of the century7 been educated in a belief in this vital force1 and deemed it indispensable for an elucidation of the ultimate sources of life2 nevertheless1 in his classical and still unrivalled ,manual of ,physiology 7#ahcc7 he gave a demonstrative proof that there is really nothing to be said for this vital force4 ,mller himself1 in a long series of remarkable observations and experiments1 showed that most of the vital processes in the human organism 7and in the other animals7 take place according to physical and chemical laws1 and that many of them are capable of mathematical determination4 ,that was no less true of the animal functions of the muscles and nerves1 and of both the higher and the lower sense-organs1 than of the vegetal functions of digestion1 assimilation1 and circulation4 ,only two branches of the life of the organism1 mental action and reproduction1 retained any element of mystery1 and seemed inexplicable without assuming a vital force4 ,but immediately after ,mller's death such important discoveries and advances were made in these two branches that the uneasy phantom of vital force was driven from its last refuge4 ,by a very remarkable coincidence ,johannes ,mller died in the year #aheh1 which saw the publication of ,darwin's first communication concerning his famous theory4 ,the theory of selection solved the great problem that had mastered ,mller--the question of the origin of orderly arrangements from purely mechanical causes4 ,darwin1 as we have often said1 had a twofold immortal merit in the field of philosophy--firstly1 the reform of ,lamarck's theory of descent1 and its establishment on the mass of facts accumulated in the course of the half-century2 secondly1 the conception of the theory of selection1 which first revealed to us the true causes of the gradual formation of species4 ,darwin was the first to point out that the struggle for life is the unconscious regulator which controls the reciprocal action of heredity and adaptation in the gradual transformation of species2 it is the great selective divinity which1 by a purely natural choice1 without preconceived design1 creates new forms1 just as selective man creates new types by an artificial choice with a definite design4 ,that gave us the solution of the great philosophic problem3 ,how can purposive contrivances be produced by purely mechanical processes without design8 ,kant held the problem to be insoluble1 although ,empedocles had pointed out the direction of the solution two thousand years before4 ,his principle of teleological mechanism has become more and more accepted of late years1 and has furnished a mechanical explanation even of the finest and most recondite processes of organic life by the functional self-production of the purposive structure4 ,thus have we got rid of the transcendental design of the ideological philosophy of the schools1 which was the greatest obstacle to the growth of a rational and monistic conception of nature4 ,very recently1 however1 this ancient phantom of a mystic vital force1 which seemed to be effectually banished1 has put in a fresh appearance2 a number of distinguished biologists have attempted to reintroduce it under another name4 ,the clearest presentation of it is to be found in the ,welt als ,that1 of the ,kiel botanist1 ,j4 ,reinke4 ,he takes upon himself the defence of the notion of miracle1 of theism1 of the ,mosaic story of creation1 and of the constancy of species2 he calls vital forces1 in opposition to physical forces1 the directive or dominant forces4 ,other neovitalists prefer1 in the good old anthropomorphic style1 a supreme engineer1 who has endowed organic substance with a purposive structure1 directed to the realization of a definite plan4 ,these curious teleological hypotheses1 and the objections to ,darwinism which generally accompany them1 do not call for serious scientific refutation to-day4 ,thirty-three years ago ,i gave the title of dysteleology to the science of those extremely interesting and significant biological facts1 which1 in the most striking fashion1 give a direct contradiction to the teleological idea of the purposive arrangement of the living organism4#cj ,this science of rudimentary1 abortive1 arrested1 distorted1 atrophied1 and cataplastic individuals is based on an immense quantity of remarkable phenomena1 which were long familiar to zoologists and botanists1 but were not properly interpreted1 and their great philosophic significance appreciated1 until ,darwin4 ,all the higher animals and plants1 or1 in general1 all organisms which are not entirely simple in structure1 but are made up of a number of organs in orderly co-operation1 are found1 on close examination1 to possess a number of useless or inoperative members1 sometimes1 indeed1 hurtful and dangerous4 ,in the flowers of most plants we find1 besides the actual sex-leaves that effect reproduction1 a number of other leaf-organs which have no use or meaning 7arrested or miscarried pistils1 fruit1 corona1 and calix-leaves1 etc474 ,in the two large and variegated classes of flying animals1 birds and insects1 there are1 besides the forms which make constant use of their wings1 a number of species which have undeveloped wings and cannot fly4 ,in nearly every class of the higher animals which have eyes there are certain types that live in the dark2 they have eyes1 as a rule1 but undeveloped and useless for vision4 ,in our own human organism we have similar useless rudimentary structures in the muscles of the ear1 in the eye-lid1 in the nipple and milk-gland of the male1 and in other parts of the body2 indeed1 the vermiform appendix of our ccum is not only useless1 but extremely dangerous1 and inflammation of it is responsible for a number of deaths every year4 ,neither the old mystic vitalism nor the new1 equally irrational1 neovitalism can give any explanation of these and many other purposeless contrivances in the structure of the plant and the animal2 but they are very simple in the light of the theory of descent4 ,it shows that these rudimentary organs are atrophied1 owing to disuse4 ,just as our muscles1 nerves1 and organs of sense are strengthened by exercise and frequent use1 so1 on the other hand1 they are liable to degenerate more or less by disuse or suspended exercise4 ,but1 although the development of the organs is promoted by exercise and adaptation1 they by no means disappear without leaving a trace after neglect2 the force of heredity retains them for many generations1 and only permits their gradual disappearance after the lapse of a considerable time4 ,the blind struggle for existence between the organs determines their historical disappearance1 just as it effected their first origin and development4 ,there is no internal purpose whatever in the drama4 ,the life of the animal and the plant bears the same universal character of incompleteness as the life of man4 ,this is directly attributable to the circumstance that nature--organic as well as inorganic--is in a perennial state of evolution1 change1 and transformation4 ,this evolution seems on the whole--at least as far as we can survey the development of organic life on our planet--to be a progressive improvement1 an historical advance from the simple to the complex1 the lower to the higher1 the imperfect to the perfect4 ,i have proved in my ,general ,morphology that this historical progress--or gradual perfecting 7teleosis7--is the inevitable result of selection1 and not the outcome of a preconceived design4 ,that is clear from the fact that no organism is perfect2 even if it does perfectly adapt itself to its environment at a given moment1 this condition would not last very long2 the conditions of existence of the environment are themselves subject to perpetual change and they thus necessitate a continuous adaptation on the part of the organism4 ,under the title of ,design in the ,living ,organism1 the famous embryologist1 ,karl ,ernst ,baer1 published a work in #ahgf which1 together with the article on ,darwinism which accompanied it1 proved very acceptable to our opponents1 and is still much quoted in opposition to evolution4 ,it was a revival of the old teleological system under a new name1 and we must devote a line of criticism to it4 ,we must premise that1 though ,baer was a scientist of the highest order1 his original monistic views were gradually marred by a tinge of mysticism with the advance of age1 and he eventually became a thorough dualist4 ,in his profound work on the evolution of animals 7#ahbh71 which he himself entitled ,observation and ,experiment1 these two methods of investigation are equally applied4 ,by careful observation of the various phenomena of the development of the animal ovum ,baer succeeded in giving the first consistent presentation of the remarkable changes which take place in the growth of the vertebrate from a simple egg-cell4 ,at the same time he endeavored1 by far-seeing comparison and keen reflection1 to learn the causes of the transformation1 and to reduce them to general constructive laws4 ,he expressed the general result of his research in the following thesis3 ,the evolution of the individual is the story of the growth of individuality in every respect4 ,he meant that the one great thought that controls all the different aspects of animal evolution is the same that gathered the scattered fragments of space into spheres and linked them into solar systems4 ,this thought is no other than life itself1 and the words and syllables in which it finds utterance are the varied forms of living things4 ,baer1 however1 did not attain to a deeper knowledge of this great genetic truth and a clearer insight into the real efficient causes of organic evolution1 because his attention was exclusively given to one half of evolutionary science1 the science of the evolution of the individual1 embryology1 or1 in a wider sense1 ontogeny4 ,the other half1 the science of the evolution of species1 phylogeny1 was not yet in existence1 although ,lamarck had already pointed out the way to it in #ahji4 ,when it was established by ,darwin in #ahei1 the aged ,baer was no longer in a position to appreciate it2 the fruitless struggle which he led against the theory of selection clearly proved that he understood neither its real meaning nor its philosophic importance4 ,teleological and1 subsequently1 theological speculations had incapacitated the ageing scientist from appreciating this greatest reform of biology4 ,the teleological observations which he published against it in his ,species and ,studies in his eighty-fourth year are mere repetitions of errors which the teleology of the dualists has opposed to the mechanical or monistic system for more than two thousand years4 ,the telic idea which1 according to ,baer1 controls the entire evolution of the animal from the ovum1 is only another expression for the eternal idea of ,plato and the entelecheia of his pupil ,aristotle4 ,our modern biogeny gives a purely physiological explanation of the facts of embryology1 in assigning the functions of heredity and adaptation as their causes4 ,the great biogenetic law1 which ,baer failed to appreciate1 reveals the intimate causal connection between the ontogenesis of the individual and the phylogenesis of its ancestors2 the former seems to be a recapitulation of the latter4 ,nowhere1 however1 in the evolution of animals and plants do we find any trace of design1 but merely the inevitable outcome of the struggle for existence1 the blind controller1 instead of the provident ,god1 that effects the changes of organic forms by a mutual action of the laws of heredity and adaptation4 ,and there is no more trace of design in the embryology of the individual plant1 animal1 or man4 ,this ontogeny is but a brief epitome of phylogeny1 an abbreviated and condensed recapitulation of it1 determined by the physiological laws of heredity4 ,baer ended the preface to his classical ,evolution of ,animals 7#ahbh7 with these words3 ,the palm will be awarded to the fortunate scientist who succeeds in reducing the constructive forces of the animal body to the general forces or life-processes of the entire world4 ,the tree has not yet been planted which is to make his cradle4 ,the great embryologist erred once more4 ,that very year1 #ahbh1 witnessed the arrival of ,charles ,darwin at ,cambridge ,university 7for the purpose of studying theology67--the fortunate scientist who richly earned the palm thirty years afterwards by his theory of selection4 ,in the philosophy of history--that is1 in the general reflections which historians make on the destinies of nations and the complicated course of political evolution--there still prevails the notion of a moral order of the universe4 ,historians seek in the vivid drama of history a leading design1 an ideal purpose1 which has ordained one or other race or state to a special triumph1 and to dominion over the others4 ,this teleological view of history has recently become more strongly contrasted with our monistic view in proportion as monism has proved to be the only possible interpretation of inorganic nature4 ,throughout the whole of astronomy1 geology1 physics1 and chemistry there is no question to-day of a moral order1 or a personal ,god1 whose hand hath disposed all things in wisdom and understanding4 ,and the same must be said of the entire field of biology1 the whole constitution and history of organic nature1 if we set aside the question of man for the moment4 ,darwin has not only proved by his theory of selection that the orderly processes in the life and structure of animals and plants have arisen by mechanical laws without any preconceived design1 but he has shown us in the struggle for life the powerful natural force which has exerted supreme control over the entire course of organic evolution for millions of years4 ,it may be said that the struggle for life is the survival of the fittest or the victory of the best2 that is only correct when we regard the strongest as the best 7in a moral sense74 ,moreover1 the whole history of the organic world goes to prove that1 besides the predominant advance towards perfection1 there are at all times cases of retrogression to lower stages4 ,even ,baer's notion of design has no moral feature whatever4 ,do we find a different state of things in the history of peoples1 which man1 in his anthropocentric presumption1 loves to call the history of the world8 ,do we find in every phase of it a lofty moral principle or a wise ruler1 guiding the destinies of nations8 ,there can be but one answer in the present advanced stage of natural and human history3 ,no4 ,the fate of those branches of the human family1 those nations and races which have struggled for existence and progress for thousands of years1 is determined by the same eternal laws of iron as the history of the whole organic world which has peopled the earth for millions of years4 ,geologists distinguish three great epochs in the organic history of the earth1 as far as we can read it in the monuments of the science of fossils--the primary1 secondary1 and tertiary epochs4 ,according to a recent calculation1 the first occupied at least thirty-four million1 the second eleven million1 and the third three million years4 ,the history of the family of vertebrates1 from which our own race has sprung1 unfolds clearly before our eyes during this long period4 ,three different stages in the evolution of the vertebrate correspond to the three epochs2 the fishes characterized the primary 7palozoic7 age1 the reptiles the secondary 7mesozoic71 and the mammals the tertiary 7cnozoic74 ,of the three groups the fishes rank lowest in organization1 the reptiles come next1 and the mammals take the highest place4 ,we find1 on nearer examination of the history of the three classes1 that their various orders and families also advanced progressively during the three epochs towards a higher stage of perfection4 ,may we consider this progressive development as the outcome of a conscious design or a moral order of the universe8 ,certainly not4 ,the theory of selection teaches us that this organic progress1 like the earlier organic differentiation1 is an inevitable consequence of the struggle for existence4 ,thousands of beautiful and remarkable species of animals and plants have perished during those forty-eight million years1 to give place to stronger competitors1 and the victors in this struggle for life were not always the noblest or most perfect forms in a moral sense4 ,it has been just the same with the history of humanity4 ,the splendid civilization of classical antiquity perished because ,christianity1 with its faith in a loving ,god and its hope of a better life beyond the grave1 gave a fresh1 strong impetus to the soaring human mind4 ,the ,papal ,church quickly degenerated into a pitiful caricature of real ,christianity1 and ruthlessly scattered the treasures of knowledge which the ,hellenic philosophy had gathered2 it gained the dominion of the world through the ignorance of the credulous masses4 ,in time the ,reformation broke the chains of this mental slavery1 and assisted reason to secure its right once more4 ,but in the new1 as in the older1 period the great struggle for existence went on in its eternal fluctuation1 with no trace of a moral order4 ,and it is just as impossible for the impartial and critical observer to detect a wise providence in the fate of individual human beings as a moral order in the history of peoples4 ,both are determined with iron necessity by a mechanical causality which connects every single phenomenon with one or more antecedent causes4 ,even the ancient ,greeks recognized ananke1 the blind heimarmene1 the fate that rules gods and men1 as the supreme principle of the universe4 ,christianity replaced it by a conscious ,providence1 which is not blind1 but sees1 and which governs the world in patriarchal fashion4 ,the anthropomorphic character of this notion1 generally closely connected with belief in a personal ,god1 is quite obvious4 ,belief in a loving ,father1 who unceasingly guides the destinies of one billion five hundred million men on our planet1 and is attentive at all times to their millions of contradictory prayers and pious wishes1 is absolutely impossible2 that is at once perceived on laying aside the colored spectacles of faith and reflecting rationally on the subject4 ,as a rule1 this belief in ,providence and the tutelage of a loving ,father is more intense in the modern civilized man--just as in the uncultured savage--when some good fortune has fallen him3 an escape from peril of life1 recovery from a severe illness1 the winning of the first prize in a lottery1 the birth of a long-delayed child1 and so forth4 ,when1 on the other hand1 a misfortune is met with1 or an ardent wish is not fulfilled1 ,providence is forgotten4 ,the wise ruler of the world slumbered--or refused his blessing4 ,in the extraordinary development of commerce of the nineteenth century the number of catastrophes and accidents has necessarily increased beyond all imagination2 of that the journal is a daily witness4 ,thousands are killed every year by shipwreck1 railway accidents1 mine accidents1 etc4 ,thousands slay each other every year in war1 and the preparation for this wholesale massacre absorbs much the greater part of the revenue in the highest civilized nations1 the chief professors of ,christian charity4 ,and among these hundreds of thousands of annual victims of modern civilization strong1 industrious1 courageous workers predominate4 ,yet the talk of a moral order goes on4 ,since impartial study of the evolution of the world teaches us that there is no definite aim and no special purpose to be traced in it1 there seems to be no alternative but to leave everything to blind chance4 ,this reproach has been made to the transformism of ,lamarck and ,darwin1 as it had been to the previous systems of ,kant and ,laplace2 there are a number of dualist philosophers who lay great stress on it4 ,it is1 therefore1 worth while to make a brief remark upon it4 ,one group of philosophers affirms1 in accordance with its teleological conception1 that the whole cosmos is an orderly system1 in which every phenomenon has its aim and purpose2 there is no such thing as chance4 ,the other group1 holding a mechanical theory1 expresses itself thus3 ,the development of the universe is a monistic mechanical process1 in which we discover no aim or purpose whatever2 what we call design in the organic world is a special result of biological agencies2 neither in the evolution of the heavenly bodies nor in that of the crust of our earth do we find any trace of a controlling purpose--all is the result of chance4 ,each party is right--according to its definition of chance4 ,the general law of causality1 taken in conjunction with the law of substance1 teaches us that every phenomenon has a mechanical cause2 in this sense there is no such thing as chance4 ,yet it is not only lawful1 but necessary1 to retain the term for the purpose of expressing the simultaneous occurrence of two phenomena1 which are not causally related to each other1 but of which each has its own mechanical cause1 independent of that of the other4 ,everybody knows that chance1 in its monistic sense1 plays an important part in the life of man and in the universe at large4 ,that1 however1 does not prevent us from recognizing in each chance event1 as we do in the evolution of the entire cosmos1 the universal sovereignty of nature's supreme law1 the law of substance4 ,,chapter ,,xv ,,god ,,and ,,the ,,world ,the ,idea of ,god in ,general--,antithesis of ,god and the ,world2 the ,supernatural and ,nature--,theism and ,pantheism--,chief ,forms of ,theism--,polytheism--,triplotheism--,am phitheism--,monotheism--,religious ,statistics--,naturalistic ,monotheism--,solarism--,anthropistic ,monotheism--,the ,three ,great ,mediterranean ,religions--,mosaism--,christianity--,th e ,cult of the ,madonna and the ,saints--,papal ,polytheism--,islam--,mixotheism--,natur e of ,theism--,an ,extra-mundane and ,anthropomorphic ,god2 a ,gaseous ,vertebrate--,pantheism--,intramundane ,god 7,nature7--,the ,hylozoism of the ,ionic ,monists 7,anaximander7--,conflict of ,pantheism and ,christianity--,spinoza--,modern ,monism--,atheism ,for thousands of years humanity has placed the last and supreme basis of all phenomena in an efficient cause1 to which it gives the title of ,god 7deus1 theos74 ,like all general ideas1 this notion of ,god has undergone a series of remarkable modifications and transformations in the course of the evolution of reason4 ,indeed1 it may be said that no other idea has had so many metamorphoses2 for no other belief affects in so high a degree the chief objects of the mind and of rational science1 as well as the deepest interests of the emotion and poetic fancy of the believer4 ,a comparative criticism of the many different forms of the idea of ,god would be extremely interesting and instructive2 but we have not space for it in the present work4 ,we must be content with a passing glance at the most important forms of the belief and their relation to the modern thought that has been evoked by a sound study of nature4 ,for further information on this interesting question the reader would do well to consult the distinguished work of ,adalbert ,svoboda1 ,forms of ,faith 7#ahig74 ,when we pass over the finer shades and the variegated clothing of the ,god-idea and confine our attention to its chief element1 we can distribute all the different presentations of it in two groups--the theistic and pantheistic group4 ,the latter is closely connected with the monistic1 or rational1 view of things1 and the former is associated with dualism and mysticism4 ,i4--,,theism ,in this view ,god is distinct from1 and opposed to1 the world as its creator1 sustainer1 and ruler4 ,he is always conceived in a more or less human form1 as an organism which thinks and acts like a man--only on a much higher scale4 ,this anthropomorphic ,god1 polyphyletically evolved by the different races1 assumes an infinity of shapes in their imagination1 from fetichism to the refined monotheistic religions of the present day4 ,the chief forms of theism are polytheism1 triplotheism1 amphitheism1 and monotheism4 ,the polytheist peoples the world with a variety of gods and goddesses1 which enter into its machinery more or less independently4 ,fetichism sees such subordinate deities in the lifeless body of nature1 in rocks1 in water1 in the air1 in human productions of every kind 7pictures1 statues1 etc474 ,demonism sees gods in living organisms of every species--trees1 animals1 and men4 ,this kind of polytheism is found in innumerable forms even in the lowest tribes4 ,it reaches the highest stage in ,hellenic polytheism1 in the myths of ancient ,greece1 which still furnish the finest images to the modern poet and artist4 ,at a much lower stage we have ,catholic polytheism1 in which innumerable saints 7many of them of very equivocal repute7 are venerated as subordinate divinities1 and prayed to to exert their mediation with the supreme divinity4 ,the dogma of the ,trinity1 which still comprises three of the chief articles of faith in the creed of ,christian peoples1 culminates in the notion that the one ,god of ,christianity is really made up of three different persons3 7#a7 ,god the ,father1 the omnipotent creator of heaven and earth 7this untenable myth was refuted long ago by scientific cosmogony1 astronomy1 and geology72 7#b7 ,jesus ,christ2 and 7#c7 the ,holy ,ghost1 a mystical being1 over whose incomprehensible relation to the ,father and the ,son millions of ,christian theologians have racked their brains in vain for the last nineteen hundred years4 ,the ,gospels1 which are the only clear sources of this triplotheism1 are very obscure as to the relation of these three persons to each other1 and do not give a satisfactory answer to the question of their unity4 ,on the other hand1 it must be carefully noted what confusion this obscure and mystic dogma of the ,trinity must necessarily cause in the minds of our children even in the earlier years of instruction4 ,one morning they learn 7in their religious instruction7 that three times one are one1 and the very next hour they are told in their arithmetic class that three times one are three4 ,i remember well the reflection that this confusion led me to in my early school-days4 ,for the rest1 the ,trinity is not an original element in ,christianity2 like most of the other ,christian dogmas1 it has been borrowed from earlier religions4 ,out of the sun-worship of the ,chaldean magi was evolved the ,trinity of ,ilu1 the mysterious source of the world2 its three manifestations were ,anu1 primeval chaos2 ,bel1 the architect of the world2 and ,aa1 the heavenly light1 the all-enlightening wisdom4 ,in the ,brahmanic religion the ,trimurti is also conceived as a divine unity made up of three persons--,brahma 7the creator71 ,vishnu 7the sustainer71 and ,shiva 7the destroyer74 ,it would seem that in this and other ideas of a ,trinity the sacred number1 three1 as such--as a symbolical number--has counted for something4 ,the three first ,christian virtues--,faith1 ,hope1 and ,charity--form a similar triad4 ,according to the amphitheists1 the world is ruled by two different gods1 a good and an evil principle1 ,god and the ,devil4 ,they are engaged in a perpetual struggle1 like rival emperors1 or pope and anti-pope4 ,the condition of the world is the result of this conflict4 ,the loving ,god1 or good principle1 is the source of all that is good and beautiful1 of joy and of peace4 ,the world would be perfect if ,his work were not continually thwarted by the evil principle1 the ,devil2 this being