(5dmu'(zt 
 
FREEDOM IN SCIENCE AND 
 TEACHING. 
 
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 Boston Library Consortium IVIember Libraries 
 
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FREEDOM 
 
 IN 
 
 SCIENCE AND TEACHING. 
 
 FROM THE GEKMAN OF 
 
 ERNST HAECKEL. 
 
 WITH A PREFATORY NOTE 
 
 By T. H. HUXLEY, F. R. S. 
 
 Der Teleolog. 
 " Welche Verehruag verdient der Weltenschopfer, der gjadig. 
 Als er den Korkbaum schuf, gleich aucli die Stopfel erfand." 
 
 Xenien. 
 
 NEW YORK: 
 D, APPLETON AND COMPANY, 
 
 549 AND 551 BROADWAY. 
 1879. 
 
 BOSTON COLLEGE LIBRARY 
 _^ gHESTIsiyT HILL, MASS^ 
 

 n 
 
PREFATORY NOTE. 
 
 In complying with the wish of the publishers of Pro- 
 fessor Haeckel's reply to Professor Virchow, that I 
 should furnish a prefatory note expressing my own 
 opinion in respect of the subject-matter of the contro- 
 versy, Gay's homely lines, prophetic of the fate of 
 those " who in quarrels interpose," emerge from some 
 brain- cupboard in which they have been hidden since 
 my childish days. In fact, the hard-hitting with 
 which both the attack and the defence abound, makes 
 me think with a shudder upon the probable sufferings 
 of the unhappy man whose intervention should lead 
 two such gladiators to turn their weapons from one 
 another upon him. In my youth, I once attempted 
 to stop a street fight, and I have never forgotten the 
 brief but impressive lesson on the value of the policy 
 of non-intervention which I then received. 
 
 But there is, happily, no need for me to place 
 myself in a position which, besides being fraught with 
 danger, would savour of presumption. Careful study 
 
vi PRE FA TOR V NO TE. 
 
 of both the attack and the reply leaves me without the 
 inclinatioii to become either a partisan or a peacemaker : 
 not a partisan, for there is a great deal with which 
 I fully agree said on both sides ; not a peacemaker, 
 because I think it is highly desirable that the impor- 
 tant questions which underlie the discussion, apart 
 from the more personal phases of the dispute, should 
 be thoroughly discussed. And if it were possible to 
 have controversy without bitterness in human affairs, 
 I should be disposed, for the general good, to use to 
 both of the eminent antagonists the famous phrase 
 of a late President of the French Chamber — " Ta^^e 
 dessus." 
 
 No profound acquaintance with the history of 
 science is needed to produce the conviction, that the 
 advancement of natural knowledge has been effected 
 by the successive or concurrent efforts of men, whose 
 minds are characterised by tendencies so opposite that 
 they are forced into conflict with one another. The 
 one intellect is imaginative and synthetic; its chief 
 aim is to arrive at a broad and coherent conception 
 of the relations of phenomena ; the other is positive, 
 critical, analytic, and sets the highest value upon the 
 exact determination and statement of the phenomena 
 themselves. 
 
 If the man of the critical school takes the pithy 
 aphorism "Melius autem est naturam secare quam 
 
PREFA TORY NOTE. vii 
 
 abstrahere"^ for his motto, the champion of free 
 speculation may retort with another from the same 
 hand, " Citius enim emergit Veritas e falsitate quam 
 e confusione ; " ^ and each may adduce abundant his- 
 torical proof that his method has contributed as much 
 to the progress of knowledge as that of his rival. 
 Every science has been largely indebted to bold, nay, 
 even to wild hypotheses, for the power of ordering and 
 grasping the endless details of natural fact which they 
 confer ; for the moral stimulus which arises out of the 
 desire to confirm or to confute them ; and last, but not 
 least, for the suggestion of paths of fruitful inquiry, 
 which, without them, would never have been fol- 
 lowed. From the days of Columbus and Kepler to 
 those of Oken, Lamarck, and Boucher de Perthes, 
 Saul, who, seeking his father's asses, found a kingdom, 
 is the prototype of many a renowned discoverer who 
 has lighted upon verities while following illusions, 
 which, had they deluded lesser men, might possibly 
 have been considered more or less asinine. 
 
 On the other hand, there is no branch of science 
 which does not owe at least an equal obligation to 
 those cool heads, which are not to be seduced into the 
 acceptance of symmetrical formulse and bold genera- 
 lisations for solid truths because of their brilliancy 
 
 1 Novum Organon, li. 
 
 2 Partis instaurationis secundse delineatio. 
 
viii PREFATORY NOTE. 
 
 and grandeur ; to the men who cannot overlook those 
 small exceptions and insignificant residual phenomena 
 which, when tracked to their causes, are so often the 
 death of brilliant hypotheses; to the men, finally, who, 
 by demonstrating the limits to human knowledge 
 which are set by the very conditions of thought, have 
 warned mankind against fruitless efforts to overstep 
 those limits. 
 
 Neither of the eminent men of science, whose 
 opinions are at present under consideration, can be 
 said to be a one-sided representative either of the 
 synthetic or of the analytic school. Haeckel, no less 
 than Yirchow, is distinguished by the number, variety, 
 and laborious accuracy of his contributions to positive 
 knowledge ; while Virchow, no less than Haeckel, has 
 dealt in wide generalisations, and, until the obscuran- 
 tists thought they could turn his recent utterances to 
 account, no one was better abused by them as a 
 typical free-thinker and materialist. But, as hap- 
 pened to the two women grinding at the same mill, 
 one has been taken and the other left. Since the pub- 
 lication of his famous oration, Yirchow has been received 
 into the bosom of orthodoxy and respectability, while 
 Haeckel remains an outcast ! 
 
 To those who pay attention to the actual facts of the 
 case, this is a very surprising event ; and I confess that 
 nothing has ever perplexed me more than the reception 
 
PREFA TOR V NOTE. ix 
 
 which Professor Virchow's oration has met with, in his 
 own and in this country ; for it owes that reception, not 
 to the undoubted literary and scientific merits which 
 it possesses, but to an imputed righteousness for which, 
 so far as I can discern, it offers no foundation. 
 It is supposed to be a recantation ; I can find no 
 word in it which, if strictly construed, is inconsistent 
 with the most extreme of those opinions which are 
 commonly attributed to its author. It is supposed to 
 be a deadly blow to the doctrine of evolution; but, 
 though I certainly hold by that doctrine with some 
 tenacity, I am able, ex animo, to subscribe to every 
 important general proposition which its author lays 
 down. 
 
 In commencing his address, Virchow adverts to the 
 complete freedom of investigation and publication in 
 regard to scientific questions which obtains in Ger- 
 many ; he points out the obligation which lies upon 
 men of science, even if for no better reason than the 
 maintenance of this state of things, to exhibit a due 
 sense of the responsibility which attaches to their 
 speaking and writing, and he dwells on the necessity of 
 drawing a clear line of demarcation between those pro- 
 positions which they have a fair right to regard as estab- 
 lished truths, and those which they know to be only more 
 or less well-founded speculations. Is any one prepared 
 to deny that this is the first great commandment of the 
 
PRE FA TOR V NOTE. 
 
 ethics of teaching ? Would any responsible scientific 
 teacher like to admit that he had not done his best 
 to separate facts from hypotheses in the minds of his 
 hearers ; and that he had not made it his chief business 
 to enable those whom he instructs to judge the latter 
 by their knowledge of the former ? 
 
 More particularly does this obligation weigh. upon 
 those who address the general public. It is indubit- 
 able, as Professor Virchow observes, that " he who 
 speaks to, or writes for, the public is doubly bound to 
 test the objective truth of that which he says," There 
 is a sect of scientific pharisees who thank God that 
 they are not as those publicans who address the public. 
 If this sect includes anybody who has attempted 
 the business without failing in it, I suspect that he 
 must have given up keeping a conscience. For 
 assuredly if a man of science, addressing the public, 
 bethinks him, as he ought to do, that the obligation 
 to be accurate — to say no more than he has warranty 
 for, without clearly marking off so much as is hypo- 
 thetical — is far heavier than if he were dealing with 
 experts, he will find his task a very admirable mental 
 exercise. For my own part, I am inclined to doubt 
 whether there is any method of self- discipline better 
 calculated to clear up one's own ideas about a difiicult 
 subject, than that which arises out of the effort to put 
 them forth, with fulness and precision, in language 
 
PREFATORY NOTE. xi 
 
 which all the world can understand. Sheridan is said 
 to have replied to some one who remarked on the 
 
 easy flow of his style, " Easy reading, sir, is 
 
 hard writing ; " and any one who is above the level of 
 a scientific charlatan will know that easy speaking is 
 " hard thinking." 
 
 Again, when Professor Virchow enlarges on the 
 extreme incompleteness of every man's knowledge 
 beyond those provinces which he has made his own 
 (and he might well have added within these also), 
 and when he dilates on the inexpediency, in the 
 interests of science, of putting forth as ascertained 
 truths propositions which the progress of knowledge 
 soon upsets— who will be disposed to gainsay him ? 
 Nor have I, for one, anything but cordial assent to 
 give to his declaration, that the modern development 
 of science is essentially due to the constant encroach- 
 ment of experiment and observation on the domain of 
 hypothetical dogma; and that the most difficult, as 
 well as the most important, object of every honest 
 worker is " sick ent-suhjectiviren " — to get rid of his 
 preconceived notions, and to keep his hypotheses 
 well in hand, as the good servants and bad masters 
 that they are. 
 
 I do not think I have omitted any one of Professor 
 Virchow's main theses in this brief enumeration. I 
 do not find that they are disputed by Haeckel, and 
 
xii PREFATORY NOTE. 
 
 I should be profoundly astonished if they were. What, 
 then, is all the coil about, if we leave aside various 
 irritating sarcasms, which need not concern peaceable 
 Englishmen? Certainly about nothing that touches 
 the present main issues of scientific thought. The 
 " plastidule-soul " and the potentialities of carbon may 
 be sound scientific conceptions, or they may be the 
 reverse, but they are no necessary part of the doctrine 
 of evolution, and I leave their defence to Professor 
 Haeckel. 
 
 On the question of equivocal generation, I have 
 been compelled, more conspicuously and frequently 
 than I could wish, during the last ten years, to 
 enunciate exactly the same views as those put forward 
 by Professor Virchow ; so that, to my mind, at any rate, 
 the denial that any such process has as yet been 
 proved to take place in the existing state of nature, 
 as little affects the general doctrine.'^ 
 
 With respect to another side issue, raised by Pro- 
 fessor Yirchow, he appears to me to be entirely in 
 the wrong. He is careful to say that he has no 
 
 ^ I may remark parenthetically that Professor Virchow's statement 
 of the attitude of Harvey towards equivocal generation is strangely 
 misleading. For Harvey, as every student of his works knows, be- 
 lieved in equivocal generation ; and, in the sense in which he uses the 
 word ovum, "nempe substantiam quandam corpoream vitam haben- 
 tem potentia," the truth of the axiom " omne vivum ex ovo," popularly 
 ascribed to him, has in no wise been affected by the discoveries of later 
 days in the manner asserted by Professor Virchow. 
 
PRE FA TOR V NO TE. xiii 
 
 unwillingness to accept the descent of man from some 
 lower form of vertebrate life ; but, reminding ns of the 
 special attention which, of late years, he has given to 
 anthropology, he affirms that such evidence as exists 
 is not only insufficient to support that hypothesis, but 
 is contrary to it. " Every positive progress which we 
 have made in the region of prehistoric anthropology 
 has removed us further from the demonstration of this 
 relation." 
 
 Well, I also have studied anthropological questions 
 in my time ; and I feel bound to remark, that this asser- 
 tion of Professor Virchow's appears to me to be a 
 typical example of the kind of incautious over-state- 
 ment which he so justly reprehends. 
 . For, unless I greatly err, all the real knowledge 
 which we possess of the fossil remains of man goes no 
 farther back than the Quaternary epoch ; and the most 
 that can be asserted on Professor Yirchow's side 
 respecting these remains is, that none of them present 
 us with more marked pithecoid characters than such 
 as are to be found among the existing races of man- 
 kind."^ But, if this be so, then the only just conclusion 
 to be drawn from the evidence as it stands is, that 
 the men of the Quaternary epoch may have proceeded 
 
 ^ I do not admit that so much can be said ; for the like of the 
 Neanderthal skull has yet to be produced from among the crania of 
 existing men. 
 
xiv PREFATORY NOTE. 
 
 from a lower type of humanity, though their remains 
 hitherto discovered show no definite approach towards 
 that type. The evidence is not inconsistent with 
 the doctrine of evolution, though it does not help it. 
 If Professor Virchow had paid as much attention to 
 comparative anatomy and palseontology as he has to 
 anthropology, he would, I doubt not, be aware that 
 the equine quadrupeds of the Quaternary period do 
 not differ from existing Eqiiidce in any more important 
 respect than these last differ from one another ; and he 
 would know that it is, nevertheless, a well-established 
 fact that, in the course of the Tertiary period, the equine 
 quadrupeds have undergone a series of changes exactly 
 such as the doctrine of evolution requires. Hence 
 sound analogical reasoning justifies the expectation 
 that, when we obtain the remains of Pliocene, Miocene, 
 and Eocene Anthropidce, they will present us with the 
 like series of gradations, notwithstanding the fact, if it 
 be a fact, that the Quaternary men, like the Quaternary 
 horses, differ in no essential respect from those which 
 now live. 
 