is the cause of all that is bad and hateful1 of contradiction and of pain4 ,amphitheism is undoubtedly the most rational of all forms of belief in ,god1 and the one which is least incompatible with a scientific view of the world4 ,hence we find it elaborated in many ancient peoples thousands of years before ,christ4 ,in ancient ,india ,vishnu1 the preserver1 struggles with ,shiva1 the destroyer4 ,in ancient ,egypt the good ,osiris is opposed by the wicked ,typhon4 ,the early ,hebrews had a similar dualism of ,aschera 7or ,keturah71 the fertile mother-earth1 and ,elion 7,moloch or ,sethos71 the stern heavenly father4 ,in the ,zend religion of the ancient ,persians1 founded by ,zoroaster two thousand years before ,christ1 there is a perpetual struggle between ,ormuzd1 the good god of light1 and ,ahriman1 the wicked god of darkness4 ,in ,christian mythology the ,devil is scarcely less conspicuous as the adversary of the good deity1 the tempter and seducer1 the prince of hell1 and lord of darkness4 ,a personal devil was still an important element in the belief of most ,christians at the beginning of the nineteenth century4 ,towards the middle of the century he was gradually eliminated by being progressively explained away1 or he was restricted to the subordinate rle he plays as ,mephistopheles in ,goethe's great drama4 ,to-day the majority of educated people look upon belief in a personal devil as a medival superstition1 while belief in ,god 7that is1 the personal1 good1 and loving ,god7 is retained as an indispensable element of religion4 ,yet the one belief is just as much 7or as little7 justified as the other4 ,in any case1 the much-lamented imperfection of our earthly life1 the struggle for existence1 and all that pertains to it1 are explained much more simply and naturally by this struggle of a good and an evil god than by any other form of theism4 ,the dogma of the unity of ,god may in some respects be regarded as the simplest and most natural type of theism2 it is popularly supposed to be the most widely accepted element of religion1 and to predominate in the ecclesiastical systems of civilized countries4 ,in reality1 that is not the case1 because this alleged monotheism usually turns out on closer inquiry to be one of the other forms of theism we have examined1 a number of subordinate deities being generally introduced besides the supreme one4 ,most of the religions which took a purely monotheistic stand-point have become more or less polytheistic in the course of time4 ,modern statistics assure us that of the one billion five hundred million men who people the earth the great majority are monotheists2 of these1 nominally1 about six hundred millions are ,brahma-,buddhists1 five hundred millions are called ,christians1 two hundred millions are heathens 7of various types71 one hundred and eighty millions are ,mohammedans1 ten millions are ,jews1 and ten millions have no religion at all4 ,however1 the vast majority of these nominal monotheists have very confused ideas about the deity1 or believe in a number of gods and goddesses besides the chief god--angels1 devils1 etc4 ,the different forms which monotheism has assumed in the course of its polyphyletic development may be distributed in two groups--those of naturalistic and anthropistic monotheism4 ,naturalistic monotheism finds the embodiment of the deity in some lofty and dominating natural phenomenon4 ,the sun1 the deity of light and warmth1 on whose influence all organic life insensibly and directly depends1 was taken to be such a phenomenon many thousand years ago4 ,sun-worship 7solarism1 or heliotheism7 seems to the modern scientist to be the best of all forms of theism1 and the one which may be most easily reconciled with modern monism4 ,for modern astrophysics and geogeny have taught us that the earth is a fragment detached from the sun1 and that it will eventually return to the bosom of its parent4 ,modern physiology teaches us that the first source of organic life on the earth is the formation of protoplasm1 and that this synthesis of simple inorganic substances1 water1 carbonic acid1 and ammonia1 only takes place under the influence of sunlight4 ,on the primary evolution of the plasmodomous plants followed1 secondarily1 that of the plasmophagous animals1 which directly or indirectly depend on them for nourishment2 and the origin of the human race itself is only a later stage in the development of the animal kingdom4 ,indeed1 the whole of our bodily and mental life depends1 in the last resort1 like all other organic life1 on the light and heat rays of the sun4 ,hence in the light of pure reason1 sun-worship1 as a form of naturalistic monotheism1 seems to have a much better foundation than the anthropistic worship of ,christians and of other monotheists who conceive their god in human form4 ,as a matter of fact1 the sun-worshippers attained1 thousands of years ago1 a higher intellectual and moral standard than most of the other theists4 ,when ,i was in ,bombay1 in #ahha1 ,i watched with the greatest sympathy the elevating rites of the pious ,parsees1 who1 standing on the sea-shore1 or kneeling on their prayer-rugs1 offered their devotion to the sun at its rise and setting4#ca ,moon-worship 7lunarism and selenotheism7 is of much less importance than sun-worship4 ,there are a few uncivilized races that have adored the moon as their only deity1 but it has generally been associated with a worship of the stars and the sun4 ,the humanization of ,god1 or the idea that the ,supreme ,being feels1 thinks1 and acts like man 7though in a higher degree71 has played a most important part1 as anthropomorphic monotheism1 in the history of civilization4 ,the most prominent in this respect are the three great religions of the ,mediterranean peoples--the old ,mosaic religion1 the intermediate ,christian religion1 and the younger ,mohammedanism4 ,these three great ,mediterranean religions1 all three arising on the east coast of the most interesting of all seas1 and originating in an imaginative enthusiast of the ,semitic race1 are intimately connected1 not only by this external circumstance of an analogous origin1 but by many common features of their internal contents4 ,just as ,christianity borrowed a good deal of its mythology directly from ancient ,judaism1 so ,islam has inherited much from both its predecessors4 ,all the three were originally monotheistic2 all three were subsequently overlaid with a great variety of polytheistic features1 in proportion as they extended1 first along the coast of the ,mediterranean with its heterogeneous population1 and eventually into every part of the world4 ,the ,hebrew monotheism1 as it was founded by ,moses 7about #afjj ,b4,c471 is usually regarded as the ancient faith which has been of the greatest importance in the ethical and religious development of humanity4 ,this high historical appreciation is certainly valid in the sense that the two other world-conquering ,mediterranean religions issued from it2 ,christ was just as truly a pupil of ,moses as ,mohammed was afterwards of ,christ4 ,so also the ,new ,testament1 which has become the foundation of the belief of the highest civilized nations in the short space of nineteen hundred years1 rests on the venerable basis of the ,old ,testament4 ,the ,bible1 which the two compose1 has had a greater influence and a wider circulation than any other book in the world4 ,even to-day the ,bible--in spite of its curious mingling of the best and the worst elements--is in a certain sense the book of books4 ,yet when we make an impartial and unprejudiced study of this notable historical source1 we find it very different in several important respects from the popular impression4 ,here again modern criticism and history have come to certain conclusions which destroy the prevalent tradition in its very foundations4 ,the monotheism which ,moses endeavored to establish in the worship of ,jehovah1 and which the prophets--the philosophers of the ,hebrew race--afterwards developed with great success1 had at first to sustain a long and severe struggle with the dominant polytheism which was in possession4 ,jehovah1 or ,yahveh1 was originally derived from the heaven-god1 which1 under the title of ,moloch or ,baal1 was one of the most popular of the ,oriental deities 7the ,sethos or ,typhon of the ,egyptians1 and the ,saturn or ,cronos of the ,greeks74 ,there were1 however1 other gods in great favor with the ,jewish people1 and so the struggle with idolatry continued4 ,still1 ,jehovah was1 in principle1 the only ,god1 explicitly claiming1 in the first precept of the decalogue3 ,i am the ,lord thy ,god2 thou shalt have no other gods beside me4 ,christian monotheism shared the fate of its mother1 ,mosaism2 it was generally only monotheistic in theory1 while it degenerated practically into every kind of polytheism4 ,in point of fact1 monotheism was logically abandoned in the very dogma of the ,trinity1 which was adopted as an indispensable foundation of the ,christian religion4 ,the three persons1 which are distinguished as ,father1 ,son1 and ,holy ,ghost1 are three distinct individuals 7and1 indeed1 anthropomorphic persons71 just as truly as the three ,indian deities of the ,trimurti 7,brahma1 ,vishnu1 and ,shiva7 or the ,trinity of the ancient ,hebrews 7,anu1 ,bel1 and ,aa74 ,moreover1 in the most widely distributed form of ,christianity the virgin mother of ,christ plays an important part as a fourth deity2 in many ,catholic countries she is practically taken to be much more powerful and influential than the three male persons of the celestial administration4 ,the cult of the madonna has been developed to such an extent in these countries that we may oppose it to the usual masculine form of monotheism as one of a feminine type4 ,the ,queen of ,heaven becomes so prominent1 as is seen in so many pictures and legends of the madonna1 that the three male persons practically disappear4 ,in addition1 the imagination of the pious ,christian soon came to increase this celestial administration by a numerous company of saints of all kinds1 and bands of musical angels1 who should see that eternal life should not prove too dull4 ,the popes--the greatest charlatans that any religion ever produced--have constantly studied to increase this band of celestial satellites by repeated canonizations4 ,this curious company received its most interesting acquisition in #ahgj1 when the ,vatican ,council pronounced the popes1 as the vicars of ,christ1 to be infallible1 and thus raised them to a divine dignity4 ,when we add the personal ,devil that they acknowledge1 and the bad angels who form his court1 we have in modern ,catholicism1 still the most extensive branch of ,christianity1 a rich and variegated polytheism that dwarfs the ,olympic family of the ,greeks4 ,islam1 or the ,mohammedan monotheism1 is the youngest and purest form of monotheism4 ,when the young ,mohammed 7born #egj7 learned to despise the polytheistic idolatry of his ,arabian compatriots1 and became acquainted with ,nestorian ,christianity1 he adopted its chief doctrines in a general way2 but he could not bring himself to see anything more than a prophet in ,christ1 like ,moses4 ,he found in the dogma of the ,trinity what every emancipated thinker finds on impartial reflection--an absurd legend which is neither reconcilable with the first principles of reason nor of any value whatever for our religious advancement4 ,he justly regarded the worship of the immaculate mother of ,god as a piece of pure idolatry1 like the veneration of pictures and images4 ,the longer he reflected on it1 and the more he strove after a purified idea of deity1 the clearer did the certitude of his great maxim appear3 ,god is the only ,god--there are no other gods beside him4 ,yet ,mohammed could not free himself from the anthropomorphism of the ,god-idea4 ,his one only ,god was an idealized1 almighty man1 like the stern1 vindictive ,god of ,moses1 and the gentle1 loving ,god of ,christ4 ,still1 we must admit that the ,mohammedan religion has preserved the character of pure monotheism throughout the course of its historical development and its inevitable division much more faithfully than the ,mosaic and ,christian religions4 ,we see that to-day1 even externally1 in its forms of prayer and preaching1 and in the architecture and adornment of its mosques4 ,when ,i visited the ,east for the first time1 in #ahgc1 and admired the noble mosques of ,cairo1 ,smyrna1 ,brussa1 and ,constantinople1 ,i was inspired with a feeling of real devotion by the simple and tasteful decoration of the interior1 and the lofty and beautiful architectural work of the exterior4 ,how noble and inspiring do these mosques appear in comparison with the majority of ,catholic churches1 which are covered internally with gaudy pictures and gilt1 and are outwardly disfigured by an immoderate crowd of human and animal figures6 ,not less elevated are the silent prayers and the simple devotional acts of the ,koran when compared with the loud1 unintelligible verbosity of the ,catholic ,mass and the blatant music of their theatrical processions4 ,under the title of mixotheism we may embrace all the forms of theistic belief which contain mixtures of religious notions of different1 sometimes contradictory1 kinds4 ,in theory this most widely diffused type of religion is not recognized at all2 in the concrete it is the most important and most notable of all4 ,the vast majority of men who have religious opinions have always been1 and still are1 mixotheists2 their idea of ,god is picturesquely compounded from the impressions received in childhood from their own sect1 and a number of other impressions which are received later on1 from contact with members of other religions1 and which modify the earlier notions4 ,in educated people there is also sometimes the modifying influence of philosophic studies in maturer years1 and especially the unprejudiced study of natural phenomena1 which reveals the futility of the theistic idea4 ,the conflict of these contradictory impressions1 which is very painful to a sensitive soul1 and which often remains undecided throughout life1 clearly shows the immense power of the heredity of ancient myths on the one hand and the early adaptation to erroneous dogmas on the other4 ,the particular faith in which the child has been brought up generally remains in power1 unless a conversion takes place subsequently1 owing to the stronger influence of some other religion4 ,but even in this supersession of one faith by another the new name1 like the old one1 proves to be merely an outward label covering a mixture of the most diverse opinions and errors4 ,the greater part of those who call themselves ,christians are not monotheists 7as they think71 but amphitheists1 triplotheists1 or polytheists4 ,and the same must be said of ,islam and ,mosaism1 and other monotheistic religions4 ,everywhere we find associated with the original idea of a sole and triune ,god later beliefs in a number of subordinate deities--angels1 devils1 saints1 etc4--a picturesque assortment of the most diverse theistic forms4 ,all the above forms of theism1 in the proper sense of the word--whether the belief assumes a naturalistic or an anthropistic form--represent ,god to be an extramundane or a supernatural being4 ,he is always opposed to the world1 or nature1 as an independent being2 generally as its creator1 sustainer1 and ruler4 ,in most religions he has the additional character of personality1 or1 to put it more definitely still1 ,god as a person is likened to man4 ,in his gods man paints himself4 ,this anthropomorphic conception of ,god as one who thinks1 feels1 and acts like man prevails with the great majority of theists1 sometimes in a cruder and more nave form1 sometimes in a more refined and abstract degree4 ,in any case the form of theosophy we have described is sure to affirm that ,god1 the supreme being1 is infinite in perfection1 and therefore far removed from the imperfection of humanity4 ,yet1 when we examine closely1 we always find the same psychic or mental activity in the two4 ,god feels1 thinks1 and acts as man does1 although it be in an infinitely more perfect form4 ,the personal anthropism of ,god has become so natural to the majority of believers that they experience no shock when they find ,god personified in human form in pictures and statues1 and in the varied images of the poet1 in which ,god takes human form--that is1 is changed into a vertebrate4 ,in some myths1 even1 ,god takes the form of other mammals 7an ape1 lion1 bull1 etc471 and more rarely of a bird 7eagle1 dove1 or stork71 or of some lower vertebrate 7serpent1 crocodile1 dragon1 etc474 ,in the higher and more abstract forms of religion this idea of bodily appearance is entirely abandoned1 and ,god is adored as a pure spirit without a body4 ,god is a spirit1 and they who worship him must worship him in spirit and in truth4 ,nevertheless1 the psychic activity of this pure spirit remains just the same as that of the anthropomorphic ,god4 ,in reality1 even this immaterial spirit is not conceived to be incorporeal1 but merely invisible1 gaseous4 ,we thus arrive at the paradoxical conception of ,god as a gaseous vertebrate4 ,,ii4--,,pantheism ,pantheism teaches that ,god and the world are one4 ,the idea of ,god is identical with that of nature or substance4 ,this pantheistic view is sharply opposed in principle to all the systems we have described1 and to all possible forms of theism although there have been many attempts made from both sides to bridge over the deep chasm that separates the two4 ,there is always this fundamental contradiction between them1 that in theism ,god is opposed to nature as an extramundane being1 as creating and sustaining the world1 and acting upon it from without1 while in pantheism ,god1 as an intramundane being1 is everywhere identical with nature itself1 and is operative within the world as force or energy4 ,the latter view alone is compatible with our supreme law--the law of substance4 ,it follows necessarily that pantheism is the world-system of the modern scientist4 ,there are1 it is true1 still a few men of science who contest this1 and think it possible to reconcile the old theistic theory of human nature with the pantheistic truth of the law of substance4 ,all these efforts rest on confusion or sophistry--when they are honest4 ,as pantheism is a result of an advanced conception of nature in the civilized mind1 it is naturally much younger than theism1 the crudest forms of which are found in great variety in the uncivilized races of ten thousand years ago4 ,we do1 indeed1 find the germs of pantheism in different religions at the very dawn of philosophy in the earliest civilized peoples 7in ,india1 ,egypt1 ,china1 and ,japan71 several thousand years before the time of ,christ2 still1 we do not meet a definite philosophical expression of it until the hylozoism of the ,ionic philosophers1 in the first half of the sixth century before ,christ4 ,all the great thinkers of this flourishing period of ,hellenic thought are surpassed by the famous ,anaximander1 of ,miletus1 who conceived the essential unity of the infinite universe 7apeiron7 more profoundly and more clearly than his master1 ,thales1 or his pupil1 ,anaximenes4 ,not only the great thought of the original unity of the cosmos and the development of all phenomena out of the all-pervading primitive matter found expression in ,anaximander1 but he even enunciated the bold idea of countless worlds in a periodic alternation of birth and death4 ,many other great philosophers of classical antiquity1 especially ,democritus1 ,heraclitus1 and ,empedocles1 had1 in the same or an analogous sense1 a profound conception of this unity of nature and ,god1 of body and spirit1 which has obtained its highest expression in the law of substance of our modern monism4 ,the famous ,roman poet and philosopher1 ,lucretius ,carus1 has presented it in a highly poetic form in his poem ,de ,rerum ,natura4 ,however1 this true pantheistic monism was soon entirely displaced by the mystic dualism of ,plato1 and especially by the powerful influence which the idealistic philosophy obtained by its blending with ,christian dogmas4 ,when the papacy attained to its spiritual despotism over the world1 pantheism was hopelessly crushed2 ,giordano ,bruno1 its most gifted defender1 was burned alive by the ,vicar of ,christ in the ,campo dei ,fiori at ,rome on ,february #ag1 #afjj4 ,it was not until the middle of the seventeenth century that pantheism was exhibited in its purest form by the great ,baruch ,spinoza2 he gave for the totality of things a definition of substance in which ,god and the world are inseparably united4 ,the clearness1 confidence1 and consistency of ,spinoza's monistic system are the more remarkable when we remember that this gifted thinker of two hundred and fifty years ago was without the support of all those sound empirical bases which have been obtained in the second half of the nineteenth century4 ,we have already spoken1 in the first chapter1 of ,spinoza's relation to the materialism of the eighteenth and the monism of the nineteenth century4 ,the propagation of his views1 especially in ,germany1 is due1 above all1 to the immortal works of our greatest poet and thinker1 ,wolfgang ,goethe4 ,his splendid ,god and the ,world1 ,prometheus1 ,faust1 etc41 embody the great thoughts of pantheism in the most perfect poetic creations4 ,atheism affirms that there are no gods or goddesses1 assuming that god means a personal1 extramundane entity4 ,this godless world-system substantially agrees with the monism or pantheism of the modern scientist2 it is only another expression for it1 emphasizing its negative aspect1 the non-existence of any supernatural deity4 ,in this sense ,schopenhauer justly remarks3 ,pantheism is only a polite form of atheism4 ,the truth of pantheism lies in its destruction of the dualist antithesis of ,god and the world1 in its recognition that the world exists in virtue of its own inherent forces4 ,the maxim of the pantheist1 ',god and the world are one1' is merely a polite way of giving the ,lord ,god his cong4 ,during the whole of the ,middle ,ages1 under the bloody despotism of the popes1 atheism was persecuted with fire and sword as a most pernicious system4 ,as the godless man is plainly identified with the wicked in the ,gospel1 and is threatened--simply on account of his want of faith--with the eternal fires of hell1 it was very natural that every good ,christian should be anxious to avoid the suspicion of atheism4 ,unfortunately1 the idea still prevails very widely4 ,the atheistic scientist who devotes his strength and his life to the search for the truth1 is freely credited with all that is evil2 the theistic church-goer1 who thoughtlessly follows the empty ceremonies of ,catholic worship1 is at once assumed to be a good citizen1 even if there be no meaning whatever in his faith and his morality be deplorable4 ,this error will only be destroyed when1 in the twentieth century1 the prevalent superstition gives place to rational knowledge and to a monistic conception of the unity of ,god and the world4 ,,chapter ,,xvi ,,knowledge ,,and ,,belief ,the ,knowledge of the ,truth and ,its ,sources3 the ,activity of the ,senses and the ,association of ,presentations--,organs of ,sense and ,organs of ,thought--,sense-,organs and their ,specific ,energy--,their ,evolution--,the ,philosophy of ,sensibility--,inestimable ,value of the ,senses--,limits of ,sensitive ,knowledge--,hypothesis and ,faith--,theory and ,faith--,essential ,difference of ,scientific 7,natural7 and ,religious 7,supernatural7 ,faith--,superstition of ,savage and of ,civilized ,races--,confessions of ,faith--,unsectarian ,schools--,the ,faith of ,our ,fathers--,spiritism--,revelation ,every effort of genuine science makes for a knowledge of the truth4 ,our only real and valuable knowledge is a knowledge of nature itself1 and consists of presentations which correspond to external things4 ,we are incompetent1 it is true1 to penetrate into the innermost nature of this real world--the thing in itself--but impartial critical observation and comparison inform us that1 in the normal action of the brain and the organs of sense1 the impressions received by them from the outer world are the same in all rational men1 and that in the normal function of the organs of thought certain presentations are formed which are everywhere the same4 ,these presentations we call true1 and we are convinced that their content corresponds to the knowable aspect of things4 ,we know that these facts are not imaginary1 but real4 ,all knowledge of the truth depends on two different1 but intimately connected1 groups of human physiological functions3 firstly1 on the sense-impressions of the object by means of sense-action1 and1 secondly1 on the combination of these impressions by an association into presentations in the subject4 ,the instruments of sensation are the sense-organs 7sensilla or aestheta72 the instruments which form and link together the presentations are the organs of thought 7phroneta74 ,the latter are part of the central1 and the former part of the peripheral1 nervous system--that important and elaborate system of organs in the higher animals which alone effects their entire psychic activity4 ,man's sense-activity1 which is the starting-point of all knowledge1 has been slowly and gradually developed from that of his nearest mammal relatives1 the primates4 ,the sense-organs are of substantially the same construction throughout this highest animal group1 and their function takes place always according to the same physical and chemical laws4 ,they have had the same historical development in all cases4 ,in the mammals1 as in the case of all other animals1 the sensilla were originally parts of the skin2 the sensitive cells of the epidermis are the sources of all the different sense-organs1 which have acquired their specific energy by adaptation to different stimuli 7light1 heat1 sound1 chemical action1 etc474 ,the rod-cells in the retina of the eye1 the auditory cells in the cochlea of the ear1 the olfactory cells in the nose1 and the taste-cells on the tongue1 are all originally derived from the simple1 indifferent cells of the epidermis1 which cover the entire surface of the body4 ,this significant fact can be directly proved by observation of the embryonic development of man or any of the higher animals4 ,and from this ontogenetic fact we confidently infer1 in virtue of the great biogenetic law1 the important phylogenetic proposition1 that in the long historical evolution of our ancestors1 likewise1 the higher sense-organs with their specific energies were originally derived from the epidermis of lower animals1 from a simple layer of cells which had no trace of such differentiated sensilla4 ,a particular importance attaches to the circumstance that different nerves are qualified to perceive different properties of the environment1 and these only4 ,the optic nerve accomplishes only the perception of light1 the auditory nerve the perception of sound1 the olfactory nerve the perception of smell1 and so on4 ,no matter what stimuli impinge on and irritate a given sense-organ1 its reaction is always of the same character4 ,from this specific energy of the sense-nerves1 which was first fully appreciated by ,johannes ,mller1 very erroneous inferences have been drawn1 especially in favor of a dualistic and priori theory of knowledge4 ,it has been affirmed that the brain1 or the soul1 only perceives a certain condition of the stimulated nerve1 and that1 consequently1 no conclusion can be drawn from the process as to the existence and nature