 I believe that the state of our knowledge on this 
 question is still justly summed up in words written 
 some seventeen years ago : — 
 
 " In conclusion, I may say, that the fossil remains 
 of man hitherto discovered do not seem to me to take 
 us appreciably nearer to that lower pithecoid form by 
 
PRE FA TOR Y NO TE. xv 
 
 the modification of which he has probably become what 
 he is. And considering what is now known of the 
 most ancient races of men ; seeing that they fashioned 
 flint axes, and flint knives, and bone skewers of much 
 the same pattern as those fabricated by the lowest 
 savages at the present day, and that we have every 
 reason to believe the habits and modes of living of 
 such people to have remained the same from the time 
 of the mammoth and the tichorhine rhinoceros till now, 
 I do not know that the result is other than might be 
 expected." ^ 
 
 I have seen no reason to change the opinion here 
 expressed, and so far from the fact being in the slightest 
 degree opposed to a belief in the evolution of man, 
 all that has been learned of late years respecting 
 the relation of the Eecent and Quaternary to the Ter- 
 tiary mammalia appears to me to be in striking har- 
 mony with what we know respecting Quaternary man, 
 supposing man to have followed the general law of 
 evolution. 
 
 The only other collateral question of importance raised 
 by Professor Virchow is, whether the doctrine of evolu- 
 tion should be generally taught in schools or not. l^ow 
 I cannot find that Professor Virchow anywhere dis- 
 tinctly repudiates the doctrine ; all that he distinctly 
 says is that it is not proven, and that things which 
 1 Man's Place in Nature, p. 159. 
 
xvi PREFA TOR V NOTE. 
 
 are not proven should not be authoritatively instilled 
 into the minds of young people. 
 
 If Professor Yirchow will agree to make this excel- 
 lent rule absolute, and applicable to all subjects that 
 are taught in schools, I should be disposed heartily to 
 concur with him. 
 
 But what will his orthodox allies say to this ? If 
 " not provenness " is susceptible of the comparative 
 degree, by what factor must we multiply the imperfec- 
 tion of the evidence for evolution in order to express 
 tliat of the evidence for special creation; or to what 
 fraction must the value of the evidence in favour of 
 the uninterrupted succession of life be reduced in 
 order to express that in support of the deluge ? l!^ay, 
 surely even Profes&or Virchow's " dearest foes," the 
 " plastidule soul " and ^' Carbon & Co.," have more to 
 say for themselves, than the linguistic accomplishments 
 of Balaam's ass and the obedience of the sun and 
 moon to the commander of a horde of bloodthirsty 
 Hebrews ! But the high principles of which Professor 
 Virchow is so admirable an exponent do not admit of 
 the .application of two weights and two measures in 
 education ; and it is surely to be regretted that a man 
 of science of great eminence should advocate the 
 stern bridling of that teaching which, at any rate, 
 never outrages common sense, nor refuses to submit 
 to criticism, while he has no whisper of remonstrance 
 
PRE FA TOR V NO TE. xvii 
 
 to offer to the authoritative propagation of the pre- 
 posterous fables by which the minds of children are 
 dazed and their sense of truth and falsehood perverted. 
 Professor Virchow solemnly warns us against the 
 danger of attempting to displace the Church by the re- 
 ligion of evolution. What this last confession of faith 
 may be I do not know, but it must be bad indeed if it 
 inculcates more falsities than are at present foisted 
 upon the young in the name of the Church. 
 
 I make these remarks simply in the interests of 
 fair play. Far be it from me to suggest that it is 
 desirable that the inculcation of the doctrine of evolution 
 should be made a prominent feature of general education. 
 I agree with Professor Yirchow so far, but for very diffe- 
 rent reasons. It is not that I think the evidence of that 
 doctrine insufficient, but that I doubt whether it is the 
 business of a teacher to plunge the young mind into 
 difficult problems concerning the origin of the existing 
 condition of things. I am disposed to think that the 
 brief period of school-life would be better spent in 
 obtaining an acquaintance with nature, as it is; in 
 fact, in laying a firm foundation for the further know- 
 ledge which is needed for the critical examination of 
 the dogmas, whether scientific or anti-scientific, which 
 are presented to the adult mind. At present, educa- 
 tion proceeds in the reverse way ; the teacher makes 
 the most confident assertions on precisely those sub- 
 
xviii PRE FA TOR V NO TE. 
 
 jects of which he knows least ; while the habit of 
 weighing evidence is disconraged, and the means of 
 forming a sound judgment are carefully withheld 
 from the pupil. 
 
 Professor Virchow is known to me only as he is 
 known to the world in general — by his high and well- 
 earned scientific reputation. With Professor Haeckel, 
 on the other hand, I have the good fortune to be on 
 terms of personal friendship. But in making the pre- 
 ceding observations, I should be sorry to have it 
 supposed that I am holding a brief for my friend, or 
 that I am disposed to adopt all the opinions which he 
 has expressed in his reply. Nevertheless, I do desire 
 to express my hearty sympathy with his vigorous 
 defence of the freedom of learning and teaching ; and 
 I think I shall have all fair-minded men with me 
 when I also give vent to my reprobation of the intro- 
 duction of the sinister arts of unscrupulous political 
 warfare into scientific controversy, manifested in the 
 attempt to connect the doctrines he advocates with 
 those of a political party which is, at present, the 
 object of hatred and persecution in his native land. 
 The one blot, so far as I know, on the fair fame of 
 Edmund Burke is his attempt to involve Price and 
 Priestley in the furious hatred of the English masses 
 against the authors and favourers of the revolution of 
 
PREFA TOR V NOTE. xix 
 
 1789. Burke, however, was too great a man to be 
 absurd, even in his errors ; and it is not upon record that 
 he asked uninformed persons- to consider what might 
 be the effect of such an innovation as the discovery of 
 oxygen on the minds of members of the Jacobin Club. 
 
 Professor Virchow is a politician — maybe a German 
 Burke, for anything that I know to the contrary ; at 
 any rate, he knows the political value of words ; and, 
 as a man of science, he is devoid of the excuses that 
 might be made for Burke. Nevertheless, he gravely 
 charges his hearers to " imagine what shape the theory 
 of descent takes in the head of a Socialist." 
 
 I have tried to comply with this request, but I have 
 utterly failed to call up the dread image ; I suppose 
 because I do not sufficiently sympathise with Soci- 
 alists. All the greater is my regret that Professor Vir- 
 chow did not himself unfold the links of the hidden 
 bonds which unite evolution with revolution, and bind 
 together the community of descent with the commu- 
 nity of goods. 
 
 Professor Virchow is, I doubt not, an accomplished 
 English scholar. Let me commend the "Eejected 
 Addresses " to his attention. For since the brothers 
 Smith sang — 
 
 " Wlio makes the quartern loaf and Luddites rise," — 
 Who fills the butchers' shops with large blue flies, 
 
 there has been nothing in literature at all comparable 
 
XX PREFA TOR V NO TE. 
 
 to the attempt to frighten sober people by the sugges- 
 tion that evolutionary speculations generate revolu- 
 tionary schemes in Socialist brains. But then the 
 authors of the " Eejected Addresses " were joking, 
 while Professor Virchow is in grim earnest ; and that 
 makes a great difference in the moral aspect of the 
 two achievements. 
 
PREFACE. 
 
 When the address delivered by Eudolph Yircliow on 
 the 2 2d of September last year, at the fiftieth meeting 
 of German ^Naturalists and Physicians at Munich, on 
 "Freedom of Science in the Modern State," appeared 
 in print in the following October, I was called upon, 
 on many sides, to prepare a reply. And such a reply 
 on my part seemed, in fact, justified by the severe 
 strictures which Yirchow in his discourse had directed 
 against one delivered by me only four days previously, 
 before the same meeting, on " The Modern Doctrine 
 of Evolution in its Eolation to General Science." The 
 general views which Yirchow then unfolded proved 
 such a fundamental opposition in our principles, and 
 touched our dearest moral convictions so nearly, that 
 any reconciliation of such antagonistic views was no 
 longer to be thought of. ^Nevertheless I forbore pub- 
 lishing the ready reply for two reasons : one relating 
 to the matter itself, the other a personal one. 
 
 With regard to the matter itself, I believed I might 
 confidently leave it to futurity to decide in the con- 
 
xxii PREFACE. 
 
 tention that lias declared itself between us. Eor on 
 one hand the doctrine of evolution which Yirchow 
 attacks has already so far become a sure basis of bio- 
 logical science and part of the most precious mental- 
 stock of cultivated humanity, that neither the ana- 
 themas of the Church nor the contradiction of the 
 greatest scientific authority — and such an one is Vir- 
 chow — can prevail against it ; and on the other hand 
 most of the arguments which he specially adduces 
 against the theory of descent have been so often dis- 
 cussed and so thoroughly refuted that any renewed 
 discussion seems in fact superfluous. 
 
 Personally, it was in the highest degree repugnant 
 to me to come forward as the opponent of a man 
 whom I learned, a quarter of a century ago, to ac- 
 knowledge and .to honour as the reformer of medical 
 science ; a man whose most ardent disciple and most 
 enthusiastic follower I at that time was, with whom I 
 subsequently stood in the closest relation as his assis- 
 tant, and with whom I long after continued in the 
 most friendly intercourse. The more keenly I lamented 
 Virchow's position, for some years past, as the anta- 
 gonist of our modern doctrine of evolution, and the 
 more I felt myself challenged to a reply by his repeated 
 attacks upon it, the less inclination I felt, never- 
 •theless, to come forward publicly as the "opponent of 
 this distinguished and highly-honoured man. 
 
PREFACE, xxiii 
 
 And if I find myself, after all, forced to reply, 
 it is in the persuasion that a longer silence will add to 
 the erroneous conclusions which my hitherto resigned 
 attitude has already given rise to ; at the same time I 
 believe that, precisely by reason of the peculiar interest 
 with which I have throughout followed Yirchow's scien- 
 tific achievements, I am specially qualified to answer 
 the question, a hundred times repeated by letter or by 
 word of mouth — " How is it possible that a man who 
 so long stood at the head of a party of progress in 
 science as in politics, who in political life indeed, has 
 outwardly maintained this position, has in science 
 become an instrument of the most perilous reaction ? " 
 
 A verbal answer, which I incidentally gave in March 
 of last year at the Concordia Banquet at Vienna, was 
 reported in the daily papers in such a different sense, 
 and was in part so misunderstood or so intentionally 
 misrepresented, that I am forced' at last, on that 
 account, to publish a clear and unambiguous reply. 
 The " Augsburger Allgemeine Zeitung," which eagerly 
 seizes every opportunity of expressing its unconquer- 
 able aversion to the evolution theory, accused me, 
 in one of its hostile articles, of a virulent and un- 
 dignified attack on Virchow. In contradiction of this 
 misrepresentation in the Augsburg paper — which was 
 copied by other journals — I must expressly assert that 
 not Virchow but I myself am the person attacked, and 
 
xxiv PREFACE. 
 
 that, therefore, the matter in question is not an -unjus- 
 tifiable attack by me on a formerly revered friend, but 
 a defence to which I am compelled by repeated and 
 sharp attacks on his part. 
 
 Another reason which urges me at last to break 
 silence consists in the continual and ample advantage 
 that all the clerical and reactionary organs have been 
 taking of Virchow's address, during the last three- 
 quarters of a year, in favour of mental retrogression. 
 The shouts of triumph with which they at once hailed 
 Virchow's "grand moral action," that is to say, his 
 perversion from a Free-thinker to the side of mental 
 darkness, was the first signal for that persistent utili- 
 sation of his authority of which the pernicious conse- 
 quences can by no means be escaped. Friedrich von 
 Hellwald, in his discussion on the speeches made at 
 Munich, has already strikingly pointed out-^ the grave 
 danger that exists when just such an one as Yirchow, 
 standing under the banner of political liberalism and 
 wrapped in the mantle of severe science, decisively 
 combats against the freedom of science and of its 
 doctrines. This serious danger has never shown so 
 threatening an aspect as at the present moment, when 
 our political and religious life appears to be encounter- 
 ing such a reaction as has not occurred for a long 
 time. The two insane attempts which, within a few 
 
 i Kosmos, Vol. II. p. 172. 
 
PREFACE. XXV 
 
 weeks, have been made by Social- democracy against 
 tlie revered and reverend person of the German 
 Emperor have raised a storm of righteous indignation 
 of such violence that calm judgment is entirely over- 
 thrown, and that many even of the most liberal of 
 liberal politicians not only impetuously urge us to the 
 severest measures against the Utopian doctrines of 
 social democracy but, far over-shooting the mark, 
 demand that free-doctrine and free-thought, that free- 
 dom of the press and even freedom of conscience shall 
 be thrown into the narrowest fetters. Can this re- 
 action, lurking in the background, find any more 
 welcome support than is afforded by the mere demand 
 of such a man as Yirchow for restriction of liberty in 
 teaching? And if he makes our present doctrines of 
 evolution in general and the theory of descent in 
 particular responsible for the mad doctrines of social- 
 democracy, it is but a natural and just consequence 
 when the famous New-Prussian " Kreuz-Zeitung " 
 throws all the blame of these treasonable attempts of 
 the democrats Hodel and INTobiling^ — as in fact it quite 
 lately did — directly on the theory of descent, and 
 especially on the hated doctrine of the " descent of 
 man from apes." And the danger which threatens us 
 shows a still graver aspect when we consider how 
 great an influence Yirchow has at the present day as 
 an advanced liberal, and how he is regarded in the 
 
 9. 
 
xxvi PREFACE. 
 