of the stimulating environment4 ,sceptical philosophy concluded that the very existence of an outer world is doubtful1 and extreme idealism went on positively to deny it1 contending that things only exist in our impressions of them4 ,in opposition to these erroneous views1 we must recall the fact that the specific energy was not originally an innate1 special quality of the various nerves1 but it has arisen by adaptation to the particular activity of the epidermic cells in which they terminate4 ,in harmony with the great law of division of labor the originally indifferent sense-cells of the skin undertook different tasks1 one group of them taking over the stimulus of the light rays1 another the impress of the sound waves1 a third the chemical impulse of odorous substances1 and so on4 ,in the course of a very long period these external stimuli effected a gradual change in the physiological1 and later in the morphological1 properties of these parts of the epidermis1 and there was a correlative modification of the sensitive nerves which conduct the impressions they receive to the brain4 ,selection improved1 step by step1 such particular modifications as proved to be useful1 and thus eventually1 in the course of many million years1 created those wonderful instruments1 the eye and the ear1 which we prize so highly2 their structure is so remarkably purposive that they might well lead to the erroneous assumption of a creation on a preconceived design4 ,the peculiar character of each sense-organ and its specific nerve has thus been gradually evolved by use and exercise--that is1 by adaptation--and has then been transmitted by heredity from generation to generation4 ,albrecht ,rau has thoroughly established this view in his excellent work on ,sensation and ,thought1 a physiological inquiry into the nature of the human understanding 7#ahif74 ,it points out the correct significance of ,mller's law of specific sense-energies1 adding searching investigations into their relation to the brain1 and in the last chapter there is an able philosophy of sensitivity based on the ideas of ,ludwig ,feuerbach4 ,i thoroughly agree with his convincing work4 ,critical comparison of sense-action in man and the other vertebrates has brought to light a number of extremely important facts1 the knowledge of which we owe to the penetrating research of the nineteenth century1 especially of the second half of the century4 ,this is particularly true of the two most elaborate sthetic organs1 the eye and the ear4 ,they present a different and more complicated structure in the vertebrates than in the other animals1 and have also a characteristic development in the embryo4 ,this typical ontogenesis and structure of the sensilla of all the vertebrates is only explained by heredity from a common ancestor4 ,within the vertebrate group1 however1 we find a great variety of structure in points of detail1 and this is due to adaptation to their manner of life on the part of the various species1 to the increasing or diminishing use of various parts4 ,in respect of the structure of his sense-organs man is by no means the most perfect and most highly-developed vertebrate4 ,the eye of the eagle is much keener1 and can distinguish small objects at a distance much more clearly than the human eye4 ,the hearing of many mammals1 especially of the carnivora1 ungulata1 and rodentia of the desert1 is much more sensitive than that of man1 and perceives slight noises at a much greater distance2 that may be seen at a glance by their large and very sensitive cochlea4 ,singing birds have attained a higher grade of development1 even in respect of musical endowment1 than the majority of men4 ,the sense of smell is much more developed in most of the mammals1 especially in the carnivora and the ungulata1 than in man2 if the dog could compare his own fine scent with that of man1 he would look down on us with compassion4 ,even with regard to the lower senses--taste1 sex-sense1 touch1 and temperature--man has by no means reached the highest stage in every respect4 ,we can naturally only pass judgment on the sensations which we ourselves experience4 ,however1 anatomy informs us of the presence in the bodies of many animals of other senses than those we are familiar with4 ,thus fishes and other lower aquatic vertebrates have peculiar sensilla in the skin which are in connection with special sense-nerves4 ,on the right and left sides of the fish's body there is a long canal1 branching into a number of smaller canals at the head4 ,in this mucous canal there are nerves with numerous branches1 the terminations of which are connected with peculiar nerve-aggregates4 ,this extensive epidermic sense-organ probably serves for the perception of changes in the pressure1 or in other properties1 of the water4 ,some groups are distinguished by the possession of other peculiar sensilla1 the meaning of which is still unknown to us4 ,but it is already clear from the above facts that our human sense-activity is limited1 not only in quantity1 but in quality also4 ,we can thus only perceive with our senses1 especially with the eye and the sense of touch1 a part of the qualities of the objects in our environment4 ,and even this partial perception is incomplete1 in the sense that our organs are imperfect1 and our sensory nerves1 acting as interpreters1 communicate to the brain only a translation of the impressions received4 ,however1 this acknowledged imperfection of our senses should not prevent us from recognizing their instruments1 and especially the eye1 to be organs of the highest type2 together with the thought-organs in the brain1 they are nature's most valuable gift to man4 ,very truly does ,albrecht ,rau say3 ,all science is sensitive knowledge in the ultimate analysis2 it does not deny1 but interpret1 the data of the senses4 ,the senses are our first and best friends4 ,long before the mind is developed the senses tell man what he must do and avoid4 ,he who makes a general disavowal of the senses in order to meet their dangers acts as thoughtlessly and as foolishly as the man who plucks out his eyes because they once fell on shameful things1 or the man who cuts off his hand lest at any time it should reach out to the goods of his neighbor4 ,hence ,feuerbach is quite right in calling all philosophies1 religions1 and systems which oppose the principle of sense-action not only erroneous1 but really pernicious4 ,without the senses there is no knowledge--,nihil est in intellectu1 quod non fuerit in sensu1 as ,locke said4 ,twenty years ago ,i pointed out1 in my chapter ,on the ,origin and ,development of the ,sense-,organs1#cb the great service of ,darwinism in giving us a profounder knowledge and a juster appreciation of the senses4 ,the thirst for knowledge of the educated mind is not contented with the defective acquaintance with the outer world which is obtained through our imperfect sense-organs4 ,he endeavors to build up the sense-impressions which they have brought him into valuable knowledge4 ,he transforms them into specific sense-perceptions in the sense-centres of the cortex of the brain1 and combines them into presentations1 by association1 in the thought-centres4 ,finally1 by a further concatenation of the groups of presentations he attains to connected knowledge4 ,but this knowledge remains defective and unsatisfactory until the imagination supplements the inadequate power of combination of the intelligence1 and1 by the association of stored-up images1 unites the isolated elements into a connected whole4 ,thus are produced new general presentative images1 and these suffice to interpret the facts perceived and satisfy reason's feeling of causality4 ,the presentations which fill up the gaps in our knowledge1 or take its place1 may be called1 in a broad sense1 faith4 ,that is what happens continually in daily life4 ,when we are not sure about a thing we say1 ,i believe it4 ,in this sense we are compelled to make use of faith even in science itself2 we conjecture or assume that a certain relation exists between two phenomena1 though we do not know it for certain4 ,if it is a question of a cause1 we form a hypothesis2 though in science only such hypotheses are admitted as lie within the sphere of human cognizance1 and do not contradict known facts4 ,such hypotheses are1 for instance--in physics the theory of the vibratory movement of ether1 in chemistry the hypothesis of atoms and their affinity1 in biology the theory of the molecular structure of living protoplasm1 and so forth4 ,the explanation of a great number of connected phenomena by the assumption of a common cause is called a theory4 ,both in theory and hypothesis faith 7in the scientific sense7 is indispensable2 for here again it is the imagination that fills up the gaps left by the intelligence in our knowledge of the connection of things4 ,a theory1 therefore1 must always be regarded only as an approximation to the truth2 it must be understood that it may be replaced in time by another and better-grounded theory4 ,but1 in spite of this admitted uncertainty1 theory is indispensable for all true science2 it elucidates facts by postulating a cause for them4 ,the man who renounces theory altogether1 and seeks to construct a pure science with certain facts alone 7as often happens with wrong-headed representatives of our exact sciences71 must give up the hope of any knowledge of causes1 and1 consequently1 of the satisfaction of reason's demand for causality4 ,the theory of gravitation in astronomy 7,newton71 the nebular theory in cosmogony 7,kant and ,laplace71 the principle of energy in physics 7,meyer and ,helmholtz71 the atomic theory in chemistry 7,dalton71 the vibratory theory in optics 7,huyghens71 the cellular theory in histology 7,schleiden and ,schwann71 and the theory of descent in biology 7,lamarck and ,darwin71 are all important theories of the first rank2 they explain a whole world of natural phenomena by the assumption of a common cause for all the several facts of their respective provinces1 and by showing that all the phenomena thereof are inter-connected and controlled by laws which issue from this common cause4 ,yet the cause itself may remain obscure in character1 or be merely a provisional hypothesis4 ,the force of gravity in the theory of gravitation and in cosmogony1 energy itself in its relation to matter1 the ether of optics and electricity1 the atom of the chemist1 the living protoplasm of histology1 the heredity of the evolutionist--these and similar conceptions of other great theories may be regarded by a sceptical philosophy as mere hypotheses and the outcome of scientific faith1 yet they are indispensable for us1 until they are replaced by better hypotheses4 ,the dogmas which are used for the explanation of phenomena in the various religions1 and which go by the name of faith 7in the narrower sense71 are of a very different character from the forms of scientific faith we have enumerated4 ,the two types1 however--the natural faith of science and the supernatural faith of religion--are not infrequently confounded1 so that we must point out their fundamental difference4 ,religious faith means always belief in a miracle1 and as such is in hopeless contradiction with the natural faith of reason4 ,in opposition to reason it postulates supernatural agencies1 and1 therefore1 may be justly called superstition4 ,the essential difference of this superstition from rational faith lies in the fact that it assumes supernatural forces and phenomena1 which are unknown and inadmissible to science1 and which are the outcome of illusion and fancy2 moreover1 superstition contradicts the well-known laws of nature1 and is therefore irrational4 ,owing to the great progress of ethnology during the century1 we have learned a vast quantity of different kinds and practices of superstition1 as they still survive in uncivilized races4 ,when they are compared with each other and with the mythological notion of earlier ages1 a manifold analogy is discovered1 frequently a common origin1 and eventually one simple source for them all4 ,this is found in the demand of causality in reason1 in the search for an explanation of obscure phenomena by the discovery of a cause4 ,that applies particularly to such phenomena as threaten us with danger and excite fear1 like thunder and lightning1 earthquakes1 eclipses1 etc4 ,the demand for a causal explanation of such phenomena is found in uncivilized races of the lowest grade1 transmitted from their primate ancestors by heredity4 ,it is even found in many other vertebrates4 ,when a dog barks at the full moon1 or at a ringing bell1 of which it sees the hammer moving1 or at a flag that flutters in the breeze1 it expresses not only fear1 but also the mysterious impulse to learn the cause of the obscure phenomenon4 ,the crude beginnings of religion among primitive races spring partly from this hereditary superstition of their primate ancestors1 and partly from the worship of ancestors1 from various emotional impulses1 and from habits which have become traditional4 ,the religious notions of modern civilized peoples1 which they esteem so highly1 profess to be on a much higher level than the crude superstition of the savage2 we are told of the great advance which civilization has made in sweeping it aside4 ,that is a great mistake4 ,impartial comparison and analysis show that they only differ in their special form of faith and the outer shell of their creed4 ,in the clear light of reason the refined faith of the most liberal ecclesiastical religion--inasmuch as it contradicts the known and inviolable laws of nature--is no less irrational a superstition than the crude spirit-faith of primitive fetichism on which it looks down with proud disdain4 ,and if1 from this impartial stand-point1 we take a critical glance at the kinds of faith that prevail to-day in civilized countries1 we find them everywhere saturated with traditional superstition4 ,the ,christian belief in ,creation1 the ,trinity1 the ,immaculate ,conception1 the ,redemption1 the ,resurrection and ,ascension of ,christ1 and so forth1 is just as purely imaginative as the belief in the various dogmas of the ,mohammedan1 ,mosaic1 ,buddhistic1 and ,brahmanic religions1 and is just as incapable of reconciliation with a rational knowledge of nature4 ,each of these religions is for the sincere believer an indisputable truth1 and each regards the other as heresy and damnable error4 ,the more confidently a particular sect considers itself the only ark of salvation1 and the more ardently this conviction is cherished1 the more zealously does it contend against all other sects and give rise to the fearful religious wars that form the saddest pages in the book of history4 ,and all the time the unprejudiced critique of pure reason teaches us that all these different forms of faith are equally false and irrational1 mere creatures of poetic fancy and uncritical tradition4 ,rational science must reject them all alike as the outcome of superstition4 ,the incalculable injury which irrational superstition has done to credulous humanity is conspicuously revealed in the ceaseless conflict of confessions of faith4 ,of all the wars which nations have waged against each other with fire and sword the religious wars have been the bloodiest2 of all the forms of discord that have shattered the happiness of families and of individuals those that arise from religious differences are still the most painful4 ,think of the millions who have lost their lives in ,christian persecutions1 in the religious conflicts of ,islam and of the ,reformation1 by the ,inquisition1 and under the charge of witchcraft4 ,or think of the still greater number of luckless men who1 through religious differences1 have been plunged into family troubles1 have lost the esteem of their fellow-citizens and their position in the community1 or have even been compelled to fly from their country4 ,the official confession of faith becomes most pernicious of all when it is associated with the political aims of a modern state1 and is enforced as religious instruction in our schools4 ,the child's mind is thus early diverted from the pursuit of the truth and impregnated with superstition4 ,every friend of humanity should do all in his power to promote unsectarian schools as one of the most valuable institutions of the modern state4 ,the great value which is1 none the less1 still very widely attached to sectarian instruction is not only due to the compulsion of a reactionary state and its dependence on a dominant clericalism1 but also to the weight of old traditions and emotional cravings of various kinds4 ,one of the strongest of these is the devout reverence which is extended everywhere to sectarian tradition1 to the faith of our fathers4 ,in thousands of stories and poems fidelity to it is extolled as a spiritual treasure and a sacred duty4 ,yet a little impartial study of the history of faith suffices to show the absurdity of the notion4 ,the dominant evangelical faith of the second half of the nineteenth century is essentially different from that of the first half1 and this again from that of the eighteenth century4 ,the faith of the eighteenth century diverges considerably from the faith of our fathers of the seventeenth1 and still more from that of the sixteenth1 century4 ,the ,reformation1 releasing enslaved reason from the tyranny of the popes1 is naturally regarded by them as darkest heresy2 but even the faith of the papacy itself had been completely transformed in the course of a century4 ,and how different is the faith of the ,christian from that of his heathen ancestors4 ,every man with some degree of independent thought frames a more or less personal religion for himself1 which is always different from that of his fathers2 it depends largely on the general condition of thought in his day4 ,the further we go back in the history of civilization1 the more clearly do we find this esteemed faith of our fathers to be an indefensible superstition which is undergoing continual transformation4 ,one of the most remarkable forms of superstition1 which still takes a very active part in modern life1 is spiritism4 ,it is a surprising and a lamentable fact that millions of educated people are still dominated by this dreary superstition2 even distinguished scientists are entangled in it4 ,a number of spiritualist journals spread the faith far and wide1 and our superior circles do not scruple to hold sances in which spirits appear1 rapping1 writing1 giving messages from the beyond1 and so on4 ,it is a frequent boast of spiritists that even eminent men of science defend their superstition4 ,in ,germany1 ,a4 ,zllner and ,fechner are quoted as instances2 in ,england1 ,wallace and ,crookes4 ,the regrettable circumstance that physicists and biologists of such distinction have been led astray by spiritism is accounted for1 partly by their excess of imagination and defect of critical faculty1 and partly by the powerful influence of dogmas which a religious education imprinted on the brain in early youth4 ,moreover1 it was precisely through the famous sances at ,leipzig1 in which the physicists1 ,zllner1 ,fechner1 and ,wilhelm ,weber1 were imposed on by the clever ,american conjuror1 ,slade1 that the fraud of the latter was afterwards fully exposed2 he was discovered to be a common impostor4 ,in other cases1 too1 where the alleged marvels of spiritism have been thoroughly investigated1 they have been traced to a more or less clever deception2 the mediums 7generally of the weaker sex7 have been found to be either smart swindlers or nervous persons of abnormal irritability4 ,their supposed gift of telepathy 7or action at a distance of thought without material medium7 has no more existence than the voices or the groans of spirits1 etc4 ,the vivid pictures which ,carl du ,prel1 of ,munich1 and other spiritists give of their phenomena must be regarded as the outcome of a lively imagination1 together with a lack of critical power and of knowledge of physiology4 ,the majority of religions have1 in spite of their great differences1 one common feature1 which is1 at the same time1 one of their strongest supports in many quarters4 ,they declare that they can elucidate the problem of existence1 the solution of which is beyond the natural power of reason1 by the supernatural way of revelation2 from that they derive the authority of the dogmas which in the guise of divine laws control morality and the practical conduct of life4 ,divine inspirations of that kind form the basis of many myths and legends1 the human origin of which is perfectly clear4 ,it is true that the ,god who reveals himself does not always appear in human shape1 but in thunder and lightning1 storm and earthquake1 fiery bush or menacing cloud4 ,but the revelation which he is supposed to bring to the credulous children of men is always anthropomorphic2 it invariably takes the form of a communication of ideas or commands which are formulated and expressed precisely as is done in the normal action of the human brain and larynx4 ,in the ,indian and ,egyptian religions1 in the mythologies of ,greece and ,rome1 in the ,old and the ,new ,testaments1 the gods think1 talk1 and act just as men do2 the revelations1 in which they are supposed to unveil for us the secrets of existence and the solution of the great world-enigma1 are creations of the human imagination4 ,the truth which the credulous discover in them is a human invention2 the childlike faith in these irrational revelations is mere superstition4 ,the true revelation--that is1 the true source of rational knowledge--is to be sought in nature alone4 ,the rich heritage of truth which forms the most valuable part of human culture is derived exclusively from the experiences acquired in a searching study of nature1 and from the rational conclusions which it has reached by the just association of these empirical presentations4 ,every intelligent man with normal brain and senses finds this true revelation in nature on impartial study1 and thus frees himself from the superstition with which the revelations of religion had burdened him4 ,,chapter ,,xvii ,,science ,,and ,,christianity ,increasing ,opposition between ,modern ,science and ,christian ,theology--,the ,old and the ,new ,faith--,defence of ,rational ,science against the ,attacks of ,christian ,superstition1 especially against ,catholicism--,four ,periods in the ,evolution of ,christianity3 ,i4 ,primitive ,christianity 7the ,first ,three ,centuries7--,the ,four ,canonical ,gospels--,the ,epistles of ,paul--,,ii4 ,the ,papacy 7,ultramontane ,christianity7--,retrogression of ,civilization in the ,middle ,ages--,ultramontane ,falsification of ,history--,the ,papacy and ,science--,the ,papacy and ,christianity--,,iii4 ,the ,reformation--,luther and ,calvin--,the ,year of ,emancipation--,,iv4 ,the ,pseudo-,christianity of the ,nineteenth ,century--,the ,papal ,declaration of ,war against ,reason and ,science3 7a7 ,infallibility1 7b7 ,the ,encyclica1 7c7 ,the ,immaculate ,conception ,one of the most distinctive features of the expiring century is the increasing vehemence of the opposition between science and ,christianity4 ,that is both natural and inevitable4 ,in the same proportion in which the victorious progress of modern science has surpassed all the scientific achievements of earlier ages has the untenability been proved of those mystic views which would subdue reason under the yoke of an alleged revelation2 and the ,christian religion belongs to that group4 ,the more solidly modern astronomy1 physics1 and chemistry have established the sole dominion of inflexible natural laws in the universe at large1 and modern botany1 zoology1 and anthropology have proved the validity of those laws in the entire kingdom of organic nature1 so much the more strenuously has the ,christian religion1 in association with dualistic metaphysics1 striven to deny the application of these natural laws in the province of the so-called spiritual life--that is1 in one section of the physiology of the brain4 ,no one has more clearly1 boldly1 and unanswerably enunciated this open and irreconcilable opposition between the modern scientific and the outworn ,christian view than ,david ,friedrich ,strauss1 the greatest theologian of the nineteenth century4 ,his last work1 ,the ,old ,faith and the ,new1 is a magnificent expression of the honest conviction of all educated people of the present day who understand this unavoidable conflict between the discredited1 dominant doctrines of ,christianity and the illuminating1 rational revelation of modern science--all those who have the courage to defend the right of reason against the pretensions of superstition1 and who are sensible of the philosophic demand for a unified system of thought4 ,strauss1 as an honorable and courageous free-thinker1 has expounded far better than ,i could the principal points of difference between the old and the new faith4 ,the absolute irreconcilability of the opponents and the inevitability of their struggle 7for life or death7 have been ably presented on the philosophic side by ,e4 ,hartmann1 in his interesting work on ,the ,self-,destruction of ,christianity4 ,when the works of ,strauss and ,feuerbach and ,the ,history of the ,conflict between ,religion and ,science of ,j4 ,w4 ,draper have been read1 it may seem superfluous for us to devote a special chapter to the subject4 ,yet we think it useful1 and even necessary for our purpose1 to cast a critical glance at the historical course of this great struggle2 especially seeing that the attacks of the ,church militant on science in general1 and on the theory of evolution in particular1 have become extremely bitter and menacing of late years4 ,unfortunately1 the mental relaxation which has lately set in1 and the rising flood of reaction in the political1 social1 and ecclesiastical world1 are only too well calculated to give point to those dangers4 ,if any one doubts it1 he has only to look over the conduct of ,christian synods and of the ,german ,reichstag during the last few years4 ,quite in harmony are the recent efforts of many secular governments to get on as good a footing as possible with the spiritual regiment1 their deadly enemy--that is1 to submit to its yoke4 ,the two forces find a common aim in the suppression of free thought and free scientific research1 for the purpose of thus more easily securing a complete despotism4 ,let us first emphatically protest that it is a question for us of the necessary defence of science and reason against the vigorous attacks of the ,christian ,church and its vast army1 not of an unprovoked attack of science on religion4 ,and1 in the first place1 our defence must be prepared against ,romanism or ,ultramontanism4 ,this one ark of salvation1 this ,catholic ,church destined for all1 is not only much larger and more powerful than the other ,christian sects1 but it has the exceptional advantage of a vast1 centralized organization and an unrivalled political ability4 ,men of science are often heard to say that the ,catholic superstition is no more astute than the other forms of supernatural faith1 and that all these insidious institutions are equally inimical to reason and science4 ,as a matter of general theoretical principle the statement may pass1 but it is certainly wrong when we look to its practical side4 ,the deliberate and indiscriminate attacks of the ultramontane ,church on science1 supported by the apathy and ignorance of the masses1 are1 on account of its powerful organization1 much more severe and dangerous than those of other religions4 ,in order to appreciate correctly the extreme importance of ,christianity in regard to the entire