 Prussian diet as the highest practical authority, and at 
 the same time as the most liberal critic when educa- 
 tional questions are under consideration. Now it is 
 well known that one of the most important problems 
 lying before the Prussian parliament is the consider- 
 ation of a new education-law, which will probably 
 exercise its restricting influence for a long time to 
 come, not in Prussia only, but throughout Germany; 
 what can we expect of such an education-law if in the 
 course of the deliberations, among the small number 
 of those specialists who are generally listened to, 
 Yirchow raises his voice as a leading authority, and 
 brings forward the principles that he proclaimed in his 
 speech at Munich as the surest guarantees for the 
 freedom of science in the modern polity ? Article XX. 
 of the Prussian Charter, and § i 5 2 of the Code of the 
 German Empire, say, " Science and its doctrines are 
 free." And Virchow's first step, according to the prin- 
 ciples he now declares, must be a motion to abrogate 
 this paragraph. 
 
 In the face of this imminent danger, I dare no 
 longer hesitate about my answer. Amicus Socrates, 
 amicus Plato, magis arnica Veritas. An unreserved 
 and public opposition can be no longer postponed. 
 As a matter of fact, at the Munich meeting, neither did 
 Virchow hear my speech nor I his. I read my paper, 
 as it is printed, on the i8th September 1877, and left 
 
PREFACE. xxvii 
 
 on the 19th. Virchow came to Munich only on the 
 20th, and delivered his speech on the 2 2d. 
 
 Bearing in mind the gratitude which I owe to Vir- 
 chow as my former master and friend at Wurzburg — a 
 gratitude which I have at all times striven to prove by 
 the further development of his mechanical theory — I 
 shall confine myself, as far as possible, to an objective 
 and special confutation of his assertions. Certainly 
 the temptation on this occasion was a strong one to 
 pay the debt in like kind. In my Munich lecture, 
 among the few names to which I alluded, I particularly 
 mentioned that of Virchow as the distinguished founder 
 of cellular-pathology (p. 12).^ Vir chow's return for 
 this was to heap scorn and ridicule on the doctrine of 
 evolution in his usual manner. The critic in the 
 " N"ational-Zeitung," Herr Isidor Kastan, says of this 
 with particular satisfaction, " The ridicule with which 
 Herr Virchow treated this side of Haeckel's visions was 
 indeed caustic enough, but this is ever Virchow's way ; 
 only in this case, if in any, he was fully justified." 
 
 I could less easily ignore Virchow's denunciation of 
 me than his satire — a denunciation which gibbeted 
 me as a confederate in the social-democratic cause, and 
 which made the theory of descent answerable for the 
 horrors of the Paris Commune, The opinion is now 
 widely spread that by this intentional connection of 
 
 * Of the German. 
 
xxviii PREFACE, 
 
 the theory of descent with Social Democracy he has 
 hit the hardest blow at that theory, and that he aimed 
 at nothing less than the removal of all " Darwinists " 
 from their academic chairs and professorships. This 
 is the inevitable consequence of his demands ; 
 for if Yirchow insists with the utmost determina- 
 tion that the theory of descent must not be taught 
 (because he does not regard it as true), what is 
 to become of the supporters of that theory who, like 
 myself, regard it as incontrovertibly true, and teach it 
 as a perfectly sound theory ? And at least nine- 
 tenths of all the teachers of zoology and botany in 
 Europe are among its supporters from immutable 
 conviction of its truth, as well as all morphologists 
 without exception. Yirchow cannot expect that these 
 teachers should collectively renounce that which they 
 believe to be immutable truth, and in its place set up 
 the dogma of the Church as the basis of their teaching, 
 in accordance with his wish ! ITo thing remains for 
 them but to vacate their professors' chairs, and — 
 according to Virchow and the " Germania " — the 
 " Modern Polity " would be in duty bound to deprive 
 them of their liberty of teaching if they did not 
 voluntarily renounce it. 
 
 If this be indeed Yirchow's purpose, as it is gene- 
 rally supposed to be, with regard to me, at least, he may 
 spare himself the trouble. Amongst us in Jena quite 
 
PREFACE. xxix 
 
 other ideas prevail as to the " Freedom of science in 
 the modern Polity " than those which obtain in the 
 capital, Berlin. And among us the Berlin students' 
 rhyme has no meaning, 
 
 " Who knows the truth and freely speaks, 
 On him the law its vengeance wreaks." ^ 
 
 The Jena students, on the contrary, sing the rhyme 
 in its original form — 
 
 " Who knows the truth and speaks it not, 
 A feeble wretch is he, God wot." ^ 
 
 The Eector Magnificentissimus of the University of 
 Jena, the Grand Duke of Saxony, who has proved 
 himself the protector of the arts and sciences, has 
 besides far more liberal views as to the liberty of 
 scientific investigation and teaching than the illus- 
 trious head of the party of progress at Berlin. The en- 
 lightened and liberal Prince at Weimar, under whose 
 particular protection we in Jena find ourselves, has 
 never conceived it necessary to limit in any way the 
 unbounded freedom of my teaching and my writing : 
 not even when in 1866 my " General Morphology," 
 and 1868 my " History of Creation" first appeared, 
 and when many people attempted to make the youth- 
 
 1 " Wer die Wahrheit kennet und saget sie frei, 
 
 Der kommt in Berlin auf die Stadt- Vogtei. " 
 
 2 *' Wer die Wahrheit kennet und saget sie nicht 
 
 Der ist fur wahr ein erbarmlicher Wicht." 
 
XXX PREFACE. 
 
 ful extravagances which were to be found in those 
 works the ground of a serious accusation. And what 
 farther mischief have these extravagances done, though 
 I now sincerely lament them ? 
 
 Faithful to the glorious traditions of a past extend- 
 ing over three centuries, the little Thuringian uni- 
 versity of Jena will find a way to preserve her perfect 
 and unlimited freedom. She will ever bear in mind 
 that she is the first Protestant university of Germany, 
 protesting against every strait-waistcoat which hier- 
 archical obstinacy would force upon human reason, 
 against every dogma by which the arrogance of the 
 learned may try to suppress all freedom of teaching. 
 She will freely seek and freely teach in accordance with 
 her highest convictions, untroubled by the fact that in 
 the " great " university of Berlin nothing may be taught, 
 as Virchow insists, but what is objectively ascertained, 
 absolutely sure ; that is to say, nothing that rises above 
 individual, indubitable, and intelligible facts ; not an 
 idea, not a conception, not a theory, in fact not any 
 real science ; mathematics, at most, excepted. It is 
 our conviction that Jena will continue to be an 
 independent city of refuge for free science and free 
 teaching as long as it remains under the faithful 
 nurture and liberal protection of the princely house of 
 Sax Weimar, that enlightened race which is linl^ed 
 with the history of German intellect through the 
 
PREFACE, xxxi 
 
 matchless traditions of its glorious past. What the 
 Wartburg was to Martin Luther, what Weimar has 
 been to the foremost heroes of German literature, what 
 Jena herself has been during three hundred years to a 
 vast number of illustrious investigators, that will the 
 tried and tested Jena of to-day undoubtedly continue 
 to be to the modern doctrine of evolution, as to every 
 other doctrine which asks free development ; a strong- 
 hold of free thought, free investigation, and free 
 doctrine. 
 
 ERNST HAECKEL. 
 Jkna, June 24th, 1878. 
 
CONTENTS. 
 
 PAOK 
 PREFATORY NOTE . . . , . . . . V 
 
 PREFACE xxi 
 
 CHAP. 
 I. DEVELOPMENT AND CREATION I 
 
 II. CERTAIN PROOFS OF THE DOCTRINE OF DESCENT . lO 
 
 III. THE SKULL THEORY AND THE APE THEORY . . 29 
 
 IV. THE CELL-SOUL AND CELLULAR PSYCHOLOGY . . 46 
 V. THE GENETIC AND DOGMATIC METHODS OF TEACHING 61 
 
 VL THE DOCTRINE OF DESCENT AND SOCIAL DEMOCRACY 88 
 
 VIL IGNORABIMUS ET RESTRINGAMUR . . . . '99 
 
FREEDOM IN SCIENCE AND TEACHING. 
 
 CHAPTEE I. 
 
 DEVELOPMENT AND CREATION. 
 
 Nothing- is more helpful for the understanding of 
 scientific controversies, or for the clearing of con-- 
 fused conceptions, than a contrasted statement, as 
 defined and clear as possible, of the simplest leading 
 propositions of the contending doctrines. Hence it is 
 highly favourable to the victory of our modern doctrine 
 of evolution that its chief problem, the question as 
 to the origin of species, is being more and more 
 pressed by these opposite alternatives : Either all 
 organisms are naturally evolved, and must in that 
 case be all descended from the simplest common 
 parent - forms — or : That is not the case, and the 
 distinct species of organisms have originated inde- 
 pendently of each other, and in that case can only 
 have been created in a supernatural way, by a 
 miracle. Natural evolution, or supernatural creation 
 
2 DEVELOPMENT AND CREATION. 
 
 of species — we must choose one of these two possi- 
 bilities, for a third there is not. 
 
 But as Virchow, like many other opponents of the 
 doctrine of evolution, constantly confounds this latter 
 proposition with the doctrine of descent, and that 
 again with Darwinism, it will not be superfluous to 
 indicate here, in a few words,- the limitation and sub- 
 ordination of these three great theories. 
 
 I. The general doctrine of development, the pro- 
 genesis-theory or evolution-hypothesis (in the widest 
 sense), as a comprehensive philosophical view of the 
 universe, assumes that a vast, uniform, uninterrupted 
 and eternal process of development obtains throughout 
 all nature ; and that all natural phenomena without 
 exception, from the motions of the heavenly bodies 
 and the fall of a rolling stone to the growth of 
 plants and the consciousness of men, obey one and 
 the same great law of causation ; that all may be 
 ultimately referred to the mechanics of atoms — the 
 mechanical or mechanistic, homogeneous or monistic 
 view of the universe ; in one word. Monism. 
 
 II. The doctrine of derivation, or theory of descent, 
 as a comprehensive theory of the natural origin of all 
 organisms, assumes that all compound organisms are 
 derived from simple ones, all many-celled animals and 
 plants from single-celled ones, and these last from 
 quite simple primary organisms — from monads. As 
 
DEVELOPMENT AND CREATION. 3 
 
 we see the organic species, the multiform varieties of 
 animals and plants, vary under our eyes through 
 adaptation, while the similarity of their internal struc- 
 ture is reasonably explicable only by inheritance from 
 common parent - forms, we are forced to assume 
 common parent - forms for at least the great main 
 divisions of the animal and vegetable kingdoms, and 
 for the classes, orders, and so forth. Thus the number 
 of these will be very limited, and the primitive 
 archigonian parent-forms can be nothing else than 
 monads. Whether we finally assume a single common 
 parent-form (the monophyletic hypothesis), or several 
 (the polyphyletic hypothesis), is wholly immaterial to 
 the essence of the theory of descent ; and it is equally 
 immaterial to its fundamental idea what mechanical 
 causes are assumed for the transformation of the 
 varieties. This assumption of a transformation or 
 metamorphosis of species is, however, indispensable, 
 and the theory of descent is very properly called also 
 the " metamorphosis hypothesis," or " doctrine of trans- 
 mutation ; " as well as Lamarckism, after Jean Lamarck, 
 who first founded it in 1809. 
 
 III. The doctrine of elimination, or the selection 
 theory, as the doctrine especially of " choice of breed 
 or selection," assumes that almost all, or at any rate 
 most, organic species have originated by a process of 
 selection ; the artificial varieties under conditions of 
 
4 DEVELOPMENT AND CREATION. 
 
 domestication — as tlie races of domestic animals and 
 cultivated plants- — throngh artificial choice of breeds ; 
 and tlie natural varieties of animals and plants in 
 their wild state by natural choice of breeds : in the 
 first case, the will of man effects the selection to suit 
 a purpose ; in the second, it is effected in a purposeless 
 way by the " struggle for existence." In both cases 
 the transformation of the organic forms takes place 
 through the reciprocal action of the laws of inheritance 
 and of adaptation ; in both cases it depends on the 
 survival or selection of the better-qualified minority. 
 This theory of elimination was first clearly recognised 
 and appreciated in its full significance by Charles 
 Darwin in 1859, and the selection-hypothesis which 
 he founded on it is Darwinism properly so called. 
 