history of civilization1 and particularly its fundamental opposition to reason and science1 we must briefly run over the principal stages of its historical evolution4 ,it may be divided into four periods3 7#a7 primitive ,christianity 7the first three centuries71 7#b7 papal ,christianity 7twelve centuries1 from the fourth to the fifteenth71 7#c7 the ,reformation 7three centuries1 from the sixteenth to the eighteenth71 and 7#d7 modern pseudo-,christianity4 ,i4--,,primitive ,,christianity ,primitive ,christianity embraces the first three centuries4 ,christ himself1 the noble prophet and enthusiast1 so full of the love of humanity1 was far below the level of classical culture2 he knew nothing beyond the ,jewish traditions2 he has not left a single line of writing4 ,he had1 indeed1 no suspicion of the advanced stage to which ,greek philosophy and science had progressed five hundred years before4 ,all that we know of him and of his original teaching is taken from the chief documents of the ,new ,testament--the four gospels and the ,pauline epistles4 ,as to the four canonical gospels1 we now know that they were selected from a host of contradictory and forged manuscripts of the first three centuries by the three hundred and eighteen bishops who assembled at the ,council of ,nica in #cbg4 ,the entire list of gospels numbered forty2 the canonical list contains four4 ,as the contending and mutually abusive bishops could not agree about the choice1 they determined to leave the selection to a miracle4 ,they put all the books 7according to the ,synodicon of ,pappus7 together underneath the altar1 and prayed that the apocryphal books1 of human origin1 might remain there1 and the genuine1 inspired books might be miraculously placed on the table of the ,lord4 ,and that1 says tradition1 really occurred6 ,the three synoptic gospels 7,matthew1 ,mark1 and ,luke--all written after them1 not by them1 at the beginning of the second century7 and the very different fourth gospel 7ostensibly after ,john1 written about the middle of the second century7 leaped on the table1 and were thenceforth recognized as the inspired 7with their thousand mutual contradictions7 foundations of ,christian doctrine4 ,if any modern unbeliever finds this story of the leap of the sacred books incredible1 we must remind him that it is just as credible as the table-turning and spirit-rapping that are believed to take place to-day by millions of educated people2 and that hundreds of millions of ,christians believe just as implicitly in their personal immortality1 their resurrection from the dead1 and the ,trinity of ,god--dogmas that contradict pure reason no more and no less than that miraculous bound of the gospel manuscripts4 ,the most important sources after the gospels are the fourteen separate 7and generally forged7 epistles of ,paul4 ,the genuine ,pauline epistles 7three in number1 according to recent criticism--to the ,romans1 ,galatians1 and ,corinthians7 were written before the canonical gospels1 and contain less incredible miraculous matter than they4 ,they are also more concerned than the gospels to adjust themselves with a rational view of the world4 ,hence the advanced theology of modern times constructs its ideal ,christianity rather on the base of the ,pauline epistles than on the gospels1 so that it has been called ,paulinism4 ,the remarkable personality of ,paul1 who possessed much more culture and practical sense than ,christ1 is extremely interesting1 from the anthropological point of view1 from the fact that the racial origin of the two great religious founders is very much the same4 ,recent historical investigation teaches that ,paul's father was of ,greek nationality1 and his mother of ,jewish4#cc ,the half-breeds of these two races1 which are so very distant in origin 7although they are branches of the same species1 the homo mediterraneus71 are often distinguished by a happy blending of talents and temperament1 as we find in many recent and actual instances4 ,the plastic ,oriental imagination and the critical ,western reason often admirably combine and complete each other4 ,that is visible in the ,pauline teaching1 which soon obtained a greater influence than the earliest ,christian notions4 ,hence it is not incorrect to consider ,paulinism a new phenomenon1 of which the father was the philosophy of the ,greeks1 and the mother the religion of the ,jews4 ,neoplatonism is an analogous combination4 ,as to the real teaching and aims of ,christ 7and as to many important aspects of his life7 the views of conflicting theologians diverge more and more1 as historical criticism 7,strauss1 ,feuerbach1 ,baur1 ,renan1 etc47 puts the accessible facts in their true light1 and draws impartial conclusions from them4 ,two things1 certainly1 remain beyond dispute--the lofty principle of universal charity and the fundamental maxim of ethics1 the golden rule1 that issues therefrom2 both1 however1 existed in theory and in practice centuries before the time of ,christ 7cf4 chap4 xix474 ,for the rest1 the ,christians of the early centuries were generally pure ,communists1 sometimes ,social ,democrats1 who1 according to the prevailing theory in ,germany to-day1 ought to have been exterminated with fire and sword4 ,,ii4--,,papal ,,christianity ,latin ,christianity1 variously called ,papistry1 ,romanism1 ,vaticanism1 ,ultramontanism1 or the ,roman ,catholic ,church1 is one of the most remarkable phenomena in the history of civilized man2 in spite of the storms that have swept over it1 it still exerts a most powerful influence4 ,of the four hundred and ten million ,christians who are scattered over the earth the majority--that is1 two hundred and twenty-five millions--are ,roman ,catholics2 there are seventy-five million ,greek ,catholics and one hundred and ten million ,protestants4 ,during a period of one thousand two hundred years1 from the fourth to the sixteenth century1 the papacy has almost absolutely controlled and tainted the spiritual life of ,europe2 on the other hand1 it has won but little territory from the ancient religions of ,asia and ,africa4 ,in ,asia ,buddhism still counts five hundred and three million followers1 the ,brahmanic religion one hundred and thirty-eight millions1 and ,islam one hundred and twenty millions4 ,it is the despotism of the papacy that lent its darkest character to the ,middle ,ages2 it meant death to all freedom of mental life1 decay to all science1 corruption to all morality4 ,from the noble height to which the life of the human mind had attained in classical antiquity1 in the centuries before ,christ and the first century after ,christ1 it soon sank1 under the rule of the papacy1 to a level which1 in respect of the knowledge of the truth1 can only be termed barbarism4 ,it is often protested that other aspects of mental life--poetry and architecture1 scholastic learning and patristic philosophy--were richly developed in the ,middle ,ages4 ,but this activity was in the service of the ,church2 it did not tend to the cultivation1 but to the suppression1 of free mental research4 ,the exclusive preparing for an unknown eternity beyond the tomb1 the contempt of nature1 the withdrawal from the study of it1 which are essential elements of ,christianity1 were urged as a sacred duty by the ,roman hierarchy4 ,it was not until the beginning of the sixteenth century that a change for the better came in with the ,reformation4 ,it is impossible for us here to describe the pitiful retrogression of culture and morality during the twelve centuries of the spiritual despotism of ,rome4 ,it is very pithily expressed in a saying of the greatest and the ablest of the ,hohenzollerns2 ,frederick the ,great condensed his judgment in the phrase that the study of history led one to think that from ,constantine to the date of the ,reformation the whole world was insane4 ,l4 ,bchner has given us an admirable1 brief description of this period of insanity in his work on ,religious and ,scientific ,systems4 ,the reader who desires a closer acquaintance with the subject would do well to consult the historical works of ,ranke1 ,draper1 ,kolb1 ,svoboda1 etc4 ,the truthful description of the awful condition of the ,christian ,middle ,ages1 which is given by these and other unprejudiced historians1 is confirmed by all the reliable sources of investigation1 and by the historical monuments which have come down from the saddest period of human history4 ,educated ,catholics1 who are sincere truth-seekers1 cannot be too frequently recommended to study these historical sources for themselves4 ,this is the more necessary as ultramontane literature has still a considerable influence4 ,the old trick of deceiving the faithful by a complete reversal of facts and an invention of miraculous circumstances is still worked by it with great success4 ,we will only mention ,lourdes and the ,holy ,coat of ,trves4 ,the ultramontane professor of history at ,frankfurt1 ,johannes ,janssen1 affords a striking example of the length they will go in distorting historical truth2 his much-read works 7especially his ,history of the ,german ,people since the ,middle ,ages7 are marred by falsification to an incredible extent4 ,the untruthfulness of these ,jesuitical productions is on a level with the credulity and the uncritical judgment of the simple ,german nation that takes them for gospel4 ,one of the most interesting of the historical facts which clearly prove the evil of the ultramontane despotism is its vigorous and consistent struggle with science4 ,this was determined on1 in principle1 from the very beginning of ,christianity1 inasmuch as it set faith above reason and preached the blind subjection of the one to the other2 that was natural1 seeing that our whole life on earth was held to be only a preparation for the legendary life beyond1 and thus scientific research was robbed of any real value4 ,the deliberate and successful attack on science began in the early part of the fourth century1 particularly after the ,council of ,nica 7#cbg71 presided over by ,constantine--called the ,great because he raised ,christianity to the position of a state religion1 and founded ,constantinople1 though a worthless character1 a false-hearted hypocrite1 and a murderer4 ,the success of the papacy in its conflict with independent scientific thought and inquiry is best seen in the distressing condition of science and its literature during the ,middle ,ages4 ,not only were the rich literary treasures that classical antiquity had bequeathed to the world destroyed for the most part1 or withdrawn from circulation1 but the rack and the stake insured the silence of every heretic--that is1 every independent thinker4 ,if he did not keep his thoughts to himself1 he had to look forward to being burned alive1 as was the fate of the great monistic philosopher1 ,giordano ,bruno1 the reformer1 ,john ,huss1 and more than a hundred thousand other witnesses to the truth4 ,the history of science in the ,middle ,ages teaches us on every page that independent thought and empirical research were completely buried for twelve sad centuries under the oppression of the omnipotent papacy4 ,all that we esteem in true ,christianity1 in the sense of its founder and of his noblest followers1 and that we must endeavor to save from the inevitable wreck of this great world religion for our new monistic religion1 lies on its ethical and social planes4 ,the principles of true humanism1 the golden rule1 the spirit of tolerance1 the love of man1 in the best and highest sense of the word--all these true graces of ,christianity were not1 indeed1 first discovered and given to the world by that religion1 but were successfully developed in the critical period when classical antiquity was hastening to its doom4 ,the papacy1 however1 has attempted to convert all those virtues into the direct contrary1 and still to hang out the sign of the old firm4 ,instead of ,christian charity1 it introduced a fanatical hatred of the followers of all other religions2 with fire and sword it has pursued1 not only the heathen1 but every ,christian sect that dared resist the imposition of ultramontane dogma4 ,tribunals for heretics were erected all over ,europe1 yielding unnumbered victims1 whose torments seemed only to fill their persecutors1 with all their ,christian charity1 with a peculiar satisfaction4 ,the power of ,rome was directed mercilessly for centuries against everything that stood in its way4 ,under the notorious ,torquemada 7#adha-ih71 in ,spain alone eight thousand heretics were burned alive and ninety thousand punished with the confiscation of their goods and the most grievous ecclesiastical fines2 in the ,netherlands1 under the rule of ,charles ,v41 at least fifty thousand men fell victims to the clerical bloodthirst4 ,and while the heavens resounded with the cry of the martyrs1 the wealth of half the world was pouring into ,rome1 to which the whole of ,christianity paid tribute1 and the self-styled representatives of ,god on earth and their accomplices 7not infrequently ,atheists themselves7 wallowed in pleasure and vice of every description4 ,and all these privileges1 said the frivolous1 syphilitic ,pope1 ,leo ,x41 have been secured to us by the fable of ,jesus ,christ4 ,yet1 with all the discipline of the ,church and the fear of ,god1 the condition of ,european society was pitiable4 ,feudalism1 serfdom1 the grace of ,god1 and the favor of the monks ruled the land2 the poor helots were only too glad to be permitted to raise their miserable huts under the shadow of the castle or the cloister1 their secular and spiritual oppressors and exploiters4 ,even to-day we suffer from the aftermath of these awful ages and conditions1 in which there was no question of care for science or higher mental culture save in rare circumstances and in secret4 ,ignorance1 poverty1 and superstition combined with the immoral operation of the law of celibacy1 which had been introduced in the eleventh century1 to consolidate the ever-growing power of the papacy4 ,it has been calculated that there were more than ten million victims of fanatical religious hatred during this ,golden ,age of papal domination2 and how many more million human victims must be put to the account of celibacy1 oral confession1 and moral constraint1 the most pernicious and accursed institutions of the papal despotism6 ,unbelieving philosophers1 who have collected disproofs of the existence of ,god1 have overlooked one of the strongest arguments in that sense--the fact that the ,roman ,vicar of ,christ could for twelve centuries perpetrate with impunity the most shameful and horrible deeds in the name of ,god4 ,,iii4--,,the ,,reformation ,the history of civilization1 which we are so fond of calling the history of the world1 enters upon its third period with the ,reformation of the ,christian ,church1 just as its second period begins with the founding of ,christianity4 ,with the ,reformation begins the new birth of fettered reason1 the reawakening of science1 which the iron hand of the ,christian papacy had relentlessly crushed for twelve hundred years4 ,at the same time the spread of general education had already commenced1 owing to the invention of printing about the middle of the fifteenth century2 and towards its close several great events occurred1 especially the discovery of ,america in #adib1 which prepared the way for the renaissance of science in company with that of art4 ,indeed1 certain very important advances were made in the knowledge of nature during the first half of the sixteenth century1 which shook the prevailing system to its very foundations4 ,such were the circumnavigation of the globe by ,magellan in #aebb1 which afforded empirical proof of its rotundity1 and the founding of the new system of the world by ,copernicus in #aedc4 ,yet the #cast of ,october in the year #aeag1 the day on which ,martin ,luther nailed his ninety-five theses to the wooden door of ,wittenburg ,cathedral1 must be regarded as the commencement of a new epoch2 for on that day was forced the iron door of the prison in which the ,papal ,church had detained fettered reason for twelve hundred years4 ,the merits of the great reformer have been partly exaggerated1 partly underestimated4 ,it has been justly pointed out that ,luther1 like all the other reformers1 remained in manifold subjection to the deepest superstition4 ,thus he was throughout life a supporter of the rigid dogma of the verbal inspiration of the ,bible2 he zealously maintained the doctrines of the resurrection1 original sin1 predestination1 justification by faith1 etc4 ,he rejected as folly the great discovery of ,copernicus1 because in the ,bible ,joshua bade the sun1 not the earth1 stand still4 ,he utterly failed to appreciate the great political revolutions of his time1 especially the profound and just agitation of the peasantry4 ,worse still was the fanatical ,calvin1 of ,geneva1 who had the talented ,spanish physician1 ,serveto1 burned alive in #aeec1 because he rejected the absurd dogma of the ,trinity4 ,the fanatical true believers of the reformed ,church followed only too frequently in the blood-stained footsteps of their papal enemies2 as they do even in our own day4 ,deeds of unparalleled cruelty followed in the train of the ,reformation--the massacre of ,st4 ,bartholomew and the persecution of the ,huguenots in ,france1 bloody heretic-hunts in ,italy1 civil war in ,england1 and the ,thirty ,years ,war in ,germany4 ,yet1 in spite of those grave blemishes1 to the sixteenth and seventeenth centuries belongs the honor of once more opening a free path to the thoughtful mind1 and delivering reason from the oppressive yoke of the papacy4 ,thus only was made possible that great development of different tendencies in critical philosophy and of new paths in science which won for the subsequent eighteenth century the honorable title of the century of enlightenment4 ,,iv4--,,the ,,pseudo-,,christianity ,,of ,,the ,,nineteenth ,,century ,as the fourth and last stage in the history of ,christianity we oppose our nineteenth century to all its predecessors4 ,it is true that the enlightenment of preceding centuries had promoted critical thought in every direction1 and the rise of science itself had furnished powerful empirical weapons2 yet it seems to us that our progress along both lines has been quite phenomenal during the nineteenth century4 ,it has inaugurated an entirely new period in the history of the human mind1 characterized by the development of the monistic philosophy of nature4 ,at its very commencement the foundations were laid of a new anthropology 7by the comparative anatomy of ,cuvier7 and of a new biology 7by the ,philosophie ,zoologique of ,lamarck74 ,the two great ,french scientists were quickly succeeded by two contemporary ,german scholars--,baer1 the founder of the science of evolution1 and ,johannes ,mller1 the founder of comparative morphology and physiology4 ,a pupil of ,mller1 ,theodor ,schwann1 created the far-reaching cellular theory in #ahch1 in conjunction with ,m4 ,schleiden4 ,lyell had already traced the evolution of the earth to natural causes1 and thus proved the application to our planet of the mechanical cosmogony which ,kant had sketched with so much insight in #agee4 ,finally1 ,robert ,mayer and ,helmholtz established the principle of energy in #ahdb--the second1 complementary half of the great law of substance1 the first half of which 7the persistence of matter7 had been previously discovered by ,lavoisier4 ,forty years ago ,charles ,darwin crowned all these profound revelations of the intimate nature of the universe by his new theory of evolution1 the greatest natural-philosophical achievement of our century4 ,what is the relation of modern ,christianity to this vast and unparalleled progress of science8 ,in the first place1 the deep gulf between its two great branches1 conservative ,romanism and progressive ,protestantism1 has naturally widened4 ,the ultramontane clergy 7and we must associate with them the orthodox evangelical alliance7 had naturally to offer a strenuous opposition to this rapid advance of the emancipated mind2 they continued unmoved in their rigid literal belief1 demanding the unconditional surrender of reason to dogma4 ,liberal ,protestantism1 on the other hand1 took refuge in a kind of monistic pantheism1 and sought a means of reconciling two contradictory principles4 ,it endeavored to combine the unavoidable recognition of the established laws of nature1 and the philosophic conclusions that followed from them1 with a purified form of religion1 in which scarcely anything remained of the distinctive teaching of faith4 ,there were many attempts at compromise to be found between the two extremes2 but the conviction rapidly spread that dogmatic ,christianity had lost every foundation1 and that only its valuable ethical contents should be saved for the new monistic religion of the twentieth century4 ,as1 however1 the existing external forms of the dominant ,christian religion remained unaltered1 and as1 in spite of a progressive political development1 they are more intimately than ever connected with the practical needs of the ,state1 there has arisen that widespread religious profession in educated spheres which we can only call pseudo-,christianity--at the bottom it is a religious lie of the worst character4 ,the great dangers which attend this conflict between sincere conviction and the hypocritical profession of modern pseudo-,christians are admirably described in ,max ,nordau's interesting work on ,the ,conventional ,lies of ,civilization4 ,in the midst of this obvious falseness of prevalent pseudo-,christianity there is one favorable circumstance for the progress of a rational study of nature3 its most powerful and bitterest enemy1 the ,roman ,church1 threw off its mask of ostensible concern for higher mental development about the middle of the nineteenth century1 and declared a guerre l'outrance against independent science4 ,this happened in three important challenges to reason1 for the explicitness and resoluteness of which modern science and culture cannot but be grateful to the ,vicar of ,christ4 7#a7 ,in ,december1 #ahed1 the pope promulgated the dogma of the immaculate conception of ,mary4 7#b7 ,ten years afterwards--in ,december1 #ahfd--the pope published1 in his famous encyclica1 an absolute condemnation of the whole of modern civilization and culture2 in the syllabus that accompanied it he enumerated and anathematized all the rational theses and philosophical principles which are regarded by modern science as lucid truths4 7#c7 ,finally1 six years afterwards--on ,july #ac1 #ahgj--the militant head of the ,church crowned his folly by claiming infallibility for himself and all his predecessors in the papal chair4 ,this triumph of the ,roman curia was communicated to the astonished world five days afterwards1 on the very day on which ,france declared war with ,prussia4 ,two months later the temporal power of the pope was taken from him in consequence of the war4 ,these three stupendous acts of the papacy were such obvious assaults on the reason of the nineteenth century that they gave rise1 from the very beginning1 to a most heated discussion even within orthodox ,catholic circles4 ,when the ,vatican ,council proceeded to define the dogma of infallibility on ,july #ac1 #ahgj1 only three-fourths of the bishops declared in its favor1 #dea out of #fja assenting2 many other bishops1 who wished to keep clear of the perilous definition1 were absent from the council4 ,but the shrewd pontiff had calculated better than the timid discreet ,catholics3 even this extraordinary dogma was blindly accepted by the credulous and uneducated masses of the faithful4 ,the whole history of the papacy1 as it is substantiated by a thousand reliable sources and accessible documents1 appears to the impartial student as an unscrupulous tissue of lying and deceit1 a reckless pursuit of absolute mental despotism and secular power1 a frivolous contradiction of all the high moral precepts which true ,christianity enunciates--charity and toleration1 truth and chastity1 poverty and self-denial4 ,when we judge the long series of popes and of the ,roman princes of the ,church1 from whom the pope is chosen1 by the standard of pure ,christian morality1 it is clear that the great majority of them were pitiful impostors1 many of them utterly worthless and vicious4 ,these well-known historical facts1 however1 do not prevent millions of educated ,catholics from admitting the infallibility which the pope has claimed for himself2 they do not prevent ,protestant princes from going to ,rome1 and doing reverence to the pontiff 7their most dangerous enemy72 they do not prevent the fate of the ,german people from being intrusted to-day to the hands of the servants and followers of this pious impostor in the ,reichstag--thanks to the incredible political indolence and credulity of the nation4 ,the most interesting of the three great events by which the papacy has endeavored to maintain and strengthen its despotism in the nineteenth century is the publication of the encyclica and the syllabus in ,december1 #ahfd4 ,in these remarkable documents all independent action was forbidden to reason and science1 and they were commanded to submit implicitly to faith--that is1 to the decrees of the infallible pope4 ,the great excitement which followed this sublime piece of effrontery in educated and independent circles was in proportion with the stupendous contents of the encyclica4 ,draper has given us an excellent discussion of its educational and political significance in his ,history of the ,conflict between ,science and ,religion4 ,the dogma of the immaculate conception seems1 perhaps1 to be less audacious and significant than the encyclica and the dogma of the infallibility of the pope4 ,yet not only the ,roman hierarchy1 but even some of the orthodox ,protestants 7the ,evangelical ,alliance1 for instance71 attach great importance to this thesis4 ,what is known as the immaculate oath--that is1 the confirmation of faith by an oath taken on the immaculate conception of ,mary--is still regarded by millions of ,christians as a sacred obligation4 ,many believers take the dogma in a twofold application2 they think that the mother of ,mary was impregnated by the ,holy ,ghost as well as ,mary herself4 ,comparative and critical theology has recently shown that this myth has no greater claim to originality than most of the other stories in the ,christian mythology2 it has been borrowed from older religions1 especially ,buddhism4 ,similar myths were widely circulated in ,india1 ,persia1 ,asia ,minor1 and ,greece several centuries before the birth of ,christ4 ,whenever a king's unwedded daughter1 or some other maid of high degree1 gave birth to a child1 the father was always pronounced to be a god1 or a demi-god2 in the ,christian case it was the ,holy ,ghost4 ,the special endowments of mind or body which often distinguished these children of love above ordinary offspring were thus partly explained by heredity4 ,distinguished sons of ,god of this kind were held in high esteem both in antiquity and during the ,middle ,ages1 while the moral code of modern civilization reproaches them with their want of honorable parentage4 ,this applies even more forcibly to daughters of ,god1 though the poor maidens are just as little to blame for their want of a father4 ,for the rest1 every one who is familiar with the beautiful mythology of classical antiquity knows that these sons and daughters of the ,greek and ,roman gods often approach nearest to the highest ideal of humanity4 ,recollect the large legitimate family1 and the still more numerous illegitimate