 The relation that these three great theories, which 
 are frequently confounded, bear to one another may, 
 according to the present position of science, be simply 
 defined as follows : — I. Monism, the universal theory 
 of development, or the monistic progenesis-hypothesis, 
 is the one only scientific theory which affords a 
 rational interpretation of the whole universe and 
 satisfies the craving of our human reason for causality, 
 by bringing all natural phenomena into a mechanical 
 causal- connection as parts of a great uniform process 
 of evolution. II. The theory of transmutation, or 
 descent, is an essential and indispensable element in 
 
DEVELOPMENT AND CREATION. 5 
 
 the monistic development hypothesis, because it is the 
 one only scientific theory which rationally explains 
 the origin of organic species — that is to say, by trans- 
 formation — and reduces it to mechanical principles. 
 III. The theory of Selection or Darwinism is, up to 
 the present time, the most important of the various 
 theories which seek to explain the transformation of 
 species by mechanical principles, but it is by no 
 means the only one. If we assume that most species 
 have originated through natural elimination, we also 
 now know, on the other hand, that many forms 
 distinguished as varieties are hybrids between two 
 different varieties, and can be propagated as such ; and 
 it is equally well worthy of consideration that other 
 causes are in activity in the formation of species of 
 which, up to the present time, we -have no conception. 
 Thus it is left to the judgment of individual naturalists 
 to decide what share is to be attributed to natural 
 selection in the origin of species, and even at the 
 present day authorities differ widely on the subject. 
 Some give it a large share, and some a very small one 
 in the result. Moritz Wagner, for instance, would 
 substitute his own migration-hypothesis for Darwin's 
 theory of selection ; while I regard the action of migra- 
 tion, which acts as isolation or separation, as merely 
 a special mode of selection. But these differing estim- 
 ates of Darwinism are quite independent of the absolute 
 
6 DEVELOPMENT AND CREA TION. . 
 
 import of tlie doctrine of descent or of transformation, 
 for the latter is as yet the only theory which ration- 
 ally explains the origin of species. If we discard it, 
 nothing remains but the irrational assumption of a 
 miracle, a supernatural creation. 
 
 In this crucial and unavoidable dilemma, Yirchow has 
 declared himself publicly in favour of the latter, and 
 against the former hypothesis. Every one who has 
 attentively followed his occasional utterances on the 
 theory of descent during the last decade with an unpreju- 
 diced eye and an unbiassed judgment, must be convinced 
 that he fundamentally rejects it. Still, his dissent has 
 always been so obscured, and his judgment on Darwin- 
 ism in particular so wrapped in ambiguities, that an 
 opportune conversion to the opposite side seemed not 
 impossible ; and many, even among those who stood 
 near to Virchow — his friends and disciples — did not 
 know to what point he was in fact an opponent 
 of the evolution hypothesis in general. Yirchow took 
 the last step towards clearing up this matter at 
 Munich ; for after his Munich address there can be 
 no farther doubt that he belongs to the most decided 
 opponents of the whole theory of evolution, including 
 those of inheritance and selection. 
 
 If any one still has doubts on the matter, let him 
 read the jubilant hymns of triumph with which 
 Virchow's friend and collaborator, Adolf Bastian, 
 
DEVELOPMENT AND CREATION. 7 
 
 greeted Ms Munich discourse. This " enfant terrible " 
 of the school — this well-nicknamed " Acting privy 
 counsellor of the board of confusion "^ — whose merits 
 in involuntarily advancing the cause of metamorphism 
 I have already done justice to in the preface to the 
 third edition of my " ISTatural History of Creation "^; — 
 expresses himself in the " Zeitschrift ftir Ethnologic/' 
 which is edited by him and Yirchow (tenth yearly 
 part, X. 1878, p. 66) as follows: — "At the Munich 
 meeting of naturalists, Yirchow by a few weighty 
 words cleared the atmosphere, which was heavy and 
 stifling under the pressure of the incubus called 
 Descent, and once more freed science from that night- 
 mare which it has so long — in many opinions so much 
 too long — ^^allowed to weigh upon it ; freed it, let us 
 hope, once and for ever. The forecasts of this storm 
 were discernible many years since, and its whole 
 course has been a strictly normal one. When the 
 germs planted by Darwin, and that promised so much, 
 were forced into growth by a feverish, hot-house heat, 
 and began to sprout into sterile weeds, their small 
 vitality was plain to our eyes. So long as the waves 
 run too high under the pressure of a psychical 
 storm, it is almost useless to protest against it, for 
 
 1 ' Wirkliche Geheime Ober-Conf usionsrath. " 
 
 2 Translated under the supervision of E. Ray Lankester. London: 
 C. Kegan Paul & Co. 
 
8 DEVELOPMENT AND CREATION. 
 
 every ear is too mucli deafened by tlie noise all round 
 to hear the voice of individuals. It is best to leave 
 things to go their own way, deeper and deeper into the 
 mire, till they come to a stand- still there of their own 
 accord ; for ' Quos dens vnlt perdere prius dementat.' 
 Thus it is in this case. When the extravagances of the 
 descent hypothesis, encouraged as they were by mutual 
 incitement, had reached their highest pitch in the ravings 
 that were uttered at Munich, the too pointed point broke 
 in this superabundance of absurdity almost by its own 
 pointedness, and so we were quit of it with one blow. 
 Now, happily, all is over with the theory of descent 
 or ascent, but natural science will not on that account 
 fare any the worse, for many of its adherents belong 
 to her ablest youth, and as they now need no longer 
 waste their best time on romantic schemes, they will 
 have it to use at the orders and for the advancement 
 of science, so as to enrich her through real and soM 
 contributions." 
 
 Furthermore, Bastian quotes Yirchow's maxim: 
 — " The plan of organisation is immutable within 
 the limits of the species ; species is not produced 
 from species." The fundamental teleological idea 
 of that school, that each species has its constant 
 and specific plan of structure, certainly cannot be 
 more emphatically expressed. Thus it is undoubtedly 
 certain that Yirchow has become a Dualist, and 
 
DEVELOPMENT AND CREATION. 9 
 
 is as thoroughly penetrated by the truth of his 
 principles as I, as a Monist, am of mine. This 
 is undoubtedly the upshot of his Munich address, 
 though he is throughout careful to avoid acknow- 
 ledging his chief standpoint in all its nakedness. 
 On the contrary, even now he still veils his anta- 
 gonism under the phrase, which is also a favourite 
 with the clerical papers, that the theory of descent is 
 an " unproved hypothesis." Now it is clear that this 
 theory never will be "proved" if the proofs that 
 already Ke before us are not sufficient. How often 
 has it been repeated that the scientific certainty of the 
 hypothesis of descent is not grounded in this or that 
 isolated experiment, but in the collective sum of 
 biological phenomena; in the causal nexus of evolu- 
 tion. Then what are the new proofs of the theory of 
 descent which Virchow demands of us ? 
 
CHAPTER 11. 
 
 CERTAIN PROOFS OF THE DOCTRINE OF DESCENT. 
 
 All the common phenomena of Morphology and 
 Physiology, of Chorology and (Ekology, of Ontology 
 and Paleontology, can be explained by the theory 
 of descent, and referred to simple mechanical causes. 
 It is precisely in this, viz., that the primary simple 
 causes of all these complex aggregates of phenomena 
 are common to them all, and that other mechanical 
 causes for them are unthinkable — it is in this that, 
 to us, the guarantee of their certainty consists. For 
 this reason all these vast and manifold aggregates of 
 facts are so many evidences of the doctrine of descent. 
 This fundamental relation of facts has been so often 
 expounded that I need dwell no farther on it in this 
 place ; those who wish for any closer discussion of 
 it are referred to my " General Morphology " (vol. ii. 
 chap, xix.), or "The History of Creation,"-^ or 
 "The Evolution of Man" (vol. i. p. 93).^ 
 
 And where is yet farther proof of the truth of the 
 
 1 Vol. ii. , p. 334 of translation. 
 
 2 London : C. Kegan Paul & Co. 1879. 
 
THE DOCTRINE OF DESCENT. ii 
 
 theory of descent to be found ? Neither Yirchow, 
 nor any one of the clerical opponents and the dualistic 
 philosophers who are perpetually reiterating this cry 
 for more certain evidence, anywhere indicate where 
 possibly such evidence is to be sought. Where in 
 all the world can we discover " facts " which will 
 speak more plainly or significantly for the truth 
 of transmutation than the facts of comparative 
 morphology and physiology ; than the facts of the 
 rudimentary organs and of embryonic development ; 
 than the facts revealed by fossils and the geographical 
 distribution of organisms — in short, than the collective 
 recognised facts of the most diverse provinces of 
 biological science ? 
 
 But I am in error — the certain proof that Yirchow 
 demands in order to be perfectly satisfied with the 
 evidence, is to be supplied by " experiment, the test 
 as well as the highest means of evidence." This 
 demand, that the doctrine of descent should be 
 grounded on experiment, is so perverse and shows 
 such ignorance of the very essence of our theory, 
 that though we have never been surprised at hear- 
 ing it continually repeated by ignorant laymen, from 
 the lips of a Virchow it has positively astounded us. 
 What can in this case be proved by experiment, and 
 what can experiment prove ? 
 
 "The variability of species, the transformation of 
 
12 CERTAIN EVIDENCE OF 
 
 species, the transition of a species into one or more 
 new varieties," is the answer.. N"ow, so far as these 
 facts can be proved by experiment, they actually 
 have long since been experimentally proved in the 
 completest manner. For what are the numberless 
 trials of artificial selection for breeding purposes 
 which men have practised for thousand of years in 
 breeding domestic animals and cultivated plants, but 
 physiological experiments which prove the transforma- 
 tion of species ? As an example we may refer to the 
 different races of horses and pigeons. The swift race- 
 horse and the heavy pack-horse, the graceful carriage- 
 horse and the sturdy cart-horse, the huge dray-horse 
 and the dwarfed pony — these and many other " races " 
 are so different from each other, that if we had found 
 them wild we should certainly have described them as 
 quite different varieties of one species, or even repre- 
 sentatives of different species. Undoubtedly, these 
 so-called " races " and " sports " of the horse tribe dif- 
 fer from each other in a much greater degree than 
 do the zebra, the quagga, the mountain horse, and the 
 other wild varieties of the horse, which every zoologist 
 distinguishes as " bonse species." And yet all these 
 artificial varieties, which man has designedly produced 
 by selection, are descended from a single common 
 parent-form, from one wild " true variety." The same 
 is the case with the numerous and highly differing 
 
THE DOCTRINE OF DESCENT. 13 
 
 varieties of pigeons. Domestic pigeons and carrier- 
 pigeons, tnrbits and cropper-pigeons, fantail pigeons 
 and owls, tumblers and pouters, trumpeters and laugh- 
 ing pigeons (or Indian doves), and tlie rest, are all, as 
 Darwin has convincingly proved, descendants of a 
 single wild variety, the rock-pigeon (Columba lima). 
 And how wonderfully various they are, not only in 
 general form, size, and colouring, but in the particular 
 form of the skull, the beak, the feet, and so forth ! 
 They differ much more in every respect each from the 
 others than the numerous wild varieties which, in 
 systems of ornithology, are recognised as true varieties, 
 and even as true species. It is the same with the 
 different artificial varieties of apples, pears, pansies, 
 dahlias, and so on ; in short, of almost all the domestic 
 varieties of animals and plants. We would lay par- 
 ticular stress on the fact that these artificial species 
 which man has produced or created by artificial breed- 
 ing and through experimental transformation out of 
 one original species, differ far more one from another 
 in physiological as well as in morphological conditions 
 than the natural species in a wild state. With these 
 it is self-evident that any proof by experiment of a 
 common origin is wholly impossible. Tor, so soon as 
 we subject any wild variety of animal or plant to such 
 an experiment, we bring it under the conditions of 
 artificial breeding. 
 
14 CERTAIN EVIDENCE OF 
 
 That the morphological conception of a Species is 
 not a positive but only a relative conception, and that 
 it has no other absolute or positive value than those 
 other similar system-categories — sports, varieties, races, 
 tribes, families, classes — is now acknowledged by 
 every systematiser who forms an honest and unpre- 
 judiced judgment of the practical systematic distinction 
 of species. From the very nature of the case there are 
 no limits to arbitrary discretion in this department, 
 and there are no two systematists who are at one in 
 every instance ; this one separating forms as true 
 varieties which that one does not. (Compare on this 
 point "History of Creation," vol. i., p. 273.) The 
 conception of variety or species has a different value 
 in every small or large department of systematic 
 Zoology and Botany. 
 
 But the conception of species has just as little 
 any fixed physiological value. In respect to this 
 we mu.st especially insist that the question of hybrid 
 offspring, the last corner of refuge of all the defenders 
 of the constancy of species, has at present lost all 
 significance as bearing on the conception of species. 
 For we know now, through numerous and reliable ex- 
 periences and experiments, that two different true varie- 
 ties can frequently unite and produce fertile hybrids 
 (as the hare and rabbit, lion and tiger, many different 
 kinds of the carp and trout tribes, of willows, brambles, 
 
777^ DOCTRINE OF DESCENT. 15 
 
 and others) ; and in the second place, the fact is equally 
 certain that descendants of one and the same species 
 which, according to the dogma of the old schools, could 
 always effect a fertile union under certain circumstances, 
 either cannot effect such a union or produce only barren 
 hybrids (the Porto- Santo rabbit, the different races of 
 horses, dogs, roses, hyacinths, &c. ; see " History of 
 Creation," vol. i., p. 146). 
 
 For a certain proof that the conception of species 
 rests on a subjective abstraction and has a merely rela- 
 tive value — like the conception of genus, family, order, 
 class, &c. — no class' of animals is of so much importance 
 as that of the ^onges. In it the fluctuating forms 
 vary with such unexampled indefiniteness and varia- 
 bility as to make all distinction of species quite illusory 
 Oscar Schmidt has already pointed this out in the sili- 
 ceous sponges and keratose sponges ; and I, in my 
 monograph, in three volumes, on the Calcareous Sponges 
 (the result of five years of most accurate investigations 
 of this small animal group), have pointed out that we 
 may* at pleasure distinguish 3, or 21, or 1 1 1, or 2%g, 
 or 591 different species. I also believe that I have 
 thus convincingly demonstrated how all these different 
 forms of the calcareous sponges may quite naturally, 
 and without any forcing, be traced to a single common 
 parent-form, the simple — and not hypothetical, but 
 
 existing at this present day — the simple Olynthus. 
 8 
 
i6 CERTAIN EVIDENCE OF 
 
 Hence I tliink I liave here produced tlie most positive 
 analytical evidence of the transformation of species, 
 and of the unity of the derivation of all the species of 
 a given group of animals, that is generally possible. 
 
 Properly, I might spare myself these disquisitions 
 on the question of species, for Yirchow does not go 
 into this main question of the theory of descent — but 
 this is very characteristic of his attitude. And just 
 as he nowhere thoroughly discusses the doctrine of 
 transformation, neither does he enter generally on the 
 refutation of any of the other certain proofs of the 
 doctrine of descent which we in fact possess at the 
 present day. ]!^either the morphological nor the 
 physiological arguments for the theory of descent, 
 neither the rudimentary organs nor the embryonic 
 forms, neither the paleontological nor the chronological 
 argument are anywhere closely examined and tested 
 as to their worth or their worthlessness as " certain 
 proofs." On the contrary, Yirchow takes them quite 
 easily, sets them aside, and declares that " certain 
 proofs " of the doctrine of descent do not exist, but 
 remain to be discovered. To be sure, he does not 
 indicate where they are to be sought, nor can he 
 indicate it. How is this strange conduct to be 
 explained ? How is. it possible that a distinguished 
 naturalist should resist the most important step for- 
 ward of modern natural science without in any way 
 
THE DOCTRINE OF DESCENT. 17 
 
 specially investigating it, without even practically 
 testing and refuting the most weighty arguments in 
 its favour ? To this question there is but one answer. 
 Virchow is not generally intimate with the modern 
 doctrine of evolution, and does not possess that know- 
 ledge of natural science which is indispensable for any 
 well-grounded judgment on it. 
 
 After collecting and carefully reading all that 
 Virchow, during many years, had written against 
 evolution, I arrived at the conviction that he had not 
 thoroughly read either Darwin's great work on the 
 Origin of Species, nor any other work on the theory of 
 descent, nor had he thought the matter out with such 
 attention as so serious and intricate a subject abso- 
 lutely demands. Virchow did with these works as it 
 has been his well-known custom to do with many 
 others — he hastily turned over the pages, caught at a 
 few leading words, and without any farther trouble 
 he has discoursed upon them, and, which is worst 
 of all, has perpetuated these discourses through the 
 press. • 
 
 To excuse this conduct, and to account for Virchow's 
 enigmatical position in the battle of evolution, we 
 must consider what changes this highly-gifted and 
 meritorious man has gone through in the course of the 
 last thirty years. The most important and fruitful 
 part of his life and labours was indisputably during 
 
i8 CERTAIN EVIDENCE OF 
 
 the eight years when he resided in Wiirzburg, from 
 1848 to 1856. There Virchow, with all the keenness 
 of his youthful intellect, with a sacred enthusiasm 
 for scientific truth, with indefatigable powers of work 
 and the rarest insight, worked out that glorious reform 
 of scientific medicine which will shiae through all 
 time as a star of the first magnitude in the history 
 of medical science. In Wiirzburg, Yirchow elaborated 
 that comprehensive application of the cellular theory 
 to pathology which culminates in the conception that 
 the cell is an independent living elementary organism, 
 and that our human organism, like that of all the 
 higher animals, is merely a congeries of cells — a 
 highly fertile conception, which Virchow now denies 
 as resolutely as he then supported it. In Wiirzburg, 
 twenty-five years since, I sat devoutly at his feet, and 
 received from him with enthusiasm that clear and 
 simple doctrine of the mechanics of all vital activity 
 — a truly monistic doctrine, which Virchow now 
 undoubtedly opposes where formerly he defended it. 
 In Wiirzburg, finally, he wrote those incomparable 
 critical and historical leading articles which are the 
 ornament of the first ten yearly series of his 
 " Archives " of pathological anatomy. All that 
 Virchow effected as the great pioneer of reform in 
 medicine, and by which he won imperishable honour 
 
THE DOCTRINE OF DESCENT. 19 
 
 in the scientific treatment of disease, — all this was 
 either carried out or preconceived in "Wiirzburg ; and 
 even the celebrated " Cellular Pathology," a course of 
 lectures which he delivered during the first year and 
 a half after quitting Wiirzburg for Berlin, consists 
 only of the collected and matured fruits of which the 
 blossoms are due to Wiirzburg. 
 
 In the autumn of 1856 Virchow left Wurzburg to 
 settle in Berlin. The exchange of a narrow sphere of 
 labours for a wider one, of small means and appliances 
 for greater ones, proved unfavourable in this case, as in 
 many similar cases. Since he has been in Berlin, in a 
 " great Institution," and with luxurious appliances, all 
 the scientific results which Yirchow has as yet brought 
 to light are not to be compared, either as to quality or 
 quantity, to the grand and immortal achievements 
 which he himself effected in the little institute of 
 Wiirzburg with the scantiest means — a new proof of 
 the maxim enunciated by me, and hitherto never con- 
 futed, that " the scientific results of an institute are in 
 inverse proportion to its size." (See " The Aim and 
 Methods of Modern Evolution." ^) 
 
 Still more grave is the circumstance that, since 
 settling in Berlin, Virchow has more and more 
 exchanged his theoretical scientific activity for prac- 
 
 ^ Jena, Zeitschriften fur Naturwisseuschaft, 1875. ^^ol. x. Supplement. 
 
20 CERTAIN EVIDENCE OF 
 
 ^ » 
 
 tical political life. It is well known how prominent 
 a part lie plays there in the Prussian Chamber of 
 Eepresentatives, how he raised himself to be the 
 leader of the party of progress, and, to give this politi- 
 cal position a broader basis, took part in the representa- 
 tion of the citizens of the capital; how he has taken 
 a most active interest, as city commissioner, in all the 
 petty anxieties and concerns which the charge of such 
 a city as Berlin entails. I am far from blaming, as 
 many have blamed, the political and civic activity to 
 which Yirchow has indefatigably devoted his best 
 powers. If a man feels in himself the inclination and 
 vocation with strength and talent enough, to play a 
 conspicuous political part, by all means let him do so ; 
 but verily I do not envy him; for the satisfaction 
 which is derived from the most successful and fruitful 
 political activity is not, to my taste, to be compared 
 with that pure and disinterested satisfaction of the 
 mind which results from absorption in serious and 
 difi&cult scientific labours. In the turmoil of the 
 political and social struggle, even the most splendid 
 civic crown will be dulled by the stifling dust of 
 practical life, which never reaches the ethereal heights 
 of pure science and never rests on the laurels of the 
 thoughtful investigator. However, as I have said, that 
 is a matter of taste. If Yirchow really believes that he 
 is doing a greater service to humanity by his practical 
 
THE DOCTRINE OF DESCENT. 21 
 
 political life in Berlin than he formerly did by his 
 theoretical scientific work in Wiirzbnrg, that is his 
 affair ; but for all that, in his former sphere he was 
 incomparable, and cannot be replaced ; in the latter 
 this is not the case. 
 
 If a distinguished man, be he never so remarkable 
 for uncommon power of work and universal gifts, 
 passes the whole day in the friction of political party- 
 struggles, and throws himself as well into all the petty 
 and wearisome details of daily civic life, it is impossible 
 for him to maintain the requisite feeling for the pro- 
 gress of science — particularly when it advances so 
 rapidly and incessantly as is the case in our day. It 
 is therefore quite intelKgible that Yirchow should soon 
 have lost this feeling, and in the course of the last two 
 decades have become more and more estranged from 
 science. And this estrangement has at last led to so 
 complete a change in his fundamental views, to such 
 a metapsychosis, that the present Yirchow of 1878 
 is hardly in a position to understand the youthful 
 Yirchow of 1848. 
 
 We have seen a similar mental change occur con- 
 temporaneously in our greatest naturalist, Carl Ernst 
 von Baer. This gifted and profound thinker and 
 biologist, whose name marks a new epoch in the 
 history of evolution, had in his later years become 
 wholly incompetent even to understand those most 
 
22 CERTAIN EVIDENCE OF 
 
 important problems of his youthful labours which 
 opened up» new paths of inquiry. While in his 
 early years he laid down principles of the greatest 
 value to our modern doctrine of evolution, and even 
 went very near to adopting this hypothesis into 
 his system, at a later period he utterly denied it, 
 and by his writings on Darwinism proved that he was 
 no longer generally capable of mastering this difficult 
 problem. As I am one of Yon Baer's warmest admirers, 
 and in my " Evolution of Man," as well as in the 
 " History of Creation," and in other places, have most 
 emphatically expressed that sincere esteem, I thought 
 I might venture to forbear from calling attention to 
 the discrepancy between the lucid, monistic principles 
 of Yon Baer in his youth, and the confused dualistic 
 views of his old age. But as many opponents of 
 Darwinism — and among them particularly the Old 
 Catholic philosopher of Munich, Huber, who has written 
 a series of articles in the " Augsburger Zeitung " — have 
 made constant capital out of the harmless talk of the 
 feeble old Yon Baer, I must in this place explicitly 
 declare that this dualistic prating of the old man is 
 quite incapable of shaking the monistic principles of 
 the young and enterprising pioneers of science, or of 
 giving them the lie. 
 
 In his autobiography Yon Baer gives us the ex- 
 planation of this striking contradiction. In 1834 he 
 
THE DOCTRINE OF DESCENT. 23 
 
 entirely and for ever abandoned the province of the 
 history of development, at which for twenty years he 
 had laboured incessantly, and where he had earned 
 splendid laurels. To escape from the haunting and 
 importunate ideas of the science which had so wholly 
 absorbed him, he fled from Konigsberg to Petersburg, 
 and subsequently busied himself in scientific inquiries 
 of a quite different character. Twenty-five long years 
 passed by, and when Darwin's work appeared in 1859, 
 Von Baer had too long undergone a metapsychosis to 
 be able to understand it. In Yon Baer, as in Yirchow, 
 the course of this remarkable metapsychosis is highly 
 instructive, and will itself afford to the thoughtful 
 psychologist an interesting evidence of the doctrine of 
 evolution. 
 
 However, the lack of comprehension of our modern 
 evolution-hypothesis is easier to explain in Yirchow's 
 case than in Yon Baer's, for this reason: morphological 
 knowledge was greatly lacking to Yirchow, while Yon 
 Baer possessed it in the highest degree. !N'ow mor- 
 phology is precisely that very department of inquiry 
 in which our theory of descent has its deepest and 
 strongest roots, and has matured the most glorious 
 fruits of knowledge. The study of organic forms, or 
 morphology, is thus, more than any other science, 
 interested in the doctrine of descent, because through 
 this doctrine it first obtained a practical know- 
 
24 CERTAIN EVIDENCE OF 
 
 ledge of effective causes, and was able to raise 
 itself from the humble rank of a descriptive study 
 of forms to the high position of an analytical science 
 of form'. It is true that by the beginning of this 
 century the most comprehensive branch of morphology 
 — i.e., comparative anatomy — which was founded by 
 Ouvier and splendidly developed by Johannes Miiller, 
 had laid the foundations on which to build a truly 
 philosophical science of form. The enormous mass of 
 various empirical material, which had been accumulated 
 by descriptive systematists and by the dissections of 
 zootomists since the time of Linnaeus and Pallas, had 
 already been abundantly matured and utilised in many 
 ways for philosophic purposes by the synthetic prin- 
 ciples of comparative anatomy. But even the most 
 important universal laws of organisation — of which 
 the old system of comparative anatomy was one — had 
 to take refuge in mystical ideas of a plan of structure 
 and of creative final causes (causae finales) ; they were 
 incapable of arriving at a true and clear perception of 
 effective mechanical causes (causce efficientes). This 
 last, most difficult, and grandest problem, Charles 
 Darwin was the first to solve in 1859, by setting 
 Lamarck's theory of descent, which was already fifty 
 years old, on a firm footing by his own theory of 
 selection. By this hypothesis it was first made 
 possible to fit together the rich materials which had 
 
THE DOCTRINE OF DESCENT. 25 
 
 been previously amassed, into the splendid edifice of 
 the mechanical science of form. (See my " General 
 Morphology," vol. i. chap, iv.) 
 