offspring1 of ,zeus4 ,to return to the particular question of the impregnation of the ,virgin ,mary by the ,holy ,ghost1 we are referred to the gospels for testimony to the fact4 ,the only two evangelists who speak of it1 ,matthew and ,luke1 relate in harmony that the ,jewish maiden ,mary was betrothed to the carpenter ,joseph1 but became pregnant without his co-operation1 and1 indeed1 by the ,holy ,ghost4 ,as we have already related1 the four canonical gospels which are regarded as the only genuine ones by the ,christian ,church1 and adopted as the foundation of faith1 were deliberately chosen from a much larger number of gospels1 the details of which contradict each other sometimes just as freely as the assertions of the four4 ,the fathers of the ,church enumerate from forty to fifty of these spurious or apocryphal gospels2 some of them are written both in ,greek and ,latin--for instance1 the gospel of ,james1 of ,thomas1 of ,nicodemus1 and so forth4 ,the details which these apocryphal gospels give of the life of ,christ1 especially with regard to his birth and childhood1 have just as much 7or1 on the whole1 just as little7 claim to historical validity as the four canonical gospels4 ,now we find in one of these documents an historical statement1 confirmed1 moreover1 in the ,sepher ,toldoth ,jeschua1 which probably furnishes the simple and natural solution of the world-riddle of the supernatural conception and birth of ,christ4 ,the author curtly gives us in one sentence the remarkable statement which contains this solution3 ,josephus ,pandera1 the ,roman officer of a ,calabrian legion which was in ,juda1 seduced ,miriam of ,bethlehem1 and was the father of ,jesus4 ,other details given about ,miriam 7the ,hebrew name for ,mary7 are far from being to the credit of the ,queen of ,heaven4 ,naturally1 these historical details are carefully avoided by the official theologian1 but they assort badly with the traditional myth1 and lift the veil from its mystery in a very simple and natural fashion4 ,that makes it the more incumbent on impartial research and pure reason to make a critical examination of these statements4 ,it must be admitted that they have much more title to credence than all the other statements about the birth of ,christ4 ,when1 on familiar principles of science1 we put aside the notion of supernatural conception through an overshadowing of the ,most ,high as a pure myth1 there only remains the widely accepted version of modern rational theology--that ,joseph1 the ,jewish carpenter1 was the true father of ,christ4 ,but this assumption is explicitly contradicted by many texts of the gospels2 ,christ himself was convinced that he was a ,son of ,god1 and he never recognized his foster-father1 ,joseph1 as his real parent4 ,joseph1 indeed1 wanted to leave his betrothed when he found her pregnant without his interference4 ,he gave up this idea when an angel appeared to him in a dream and pacified him4 ,as it is expressly stated in the first chapter of ,matthew 7vv4 #bd1 #be71 there was no sexual intercourse between ,joseph and ,mary until after ,jesus was born4 ,the statement of the apocryphal gospels1 that the ,roman officer1 ,pandera1 was the true father of ,christ1 seems all the more credible when we make a careful anthropological study of the personality of ,christ4 ,he is generally regarded as purely ,jewish4 ,yet the characteristics which distinguish his high and noble personality1 and which give a distinct impress to his religion1 are certainly not ,semitical2 they are rather features of the higher ,arian race1 and especially of its noblest branch1 the ,hellenes4 ,now1 the name of ,christ's real father1 ,pandera1 points unequivocally to a ,greek origin2 in one manuscript1 in fact1 it is written ,pandora4 ,pandora was1 according to the ,greek mythology1 the first woman1 born of the earth by ,vulcan and adorned with every charm by the gods1 who was espoused by ,epimetheus1 and sent by ,zeus to men with the dread ,pandora-box1 containing every evil1 in punishment for the stealing of divine fire from heaven by ,prometheus4 ,and it is interesting to see the different reception that the love-story of ,miriam has met with at the hands of the four great ,christian nations of civilized ,europe4 ,the stern morality of the ,teutonic races entirely repudiates it2 the righteous ,german and the prudish ,briton prefer to believe blindly in the impossible thesis of a conception by the ,holy ,ghost4 ,it is well known that this strenuous and carefully paraded prudery of the higher classes 7especially in ,england7 is by no means reflected in the true condition of sexual morality in high quarters4 ,the revelations which the ,pall ,mall ,gazette1 for instance1 made on the subject twelve years ago vividly recalled the condition of ,babylon4 ,the ,romantic races1 which ridicule this prudery and take sexual relations less seriously1 find ,mary's ,romance attractive enough2 the special cult which ,our ,lady enjoys in ,france and ,italy is often associated with this love-story with curious navet4 ,thus1 for example1 ,paul de ,regla 7,dr4 ,desjardin71 author of ,jesus of ,nazareth considered from a ,scientific1 ,historical1 and ,social ,standpoint 7#ahid71 finds precisely in the illegitimate birth of ,christ a special title to the halo that irradiates his noble form4 ,it seemed to me necessary to enter fully into this important question of the origin of ,christ in the sense of impartial historical science1 because the ,church militant itself lays great emphasis on it1 and because it regards the miraculous structure which has been founded on it as one of its strongest weapons against modern thought4 ,the highest ethical value of pure primitive ,christianity and the ennobling influence of this religion of love on the history of civilization are quite independent of those mythical dogmas4 ,the so-called revelations on which these myths are based are incompatible with the firmest results of modern science4 ,,chapter ,,xviii ,,our ,,monistic ,,religion ,monism as a ,connecting ,link between ,religion and ,science--,the ,cultur-,kampf--,the ,relations of ,church and ,state--,principles of the ,monistic ,religion--,its ,three-fold ,ideal3 the ,good1 the ,true1 and the ,beautiful--,contradiction between ,scientific and ,christian ,truth--,harmony of the ,monistic and the ,christian ,idea of ,virtue--,opposition between ,monistic and ,christian ,views of ,art--,modern ,expansion and ,enrichment of ,our ,idea of the ,world--,landscape-,painting and the ,modern ,enjoyment of ,nature--,the ,beauties of ,nature--,this ,world and ,beyond--,monistic ,churches ,many distinguished scientists and philosophers of the day1 who share our monistic views1 consider that religion is generally played out4 ,their meaning is that the clear insight into the evolution of the world which the great scientific progress of the nineteenth century has afforded us will satisfy1 not only the causal feeling of our reason1 but even our highest emotional cravings4 ,this view is correct in the sense that the two ideas1 religion and science1 would indeed blend into one if we had a perfectly clear and consecutive system of monism4 ,however1 there are but a few resolute thinkers who attain to this most pure and lofty conception of ,spinoza and ,goethe4 ,most of the educated people of our time 7as distinct from the uncultured masses7 remain in the conviction that religion is a separate branch of our mental life1 independent of science1 and not less valuable and indispensable4 ,if we adopt this view1 we can find a means of reconciling the two great and apparently quite distinct branches in the idea ,i put forward in ,monism1 as a ,connecting-,link between ,religion and ,science1 in #ahib4 ,in the preface to this ,confession of ,faith of a ,man of ,science ,i expressed myself in the following words with regard to its double object3 ,in the first place1 ,i must give expression to the rational system which is logically forced upon us by the recent progress of science2 it dwells in the intimate thoughts of nearly every impartial and thoughtful scientist1 though few have the courage or the disposition to avow it4 ,in the second place1 ,i would make of it a connecting-link between religion and science1 and thus do away with the antithesis which has been needlessly maintained between these two branches of the highest activity of the human mind4 ,the ethical craving of our emotion is satisfied by monism no less than the logical demand for causality on the part of reason4 ,the remarkable interest which the discourse enkindled is a proof that in this monistic profession of faith ,i expressed the feeling not only of many scientists1 but of a large number of cultured men and women of very different circles4 ,not only was ,i rewarded by hundreds of sympathetic letters1 but by a wide circulation of the printed address1 of which six editions were required within six months4 ,i had the more reason to be content with this unexpected success1 as this confession of faith was originally merely an occasional speech which ,i delivered unprepared on ,october #i1 #ahib1 at ,altenburg1 during the jubilee of the ,scientific ,society of ,east ,germany4 ,naturally there was the usual demonstration on the other side2 ,i was fiercely attacked1 not only by the ultramontane press1 the sworn defenders of superstition1 but also by the liberal controversialists of evangelical ,christianity1 who profess to defend both scientific truth and purified faith4 ,in the seven years that have ensued since that time the great struggle between modern science and orthodox ,christianity has become more threatening2 it has grown more dangerous for science in proportion as ,christianity has found support in an increasing mental and political reaction4 ,in some countries the ,church has made such progress that the freedom of thought and conscience1 which is guaranteed by the laws1 is in practice gravely menaced 7for instance1 in ,bavaria74 ,the great historic struggle which ,draper has so admirably depicted in his ,conflict between ,religion and ,science is to-day more acute and significant than ever4 ,for the last twenty-seven years it has been rightly called the cultur-kampf4 ,the famous encyclica and syllabus which the militant pope1 ,pius ,,ix41 sent out into the entire world in #ahfd were a declaration of war on the whole of modern science2 they demanded the blind submission of reason to the dogmas of the infallible pope4 ,the enormity of this crude assault on the highest treasures of civilization even roused many indolent minds from the slumber of belief4 ,together with the subsequent promulgation of the papal infallibility 7#ahgj71 the encyclica provoked a deep wave of irritation and an energetic repulse which held out high hopes4 ,in the new ,german empire1 which had attained its indispensable national unity by the heavy sacrifices of the wars of #ahff and #ahga1 the insolent attacks of the pope were felt to be particularly offensive4 ,on the one hand1 ,germany is the cradle of the ,reformation and the modern emancipation of reason2 on the other hand1 it unfortunately has in its #ah1jjj1jjj ,catholics a vast host of militant believers1 who are unsurpassed by any other civilized people in blind obedience to their chief shepherd4 ,the dangers of such a situation were clearly recognized by the great statesman who had solved the political world-riddle of the dismemberment of ,germany1 and had led us by a marvellous statecraft to the long-desired goal of national unity and power4 ,prince ,bismarck began the famous struggle with the ,vatican1 which is known as the cultur-kampf1 in #ahgb1 and it was conducted with equal ability and energy by the distinguished ,minister of ,worship1 ,falk1 author of the ,may laws of #ahgc4 ,unfortunately1 ,bismarck had to desist six years afterwards4 ,although the great statesman was a remarkable judge of men and a realistic politician of immense tact1 he had underestimated the force of three powerful obstacles--first1 the unsurpassed cunning and unscrupulous treachery of the ,roman curia2 secondly1 the correlative ingratitude and credulity of the uneducated ,catholic masses1 on which the papacy built2 and1 thirdly1 the power of apathy1 the continuance of the irrational1 simply because it is in possession4 ,hence1 in #ahgh1 when the abler ,leo ,,xiii4 had ascended the pontifical throne1 the fatal ,to ,canossa was heard once more4 ,from that time the newly established power of ,rome grew in strength2 partly through the unscrupulous intrigues and serpentine bends of its slippery ,jesuitical politics1 partly through the false ,church-politics of the ,german government and the marvellous political incompetence of the ,german people4 ,we have1 therefore1 at the close of the nineteenth century to endure the pitiful spectacle of the ,catholic ,centre being the most important section of the ,reichstag1 and the fate of our humiliated country depending on a papal party1 which does not constitute numerically a third part of the nation4 ,when the cultur-kampf began in #ahgb1 it was justly acclaimed by all independent thinkers as a political renewal of the ,reformation1 a vigorous attempt to free modern civilization from the yoke of papal despotism4 ,the whole of the ,liberal press hailed ,bismarck as a political ,luther--as the great hero1 not only of the national unity1 but also of the rational emancipation of ,germany4 ,ten years afterwards1 when the papacy had proved victorious1 the same ,liberal press changed its colors1 and denounced the cultur-kampf as a great mistake2 and it does the same thing to-day4 ,the facts show how short is the memory of our journalists1 how defective their knowledge of history1 and how poor their philosophic education4 ,the so-called ,peace between ,church and ,state is never more than a suspension of hostilities4 ,the modern papacy1 true to the despotic principles it has followed for the last sixteen hundred years1 is determined to wield sole dominion over the credulous souls of men2 it must demand the absolute submission of the cultured ,state1 which1 as such1 defends the rights of reason and science4 ,true and enduring peace there cannot be until one of the combatants lies powerless on the ground4 ,either the ,church wins1 and then farewell to all free science and free teaching--then are our universities no better than jails1 and our colleges become cloistral schools2 or else the modern rational ,state proves victorious--then1 in the twentieth century1 human culture1 freedom1 and prosperity will continue their progressive development until they far surpass even the height of the nineteenth century4 ,in order to compass these high aims1 it is of the first importance that modern science not only shatter the false structures of superstition and sweep their ruins from the path1 but that it also erect a new abode for human emotion on the ground it has cleared--a palace of reason1 in which1 under the influence of our new monistic views1 we do reverence to the real trinity of the nineteenth century--the trinity of the true1 the good1 and the beautiful4 ,in order to give a tangible shape to the cult of this divine ideal1 we must first of all compare our position with the dominant forms of ,christianity1 and realize the changes that are involved in the substitution of the one for the other4 ,for1 in spite of its errors and defects1 the ,christian religion 7in its primitive and purer form7 has so high an ethical value1 and has entered so deeply into the most important social and political movements of civilized history for the last fifteen hundred years1 that we must appeal as much as possible to its existing institutions in the establishment of our monistic religion4 ,we do not seek a mighty revolution1 but a rational reformation1 of our religious life4 ,and just as1 two thousand years ago1 the classic poetry of the ancient ,greeks incarnated their ideals of virtue in divine shapes1 so may we1 too1 lend the character of noble goddesses to our three rational ideals4 ,we must inquire into the features of the three goddesses of the monist--truth1 beauty1 and virtue2 and we must study their relation to the three corresponding ideals of ,christianity which they are to replace4 ,i4 ,the preceding inquiries 7especially those of the first and third sections7 have convinced us that truth unadulterated is only to be found in the temple of the study of nature1 and that the only available paths to it are critical observation and reflection--the empirical investigation of facts and the rational study of their efficient causes4 ,in this way we arrive1 by means of pure reason1 at true science1 the highest treasure of civilized man4 ,we must1 in accordance with the arguments of our sixteenth chapter1 reject what is called revelation1 the poetry of faith1 that affirms the discovery of truth in a supernatural fashion1 without the assistance of reason4 ,and since the entire structure of the ,judo-,christian religion1 like that of the ,mohammedan and the ,buddhistic1 rests on these so-called revelations1 and these mystic fruits of the imagination directly contradict the clear results of empirical research1 it is obvious that we shall only attain to a knowledge of the truth by the rational activity of genuine science1 not by the poetic imagining of a mystic faith4 ,in this respect it is quite certain that the ,christian system must give way to the monistic4 ,the goddess of truth dwells in the temple of nature1 in the green woods1 on the blue sea1 and on the snowy summits of the hills--not in the gloom of the cloister1 nor in the narrow prisons of our jail-like schools1 nor in the clouds of incense of the ,christian churches4 ,the paths which lead to the noble divinity of truth and knowledge are the loving study of nature and its laws1 the observation of the infinitely great star-world with the aid of the telescope1 and the infinitely tiny cell-world with the aid of the microscope--not senseless ceremonies and unthinking prayers1 not alms and ,peter's ,pence4 ,the rich gifts which the goddess of truth bestows on us are the noble fruits of the tree of knowledge and the inestimable treasure of a clear1 unified view of the world--not belief in supernatural miracles and the illusion of an eternal life4 ,,ii4 ,it is otherwise with the divine ideal of eternal goodness4 ,in our search for the truth we have entirely to exclude the revelation of the churches1 and devote ourselves solely to the study of nature2 but1 on the other hand1 the idea of the good1 which we call virtue1 in our monistic religion coincides for the most part with the ,christian idea of virtue4 ,we are speaking1 naturally1 of the primitive and pure ,christianity of the first three centuries1 as far as we learn its moral teaching from the gospels and the epistles of ,paul2 it does not apply to the ,vatican caricature of that pure doctrine which has dominated ,european civilization1 to its infinite prejudice1 for twelve hundred years4 ,the best part of ,christian morality1 to which we firmly adhere1 is represented by the humanist precepts of charity and toleration1 compassion and assistance4 ,however1 these noble commands1 which are set down as ,christian morality 7in its best sense71 are by no means original discoveries of ,christianity2 they are derived from earlier religions4 ,the ,golden ,rule1 which sums up these precepts in one sentence1 is centuries older than ,christianity4 ,in the conduct of life this law of natural morality has been followed just as frequently by non-,christians and atheists as it has been neglected by pious believers4 ,moreover1 ,christian ethics was marred by the great defect of a narrow insistence on altruism and a denunciation of egoism4 ,our monistic ethics lays equal emphasis on the two1 and finds perfect virtue in the just balance of love of self and love of one's neighbor 7cf4 chap4 xix474 ,,iii4 ,but monism enters into its strongest opposition to ,christianity on the question of beauty4 ,primitive ,christianity preached the worthlessness of earthly life1 regarding it merely as a preparation for an eternal life beyond4 ,hence it immediately followed that all we find in the life of man here below1 all that is beautiful in art and science1 in public and in private life1 is of no real value4 ,the true ,christian must avert his eyes from them2 he must think only of a worthy preparation for the life beyond4 ,contempt of nature1 aversion from all its inexhaustible charms1 rejection of every kind of fine art1 are ,christian duties2 and they are carried out to perfection when a man separates himself from his fellows1 chastises his body1 and spends all his time in prayer in the cloister or the hermit's cell4 ,history teaches us that this ascetical morality that would scorn the whole of nature had1 as a natural consequence1 the very opposite effect to that it intended4 ,monasteries1 the homes of chastity and discipline1 soon became dens of the wildest orgies2 the sexual commerce of monks and nuns has inspired shoals of novels1 as it is so faithfully depicted in the literature of the ,renaissance4 ,the cult of the beautiful1 which was then practised1 was in flagrant contradiction with the vaunted abandonment of the world2 and the same must be said of the pomp and luxury which soon developed in the immoral private lives of the higher ecclesiastics and in the artistic decoration of ,christian churches and monasteries4 ,it may be objected that our view is refuted by the splendor of ,christian art1 which1 especially in the best days of the ,middle ,ages1 created works of undying beauty4 ,the graceful ,gothic cathedrals and ,byzantine basilicas1 the hundreds of magnificent chapels1 the thousands of marble statues of saints and martyrs1 the millions of fine pictures of saints1 of profoundly conceived representations of ,christ and the madonna--all are proofs of the development of a noble art in the ,middle ,ages1 which is unique of its kind4 ,all these splendid monuments of medival art are untouched in their high sthetic value1 whatever we say of their mixture of truth and fancy4 ,yes2 but what has all that to do with the pure teaching of ,christianity--with that religion of sacrifice that turned scornfully away from all earthly parade and glamour1 from all material beauty and art2 that made light of the life of the family and the love of woman2 that urged an exclusive concern as to the immaterial goods of eternal life8 ,the idea of a ,christian art is a contradiction in terms--a contradictio in adjecto4 ,the wealthy princes of the ,church who fostered it were candidly aiming at very different ideals1 and they completely attained them4 ,in directing the whole interest and activity of the human mind in the ,middle ,ages to the ,christian ,church and its distinctive art they were diverting it from nature and from the knowledge of the treasures that were hidden in it1 and would have conducted to independent science4 ,moreover1 the daily sight of the huge images of the saints and of the scenes of sacred history continually reminded the faithful of the vast collection of myths that the ,church had made4 ,the legends themselves were taught and believed to be true narratives1 and the stories of miracles to be records of actual events4 ,it cannot be doubted that in this respect ,christian art has exercised an immense influence on general culture1 and especially in the strengthening of ,christian belief--an influence which still endures throughout the entire civilized world4 ,the diametrical opposite of this dominant ,christian art is the new artistic tendency which has been developed during the present century in connection with science4 ,the remarkable expansion of our knowledge of nature1 and the discovery of countless beautiful forms of life1 which it includes1 have awakened quite a new sthetic sense in our generation1 and thus given a new tone to painting and sculpture4 ,numerous scientific voyages and expeditions for the exploration of unknown lands and seas1 partly in earlier centuries1 but more especially in the nineteenth1 have brought to light an undreamed abundance of new organic forms4 ,the number of new species of animals and plants soon became enormous1 and among them 7especially among the lower groups that had been neglected before7 there were thousands of forms of great beauty and interest1 affording an entirely new inspiration for painting1 sculpture1 architecture1 and technical art4 ,in this respect a new world was revealed by the great advance of microscopic research in the second half of the century1 and especially by the discovery of the marvellous inhabitants of the deep sea1 which were first brought to light by the famous expedition of the ,challenger 7#ahgb-gf74 ,thousands of graceful radiolaria and thalamophora1 of pretty medus and corals1 of extraordinary molluscs1 and crabs1 suddenly introduced us to a wealth of hidden organisms beyond all anticipation1 the peculiar beauty and diversity of which far transcend all the creations of the human imagination4 ,in the fifty large volumes of the account of the ,challenger expedition a vast number of these beautiful forms are delineated on three thousand plates2 and there are millions of other lovely organisms described in other great works that are included in the fast-growing literature of zoology and botany of the last ten years4 ,i began on a small scale to select a number of these beautiful forms for more popular description in my ,art ,forms in ,nature 7#ahii74 ,however1 there is now no need for long voyages and costly works to appreciate the beauties of this world4 ,a man needs only to keep his eyes open and his mind disciplined4 ,surrounding nature offers us everywhere a marvellous wealth of lovely and interesting objects of all kinds4 ,in every bit of moss and blade of grass1 in every beetle and butterfly1 we find1 when we examine it carefully1 beauties which are usually overlooked4 ,above all1 when we examine them with a powerful glass or1 better still1 with a good microscope1 we find everywhere in nature a new world of inexhaustible charms4 ,but the nineteenth century has not only opened our eyes to the sthetic enjoyment of the microscopic world2 it has shown us the beauty of the greater objects in nature4 ,even at its commencement it was the fashion to regard the mountains as magnificent but forbidding1 and the sea as sublime but dreaded4 ,at its close the majority of educated people--especially they who dwell in the great cities--are delighted to enjoy the glories of the ,alps and the crystal splendor of the glacier world for a fortnight every year1 or to drink in the majesty of the ocean and the lovely scenery of its coasts4 ,all these sources of the keenest enjoyment of nature have only recently been revealed to us in all their splendor1 and the remarkable progress we have made in facility and rapidity of conveyance has given even the less wealthy an opportunity of approaching them4 ,all this progress in the sthetic enjoyment of nature--and1 proportionately1 in the scientific understanding of nature--implies an equal advance in higher mental development and1 consequently1 in the direction of our monistic religion4 ,the opposite character of our naturalistic century to that of the anthropistic centuries that preceded is especially noticeable in the different appreciation and spread of illustrations of the most diverse natural objects4 ,in our own days a lively interest in artistic work of that kind has been developed1 which did not exist in earlier ages2 it has been supported by the remarkable progress of commerce and technical art which have facilitated a wide popularization of such illustrations4 ,countless illustrated periodicals convey along with their general information a sense of the inexhaustible beauty of nature in all its departments4 ,in particular1 landscape-painting has acquired an importance that surpassed all imagination4 ,in the first half of the century one of our greatest and most erudite scientists1 ,alexander ,humboldt1 had pointed out that the development of modern landscape-painting is not only of great importance as an incentive to the study of nature and as a means of geographical description1 but that it is to be commended in other respects as a noble educative medium4 ,since that time the taste for it has considerably increased4 ,it should be the aim at every school to teach the children to enjoy scenery at an early age1 and to give them the valuable art of imprinting on the memory by a drawing or water-color sketch4 ,the infinite wealth of nature in what is beautiful and sublime offers every man with open eyes and an sthetic sense an incalculable sum of choicest gifts4 ,still1 however valuable and agreeable is the immediate enjoyment of each single gift1 its worth is doubled by a knowledge of its meaning and its connection with the rest of nature4 ,when ,humboldt gave us the outline of a physical description of the world in his magnificent ,cosmos forty years ago1 and when he combined scientific and sthetic consideration so happily in his standard ,prospects of ,nature1 he justly indicated how closely the higher enjoyment of nature is connected with the scientific establishment of cosmic laws1 and that the conjunction of the two serves to raise human nature to a higher stage of perfection4 ,the astonishment with which we gaze upon the starry heavens and the microscopic life in a drop of water1 the awe with which we trace the marvellous working of energy in the motion of matter1 the reverence with which we grasp the universal dominance of the law of substance throughout the universe--all these are part of our emotional life1 falling under the heading of natural religion4 ,this progress of modern times in knowledge of the true and enjoyment of the beautiful expresses1 on the one hand1 a valuable element of our monistic religion1 but is1 on the other hand1 in fatal opposition to ,christianity4 ,for the human mind is thus made to live on this side of the grave2 ,christianity would have it ever gaze beyond4 ,monism teaches that we are perishable children of the earth1 who for one or two1 or1 at the most1 three generations1 have the good fortune to enjoy the treasures of our planet1 to drink of the inexhaustible fountain of its beauty1 and to trace out the marvellous play of its forces4 ,christianity would teach us that the earth is a vale of tears1 in which we have but a brief period to chasten and torment ourselves in order to merit the life of eternal bliss beyond4 ,where this beyond is1 and of what joys the glory of this eternal life is compacted1 no revelation has ever told us4 ,as long as heaven was thought to be the blue vault that hovers over the disk of our planet1 and is illumined by the twinkling light of a few thousand stars1 the human imagination could picture to itself the ambrosial banquets of the ,olympic gods above or the laden tables of the happy dwellers in ,valhalla4 ,but now all these deities and the immortal souls that sat at their tables are houseless and homeless1 as ,david ,strauss has so ably described2 for we know from astrophysical science that the immeasurable depths of space are filled with a prosaic ether1 and that millions of heavenly bodies1 ruled by eternal laws of iron1 rush hither and thither in the great ocean1 in their eternal rhythm of life and death4 ,the places of devotion1 in which men seek the satisfaction of their religious emotions and worship the objects of their reverence1 are regarded as sacred churches4 ,the pagodas of ,buddhistic ,asia1 the ,greek temples of classical antiquity1 the synagogues of ,palestine1 the mosques of ,egypt1 the ,catholic cathedrals of the south1 and the ,protestant cathedrals of the north1 of ,europe--all these houses of ,god serve to raise man above the misery and the prose of daily life1 to lift him into the sacred1 poetic atmosphere of a higher1 ideal world4 ,they attain this end in a thousand different ways1 according to their various forms of worship and their age4 ,the modern man who has science and art--and1 therefore1 religion--needs no special church1 no narrow1 enclosed portion of space4 ,for through the length and breadth of free nature1 wherever he turns his gaze1 to the whole universe or to any single part of it1 he finds1 indeed1 the grim struggle for life1 but by its side are ever the good1 the true1 and the beautiful2 his church is commensurate with the whole of glorious nature4 ,still1 there will always be men of special temperament who will desire to have decorated temples or churches as places of devotion to which they may withdraw4 ,just as the ,catholics had to relinquish a number of churches to the ,reformation in the sixteenth century1 so a still larger number will pass over to free societies of monists in the coming years4 ,,chapter ,,xix ,,our ,,monistic ,,ethics ,monistic and ,dualistic ,ethics--,contradiction of ,pure and ,practical ,reason in ,kant--,his ,categorical ,imperative--,the ,neo-,kantians--,herbert ,spencer--,egoism and ,altruism--,equivalence of the ,two ,instincts--,the ,fundamental ,law of ,ethics3 the ,golden ,rule--,its ,antiquity--,christian ,ethics--,contempt of ,self1 the ,body1 ,nature1 ,civilization1 the ,family1 ,woman--,roman ,catholic ,ethics--,immoral ,results of ,celibacy--,necessity for the ,abolition of the ,law of ,celibacy1 ,oral ,confession1 and ,indulgences--,state and ,church--,religion a ,private ,concern--,church and ,school--,state and ,school--,need of ,school ,reform ,the practical conduct of life makes a number of definite ethical claims on a man which can only be duly and naturally satisfied when they are in complete harmony with his view of the world4 ,in accordance with this fundamental principle of our monistic philosophy1 our whole system of ethics must be rationally connected with the unified conception of the cosmos which we have formed by our advanced knowledge of the laws of nature4 ,just as the infinite universe is one great whole in the light of our monistic teaching1 so the spiritual and moral life of man is a part of this cosmos1 and our naturalistic ordering of it must also be monistic4 ,there are not two different1 separate worlds--the one physical and material1 and the other moral and immaterial4 ,the great majority of philosophers and theologians still hold the contrary opinion4 ,they affirm1 with ,kant1 that the moral world is quite independent of the physical1 and is subject to very different laws2 hence a man's conscience1 as the basis of his moral life1 must also be quite independent of our scientific knowledge of the world1 and must be based rather on his religious faith4 ,on that theory the study of the moral world belongs to practical reason1 while that of nature1 or of the physical world1 is referred to pure or theoretical reason4 ,this unequivocal and conscious dualism of ,kant's philosophy was its greatest defect2 it has caused1 and still causes1 incalculable mischief4 ,first of all the critical ,kant had built up the splendid and marvellous palace of pure reason1 and convincingly proved that the three great central dogmas of metaphysics--a personal ,god1 free will1 and the immortal soul--had no place whatever in it1 and that no rational proof could be found of their reality4 ,afterwards1 however1 the dogmatic ,kant superimposed on this true crystal palace of pure reason the glittering1 ideal castle in the air of practical reason1 in which three imposing church-naves were designed for the accommodation of those three great mystic divinities4 ,when they had been put out at the front door by rational knowledge they returned by the back door under the guidance of irrational faith4 ,the cupola of his great cathedral of faith was crowned by ,kant with his curious idol1 the famous categorical imperative4 ,according to it1 the demand of the universal moral law is unconditional1 independent of any regard to actuality or potentiality4 ,it runs3 ,act at all times in such wise that the maxim 7or the subjective law of thy will7 may hold good as a principle of a universal law4 ,on that theory all normal men would have the same sense of duty4 ,modern anthropology has ruthlessly dissipated that pretty dream2 it has shown that conceptions of duty differ even more among uncivilized than among civilized nations4 ,all the actions and customs which we regard as sins or loathsome crimes 7theft1 fraud1 murder1 adultery1 etc47 are considered by other nations in certain circumstances to be virtues1 or even sacred duties4 ,although the obvious contradiction of the two forms of reason in ,kant's teaching1 the fundamental antagonism of pure and practical reason1 was recognized and attacked at the very beginning of the century1 it is still pretty widely accepted4 ,the modern school of neo-,kantians urges a return to ,kant so pressingly precisely on account of this agreeable dualism2 the ,church militant zealously supports it because it fits in admirably with its own mystic faith4 ,but it met with an effective reverse at the hands of modern science in the second half of the nineteenth century1 which entirely demolished the theses of the system of practical reason4 ,monistic cosmology proved1 on the basis of the law of substance1 that there is no personal ,god2 comparative and genetic psychology showed that there cannot be an immortal soul2 and monistic physiology proved the futility of the assumption of free will4 ,finally1 the science of evolution made it clear that the same eternal iron laws that rule in the inorganic world are valid too in the organic and moral world4 ,but modern science gives not only a negative support to practical philosophy and ethics in demolishing the ,kantian dualism1 but it renders the positive service of substituting for it the new structure of ethical monism4 ,it shows that the feeling of duty does not rest on an illusory categorical imperative1 but on the solid ground of social instinct1 as we find in the case of all social animals4 ,it regards as the highest aim of all morality the re-establishment of a sound harmony between egoism and altruism1 between self-love and the love of one's neighbor4 ,it is to the great ,english philosopher1 ,herbert ,spencer1 that we owe the founding of this monistic ethics on a basis of evolution4 ,man belongs to the social vertebrates1 and has1 therefore1 like all social animals1 two sets of duties--first to himself1 and secondly to the society to which he belongs4 ,the former are the behests of self-love or egoism1 the latter of love for one's fellows or altruism4 ,the two sets of precepts are equally just1 equally natural1 and equally indispensable4 ,if a man desire to have the advantage of living in an organized community1 he has to consult not only his own fortune1 but also that of the society1 and of the neighbors who form the society4 ,he must realize that its prosperity is his own prosperity1 and that it cannot suffer without his own injury4 ,this fundamental law of society is so simple and so inevitable that one cannot understand how it can be contradicted in theory or in practice2 yet that is done to-day1 and has been done for thousands of years4 ,the equal appreciation of these two natural impulses1 or the moral equivalence of self-love and love of others1 is the chief and the fundamental principle of our morality4 ,hence the highest aim of all ethics is very simple--it is the re-establishment of the natural equality of egoism and altruism1 of the love of one's self and the love of one's neighbor4 ,the ,golden ,rule says3 ,do unto others as you would that they should do unto you4 ,from this highest precept of ,christianity it follows of itself that we have just as sacred duties towards ourselves as we have towards our fellows4 ,i have explained my conception of this principle in my ,monism1 and laid down three important theses4 7#a7 ,both these concurrent impulses are natural laws1 of equal importance and necessity for the preservation of the family and the society2 egoism secures the self-preservation of the individual1 altruism that of the species which is made up of the chain of perishable individuals4 7#b7 ,the social duties which are imposed by the social structure of the associated individuals1 and by means of which it secures its preservation1 are merely higher evolutionary stages of the social instincts1 which we find in all higher social animals 7as habits which have become hereditary74 7#c7 ,in the case of civilized man all ethics1 theoretical or practical1 being a science of rules1 is connected with his view of the world at large1 and consequently with his religion4 ,from the recognition of the fundamental principle of our morality we may immediately deduce its highest precept1 that noble command1 which is often called the ,golden ,rule of morals1 or1 briefly1 the ,golden ,rule4 ,christ repeatedly expressed it in the simple phrase3 ,thou shalt love thy neighbor as thyself4 ,mark adds that there is no greater commandment than this1 and ,matthew says3 ,in these two commandments is the whole law and the prophets4 ,in this greatest and highest commandment our monistic ethics is completely at one with ,christianity4 ,we must1 however1 recall the historical fact that the formulation of this supreme command is not an original merit of ,christ1 as the majority of ,christian theologians affirm and their uncritical supporters blindly accept4 ,the ,golden ,rule is five hundred years older than ,christ2 it was laid down as the highest moral principle by many ,greek and ,oriental sages4 ,pittacus1 of ,mylene1 one of the seven wise men of ,greece1 said six hundred and twenty years before ,christ3 ,do not that to thy neighbor that thou wouldst not suffer from him4 ,confucius1 the great ,chinese philosopher and religious founder 7who rejected the idea of a personal ,god and of the immortality of the soul71 said five hundred years ,b4,c43 ,do to every man as thou wouldst have him do to thee2 and do not to another what thou wouldst not have him do to thee4 ,this precept only dost thou need2 it is the foundation of all other commandments4 ,aristotle taught about the middle of the fourth century ,b4,c43 ,we must act towards others as we wish others to act towards us4 ,in the same sense1 and partly in the same words1 the ,golden ,rule was given by ,thales1 ,isocrates1 ,aristippus1 ,sextus1 the ,pythagorean1 and other philosophers of classic antiquity--several centuries before ,christ4 ,from this collection it is clear that the ,golden ,rule had a polyphyletic origin--that is1 it was formulated by a number of philosophers at different times and in different places1 quite independently of each other4 ,otherwise it must be assumed that ,jesus derived it from some other ,oriental source1 from ancient ,semitic1 ,indian1 ,chinese1 or especially ,buddhistic traditions1 as has been proved in the case of most of the other ,christian doctrines4 ,as the great ethical principle is thus twenty-five hundred years old1 and as ,christianity itself has put it at the head of its moral teaching as the highest and all-embracing commandment1 it follows that our monistic ethics is in complete harmony on this important point1 not only with the ethics of the ancient heathens1 but also with that of ,christianity4 ,unfortunately this harmony is disturbed by the fact that the gospels and the ,pauline epistles contain many other points of moral teaching1 which contradict our first and supreme commandment4 ,christian theologians have fruitlessly striven to explain away these striking and painful contradictions by their ingenious interpretations4 ,we need not enter into that question now1 but we must briefly consider those unfortunate aspects of ,christian ethics which are incompatible with the better thought of the modern age1 and which are distinctly injurious in their practical consequences4 ,of that character is the contempt which ,christianity has shown for self1 for the body1 for nature1 for civilization1 for the family1 and for woman4 ,i4 ,the supreme mistake of ,christian ethics1 and one which runs directly counter to the ,golden ,rule1 is its exaggeration of love of one's neighbor at the expense of self-love4 ,christianity attacks and despises egoism on principle4 ,yet that natural impulse is absolutely indispensable in view of self-preservation2 indeed1 one may say that even altruism1 its apparent opposite1 is only an enlightened egoism4 ,nothing great or elevated has ever taken place without egoism1 and without the passion that urges us to great sacrifices4 ,it is only the excesses of the impulse that are injurious4 ,one of the ,christian precepts that were impressed upon us in our early youth as of great importance1 and that are glorified in millions of sermons1 is3 ,love your enemies1 bless them that curse you1 do good to them that hate you1 and pray for them which despitefully use you and persecute you4 ,it is a very ideal precept1 but as useless in practice as it is unnatural4 ,so it is with the counsel1 ,if any man will take away thy coat1 let him have thy cloak also4 ,translated into the terms of modern life1 that means3 ,when some unscrupulous scoundrel has defrauded thee of half thy goods1 let him have the other half also4 ,or1 again1 in the language of modern politics3 ,when the pious ,english take from you simple ,germans one after another of your new and valuable colonies in ,africa1 let them have all the rest of your colonies also--or1 best of all1 give them ,germany itself4 ,and1 while we touch on the marvellous world-politics of modern ,england1 we may note in passing its direct contradiction of every precept of ,christian charity1 which is more frequently on the lips of that great nation than of any other nation in the world4 ,however1 the glaring contradiction between the theoretical1 ideal1 altruistic morality of the human individual and the real1 purely selfish morality of the human community1 and especially of the civilized ,christian state1 is a familiar fact4 ,it would be interesting to determine mathematically in what proportion among organized men the altruistic ethical ideal of the individual changes into its contrary1 the purely egoistic real politics of the state and the nation4 ,,ii4 ,since the ,christian faith takes a wholly dualistic view of the human organism and attributes to the immortal soul only a temporary sojourn in the mortal frame1 it very naturally sets a much greater value on the soul than on the body4 ,hence results that neglect of the care of the body1 of training1 and of cleanliness which contrasts the life of the ,christian ,middle ,ages so unfavorably with that of pagan classical antiquity4 ,christian ethics contains none of those firm commands as to daily ablutions which are theoretically laid down and practically fulfilled in the ,mohammedan1 ,hindoo1 and other religions4 ,in many monasteries the ideal of the pious ,christian is the man who does not wash and clothe himself properly1 who never changes his malodorous gown1 and who1 instead of regular work1 fills up his useless life with mechanical prayers1 senseless fasts1 and so forth4 ,as a special outgrowth of this contempt of the body we have the disgusting discipline of the flagellants and other ascetics4 ,,iii4 ,one source of countless theoretical errors and practical blemishes1 of deplorable crudity and privation1 is found in the false anthropism of ,christianity--that is1 in the unique position which it gives to man1 as the image of ,god1 in opposition to all the rest of nature4 ,in this way it has contributed1 not only to an extremely injurious isolation from our glorious mother nature1 but also to a regrettable contempt of all other organisms4 ,christianity has no place for that well-known love of animals1 that sympathy with the nearly related and friendly mammals 7dogs1 horses1 cattle1 etc471 which is urged in the ethical teaching of many of the older religions1 especially ,buddhism4 ,whoever has spent much time in the south of ,europe must have often witnessed those frightful sufferings of animals which fill us friends of animals with the deepest sympathy and indignation4 ,and when one expostulates with these brutal ,christians on their cruelty1 the only answer is1 with a laugh3 ,but the beasts are not ,christians4 ,unfortunately ,descartes gave some support to the error in teaching that man only has a sensitive soul1 not the animal4 ,how much more elevated is our monistic ethics than the ,christian in this regard6 ,darwinism teaches us that we have descended immediately from the primates1 and1 in a secondary degree1 from a long series of earlier mammals1 and that1 therefore1 they are our brothers2 physiology informs us that they have the same nerves and sense-organs as we1 and the same feelings of pleasure and pain4 ,no sympathetic monistic scientist would ever be guilty of that brutal treatment of animals which comes so lightly to the ,christian in his anthropistic illusion--to the child of the ,god of love4 ,moreover1 this ,christian contempt of nature on principle deprives man of an abundance of the highest earthly joys1 especially of the keen1 ennobling enjoyment of nature4 ,,iv4 ,since1 according to ,christ's teaching1 our planet is a vale of tears1 and our earthly life is valueless and a mere preparation for a better life to come1 it has succeeded in inducing men to sacrifice all happiness on this side of eternity and make light of all earthly goods4 ,among these earthly goods1 in the case of the modern civilized man1 we must include the countless great and small conveniences of technical science1 hygiene1 commerce1 etc41 which have made modern life cheerful and comfortable2 we must include all the gratifications of painting1 sculpture1 music1 and poetry1 which flourished exceedingly even during the ,middle ,ages 7in spite of its principles71 and which we esteem as ideal pleasures2 we must include all that invaluable progress of science1 especially the study of nature1 of which the nineteenth century is justly proud4 ,all these earthly goods1 that have so high a value in the eyes of the monist1 are worthless--nay1 injurious--for the most part1 according to ,christian teaching2 the stern code of ,christian morals should look just as unfavorably on the pursuit of these pleasures as our humanistic ethics fosters and encourages it4 ,once more1 therefore1 ,christianity is found to be an enemy to civilization1 and the struggle which modern thought and science are compelled to conduct with it is1 in this additional sense1 a cultur-kampf4 ,v4 ,another of the most deplorable aspects of ,christian morality is its belittlement of the life of the family1 of that natural living together with our next of kin which is just as necessary in the case of man as in the case of all the higher social animals4 ,the family is justly regarded as the foundation of society1 and the healthy life of the family is a necessary condition of the prosperity of the ,state4 ,christ1 however1 was of a very different opinion3 with his gaze ever directed to the beyond1 he thought as lightly of woman and the family as of all other goods of this life4 ,of his infrequent contact with his parents and sisters the gospels have very little to say2 but they are far from representing his relations with his mother to have been so tender and intimate as they are poetically depicted in so many thousands of pictures4 ,he was not married himself4 ,sexual love1 the first foundation of the family union1 seems to have been regarded by ,jesus as a necessary evil4 ,his most enthusiastic apostle1 ,paul1 went still farther in the same direction1 declaring it to be better not to marry than to marry3 ,it is good for a man not to touch a woman4 ,if humanity were to follow this excellent counsel1 it would soon be rid of all earthly misery and suffering3 it would be killed off by such a radical cure within half a century4 ,,vi4 ,as ,christ never knew the love of woman1 he had no personal acquaintance with that refining of man's true nature that comes only from the intimate life of man with woman4 ,the intimate sexual union1 on which the preservation of the human race depends1 is just as important on that account as the spiritual penetration of the two sexes1 or the mutual complement which they bring to each other in the practical wants of daily life as well as in the highest ideal functions of the soul4 ,for man and woman are two different organisms1 equal in worth1 each having its characteristic virtues and defects4 ,as civilization advanced1 this ideal value of sexual love was more appreciated1 and woman held in higher honor1 especially among the ,teutonic races2 she is the inspiring source of the highest achievements of art and poetry4 ,but ,christ was as far from this view as nearly the whole of antiquity2 he shared the idea that prevailed everywhere in the ,east--that woman is subordinate to man1 and intercourse with her is unclean4 ,long-suffering nature has taken a fearful revenge for this blunder2 its sad consequences are written in letters of blood in the history of the papal ,middle ,ages4 ,the marvellous hierarchy of the ,roman ,church1 that never disdained any means of strengthening its spiritual despotism1 found an exceptionally powerful instrument in the manipulation of this unclean idea1 and in the promotion of the ascetic notion that abstinence from intercourse with women is a virtue of itself4 ,in the first few centuries after ,christ a number of priests voluntarily abstained from marriage1 and the supposed value of this celibacy soon rose to such a degree that it was made obligatory4 ,in the ,middle ,ages the seduction of women of good repute and of their daughters by ,catholic priests 7the confessional was an active agency in the business7 was a public scandal3 many communities1 in order to prevent such things1 pressed for a license of concubinage to be given to the clergy4 ,and it was done in many1 and sometimes very romantic1 ways4 ,thus1 for instance1 the canon law that the priest's cook should not be less than forty years old was very cleverly explained in the sense that the priest might have two cooks1 one in the presbytery1 another without2 if one was twenty-four and the other eighteen1 that made forty-two together--two years above the prescribed age4 ,at the ,christian councils1 at which heretics were burned alive1 the cardinals and bishops sat down with whole troops of prostitutes4 ,the private and public debauchery of the ,catholic clergy was so scandalous and dangerous to the commonwealth that there was a general rebellion against it before the time of ,luther1 and a loud demand for a reformation of the church in head and members4 ,it is well known that these immoral relations still continue in ,roman ,catholic lands1 although more in secret4 ,formerly proposals were made from time to time for the definitive abrogation of celibacy1 as was done1 for instance1 in the chambers of ,baden1 ,bavaria1 ,hesse1 ,saxony1 and other lands2 but they have1 unfortunately1 hitherto proved unavailing4 ,in the ,german ,reichstag1 in which the ultramontane ,centre is now proposing the most ridiculous measures for the suppression of sexual immorality1 there is now no party that will urge the abolition of celibacy in the interest of public morality4 ,the so-called ,freethought ,party and the utopian social democracy coquette with the favor of the ,centre4 ,the modern state that would lift not only the material1 but the moral1 life of its people to a higher level is