 The immeasurable step which Darwin thus made in 
 organic morphology can be adequately appreciated 
 only by those who, like myself, were brought up in the 
 school of the old teleological morphology, and whose 
 eyes were suddenly opened by the theory of selection 
 to a comprehension of that greatest of all biological 
 riddles, the creation of specific forms. The dogma 
 of creation, the mystic and dualistic doctrine of 
 the isolated creation of each separate variety, was 
 annihilated at one blow; the belief in transmutation 
 has now for ever taken its place — the mechanistic and 
 monistic doctrine of the metamorphosis of organic 
 forms, of the descent of all the species of one natural 
 class from a common parent-form. How complete a 
 change the science of mechanical morphology has by 
 this means been compelled to undergo, I have endea- 
 voured to point out in my " General Morphology ; " 
 and any one who wishes to convince himself clearly of 
 what an enormous revolution has been brought about, 
 particularly in comparative anatomy, may compare the 
 " Outlines of Comparative Anatomy " (Grundziige der 
 vergleichenden Anatomic), by Carl Gegenbaur, 1870, 
 and the latest edition of his " Elements " (Grundrisses), 
 with the old text-books of that science. 
 
26 CERTAIN EVIDENCE OF 
 
 Yircliow has no suspicion even of all these im- 
 measurable strides in morphology, for this department 
 always lay out of his ken. His great reforms in 
 pathology were founded in the province of physiology, 
 and more especially in cellular physiology. But within 
 the last twenty years these two main branches of 
 biological inquiry have grown more and more apart. 
 The great Johannes .Miiller was the last biologist who 
 was able to keep these departments of organic inquiry 
 together, and who won equally immortal honours in 
 both divisions of the subject. After Miiller's death in 
 1858 they fell asunder. Physiology, as the science 
 especially of the functions or living activity of the 
 organism, addressed itself more and more to exact and 
 experimental methods : morphology, on the contrary, as 
 the science of the forms and structure of animals and 
 plants, could naturally make but very small use of 
 this method ; it must take refuge more and more in 
 the history of evolution, and so constitute an historical 
 natural science. It was on this very historical and 
 genetic method of morphology, in contradistinction to 
 the exact and experimental method of physiology, that 
 I based my Munich address ; and if Yirchow in his 
 answer had really and thoroughly refuted this position, 
 instead of fighting with mere phrases and denuncia- 
 tions, this radical opposition would have been well 
 worthy of the fullest discussion. At the same time 
 
THE DOCTRINE OF DESCENT. 27 
 
 I have no wish to reproach Virchow for being 
 wholly fettered by the one-sided views of the modern 
 school-physiology, nor because morphology lies so far 
 out of his ken that he has not been able to form an 
 independent judgment of its aims and methods ; but 
 when, in spite of all this, he on every occasion lets 
 faU a disparaging judgment of it, we must dispute his 
 competence. It is true that in his Munich address he 
 emphasises the statement, " That which graces me best 
 is that I know my ignorance," by printing it in italics. 
 I only regret that I am forced to deny his possession 
 of this very grace. Yirchow does not know how 
 ignorant he is of morphology, else he would never 
 have uttered his annihilating verdict on it, else he 
 would not continually designate the study of the 
 theory of descent as dilettanteism and vain dreaming, 
 as " a fanciful private speculation which is now making 
 its way in several departments of natural science." 
 In truth, Yirchow does me greatly too much honour 
 when he designates as my " personal crotchet " an idea 
 which for the last ten years has been the most precious 
 common possession of all morphological science. If 
 Virchow were not so unfamiliar with the literature 
 of morphology, he must have known that it is pene- 
 trated throughout by this principle of descent, that 
 every morphological inquiry which conscientiously 
 pursues a well-considered problem now assumes the 
 
28 CERTAIN EVIDENCE, ETC. 
 
 doctrine of descent as granted and indisputable. Of 
 all this lie is ignorant, and so it is intelligible tbat lie 
 should continue to demand " certain proofs " of this 
 hypothesis, although those proofs have long since been 
 produced. 
 
( 29 ) 
 
 CHAPTEE III. 
 
 THE SKULL THEOEY AND THE APE THEORY. 
 
 Inasmuch as Virchow persists in treating the theory 
 of descent as an " unproved hypothesis," inasmuch as 
 he ignores all the forcible evidences of that hypothesis, 
 he deprives himself of the right of speaking a decisive 
 word in this, the most important scientific dispute of 
 the present day. Yirchow is, in fact, simply incom- 
 petent in the great question of evolution, as he is 
 deficient in the greater part of that knowledge — more 
 especially morphological knowledge — which is indis- 
 pensable to forming a judgment upon it. Hence on 
 the turning-point of the whole matter — viz., the pro- 
 blem as to the origin of species — he can have no 
 opinion, as he has never turned his attention to the 
 systematic treatment of species : those transitions of 
 one species into another, which he asks to see, abound 
 on all sides, as is well known to every systematic 
 naturalist. Only consider, for example, the genera of 
 Eubus and Salix among the living plants of the present 
 period, and the Ammonites and Brachiopoda among 
 
30 THE SKULL THEORY 
 
 extinct animals. Hence, too, Yirchow can have no 
 independent views as to the historical development of 
 the higher from the lower animals, because the abun- 
 dant living forms of the lower animals are almost 
 unknown to him, and because he has hardly any 
 conTjeption of the marvellous strides which hundreds of 
 industrious workers have made in this very depart- 
 ment within the last twenty years. But there can 
 be no doubt, indeed it is already universally acknow- 
 ledged, that it is precisely the comparative anatomy of 
 the lower — nay, of the very lowest animals — that has 
 solved the greatest riddles of life, and removed the 
 greatest obstacles from the path of the doctrine of 
 descent. He simply ignores the fact that true Monads 
 actually exist, and have been positively identified by 
 many different observers as structureless " organisms 
 without organs," and he turns out the poor Bathybius 
 with a kick. And yet I believe that in " Kosmos " ^ 
 I have conclusively proved that Monads must retain 
 their vast elementary importance whether the Bathy- 
 bius actually exists or not. 
 
 But even as regards the higher animals — nay, even 
 as to the comparative anatomy of the highest next to 
 man, the apes — Virchow stands apart, not understand- 
 ing the views of modern morphology. 
 
 "We must here examine more closely into this, 
 
 1 Vol. i. p. 293. 
 
AND THE APE THEORY. 31 
 
 because it is precisely in tMs department that 
 Virchow's only morphological experiments have been 
 made ; viz., his investigations as to the skulls of apes 
 and of men. This is precisely the one only point 
 on which he has sought a closer acquaintance with 
 morphology, and precisely here it is most clearly to be 
 seen how little he is acquainted with the recent 
 advances our science has made, and that he has hardly 
 any conception of the extraordinary importance to that 
 science of the theory of descent. 
 
 The skull theory, as is well known, has for a long 
 time been a very favourite theme, not only with pro- 
 minent naturalists, but also with talented amateurs. 
 Undoubtedly the skull, viewed as the bony capsule 
 which encloses our most important organ of sense, our 
 brain, has a special claim to morphological impor- 
 tance; for the general conformation of the skull 
 corresponds on the whole to the development of the 
 brain, and its inner surface gives an approximate idea 
 of the outer surface of the brain. In this correspon- 
 dence lies the only sound kernel of the sickly, over- 
 grown fancies of phrenology. The various development 
 of the skull allows of an approximate inference as to 
 the various degrees of development of the brain and 
 of the mental faculties. The comparative study of the 
 skulls of the vertebrate animals had excited the lively 
 interest of morphologists by the end of the last 
 
32 THE SKULL THEORY 
 
 century, wlien comparative anatomy was beginning to 
 constitute a special science; and the genetic inquiry 
 as to the morphological significance and development 
 of the skull soon grew out of it. It was no less a 
 man than our greatest German poet who first answered 
 this question, and propounded the theory that the 
 skull was neither more nor less than the modified 
 foremost end of the vertebral column, and that the 
 separate groups of bones which lie behind one another 
 in the human skull, as in that of all the higher 
 vertebrata, answer to the separate modified vertebrae. 
 This " vertebral theory " of the skull, which Yon 
 Goethe and Oken simultaneously and independently 
 attempted to prove, aroused universal interest and 
 maintained its ground for seventy years* while many 
 attempts were made to improve and enlarge upon it in 
 detail. 
 
 A quite new light was thrown on this, as on every 
 other morphological question, as soon as Darwin in 
 1859 had once more put into our hands the torch of 
 the doctrine of descent. The inquiry as to the origin 
 of the skull now assumed a real and tangible form. 
 Since all vertebrate animals, from fishes up to man, agree 
 so completely as to their essential internal structure 
 that they can be rationally conceived of no otherwise 
 than as branches of one stock and as descendants of one 
 parent-form, the distinctly formulated question as to 
 
AND THE APE THEORY. 33 
 
 the skull theory which now started into prominence 
 was this : " How, historically, has the skull of man and 
 of the higher animals originated from that of the lower 
 animals ? How is the development of the bones of 
 the skull from the vertebrae to be proved?" The 
 answer to these difficult questions was supplied by the 
 first comparative anatomist of the present day, by Carl 
 Gegenbaur. After Huxley had pointed out that the 
 ontogenesis or individual development of the skull by 
 no means favoured the older hypothesis of Goethe and 
 Oken, Gegenbaur brought forward evidence that the 
 fundamental idea of that theory was correct ; that the 
 skull does in fact correspond to a series of coalescent 
 vertebrae, but that the separate bones of the skull are not 
 to be regarded as representing parts of such modified 
 vertebrae. The skull-bones of all recent vertebrate ani- 
 mals are rather, for the most part, dermal bones, which 
 have come into closer connection as supplementary to 
 the cartilaginous primitive skull. We can even now 
 trace the number and position of the original vertebrae, 
 from which this primitive skull originated, by the 
 number of the vertebral arches (gill -arches) which are 
 attached to it, as well as by the number and position 
 of those vertebrae, from nine to ten. Of all the recent 
 vertebrata, the cartilaginous fishes, or Selachians, have 
 most nearly preserved the form and structure of this 
 primordial skull. These Selachians, the Eays and 
 
34 THE SKULL THEORY " 
 
 Sharks, are onthe whole the creatures which throw the 
 clearest light on the history of the lineage of the ver- 
 tebrata and on the organisation of our primeval fish- 
 natured ancestors. It is one of the particular merits 
 of Gegenbaur that he clearly and firmly estab- 
 lished the place in nature of the Selachians as the 
 common ancestors of all vertebrate animals from fish 
 up to man. 
 
 ISTone but those who have thoroughly studied the 
 comparative morphology of the vertebrata, who have 
 sought the genetic issue from that labyrinth of intricate 
 morphological problems at the hands of the theory of 
 descent, can duly value the immeasurable service which 
 Gegenbaur has done by this and other " Investigations 
 into the Comparative Anatomy of the Yertebrata." These 
 investigations are as much distinguished by a profound 
 knowledge and careful working out of the wonderfully- 
 extensive empirical materials for the subject, as by their 
 critical acumen and philosophic grasp. At the same 
 time they set in the clearest light the immeasurable 
 value of the theory of descent in the causal explana- 
 tion of the most difficult morphological problems. 
 Gegenbaur might, therefore, with perfect right, enun- 
 ciate this axiom in the Introduction to his " Comparative 
 Anatomy." " The theory of descent will at once find a 
 touchstone of proof in comparative anatomy. Up to 
 this time no experience in comparative anatomy has 
 
AND THE APE THEORY. 35 
 
 transpired which contradicts that theory ; on the con- 
 trary, they all lead up to it. Thus it will receive back 
 from science that which it has given to scientific method: 
 clearness and certainty." In point of fact we can adduce 
 no morphological investigations which better support 
 this declaration than those very phylogenetic researches 
 " as to the cranium of the Selachians, as a basis for the 
 critical examination of the genesis of the cranium of 
 the vertebrata," 1872. As Yirchow had formerly 
 thoroughly studied the old skull-hypothesis, and in his 
 admirable discourse on " Goethe as a Naturalist," 1861, 
 had given an excellent exposition of it ; as moreover 
 he had produced most valuable contributions to the 
 normal and pathological anatomy of the human skull, 
 we might have expected that he would have received 
 Gegenbaur's grand reform of the theory of the skull, 
 and historical solution of the skull-problem, with the 
 greatest interest, and have made it the clue to his own 
 further researches. But we seek in vain through 
 Yirchow's latest contributions to the study of the 
 human skull, for any indication of his knowing or 
 appreciating Gegenbaur's investigations. On the con- 
 trary, we see him persistently moving, without any 
 clear goal in view, on that trodden and devious path 
 of investigation which finds the highest aim of cranio- 
 logical science in the measuring of skulls, or cranio- 
 metry. 
 