entitled1 and indeed bound1 to sweep away such unworthy and harmful conditions4 ,the obligatory celibacy of the ,catholic clergy is as pernicious and immoral as the practice of auricular confession or the sale of indulgences4 ,all three have nothing whatever to do with primitive ,christianity4 ,all three are directly opposed to true ,christian morality4 ,all three are disreputable inventions of the papacy1 designed for the sole purpose of strengthening its despotic rule over the credulous masses and making as much material profit as possible out of them4 ,the ,nemesis of history will sooner or later exact a terrible account of the ,roman papacy1 and the millions who have been robbed of their happiness by this degenerate religion will help to give it its death-blow in the coming twentieth century--at least1 in every truly civilized state4 ,it has been recently calculated that the number of men who lost their lives in the papal persecutions of heretics1 the ,inquisition1 the ,christian religious wars1 etc41 is much more than ten millions4 ,but what is this in comparison with the tenfold greater number of the unfortunate moral victims of the institutions and the priestly domination of the degenerate ,christian ,church--with the unnumbered millions whose higher mental life was extinguished1 whose conscience was tortured1 whose family life was destroyed1 by the ,church8 ,we may with truth apply the words of ,goethe in his ,bride of ,corinth3 ,victims fall1 nor lambs nor bulls1 ,but human victims numberless4 ,in the great cultur-kampf1 which must go on as long as these sad conditions exist1 the first aim must be the absolute separation of ,church and ,state4 ,there shall be a free ,church in a free ,state--that is1 every ,church shall be free in the practice of its special worship and ceremonies1 and in the construction of its fantastic poetry and superstitious dogmas--with the sole condition that they contain no danger to social order or morality4 ,then there will be equal rights for all4 ,free societies and monistic religious bodies shall be equally tolerated1 and just as free in their movements as ,liberal ,protestant and orthodox ultramontane congregations4 ,but for all these faithful of the most diverse sects religion will have to be a private concern4 ,the state shall supervise them1 and prevent excesses2 but it must neither oppress nor support them4 ,above all1 the ratepayers shall not be compelled to contribute to the support and spread of a faith which they honestly believe to be a harmful superstition4 ,in the ,united ,states such a complete separation of ,church and ,state has been long accomplished1 greatly to the satisfaction of all parties4 ,they have also the equally important separation of the ,church from the school2 that is1 undoubtedly1 a powerful element in the great advance which science and culture have recently made in ,america4 ,it goes without saying that this exclusion of the ,church from the school only refers to its sectarian principles1 the particular form of belief which each ,church has evolved in the course of its life4 ,this sectarian education is purely a private concern1 and should be left to parents and tutors1 or to such priests or teachers as may have the personal confidence of the parents4 ,instead of the rejected sectarian instruction1 two important branches of education will be introduced--monistic or humanist ethics and comparative religion4 ,during the last thirty years an extensive literature has appeared dealing with the new system of ethics which has been raised on the basis of modern science--especially evolutionary science4 ,comparative religion will be a natural companion to the actual elementary instruction in biblical history and in the mythology of ,greece and ,rome4 ,both of these will remain in the curriculum4 ,the reason for that is obvious enough2 the whole of our painting and sculpture1 the chief branches of monistic sthetics1 are intimately blended with the ,christian1 ,greek1 and ,roman mythologies4 ,there will only be this important difference--that the ,christian myths and legends will not be taught as truths1 but as poetic fancies1 like the ,greek and ,roman myths2 the high value of the ethical and sthetical material they contain will not be lessened1 but increased1 by this means4 ,as regards the ,bible1 the book of books will only be given to the children in carefully selected extracts 7a sort of school ,bible72 in this way we shall avoid the besmirching of the child's imagination with the unclean stories and passages which are so numerous in the ,old ,testament4 ,once the modern ,state has freed itself and its schools from the fetters of the ,church1 it will be able to devote more attention to the improvement of education4 ,the incalculable value of a good system of education has forced itself more and more upon us as the many aspects of modern civilized life have been enlarged and enriched in the course of the century4 ,but the development of the educational methods has by no means kept pace with life in general4 ,the necessity for a comprehensive reform of our schools is making itself felt more and more4 ,on this question1 too1 a number of valuable works have appeared in the course of the last forty years4 ,we shall restrict ourselves to making a few general observations which we think of special importance4 #a4 ,in all education up to the present time man has played the chief part1 and especially the grammatical study of his language2 the study of nature was entirely neglected4 #b4 ,in the school of the future nature will be the chief object of the study2 a man shall learn a correct view of the world he lives in2 he will not be made to stand outside of and opposed to nature1 but be represented as its highest and noblest product4 #c4 ,the study of the classical tongues 7,latin and ,greek71 which has hitherto absorbed most of the pupils' time and energy1 is indeed valuable2 but it will be much restricted1 and confined to the mere elements 7obligatory for ,latin1 optional for ,greek74 #d4 ,in consequence1 modern languages must be all the more cultivated in all the higher schools 7,english and ,french to be obligatory1 ,italian optional74 #e4 ,historical instruction must pay more attention to the inner mental and spiritual life of a nation1 and to the development of its civilization1 and less to its external history 7the vicissitudes of dynasties1 wars1 and so forth74 #f4 ,the elements of evolutionary science must be learned in conjunction with cosmology1 geology must go with geography1 and anthropology with biology4 #g4 ,the first principles of biology must be familiar to every educated man2 the modern training in observation furnishes an attractive introduction to the biological sciences 7anthropology1 zoology1 and botany74 ,a start must be made with descriptive system 7in conjunction with tiology or bionomy72 the elements of anatomy and physiology to be added later on4 #h4 ,the first principles of physics and chemistry must also be taught1 and their exact establishment with the aid of mathematics4 #i4 ,every pupil must be taught to draw well1 and from nature2 and1 wherever it is possible1 the use of water-colors4 ,the execution of drawings and of water-color sketches from nature 7of flowers1 animals1 landscapes1 clouds1 etc47 not only excites interest in nature and helps memory to enjoy objects1 but it gives the pupil his first lesson in seeing correctly and understanding what he has seen4 #aj4 ,much more care and time must be devoted than has been done hitherto to corporal exercise1 to gymnastics and swimming2 but it is especially important to have walks in common every week1 and journeys on foot during the holidays4 ,the lesson in observation which they obtain in this way is invaluable4 ,the chief aim of higher education up to the present time1 in most countries1 has been a preparation for the subsequent profession1 and the acquisition of a certain amount of information and direction for civic duties4 ,the school of the twentieth century will have for its main object the formation of independent thought1 the clear understanding of the knowledge acquired1 and an insight into the natural connection of phenomena4 ,if the modern state gives every citizen a vote1 it should also give him the means of developing his reason by a proper education1 in order to make a rational use of his vote for the commonweal4 ,,chapter ,,xx ,,solution ,,of ,,the ,,world-,,problems ,a ,glance at the ,progress of the ,nineteenth ,century in ,solving ,cosmic ,problems--,i4 ,progress of ,astronomy and ,cosmology--,physical and ,chemical ,unity of the ,universe--,cosmic ,metamorphoses--,evolution of the ,planetary ,system--,analogy of the ,phylogenetic ,processes on the ,earth and on ,other ,planets--,organic ,inhabitants of ,other ,heavenly ,bodies--,periodic ,variation in the ,making of ,worlds--,,ii4 ,progress of ,geology and ,palontology--,neptunism and ,vulcanism--,theory of ,continuity--,,iii4 ,progress of ,physics and ,chemistry--,,iv4 ,progress of ,biology--,cellular ,theory and ,theory of ,descent--,v4 ,anthropology--,origin of ,man--,general ,conclusion ,at the close of our philosophic study of the riddles of the universe we turn with confidence to the answer to the momentous question1 ,how nearly have we approached to a solution of them8 ,what is the value of the immense progress which the passing nineteenth century has made in the knowledge of nature8 ,and what prospect does it open out to us for the future1 for the further development of our system in the twentieth century1 at the threshold of which we pause8 ,every unprejudiced thinker who impartially considers the solid progress of our empirical science1 and the unity and clearness of our philosophic interpretation of it1 will share our view3 the nineteenth century has made greater progress in knowledge of the world and in grasp of its nature than all its predecessors2 it has solved many great problems that seemed insoluble a hundred years ago2 it has opened out to us new provinces of learning1 the very existence of which was unsuspected at the beginning of the century4 ,above all1 it has put clearly before our eyes the lofty aim of monistic cosmology1 and has pointed out the path which alone will lead us towards it--the way of the exact empirical investigation of facts1 and of the critical genetic study of their causes4 ,the great abstract law of mechanical causality1 of which our cosmological law--the law of substance--is but another and a concrete expression1 now rules the entire universe1 as it does the mind of man2 it is the steady1 immovable pole-star1 whose clear light falls on our path through the dark labyrinth of the countless separate phenomena4 ,to see the truth of this more clearly1 let us cast a brief glance at the astonishing progress which the chief branches of science have made in this remarkable period4 ,i4--,,progress ,,of ,,astronomy ,the study of the heavens is the oldest1 the study of man the youngest1 of the sciences4 ,with regard to himself and the character of his being man only obtained a clear knowledge in the second half of the present century2 with regard to the starry heavens1 the motions of the planets1 and so on1 he had acquired astonishing information forty-five hundred years ago4 ,the ancient ,chinese1 ,hindoos1 ,egyptians1 and ,chaldans in the distant ,east knew more of the science of the spheres than the majority of educated ,christians did in the ,west four thousand years after them4 ,an eclipse of the sun was astronomically observed in ,china in the year #bfig ,b4,c41 and the plane of the ecliptic was determined by means of a gnome eleven hundred years ,b4,c41 while ,christ himself had no knowledge whatever of astronomy--indeed1 he looked out upon heaven and earth1 nature and man1 from the very narrowest geocentric and anthropocentric point of view4 ,the greatest advance of astronomy is generally1 and rightly1 said to be the founding of the heliocentric system of ,copernicus1 whose famous work1 ,de ,revolutionibus ,orbium ,celestium1 of itself caused a profound revolution in the minds of thoughtful men4 ,in overthrowing the ,ptolemaic system1 he destroyed the foundation of the ,christian theory1 which regarded the earth as the centre of the universe and man as the godlike ruler of the earth4 ,it was natural1 therefore1 that the ,christian clergy1 with the pope at its head1 should enter upon a fierce struggle with the invaluable discovery of ,copernicus4 ,yet it soon cleared a path for itself1 when ,kepler and ,galileo grounded on it their true mechanics of the heavens1 and ,newton gave it a solid foundation by his theory of gravitation 7#afhf74 ,a further great advance1 comprehending the entire universe1 was the application of the idea of evolution to astronomy4 ,it was done by the youthful ,kant in #agee2 in his famous general natural history and theory of the heavens he undertook the discussion1 not only of the constitution1 but also of the mechanical origin of the whole world-structure on ,newtonian principles4 ,the splendid ,systme du ,monde of ,laplace1 who had independently come to the same conclusions as ,kant on the world-problem1 gave so firm a basis to this new ,mcanique ,cleste in #agif that it looked as if nothing entirely new of equal importance was left to be discovered in the nineteenth century4 ,yet here again it had the honor of opening out entirely new paths and infinitely enlarging our outlook on the universe4 ,the invention of photography and photometry1 and especially of spectral analysis 7in #ahfj by ,bunsen and ,kirchoff71 introduced physics and chemistry into astronomy and led to cosmological conclusions of the utmost importance4 ,it was now made perfectly clear that matter is the same throughout the universe1 and that its physical and chemical properties in the most distant stars do not differ from those of the earth under our feet4 ,the monistic conviction1 which we thus arrived at1 of the physical and chemical unity of the entire cosmos is certainly one of the most valuable general truths which we owe to astrophysics1 the new branch of astronomy which is honorably associated with the name of ,friedrich ,zllner4 ,not less important is the clear knowledge we have obtained that the same laws of mechanical development that we have on the earth rule throughout the infinite universe4 ,a vast1 all-embracing metamorphosis goes on continuously in all parts of the universe1 just as it is found in the geological history of the earth2 it can be traced in the evolution of its living inhabitants as surely as in the history of peoples or in the life of each human individual4 ,in one part of space we perceive1 with the aid of our best telescopes1 vast nebul of glowing1 infinitely attenuated gas2 we see in them the embryos of heavenly bodies1 billions of miles away1 in the first stage of their development4 ,in some of these stellar embryos the chemical elements do not seem to be differentiated yet1 but still buried in the homogeneous primitive matter 7prothyl7 at an enormous temperature 7calculated to run into millions of degrees72 it is possible that the original basic substance 7vide p4 #bbi7 is not yet divided into ponderable and imponderable matter4 ,in other parts of space we find stars that have cooled down into glowing fluid1 and yet others that are cold and rigid2 we can tell their stage of evolution approximately by their color4 ,we find stars that are surrounded with rings and moons like ,saturn2 and we recognize in the luminous ring of the nebula the embryo of a new moon1 which has detached itself from the mother-planet1 just as the planet was released from the sun4 ,many of the stars1 the light of which has taken thousands of years to reach us1 are certainly suns like our own mother-sun1 and are girt about with planets and moons1 just as in our own solar system4 ,we are justified in supposing that thousands of these planets are in a similar stage of development to that of our earth--that is1 they have arrived at a period when the temperature at the surface lies between the freezing and boiling point of water1 and so permits the existence of water in its liquid condition4 ,that makes it possible that carbon has entered into the same complex combinations on those planets as it has done on our earth1 and that from its nitrogenous compounds protoplasm has been evolved--that wonderful substance which alone1 as far as our knowledge goes1 is the possessor of organic life4 ,the monera 7for instance1 chromacea and bacteria71 which consist only of this primitive protoplasm1 and which arise by spontaneous generation from these inorganic nitrocarbonates1 may thus have entered upon the same course of evolution on many other planets as on our own2 first of all1 living cells of the simplest character would be formed from their homogeneous protoplasmic body by the separation of an inner nucleus from the outer cell body 7cytostoma74 ,further1 the analogy that we find in the life of all cells--whether plasmodomous plant-cells or plasmophagous animal-cells--justifies the inference that the further course of organic evolution on these other planets has been analogous to that of our own earth--always1 of course1 given the same limits of temperature which permit water in a liquid form4 ,in the glowing liquid bodies of the stars1 where water can only exist in the form of steam1 and on the cold extinct suns1 where it can only be in the shape of ice1 such organic life as we know is impossible4 ,the similarity of phylogeny1 or the analogy of organic evolution1 which we may thus assume in many stars which are at the same stage of biogenetic development1 naturally opens out a wide field of brilliant speculation to the constructive imagination4 ,a favorite subject for such speculation has long been the question whether there are men1 or living beings like ourselves1 perhaps much more highly developed1 in other planets8 ,among the many works which have sought to answer the question1 those of ,camille ,flammarion1 the ,parisian astronomer1 have recently been extremely popular2 they are equally distinguished by exuberant imagination and brilliant style1 and by a deplorable lack of critical judgment and biological knowledge4 ,we may condense in the following thesis the present condition of our knowledge on the subject3 ,i4 ,it is very probable that a similar biogenetic process to that of our own earth is taking place on some of the other planets of our solar system 7,mars and ,venus71 and on many planets of other solar systems2 first simple monera are formed by spontaneous generation1 and from these arise unicellular protists 7first plasmodomous primitive plants1 and then plasmophagous primitive animals74 ,,ii4 ,it is very probable that from these unicellular protists arise1 in the further course of evolution1 first social cell-communities 7coenobia71 and subsequently tissue-forming plants and animals 7metaphyta and metazoa74 ,,iii4 ,it is also very probable that thallophyta 7alg and fungi7 were the first to appear in the plant-kingdom1 then diaphyta 7mosses and ferns71 finally anthophyta 7gymnosperm and angiosperm flowering plants74 ,,iv4 ,it is equally probable that the biogenetic process took a similar course in the animal kingdom--that from the blastads 7catallacta7 first gastrads were formed1 and from these lower animal forms 7coelenteria7 higher organisms 7coelomaria7 were afterwards evolved4 ,v4 ,on the other hand1 it is very questionable whether the different stems of these higher animals 7and those of the higher plants as well7 run through the same course of development on other planets as on our earth4 ,,vi4 ,in particular1 it is wholly uncertain whether there are vertebrates on other planets1 and whether1 in the course of their phyletic development1 taking millions of years1 mammals are formed as on earth1 reaching their highest point in the formation of man2 in such an event1 millions of changes would have to be just the same in both cases4 ,,vii4 ,it is much more probable1 on the contrary1 that other planets have produced other types of the higher plants and animals1 which are unknown on our earth2 perhaps from some higher animal stem1 which is superior to the vertebrate in formation1 higher beings have arisen who far transcend us earthly men in intelligence4 ,,viii4 ,the possibility of our ever entering into direct communication with such inhabitants of other planets seems to be excluded by the immense distance of our earth from the other heavenly bodies1 and the absence of the requisite atmosphere in the intervening space1 which contains only ether4 ,but while many of the stars are probably in a similar stage of biogenetic development to that of our earth 7for the last one hundred million years at least71 others have advanced far beyond this stage1 and1 in their planetary old age1 are hastening towards their end--the same end that inevitably awaits our own globe4 ,the radiation of heat into space gradually lowers the temperature until all the water is turned into ice2 that is the end of all organic life4 ,the substance of the rotating mass contracts more and more2 the rapidity of its motion gradually falls off4 ,the orbits of the planets and of their moons grow narrower4 ,at length the moons fall upon the planets1 and the planets are drawn into the sun that gave them birth4 ,the collision again produces an enormous quantity of heat4 ,the pulverized mass of the colliding bodies is distributed freely through infinite space1 and the eternal drama of sun-birth begins afresh4 ,the sublime picture which modern astrophysics thus unveils before the mind's eye shows us an eternal birth and death of countless heavenly bodies1 a periodic change from one to the other of the different cosmogenetic conditions1 which we observe side by side in the universe4 ,while the embryo of a new world is being formed from a nebula in one corner of the vast stage of the universe1 another has already condensed into a rotating sphere of liquid fire in some far distant spot2 a third has already cast off rings at its equator1 which round themselves into planets2 a fourth has become a vast sun whose planets have formed a secondary retinue of moons1 and so on4 ,and between them are floating about in space myriads of smaller bodies1 meteorites1 or shooting-stars1 which cross and recross the paths of the planets apparently like lawless vagabonds1 and of which a great number fall onto the planets every day4 ,thus there is a continuous but slow change in the velocities and the orbits of the revolving spheres4 ,the frozen moons fall onto the planets1 the planets onto their suns4 ,two distant suns1 perhaps already stark and cold1 rush together with inconceivable force and melt away into nebulous clouds4 ,and such prodigious heat is generated by the collision that the nebula is once more raised to incandescence1 and the old drama begins again4 ,yet in this perpetual motion the infinite substance of the universe1 the sum total of its matter and energy1 remains eternally unchanged1 and we have an eternal repetition in infinite time of the periodic dance of the worlds1 the metamorphosis of the cosmos that ever returns to its starting-point4 ,over all rules the law of substance4 ,,ii4--,,progress ,,of ,,geology ,the earth and its origin were much later than the heavens in becoming the object of scientific investigation4 ,the numerous ancient and modern cosmogonies do1 indeed1 profess to give us as good an insight into the origin of the earth as into that of the heavens2 but the mythological raiment1 in which all alike are clothed1 betrays their origin in poetic fancy4 ,among the countless legends of creation which we find in the history of religions and of thought there is one that soon took precedence of all the rest--the ,mosaic story of creation as told in the first book of the ,hexateuch4 ,it did not exist in its present form until long after the death of ,moses 7probably not until eight hundred years afterwards72 but its sources are much older1 and are to be found for the most part in ,assyrian1 ,babylonian1 and ,hindoo legends4 ,this ,hebrew legend of creation obtained its great influence through its adoption into the ,christian faith and its consecration as the ,word of ,god4 ,greek philosophers had already1 five hundred years before ,christ1 explained the natural origin of the earth in the same way as that of other cosmic bodies4 ,xenophanes of ,colophon had even recognized the true character of the fossils which were afterwards to prove of such moment2 the great painter1 ,leonardo da ,vinci1 of the fifteenth century1 also explained the fossils as the petrified remains of animals which had lived in earlier periods of the earth's history4 ,but the authority of the ,bible1 especially the myth of the deluge1 prevented any further progress in this direction1 and insured the triumph of the ,mosaic legend until about the middle of the last century4 ,it survives even at the present day among orthodox theologians4 ,however1 in the second half of the eighteenth century1 scientific inquiry into the structure of the crust of the earth set to work independently of the ,mosaic story1 and it soon led to certain conclusions as to the origin of the earth4 ,the founder of geology1 ,werner of ,freiberg1 thought that all the rocks were formed in water1 while ,voigt and ,hutton 7#aghh7 rightly contended that only the stratified1 fossil-bearing rocks had had an aquatic origin1 and that the ,vulcanic or ,plutonic mountain ranges had been formed by the cooling down of molten matter4 ,the heated conflict of these ,neptunian and ,plutonic schools was still going on during the first three decades of the present century2 it was only settled when ,karl ,hoff 7#ahbb7 established the principle of actualism1 and ,sir ,charles ,lyell applied it with signal success to the entire natural evolution of the earth4 ,the ,principles of ,geology of ,lyell 7#ahcj7 secured the full recognition of the supremely important theory of continuity in the formation of the earth's crust1 as opposed to the catastrophic theory of ,cuvier4#cd ,palontology1 which had been founded by ,cuvier's work on fossil bones 7#ahab71 was of the greatest service to geology2 by the middle of the present century it had advanced so far that the chief periods in the history of the earth and its inhabitants could be established4 ,the comparatively thin crust of the earth was now recognized with certainty to be the hard surface formed by the cooling of an incandescent fluid planet1 which still continues its slow1 unbroken course of refrigeration and condensation4 ,the crumpling of the stiffened crust1 the reaction of the molten fiery contents on the cool surface1 and especially the unceasing geological action of water1 are the natural causes which are daily at work in the secular formation of the crust of the earth and its mountains4 ,to the brilliant progress of modern geology we owe three extremely important results of general import4 ,in the first place1 it has excluded from the story of the earth all questions of miracle1 all questions of supernatural agencies1 in the building of the mountains and the shaping of the continents4 ,in the second place1 our idea of the length of the vast period of time which had been absorbed in their formation has been considerably enlarged4 ,we now know that the huge mountains of the palozoic1 mesozoic1 and cenozoic formations have taken1 not thousands1 but millions of years in their growth4 ,in the third place1 we now know that all the countless fossils that are found in those formations are not sports of nature1 as was believed one hundred and fifty years ago1 but the petrified remains of organisms that lived in earlier periods of the