36 THE SKULL THEORY 
 
 We are far from undervaluing the full significance 
 of the results of exact and careful descriptions and 
 measurements of various conformations of the skull as 
 an empirical basis for a true and scientific study of the 
 skull — f.^., for comparative and genetic craniology. 
 But still we must say that the way and method by 
 which this skull measurement has, for ten years now, 
 been pursued by numerous craniologists can never yield 
 corresponding scientific results ; on the contrary, though 
 it is cried up as the " exact morphology " of the skull, it 
 simply loses itself in the domains of harmless trifling. 
 A large amount of time has in the last ten years been 
 squandered in disputes as to the best method of mea- 
 suring skulls, while the craniologists concerned have 
 not, in the first place, answered the obviously most 
 important question : What end they propose to gain 
 by this specialist measuring, what proposition they 
 mean to prove by it ? Most of those numerous skull 
 measurers know nothing beyond the perfect human 
 skull, or at most the skulls of a few other mammalia, 
 while the comparative morphology and historical 
 development of the crania of the lower vertebrata are 
 wholly unknown to them ; and yet these last con- 
 tain the true key to the comprehension of the others. 
 One single month devoted by these " exact skull 
 measurers " to the study of Gegenbaur's theory of the 
 skull, and to testing the hypothesis by the skulls of 
 
AND THE APE THEORY. 37 
 
 Selachians, would have yielded them more fruit and 
 have given them more light than long years of 
 describing and measuring human skulls, however 
 various. 
 
 Yirchow himself affords the most striking example 
 of the usual results of this so-called " exact method " 
 of studying skulls. In his popular eSsay on " The 
 Skulls of Men and Apes," 1870, he concludes with 
 this notable proposition : — " It is therefore self-evident 
 that Man can never by any progressive development 
 have originated from the Apes." Every evolutionist 
 who is familiar with the surprising facts of compara- 
 tive morphology will draw from them the opposite 
 conclusion : " It is self-evident that Man could only 
 have originated from the progressive development of 
 the Ape (organism)." 
 
 This brings us to that question which, in the 
 popular treatment of the theory of descent, is justly 
 considered as its most important outcome and as the 
 keystone of the evolutionist edifice — to the well- 
 known proposition, " Man is descended from the Ape." 
 While we simply ignore all the misrepresentation, 
 distortion, and misinterpretation which this ape, or 
 pithecoid hypothesis, has met with on all sides, we 
 will only remark that this fundamental proposition, in 
 the sense of our modern doctrine of evolution, can 
 rationally have only this plain meaning : that the 
 
38 THE SKULL THEORY 
 
 human species as a whole was long since developed 
 from the order of apes, indeed actually from one (or 
 perhaps more) long since extinct form of ape; the 
 immediate progenitors of man in -the long series of his 
 vertebrate ancestry were apes or ape-like animals. Of 
 course none of the now surviving species of apes is 
 to be regarded as the unaltered posterity of that 
 primeval parent-form. Virchow, however, understand- 
 ing the " ape question " in this sense, answers it, as 
 Bastian also does, with the most positive contradiction. 
 " We cannot teach the doctrine that man is descended 
 from apes or from any other animal, foi we cannot 
 regard it as a real acquisition of science" (p. 31). 
 Although I myself, in direct opposition to this view, 
 and in agreement with almost all my professional 
 colleagues, look upon the descent of man from apes as 
 one of the surest of phylogenetic hypotheses, I will 
 here expressly admit that the relative certainty of this, 
 as of all other historical hypotheses of descent, is not 
 comparable with the absolute certainty of the general 
 theory of descent. It is now ten years since I first 
 explicitly stated (in my " Natural History of Crea- 
 tion," vol. ii. p. 358) : " The pedigree of the 
 human race, like that of every animal or plant, 
 remains in detail a more or less approximate 
 general hypothesis. This, however, in no way 
 affects the application of the theory of descent 
 
AND THE APE THEORY. 39 
 
 to man. In this, as in all researches into the deriva- 
 tion of our organism, we must distinguish between 
 the general theory of descent and the sjgedfic hypo- 
 thesis of descent. The general theory of descent 
 claims full and permanent value, because it is induc- 
 tively based on the whole range of common biological 
 phenomena and on their internal causal connection. 
 Each special hypothesis of descent, on the other 
 hand, is conditional as to its specific value on the 
 existing state of our biological information, and on 
 the extent of those objective empirical grounds on 
 which we deductively found the hypothesis, by our 
 subjective inferences." And I must here emphatically 
 add that I have on every opportunity repeated that 
 reservation, and have always insisted on the difference 
 which exists between the absolute certainty of trans- 
 mutation in general and the relative certainty of each 
 individual specific pedigree. So that when Semper 
 and others of my opponents assert that I teach my 
 specific genealogies as " infallible dogmas," it is 
 simply false. I have, on the contrary, pointed out 
 on all occasions that I regard them only as heuristic 
 or provisional hypotheses, and as a means of investi- 
 gating the actual relations of cognate races of organic 
 forms more and more approximately. 
 
 Since the conception of the natural animal sys- 
 tem as a hypothetical genealogical tree, and the 
 4 
 
40 THE SKULL THEORY 
 
 phylogenetic interpretation of morphological affinity 
 which, that conception involves, afford in fact the 
 only rational interpretation of that affinity in general, 
 my first genealogical attempts soon found many 
 imitators, and at the present time numerous industrious 
 labourers in the different departments of systematic 
 zoology are endeavouring to find in the construction of 
 such hypothetical genealogies the shortest and com- 
 pletest expression of the modern conception of struc- 
 tural affinity. If Yirchow had not been as ignorant 
 of the true significance and method of systematic 
 morphology as he is of its progress and scientific 
 contents, he must certainly have known this, and then 
 he would surely have withheld his mockery of all 
 these grave phylogenetic studies as " personal crotchets ** 
 and worthless dreams. * 
 
 What mighty strides towards a mechanical mor- 
 phology we have made by this phylogenetic work- 
 ing out of the system, and how much light and 
 life it has at once thrown into the system that 
 before was dead and cold, can only be known to 
 those who have long and deeply studied specific 
 systematisation and the grouping of species ; Yirchow 
 has not the remotest suspicion of it. Moreover, 
 these attempts have now proceeded so far, that a 
 large proportion of the phylogenetic hypotheses are 
 regarded as very nearly certain, and can hardly 
 
AND THE APE THEORY, 41 
 
 undergo any further essential modifications ; while the 
 greater number of them are still in an unfixed state, 
 and one systematist tries to improve them in this 
 direction, and another in that. 
 
 The following phylogenetic hypotheses are held to 
 be almost certain : — The descent of many-celled ani- 
 mals from single-celled, of the Medusse from the 
 hydroid Polyps, of the jointed from the unjointed 
 worms, of the sucking from the gnawing insects, of 
 amphibious animals from fishes, of birds from reptiles, 
 of the placental mammalia from the marsupials, and 
 so forth. I personally consider the descent of man 
 from the apes as equally certain ; nay, I regard this 
 most important and pregnant genealogical hypothesis 
 as one of those which, up to the present time, rest on 
 the best empirical basis. 
 
 Huxley, in particular, fifteen years ago, in his 
 celebrated "Man's Place in ISTature," 1863, so ad- 
 mirably proved the undoubted " descent of man from 
 apes," and so clearly discussed all the relations 
 that had to be taken into consideration, that very 
 little was left to others to do. The result of 
 his comparative morphological investigations is con- 
 tained in this proposition — " If we take up a system 
 of organs, be it which we will, the comparison of its 
 modifications throughout the series of apes leads us to 
 the same conclusion : that in every single visible 
 
42 THE SKULL THEORY 
 
 character man differs less from tlie higher apes than 
 these do from the lower members of the same order/' 
 It is therefore impossible for any objective zoologist, 
 according to the principles of comparative systematisa- 
 tion, to ascribe to man any other place in the animal 
 world than in the order of apes; and it is quite 
 immaterial whether we designate this individual group 
 as the Order of Apes, or, with Linnaeus, as the Primates. 
 For the phylogenetic construction of the system, the 
 common descent of man and of apes from one common 
 parent-form, necessarily follows from this inevitable 
 grouping, and on this proposition only all the general 
 inferences of the " ape-hypothesis " depend. As to 
 what that common parent-form of men and apes may 
 have been, very different views might probably be 
 brought on opposite sides ; but any one who knows 
 the collected facts that bear upon the matter, and 
 estimates them impartially, must, in conclusion, arrive 
 at the certain conviction that that hypothetical and 
 long-since extinct parent-form can only have been 
 genuine apes; that is to say, of the placental mammalian 
 type, such as when we see them now living before our 
 eyes we unhesitatingly class, on the ground of their 
 zoological characters, as true apes, in the order of Apes 
 or Primates. 
 
 In this, and all other sound phylogenetic hypotheses, 
 we may most easily attain to a conviction of their 
 
AND THE APE THEORY. 43 
 
 truth by taking into consideration and comparison the 
 other possible hypotheses. But in fact no single 
 opponent of the ape-hypothesis has been able to 
 combat it with any other phylogenetic hypothesis that 
 has the faintest glimmer of probability. ISTot one 
 opponent has suggested, or can suggest, any other 
 animal form that can serve as our nearest ancestor 
 than the ape. E'o one has ever reproached me by 
 saying that Mother Nature has endowed me with too 
 little imagination ; on the contrary, I am often accused 
 of having a superfluity of that gift of the gods ; but I 
 have often and repeatedly exerted my imagination to 
 picture to myself any known or unknown animal-form 
 as the nearest parent-form to man in the place of the 
 apes, and have always found myself under the neces- 
 sity of falling back upon the stock of apes. Let me 
 conceive of the outward conformation and the internal 
 structure of the nearest mammalian ancestors of men 
 as I will, I am always forced to acknowledge that this 
 hypothetical parent-form ranges under the zoologically- 
 conceived order of apes, and cannot possibly be 
 separated from the Simiadoe or Primates. If, in spite 
 of this, any one chooses, out of a " personal crotchet," 
 to accept some other series of unknown animal ancestors 
 of man that have nothing to do with apes, that is but 
 a mere empty hypothesis floating in the air. Our ape- 
 hypothesis, on the other hand, is objectively and 
 
44 THE SKULL THEORY 
 
 thoroughly proved by the essential agreement of the 
 internal bodily structure of man and of apes, and by 
 the identity of their embryonic development, as I have 
 fully shown in my " Evolution of Man " (chaps, xix. and 
 xxvi.) The mode and manner in which he here puts 
 palseontology in the foreground, and throws on the 
 theory of descent the task of producing an unbroken 
 gradation of fossil transitional forms between the 
 apes and man, is very indicative of Virchow's ignor- 
 ance of this zoological question — in which I, as a 
 professional zoologist, must decisively declare his in- 
 competence. The reasons why such a solution of the 
 problem is not to be expected, the extraordinary im- 
 perfection of the palseontological record, the natural 
 impediments to the palseontological evidence of the 
 genealogical table, have been so lucidly unfolded by 
 Darwin himself (chaps, ix. and x. of the " Origin of 
 Species ") that I am obliged once more to come to the 
 conclusion that Virchow has never read it with any 
 attention. 
 
 Besides, long before Darwin, the gifted Lyell, the 
 great originator of modern geology, showed clearly and 
 convincingly how, for many reasons, the greater part 
 of the fossil series must remain most imperfect, and 
 these reasons were at a later period so often and so 
 fully discussed (by myself among others, in chap. xv. 
 
AND THE APE THEORY. 45 
 
 of the "History of Creation," vol. ii. pp. 24-32) that 
 it is wholly superfluous once more and in this place to 
 state these, well-known and time-worn questions. It 
 only shows how little Yirchow was acquainted with 
 geology and palaeontology, and what a limited judgment 
 he can form of these historical causal relations. 
 
( 46 ) 
 
 CHAPTEK IV. 
 
 THE CELL-SOUL AND CELLULAE PSYCHOLOGY. 
 
 No attack in Yircliow's Munich address surprised me 
 so mucli, and none so plainly betrayed the subversion 
 of his most important scientific views, as that which 
 he directed against my observations on psychology and 
 cellular physiology. A mystic dualism in his funda- 
 mental views is here revealed, which stands in the 
 sharpest contrast to the mechanical monism formerly 
 upheld by the famous pathologist of Wurzburg. 
 
 In my Munich discourse (p. 1 2), I had alluded to 
 the "grand and fruitful application which Virchow 
 had made, in his system of ceUular pathology, of the 
 cell-theory to the general province of theoretic medi- 
 cine ;" and as a logical amplification of that idea, I 
 asserted emphatically that we must ascribe an inde- 
 pendent soul-life to every individual organic cell. 
 " This conception is validly proved by the study of 
 infusoria, amoebae, and other one-celled organisms ; for, 
 in these individual, isolated, living cells we find the 
 same manifestations of soul-life — feelings, and ideas 
 
THE CELL-SOUL. 47 
 
 (mental images), will and motion, as is in the higher 
 animals compounded of many cells " (p. 13). Yirchow 
 now rises np in the strongest protest against this 
 theory of a cellular sensibility, which I regard as the 
 inevitable consequence of his early views of cellular 
 physiology ; it is to him " mere trifling with words." 
 He combats with equal decisiveness "the scientific 
 necessity of extending the province of psychical pro- 
 cesses beyond the circle of those bodies in and by 
 which we actually see them exhibited." He further 
 says, " If I explain attraction and repulsion as psychical 
 phenomena, I simply throw the psyche out of the 
 window ; the psyche ceases to be a psyche." Finally 
 he says, " I assert without any hesitation that for us 
 the sum total of psychical phenomena is connected 
 with certain animals only, and not with the collective 
 mass of all organic beings ; nay, not even with all 
 animals in general. We have no ground as yet for 
 speaking of the lowest animals as possessing psychical 
 properties; we find such properties only in the higher 
 grades, and with perfect certainty only in the very 
 highest." 
 