earth's history1 and arose by gradual transformation from a long series of ancestors4 ,,iii4--,,progress ,,of ,,physics ,,and ,,chemistry ,the many important discoveries which these fundamental sciences have made during the nineteenth century are so well known1 and their practical application in every branch of modern life is so obvious1 that we need not discuss them in detail here4 ,in particular1 the application of steam and electricity has given to our nineteenth century its characteristic machinist-stamp4 ,but the colossal progress of inorganic and organic chemistry is not less important4 ,all branches of modern civilization--medicine and technology1 industry and agriculture1 mining and forestry1 land and water transport--have been so much improved in the course of the century1 especially in the second half1 that our ancestors of the eighteenth century would find themselves in a new world1 could they return4 ,but more valuable and important still is the great theoretical expansion of our knowledge of nature1 which we owe to the establishment of the law of substance4 ,once ,lavoisier 7#aghi7 had established the law of the persistence of matter1 and ,dalton 7#ahjh7 had founded his new atomic theory with its assistance1 a way was open to modern chemistry along which it has advanced with a rapidity and success beyond all anticipation4 ,the same must be said of physics in respect of the law of the conservation of energy4 ,its discovery by ,robert ,mayer 7#ahdb7 and ,hermann ,helmholtz 7#ahdg7 inaugurated for this science also a new epoch of the most fruitful development2 for it put physics in a position to grasp the universal unity of the forces of nature and the eternal play of natural processes1 in which one force may be converted into another at any moment4 ,,iv4--,,progress ,,of ,,biology ,the great discoveries which astronomy and geology have made during the nineteenth century1 and which are of extreme importance to our whole system1 are1 nevertheless1 far surpassed by those of biology4 ,indeed1 we may say that the greater part of the many branches which this comprehensive science of organic life has recently produced have seen the light in the course of the present century4 ,as we saw in the first section1 during the century all branches of anatomy and physiology1 botany and zoology1 ontogeny and phylogeny1 have been so marvellously enriched by countless discoveries that the present condition of biological science is immeasurably superior to its condition a hundred years ago4 ,that applies first of all quantitatively to the colossal growth of our positive information in all those provinces and their several parts4 ,but it applies with even greater force qualitatively to the deepening of our comprehension of biological phenomena1 and our knowledge of their efficient causes4 ,in this ,charles ,darwin 7#ahei7 takes the palm of victory2 by his theory of selection he has solved the great problem of organic creation1 of the natural origin of the countless forms of life by gradual transformation4 ,it is true that ,lamarck had recognized fifty years earlier that the mode of this transformation lay in the reciprocal action of heredity and adaptation4 ,however1 ,lamarck was hampered by his lack of the principle of selection1 and of that deeper insight into the true nature of organization which was only rendered possible after the founding of the theory of evolution and the cellular theory4 ,when we collated the results of these and other disciplines1 and found the key to their harmonious interpretation in the ancestral development of living beings1 we succeeded in establishing the monistic biology1 the principles of which ,i have endeavored to lay down securely in my ,general ,morphology4 ,v4--,,progress ,,of ,,anthropology ,in a certain sense1 the true science of man1 rational anthropology1 takes precedence of every other science4 ,the saying of the ancient sage1 ,man1 know thyself1 and that other famous maxim1 ,man is the measure of all things1 have been accepted and applied from all time4 ,and yet this science--taking it in its widest sense--has languished longer than all other sciences in the fetters of tradition and superstition4 ,we saw in the first section how slowly and how late the science of the human organism was developed4 ,one of its chief branches--embryology--was not firmly established until #ahbh 7by ,baer71 and another1 of equal importance--the cellular theory--until #ahch 7by ,schwann74 ,and it was even later still when the answer was given to the question of all questions1 the great riddle of the origin of man4 ,although ,lamarck had pointed out the only path to a correct solution of it in #ahji1 and had affirmed the descent of man from the ape1 it fell to ,darwin to establish the affirmation securely fifty years afterwards1 and to ,huxley to collect the most important proofs of it in #ahfc1 in his ,place of ,man in ,nature4 ,i have myself made the first attempt1 in my ,anthropogeny 7#ahgd71 to present in their historical connection the entire series of ancestors through which our race has been slowly evolved from the animal kingdom in the course of many millions of years4 ,,conclusion ,the number of world-riddles has been continually diminishing in the course of the nineteenth century through the aforesaid progress of a true knowledge of nature4 ,only one comprehensive riddle of the universe now remains--the problem of substance4 ,what is the real character of this mighty world-wonder that the realistic scientist calls ,nature or the ,universe1 the idealist philosopher calls ,substance or the ,cosmos1 the pious believer calls ,creator or ,god8 ,can we affirm to-day that the marvellous progress of modern cosmology has solved this problem of substance1 or at least that it has brought us nearer to the solution8 ,the answer to this final question naturally varies considerably according to the stand-point of the philosophic inquirer and his empirical acquaintance with the real world4 ,we grant at once that the innermost character of nature is just as little understood by us as it was by ,anaximander and ,empedocles twenty-four hundred years ago1 by ,spinoza and ,newton two hundred years ago1 and by ,kant and ,goethe one hundred years ago4 ,we must even grant that this essence of substance becomes more mysterious and enigmatic the deeper we penetrate into the knowledge of its attributes1 matter and energy1 and the more thoroughly we study its countless phenomenal forms and their evolution4 ,we do not know the thing in itself that lies behind these knowable phenomena4 ,but why trouble about this enigmatic thing in itself when we have no means of investigating it1 when we do not even clearly know whether it exists or not8 ,let us1 then1 leave the fruitless brooding over this ideal phantom to the pure metaphysician1 and let us instead1 as real physicists1 rejoice in the immense progress which has been actually made by our monistic philosophy of nature4 ,towering above all the achievements and discoveries of the century we have the great1 comprehensive law of substance1 the fundamental law of the constancy of matter and force4 ,the fact that substance is everywhere subject to eternal movement and transformation gives it the character also of the universal law of evolution4 ,as this supreme law has been firmly established1 and all others are subordinate to it1 we arrive at a conviction of the universal unity of nature and the eternal validity of its laws4 ,from the gloomy problem of substance we have evolved the clear law of substance4 ,the monism of the cosmos which we establish thereon proclaims the absolute dominion of the great eternal iron laws throughout the universe4 ,it thus shatters1 at the same time1 the three central dogmas of the dualistic philosophy--the personality of ,god1 the immortality of the soul1 and the freedom of the will4 ,many of us certainly view with sharp regret1 or even with a profound sorrow1 the death of the gods that were so much to our parents and ancestors4 ,we must console ourselves in the words of the poet3 ,the times are changed1 old systems fall1 ,and new life o'er their ruins dawns4 ,the older view of idealistic dualism is breaking up with all its mystic and anthropistic dogmas2 but upon the vast field of ruins rises1 majestic and brilliant1 the new sun of our realistic monism1 which reveals to us the wonderful temple of nature in all its beauty4 ,in the sincere cult of the true1 the good1 and the beautiful1 which is the heart of our new monistic religion1 we find ample compensation for the anthropistic ideals of ,god1 freedom1 and immortality which we have lost4 ,throughout this discussion of the riddles of the universe ,i have clearly defined my consistent monistic position and its opposition to the still prevalent dualistic theory4 ,in this ,i am supported by the agreement of nearly all modern scientists who have the courage to accept a rounded philosophical system4 ,i must not1 however1 take leave of my readers without pointing out in a conciliatory way that this strenuous opposition may be toned down to a certain degree on clear and logical reflection--may1 indeed1 even be converted into a friendly harmony4 ,in a thoroughly logical mind1 applying the highest principles with equal force in the entire field of the cosmos--in both organic and inorganic nature--the antithetical positions of theism and pantheism1 vitalism and mechanism1 approach until they touch each other4 ,unfortunately1 consecutive thought is a rare phenomenon in nature4 ,the great majority of philosophers are content to grasp with the right hand the pure knowledge that is built on experience1 but they will not part with the mystic faith based on revelation1 to which they cling with the left4 ,the best type of this contradictory dualism is the conflict of pure and practical reason in the critical philosophy of the most famous of modern thinkers1 ,immanuel ,kant4 ,on the other hand1 the number is always small of the thinkers who will boldly reject dualism and embrace pure monism4 ,that is equally true of consistent idealists and theists1 and of logical realists and pantheists4 ,however1 the reconciliation of these apparent antitheses1 and1 consequently1 the advance towards the solution of the fundamental riddle of the universe1 is brought nearer to us every year in the ever-increasing growth of our knowledge of nature4 ,we may1 therefore1 express a hope that the approaching twentieth century will complete the task of resolving the antitheses1 and1 by the construction of a system of pure monism1 spread far and wide the long-desired unity of world-conception4 ,germany's greatest thinker and poet1 whose one hundred and fiftieth anniversary will soon be upon us--,wolfgang ,goethe--gave this philosophy of unity a perfect poetic expression1 at the very beginning of the century1 in his immortal poems1 ,faust1 ,prometheus1 and ,god and the ,world3 ,by eternal laws ,of iron ruled1 ,must all fulfil ,the cycle of ,their destiny4 ,,footnotes3 #a ,there are two ,english translations1 ,the ,evolution of ,man 7#ahgi7 and ,the ,pedigree of ,man 7#ahhj74 #b ,the ,english translation1 by ,dr4 ,hans ,gadow1 bears the title of ,the ,last ,link4 #c ,english translation1 by ,j4 ,gilchrist1 with the title of ,monism4 #d ,e4 ,haeckel1 ,systematische ,phylogenie1 #ahie1 vol4 iii41 pp4 #fdf-ej4 7,anthropolatry means ,a divine worship of human nature47 #e ,cf4 my ,cambridge lecture1 ,the ,last ,link1 ,geological ,time and ,evolution4 #f ,as to induction and deduction1 vide ,the ,natural ,history of ,creation4 #g ,rudolph ,virchow1 ,die ,grndung der ,berliner ,universitt und der ,uebergang aus dem ,philosophischen in das naturwissenschaftliche ,zeitalter4 7,berlin2 #ahic47 #h ,cf4 chap4 iv4 of my ,general ,morphology1 #ahff2 ,kritik der naturwissenschaftlichen ,methoden4 #i ,systematische ,phylogenie1 #ahif1 part iii41 pp4 #dij1 #did1 and #dif4 #aj ,translated in the ,international ,science ,series1 #ahgb4 #aa ,zell-,seelen und ,seelen-,zellen4 ,ernst ,haeckel1 ,gesammelte populre ,vortrge4 ,i4 ,heft4 #ahgh4 #ab ,cf4 ,e4 ,haeckel1 ,the ,systems of ,darwin1 ,goethe1 and ,lamarck4 ,lecture given at ,eisenach in #ahhb4 #ac ,vide the translation of ,dr4 ,hans ,gadow3 ,the ,last ,link4 7,a4 ,c4 ,black47 #ad ,cf4 ,max ,verworn1 ,psychophysiologische ,protisten-,studien1 pp4 #ace1 #adj4 #ae ,e4 ,haeckel1 ,general ,natural ,history of the ,radiolaria2 #ahhg4 #af ,vide ,natural ,history of ,creation1 ,e4 ,haeckel4 #ag ,law of individual variation4 ,vide ,natural ,history of ,creation4 #ah ,cf4 ,e4 ,haeckel1 ,systematic ,phylogeny1 vol4 i4 #ai ,cf4 ,anthropogeny and ,natural ,history of ,creation4 #bj ,cf4 ,natural ,history of ,creation4 #ba ,see chaps4 xvi4 and xvii4 of my ,anthropogeny4 #bb ,e4 ,haeckel1 ,a ,visit to ,ceylon4 #bc ,cf4 ,monism1 by ,ernst ,haeckel4 #bd ,cf4 ,monism1 by ,ernst ,haeckel4 #be ,cf4 ,monism1 by ,ernst ,haeckel4 #bf ,reinke1 ,die ,welt als ,that 7#ahii74 #bg ,cf4 ,monism1 by ,ernst ,haeckel4 #bh ,the ,last ,link1 translated by ,dr4 ,gadow4 #bi ,general ,morphology1 book #b1 chap4 v4 #cj ,cf4 ,general ,morphology1 vol4 ii41 and ,the ,natural ,history of ,creation4 #ca ,vide ,a ,visit to ,ceylon1 ,e4 ,haeckel1 translated by ,c4 ,bell4 #cb ,collected ,popular ,lectures2 ,bonn1 #ahgh4 #cc ,as to the ,greek paternity of ,christ1 vide p4 #cbh4 #cd ,cf4 ,the ,natural ,history of ,creation1 chaps4 iii41 vi41 xv41 and xvi4 ,,index ,abiogenesis1 #beg1 #cfi4 ,abortive organs1 #bfd4 ,accidents1 #baf4 ,acrania1 #aff4 ,action at a distance1 #bag4 ,actualism1 #bdi4 sthesis1 #bbe4 ,affinity1 #bbd4 ,altruism1 #cej4 ,amphibia1 #afg4 ,amphimixis1 #ada4 ,ampitheism1 #bgh4 ,ananke1 #bgb4 ,anatomy1 #bb1 etc4 comparative1 #bd4 ,anaximander1 #bhi1 #cgi4 ,anthropism1 #aa4 ,anthropistic illusion1 #ad1 etc4 world-theory1 #ac4 ,anthropocentric dogma1 #aa1 etc4 ,anthropogeny1 #hc4 ,anthropolatric dogma1 #ab4 ,anthropomorpha1 #cf4 ,anthropomorphic dogma1 #ab4 ,apes1 #cf1 #cg1 #afg4 anthropoid1 #cg4 ,archus1 #dc4 ,archigony1 #beg4 ,aristotle1 #bc1 #bfh4 ,association1 centres of1 #ahc4 of ideas1 #aba4 of presentations1 #aba1 #abb4 ,astronomy1 progress of1 #cff4 ,astro-physics1 #cfh4 ,atavism1 #adb4 ,athanatism1 #ahi4 ,athanatistic illusions1 #bje4 ,atheism1 #bij4 ,atheistic science1 #bfj4 ,atom1 the1 #bbb4 ,atomism1 #bbc4 ,atomistic consciousness1 #ahg4 ,attributes of ether1 #bbg4 of substance1 #baf4 ,augustine of ,hippo1 #acj4 ,auricular confession1 #cai1 #cei4 ,autogony1 #beg4 ,baer 7,carl ,ernst71 #eg4 ,bastian 7,adolf71 #ajc4 ,beginning of the world1 #bdj1 #bdg4 ,bible1 the1 #bhb1 #cfb4 ,biogenesis1 #beg4 ,biogenetic law1 #ha1 #adc4 ,bismarck1 #ccd4 ,blastoderm1 #aej1 #aee4 ,blastosphere1 #aec4 ,blastula1 #aec4 ,bruno 7,giordano71 #bij1 #cag4 ,bchner 7,ludwig71 #ic4 ,buddhism1 #cbf1 #cee4 ,calvin1 #acj4 ,canonical gospels1 #cab4 ,carbon as creator1 #bef4 theory1 #beg4 ,catarrhin1 #ce4 ,catastrophic theory1 #gd4 ,categorical imperative1 #cej4 ,causes1 efficient1 #beh4 final1 #beh4 ,celibacy1 #ceh4 ,cell-love1 #acg4 community1 soul of the1 #aee4 soul1 #aea4 state1 #aeg4 ,cellular pathology1 #ej4 physiology1 #dh4 psychology1 #aec1 #agg4 theory1 #bf4 ,cenobitic soul1 #aee4 ,cenogenesis1 #hb4 of the psyche1 #add4 ,chance1 #bgd4 ,chemicotropism1 #fd1 #acf4 ,chordula1 #fd4 ,chorion1 #fh4 ,christ1 father of1 #cbg4 ,christian art1 #cci4 civilization1 #cef4 contempt of the body1 #ced4 animals1 #cee4 nature1 #cee4 self1 #cec4 the family1 #ceg4 woman1 #ceh4 ethics1 #ceb4 ,christianity1 #cdg4 ,church and school1 #cfb4 state1 #cfa4 ,cnidaria1 #afa4 ,conception1 #fd4 ,concubinage of the clergy1 #ceh4 ,confession of faith1 #cjb4 ,consciousness1 #agj4 animal1 #agf4 atomistic1 #agh4 biological1 #agf4 cellular1 #agg4 development of1 #ahe4 dualistic1 #ahb4 human1 #agc4 monistic1 #ahb4 neurological1 #agd4 ontogeny of1 #ahf4 pathology of1 #ahb4 physiological1 #ahj4 transcendental1 #ahj4 ,constancy of energy1 #bab1 #bca4 matter1 #bab4 ,constantine the ,great1 #caf4 ,constellations of substance1 #bah4 ,conventional lies1 #cbc4 ,copernicus1 #bd1 #cbj1 #cfg4 ,cosmic immortality1 #aia4 ,cosmogonies1 #bcd4 ,cosmological dualism1 #beg4 creationism1 #bce4 law1 #baa4 perspective1 #ad4 ,cosmos1 the1 #bbi4 ,creation1 #gc1 #gi1 #bcd4 cosmological1 #bce4 dualistic1 #bcf4 heptameral1 #bcg4 individual1 #bcg4 myths of1 #bcf4 periodic1 #bcg4 trialistic1 #bcg4 ,cultur-kampf1 #ccd4 ,cuvier1 #gd4 ,cyclostomata1 #afg4 ,cynopitheci1 #df4 ,cytology1 #bf1 etc4 ,cytopsyche1 #aea4 ,cytula1 #fd4 ,darwin 7,charles71 #gh1 etc4 ,decidua1 #fi4 ,deduction1 #af4 ,demonism1 #bgf4 ,descartes1 #ii1 #cee4 ,descent of the ape1 #he1 etc4 of man1 #hg4 theory of1 #gg4 ,design1 #bfd1 #bff4 in nature1 #bfj4 in organisms1 #bff4 in selection1 #bfa4 ,destruction of heavenly bodies1 #bdc4 ,determinists1 #acj4 ,diaphragm1 #ca4 ,division of labor in matter1 #bbi4 ,draper1 #cji1 #ccc4 ,dualism1 #bj1 etc4 ,du ,bois-,reymond1 #ae #ahj1 #bce4 ,du ,prel 7,carl71 #cje4 ,duty1 feeling of1 #cej4 ,dynamodes1 #baf4 ,dysteleology1 #bfj4 ,echinodermata1 #fb4 ,ectoderm1 #afj4 sense-cells in the1 #bic4 ,egoism1 #cej4 ,elements1 chemical1 #bbb4 system of the1 #bbb4 ,embryo1 human1 #fd4 ,embryology1 #ed4 ,embryonic psychogeny1 #add4 sleep1 #adf4 ,empedocles1 #bc1 #bbd4 ,encyclica 7of ,pius ,,ix471 #cbc4 ,end of the world1 #bdg4 ,energy1 kinetic1 #bca4 potential1 #bca4 principle of1 #bcj4 specific1 #bid4 ,entelecheia1 #bfh4 ,entoderm1 #afj4 ,entropy of the universe1 #bdg4 ,epigenesis1 #ef1 #acc4 ,ergonomy of matter1 #bbi4 ,eternity of the world1 #bdb4 ,ether1 #bbe4 ,etheric souls1 #aii4 ,ethics1 fundamental law of1 #cej4 ,evolution1 theory of1 #ed1 #bci1 #bdc4 chief element in1 #bfg4 ,experience1 #af4 ,extra-mundane ,god1 #bhh4 ,faith1 confession of1 #cjc4 of our fathers1 #cjd4 ,family1 the1 and ,christianity1 #ceg4 ,fate1 #bgb4 ,fechner1 #ig1 etc4 ,fecundation1 #fc4 ,fetishism1 #bgf4 ,feuerbach 7,ludwig71 #bie4 ,flechsig1 #ahc4 ,foetal membranes1 #ff4 ,folk-psychology1 #ajc4 ,forces1 conversion of1 #bca4 ,frederick the ,great1 #aid1 #cae4 ,galen1 #bc1 #dj4 ,gaseous souls1 #aii4 vertebrates1 #bhh4 ,gastra1 #afj4 theory of the1 #fj4 ,gastrads1 #aei4 ,gastrula1 #fa4 ,gegenbaur1 #be1 #cj4 ,generation1 theory of1 #ee4 ,genus1 #gc4 ,geology1 periods of1 #bgj4 progress of1 #cgc4 ,germinal disk1 #eg4 ,gills1 #fe4 ,god1 #bge4 the father1 #bgg4 the son1 #bgg1 #cbh4 ,goethe1 #bj1 etc4 ,goethe's monism1 #cca4 ,golden ,rule1 the1 #cea4 ,gospels1 #cab4 ,gravitation1 theory of1 #bag4 ,gut-layer1 #aei4 ,haller1 #db4 ,harvey1 #db4 ,helmholtz 7,hermann71 #bac1 #bcj4 ,heredity1 psychic1 #ach4 ,hertz 7,heinrich71 #bbe4 ,hippocrates1 #bc4 ,histology1 #bf4 ,histopsyche1 #aef4 ,hoff 7,carl71 #bej4 ,holbach 7,paul71 #aic4 ,holy ,ghost1 #bgg1 #cbf4 ,humboldt 7,alexander71 #cdc4 ,hydra1 #afa4 ,hylozoism1 #bhi4 ,hypothesis1 #bii4 ,iatrochemicists1 #de4 ,iatromechanicists1 #de4 ,ideal of beauty1 #cch4 of truth1 #ccg4 of virtue1 #cci4 ,ignorabimus1 #ahj4 ,immaculate conception1 #cbf4 ,immaterial substance1 #bba4 ,immortality of animals1 #bja4 of the human soul1 #ahh4 of unicellular organisms1 #aij4 personal1 #aib4 ,imperfection of nature1 #bfd4 ,imponderable matter1 #bbe4 ,impregnation1 #fd4 ,indeterminists1 #acj4 ,induction1 #af4 ,indulgences1 #cei4 ,infallibility of the pope1 #cbd4 ,instinct1 #aje1 #abc4 ,intellect1 #abe1 etc4 ,intramundane ,god1 #bhh4 ,introspective psychology1 #ie4 ,islam1 #bhd4 ,janssen 7,johannes71 #caf4 ,jehovah1 #bhc4 ,journeys on foot1 #cfd4 ,kant1 #beh1 etc4 ,kant's metamorphosis1 #ib1 etc4 ,kinetic energy1 #bca4 theory of substance1 #baf4 ,klliker1 #bf1 #dh4 ,lamarck1 #gf1 etc4 ,lamettrie1 #aid4 ,landscape-painting1 #cdc4 ,language1 #abf4 study of1 #cfc4 ,last judgment1 #bji4 ,lavoisier1 #bab4 ,leap of the gospels1 miraculous1 #cab4 ,leydig1 #bg4 ,life1 definition of1 #ci4 ,limits of our knowledge1 #ahb4 ,love1 #ceg4 of animals1 #cee4 of neighbor1 #cej4 of self1 #cej4 ,lucretius ,carus1 #bij4 ,lunarism1 #bha4 ,luther1 #cbj4 ,lyell1 #gg1 #bej4 ,madonna1 cult of the1 #bhd1 #cbg4 ,malphigi1 #ed4 ,mammals1 #cj1 etc4 ,mammary glands1 #ca4 ,man1 ancestors of1 #hb4 ,marsupials1 #cb1 #hf4 ,mass1 #bbb4 ,materialism1 #bj4 ,mayer 7,robert71 #bac1 #cgg4 ,mechanical causality1 #cff4 explanation1 #bei4 theory of heat1 #bdg4 ,mechanicism1 #bei4 ,mediterranean religions1 the1 #bhb4 ,memory1 cellular1 #ab,o4 conscious1 #aba4 histionic1 #aba4 unconscious1 #aba4 ,mephistopheles1 #bgi4 ,metabolism1 #bcb4 ,metamorphoses of the cosmos1 #cgb4 of philosophers1 #ib4 ,metaphyta1 #aef4 ,metasitism1 #aec4 ,metazoa1 #fj1 #aeg4 ,middle ,ages1 #cae1 #ceh4 ,mixotheism1 #bhf4 ,mohammedanism1 #bhd4 ,mohr 7,friedrich71 #bac4 ,monera1 #beg1 #cfi4 ,monism1 #bj1 and passim4 of energy1 #bed4 of ,spinoza1 #cca4 of the cosmos1 #bee4 ,monistic anthropogeny1 #beb4 art1 #cda4 biogeny1 #bea4 churches1 #cde4 cosmology1 #cfh4 ethics1 #cdg4 geogeny1 #bdh4 ,monotheism1 #bgi4 ,monotrema1 #cb4 ,moon-worship1 #bha4 ,moral order of the universe1 #bfi4 ,morula1 #aee4 ,mosaism1 #bhc4 ,mller 7,johannes71 #be1 #de1 #bfb4 ,mythology of the soul1 #ace4 ,natural religion1 #cdd4 ,navel-cord1 #fi4 ,neokantians1 #cdi4 ,neovitalism1 #bfd4 ,neptunian geology1 #cge4 ,neuro-muscular cells1 #aad4 ,neuroplasm1 #ia1 #aji4 ,neuropsyche1 #afb4 ,nomocracy1 #i4 ,ontogenetic psychology1 #ajc4 ,ontological creationism1 #bce4 methods1 #bdi4 ,orbits of the heavenly bodies1 #bda4 ,origin of movement1 #ae1 #bda4 of feeling1 #ae1 #bda4 ,ovary1 #fc4 ,palingenesis1 #hb4 of the psyche1 #adc4 ,pandera 7the father of ,christ71 #cbh4 ,pantheism1 #bhh4 ,papacy1 #cad4 ,papal ethics1 #cei4 ,papiomorpha1 #cg4 ,paul1 #cac1 #ceg4 epistles of1 #cab4 ,paulinism1 #cac4 ,pedicle of the allantois1 #fi4 ,perpetual motion1 #bde4 ,persistence of force1 #bab1 #bca4 of matter1 #bab4 ,phroneta1 #bic4 ,phylogeny1 #ga1 #ha4 of the apes1 #ea4 systematic1 #ha4 ,physiology1 #ci4 ,phytopsyche1 #aeg4 ,pithecanthropus1 #hg4 ,pithecoid theory1 #hb1 etc4 ,pithecometra-thesis1 #fi1 #he4 ,placenta1 #cb1 #fh4 ,placentals1 #cb1 #hf4 ,plasmodoma1 #aec4 ,plasmogony1 #beg4 ,plasmophaga1 #aed4 ,plato1 #ii1 #aig4 ,plato's theory of ideas1 #bfi4 ,platodaria1 #afj4 ,platodes1 #afj4 ,platyrrhin1 #ce4 ,pneuma zoticon1 #dj4 ,polytheism1 #bgf4 ,ponderable matter1 #bbb4 ,preformation theory1 #ed4 ,primaria1 #cc4 ,primates1 #cc1 #hf4 ,primitive ,christianity1 #caa4 gut1 #fa1 #afa4 ,prodynamis1 #baf4 ,progaster1 #afa4 ,proplacentals1 #he4 ,prosimi1 #cd4 ,prostoma1 #afa4 ,prothyl1 #bbc4 ,protoplasm1 #ij4 ,protozoa1 #fj4 ,provertebr1 #aff4 ,pseudo-,christianity1 #cba4 ,psychade theory1 #agh4 ,psyche1 #hh4 ,psychogeny1 #ace4 phyletic1 #adi4 post-embryonic1 #adf4 ,psychology1 #hh et seqq4 ontogenetic1 #ajd4 phylogenetic1 #ajd4 ,psychomonism1 #bbf4 ,psychophysics1 #ig4 ,psychoplasm1 #ia1 #aaj4 ,pupa1 sleep of the1 #adf4 ,pyknosis1 #bah4 ,pyknotic theory of substance1 #bah4 ,reason1 #ag1 #abe4 ,reflex action1 #aab4 arches1 #aad4 ,reformation1 the1 #cai4 ,religion a private concern1 #cfa4 ,remak1 #eh4 ,revelation1 #cjf4 ,reversion1 #adb4 ,romance of the ,virgin ,mary1 #cbg4 ,romanes1 #ajf4 ,rudimentary organs1 #bfd4 ,saints1 #bhd4 ,scale of emotion1 #abg4 of memory1 #abj4 of movement1 #aaa4 of presentation1 #aah4 of reason1 #abb4 of reflex action1 #aac4 of will1 #abg4 ,scatulation theory1 #ee4 ,schleiden1 #bf1 #dg4 ,school1 and ,church1 #cfa4 and ,state1 #cfb4 reform of the1 #cfc4 ,schwann1 #bf1 #dg4 ,selachii1 #aff4 ,selection1 theory of1 #gi4 ,self-consciousness1 #aga4 ,sense-knowledge1 #big4 organs1 #bic4 ,senses1 philosophy of the1 #bie4 ,sentiment1 #ag1 etc41 #cca4 ,siebold1 #bg4 ,simi1 #cd4 ,social duties1 #cea4 instincts1 #cej4 ,solar systems1 #bda1 #cfi4 ,solarism1 #bhj4 ,soul1 #hh et seqq4 apparatus of the1 #afb4 blending of the1 #ada4 creation of the1 #ace4 division of the1 #ace4 etheric1 #aii4 gaseous1 #aii4 histionic1 #aeg4 history of the1 #afg4 hydra1 #afa4 life of the1 #ij4 liquid1 #bjj4 mammal1 #afg4 nerve1 #afb4 origin of the1 #ace4 of the plant1 #aeg4 personal1 #afb4 solid1 #bja4 substance of the1 #aih4 transmigration of the1 #ace4 ,sources of knowledge1 #bic4 ,space and time1 #bdd4 infinity of1 #bdb4 reality of1 #bdd4 ,species1 #gc4 ,spectral analysis1 #bda4 ,spermarium1 #fc4 ,spermatozoa1 #eh4 ,spinal cord1 #afe4 ,spinoza1 #ba1 #bae1 #bij4 ,spirit world1 #bba4 ,spirit-rapping1 #cje4 ,spiritism1 #cjd4 ,spiritualism1 #bj4 ,sponge1 soul of the1 #afa4 ,stem-cell1 #fc1 #ach1 #aea4 ,stimulated movement1 #aac1 #aaf4 ,stimuli1 conduction of1 #aeh4 ,strauss 7,david71 #cji1 #cac4 ,struggle for life1 #bgj4 ,substance1 #bae4 law of1 #baa1 etc4 structure of1 #bbi4 ,superstition1 #cja4 ,sss 7,edward71 #bej4 ,syllabus1 #cbc4 ,synodikon 7of ,pappus71 #cab4 ,table-turning1 #cje4 ,teleological explanation1 #bei4 ,teleology1 #beh4 ,tetrapoda1 #bi4 ,thanatism1 #ahi4 primary1 #aib4 secondary1 #aib4 ,theism1 #bgf4 ,theocracy1 #i4 ,theory1 #bii4 ,thought1 organs of1 #abf1 #ahc1 #bic4 ,time and space1 #bdd4 reality of1 #bdf4 ,tissue1 theory of1 #bf4 ,tissue-forming animals1 #aeg4 plants1 #aef4 ,transformism1 #gf4 ,trimurti1 #bgh4 ,trinity1 dogma of the1 #bgg4 monistic1 #ccf4 ,triplotheism1 #bgg4 ,tropesis1 #bbe4 ,tropismata1 #abh4 ,tunicata1 #afe4 ,turbellaria1 #afa4 ,ultramontanism1 #caj4 ,understanding1 #abe4 ,unity of natural forces1 #bca4 of substance1 #bad4 ,universum perpetuum mobile1 #bde4 ,uterus1 #cd4 ,vaticanism1 #cad4 ,vertebrates1 #bg1 passim4 ,verworn 7,max71 #dh1 #aaf4 ,vesalius1 #bd4 ,vibration1 theory of1 #baf4 ,virchow1 #bf1 #ej4 ,virchow's metamorphosis1 #ic4 ,vital force1 #db1 #bfb4 ,vitalism1 #dc1 #bfb4 ,vivisection1 #da4 ,vogt 7,carl71 #ic4 ,vogt 7,j4,e471 #bah4 ,water-color drawing1 #cfd4 ,weismann1 #aij4 ,will1 liberty of the1 #abi4 scale of the1 #abh4 ,wolff 7,c4,f471 #ef4 ,woman and ,christianity1 #ceh4 ,world-consciousness1 #aga4 ,world-riddles1 number of1 #ae4 ,wundt 7,wilhelm71 #ajj1 #aga4 ,,the ,,end ,transcriber's notes3 ,the following is a list of changes made to the original4 ,the first line is the original line1 the second the corrected one4 7#ab7 ,consequently1 the so-called history of the world 7#ab7 ,consequently1 the so-called history of the world structure of the primates forces us to distingiush two structure of the primates forces us to distinguish two of the geneaology of our race2 for man bears all the of the genealogy of our race2 for man bears all the world of which we have direct and certain cognizanze world of which we have direct and certain cognizance the law of substance by ,robert ,mayer and ,helmholz the law of substance by ,robert ,mayer and ,helmholtz ,the more impotant of these works we owe to ,romanes ,the more important of these works we owe to ,romanes ,formerly assistant and pupil of ,helmholz1 ,wundt had early ,formerly assistant and pupil of ,helmholtz1 ,wundt had early all other viviporous animals1 precisely because the complete all other viviparous animals1 precisely because the complete recent students of the protists1 afford conlcusive evidence recent students of the protists1 afford conclusive evidence a thinker is very striking2 in explaning it1 it is not a thinker is very striking2 in explaining it1 it is not have no individuals and no generations in the matazoic sense4 have no individuals and no generations in the metazoic sense4 in his ,species and ,studies in his eighty-fouth year in his ,species and ,studies in his eighty-fourth year ,chief ,forms of ,theism--,polytheism--,tritheism--,ampit heism ,chief ,forms of ,theism--,polytheism--,triplotheism--,am phitheism faith1 and that all these insiduous institutions are faith1 and that all these insidious institutions are nor in the narnow prisons of our jail-like schools1 nor in the narrow prisons of our jail-like schools1 ,and it was done in many1 and sometimes very romatic1 ways4 ,and it was done in many1 and sometimes very romantic1 ways4