 When I first read this and other astounding state- 
 ments in Virchow's paper, I involuntarily asked my- 
 self, " Can this be the same Virchow from whom, 
 twenty-five years ago, I learnt in Wurzburg that the 
 soul-functions of man and animals depend on me- 
 
48 THE CELL-SOUL 
 
 clianical processes in the soul-organs ; that tliese organs 
 are, like all other organs, composed of cells, and that 
 the functional activity of an organ is nothing more 
 than the sum of the activity of all the cells which 
 compose it ? Is this the same Virchow whose most 
 vital doctrine it was that all the physical and psychical 
 processes of the human organism were to be referred 
 to the mechanics of cell life ; who supported the view 
 of the unity of all the phenomena of life with the 
 same emphasis with which we are now obliged to 
 defend it against his attacks ? " 
 
 In fact, and beyond a doubt, we have here a new 
 proof of Yirchow's complete change in all fundamental 
 scientific principles. For the ceUular psychology 
 which I advance is only a necessary consequence of 
 the cellular physiology promulgated by Virchow. His 
 present opposition to the former is either a renuncia- 
 tion of the latter or an untenable and inconsequent 
 position. To explain this astonishing meta-psychosis, 
 we shall do well first to glance at the soul in general, 
 and then give particular consideration to the cell-soul. 
 
 What is the Soul or Psyche ? The innumerable 
 different answers which have been given to this 
 crowning question of psychology, may collectively, 
 when freed from all extraneous matter, be brought 
 under two groups which we may shortly designate as 
 the dualistic and the monistic soul-hypothesis. Ac- 
 
AND CELLULAR PSYCHOLOGY. 49 
 
 cording to the monistic (or realistic) soul-hypothesis, 
 the " soul " is nothing more than the sum or aggre- 
 gate of a multitude of special cell-activities, among 
 which sensation and volition — sensual perception and 
 voluntary movement — are the most important, the most 
 common, and the most widely diffused ; associated with 
 these in the higher animals and in man, we find the 
 more developed activities of the ganglionic cells which 
 are included under the conceptions of Thought, Con- 
 sciousness, Intellect, and Eeason. Like all the other 
 functional-activities of the organic cells, these soul- 
 functions depend ultimately on material phenomena 
 of motion, and more particularly on the motions of the 
 ■ plasson- molecules or plastidules, the ultimate atoms of 
 the protoplasma, and perhaps of the nucleus also; there- 
 fore we should be able actually to grasp and explain 
 them, as well as every other cognisable natural process, 
 if we were in a position to refer them to the mechanics 
 of atoms. ■ This monistic soul-hypothesis, then, is at 
 bottom mechanistia If psychical mechanics — psycho- 
 physics — were not so infinitely complex and involved, 
 if we were in a position to take a complete view of 
 the historical evolution of the psychic functions, we 
 could reduce the whole of them (including conscious- 
 ness) to a mathematical " soul-formula." 
 
 According to the opposite, or dualistic (or spiritu- 
 alistic) soul-hypothesis, the soul is, on the contrary, a 
 
so THE CELL-SOUL 
 
 peculiar substance, which most people somewhat 
 grossly conceive of as a gaseous body, while others 
 picture it with more subtlety, as an immaterial essence. 
 This " soul-substance " subsists independently of the 
 animal-body, and stands in only a temporary connection 
 with certain organs of that body — the soul-, or mental- 
 organs. It has been imagined that this soul-matter, 
 which resembles that imponderable ether which is the 
 medium of light, is diffused between the ponderable 
 molecules of the soul-organs and especially of the 
 nerve-cells, and that this connection of the imponder- 
 able " soul " with the ponderable body subsists only so 
 long as the individual life lasts. At the instant of 
 the first beginning of the individual organism, at 
 the moment of generation, this imponderable "soul" 
 passes into the body, and at the instant of death, at 
 the annihilation of the living individual, it again quits 
 the body. This mystical or dualistic soul-hypothesis, 
 which, as is well known, is to this day universally 
 accepted, is fundamentally vitalistic, inasmuch as 
 it regards the force which is bound up with the 
 soul- substance, like the " vital force " of a past 
 time, as a peculiar force quite independent of 
 mechanical forces. This force does not depend 
 on the material phenomena of motion, and is quite 
 independent of the mechanics of atoms. The 
 highest law of modern natural science, the law of 
 
AND CELLULAR PSYCHOLOGY. 51 
 
 the conservation of force, lias, therefore, no application 
 in the region of soul-life, and* that mechanical causality 
 which prevails throughout all the processes of nature 
 does not exist for the soul. The Psyche, in a word, 
 is a supernatural phenomenon, and the supernatural 
 department of the spiritual world stands free and 
 independent of the natural department of the material 
 world. 
 
 If we now compare the psychological views of the 
 youthful and unprejudiced Virchow of Wiirzburg with 
 those of the older and mystical Yirchow of Berlin, 
 there can be no doubt in the minds of the impartial 
 that the former, a quarter of a century ago, was as 
 decided and logical a monist as the latter is at present 
 a confessed and convicted dualist. The distinguished 
 position which Yirchow, twenty- five years since, won 
 by his natural conception of the nature of man, and the 
 great fame which he then earned in the fight for the 
 truth, rest precisely on this, that on every occasion he 
 maintained with his utmost vigour the unity of all vital 
 phenomena, and asserted their mechanical character. 
 All organic life, even the soul-life, rests on mechanical 
 principles, on that causal mechanism of which Kant 
 said that "it alone contained a practical interpreta- 
 tion of nature," and that " without it no natural science 
 can exist." On this point Yirchow says well in his 
 discourse on " Ejtforts at Unity in Scientific Medicine," 
 
52 THE CELL-SOUL 
 
 1 849 : — " Life is only a peculiar sort of raechanics, 
 thougii it is indeed the" most complex form of me- 
 chanics ; that in which the usual mechanical laws fall 
 under the most unusual and manifold conditions. Thus 
 life, compared with the universal processes of motion 
 in nature, is a thing peculiar in itself; but it does not 
 constitute a diametrical, dualistic opposition to those 
 laws ; it is only a peculiar species of motion. The. 
 motion itself is a mechanical one, for how should we 
 become cognisant of it if it were not based on the 
 sensible properties of bodies ? The media of the 
 motion are certain chemical matters, for we recognise 
 none but chemical matter in bodies. The individual acts 
 of motion reduce themselves to mechanical, or physico- 
 chemical, modifications of the constituent elements of 
 the organic unities, the cells and their equivalents." 
 These and many similar utterances in Yirchow's earlier 
 writings, and especially in the essay I have mentioned, 
 " On the Mechanical Conception of Life," leave no 
 doubt that he formerly supported, with a clear con- 
 science and his utmost energy, in psychology as in 
 the other collected departments of physiology, that 
 very mechanical standpoint which we to-day accept 
 as the essential basis of our monism, and which stands 
 in irreconcilable antagonism to the dualism of the 
 vitalistic doctrine. To none of my teachers am I so 
 deeply indebted for my emancipation from all the 
 
AND CELLULAR PSYCHOLOGY. 53 
 
 prejudices of tlie dualistic doctrine, and for my con- 
 version to the monistic, as to Eudolf Virchow ; for it 
 was his superior guidance which most firmly con- 
 vinced me, and many others, of the exclusive import- 
 ance of the mechanical view of nature. He led me 
 to a clear recognition of the fact that the nature of 
 man, like every other organism, can only be rightly 
 understood as a united whole, that this spiritual and 
 corporeal being are inseparable, and that the pheno- 
 mena of the soul-life depend, like all other vital 
 phenomena, on material motion only — on mechanical 
 (or physico-chemical) modifications of cells. And it 
 was in perfect agreement with my most honoured master 
 that- I subscribed then, and at this day still subscribe, 
 to the proposition with which he, in September 1 849, 
 closed the preface to the above-mentioned " Efforts at 
 ♦ Unity." " It is possible that I may have erred in 
 details ; in the future I shall be ready and willing to 
 acknowledge my mistakes and to rectify them, but 
 I enjoy this conviction, that I shall never find myself 
 in the position of denying the principle of the unity of 
 the human nature with all its consequences ! " 
 
 To err is human ! Who can say to what diametrical 
 contradiction to his firmest convictions man may not in 
 the future be driven by his adaptation to new relations in 
 life ? If we compare these stout monistic declarations 
 of 1849 and 1858 with the equally decided dualistic 
 
54 THE CELL-SOUL 
 
 utterances in Virchow's Municli address of 1877, we 
 perceive that he could not give the lie more fiercely 
 to his former fundamental opinions than he has there 
 done. E'ot quite twenty years have passed by, and 
 yet, in the course of that time, in Yirchow's views of 
 the universe, in his conception of human nature, and of 
 the soul-life, a change has been effected than which we 
 can conceive of no greater. We learn to our surprise 
 that psychical and corporeal processes are wholly dif- 
 ferent phenomena ; that no scientific necessity whatever 
 exists for extending the province of psychical processes 
 beyond the circle of those bodies in which, and by 
 which, we see them actually exhibited. "We may 
 ultimately explain the processes of the human mind 
 as chemical, but at any rate, it is not yet our business 
 to amalgamate these two subjects ! " 
 
 From the whole psychological discussion which is 
 involved in Yirchow's Munich address, it is made clear 
 that at the present time he regards the " soul " in a 
 purely dualistic sense as a substance, an immaterial 
 essence which only temporarily takes up its abode in 
 the body. Highly characteristic of this is the remark- 
 able sentence, " If I explain attraction and repulsion 
 as psychical phenomena, I simply throw the psyche 
 out of the window ; the psyche ceases to be a 
 psyche." If we substitute for the word " psyche " 
 the word which corresponds to Yirchow's earlier me- 
 
AND CELLULAR PSYCHOLOGY. 55 
 
 chanistic view — the word " motion " (or peculiar mode 
 of motion) — the sentence runs thus : " If I explain 
 attraction and repulsion as phenomena of motion, I 
 simply throw motion out of the window." 
 
 Almost more remarkable is Yirchow's assertion that 
 the lowest animals have no psychic properties ; that, 
 on the contrary, " these are only to be found in the 
 higher, and, with perfect certainty, only in the highest 
 animals." It is only to be regretted that Vh^chow has 
 not here stated what he understands by the higher and 
 the highest animals ; where that remarkable dividing 
 line is, beyond which the soul suddenly appears in the 
 hitherto soulless body. Every zoologist who is in 
 some degree familiar with the results of comparative 
 morphology and physiology will here clasp his hands 
 in astonishment, for by this proposition Yirchow seems 
 to mean that we must ascribe a soul-life only to those 
 animals in which special soul-organs, in the form of a 
 central and peripheral nerve-system, are developed 
 from sense-organs and muscles. But it is admitted 
 that all these different soul-organs with their charac- 
 teristic properties have originated from single cells 
 through the division of labour (differentiation) ; and 
 the nerves and muscles especially have been developed 
 by differentiation from the neuro-muscular cells. 
 The cells from which all these different nerve-cells, 
 muscle-cells, mind-ceUs, and so forth, are derived, are 
 
S6 THE CELL-SOUL 
 
 originally tlie simple neutral cells of the epithelium 
 of the ectoderm or exterior germ-layer, and these 
 cells, again, like all the cells of many- celled animal 
 bodies, originated in the repeated division of one single 
 original cell, the ovum- cell. 
 
 The individual development or ontogenesis of each 
 of these many-celled animal-forms, brings this histo- 
 logical process of development so clearly and evidently 
 before our eyes that we can but directly infer from it 
 the truth of the phylogenesis, or gradual historical evo- 
 lution of the soul-organs. The association of cells and 
 the division of labour among them are the modes by 
 which, in the first instance, the compound many-celled 
 organism has originated, historically, from the simple 
 one-celled organism. And an impartial comparative 
 consideration teaches us in the clearest way that a 
 functional-activity of the soul-cells exists in the lowest 
 one-celled animals as well as in the highest and many- 
 celled ; in the infusoria as well as in man. Volition and 
 sensation, the universal and unmistakable signs of soul- 
 life, may be observed among the former as well as in 
 the latter. Voluntary motion and conscious sensation 
 (of pressure, light, warmth, &c.) come under our obser- 
 vation so undoubtedly in the commonest forms of in- 
 fusorial animals — 'for instance the Ciliata, that one of 
 their most persevering observers, Ehrenberg, asserted 
 undeviatingly to the day of his death that all Infusoria 
 
AND CELLULAR PSYCHOLOGY. $7 
 
 must possess nerves and muscles, organs of sense and 
 of soul, as well as the higher animals. 
 
 It is well known that the enormous advance which 
 our science has lately made in the natural history of 
 these lowest organisms culminates in the statement — 
 clearly made by Siebold thirty years since, but only 
 recently " ascertained as proved " — that these minute 
 creatures are one-celled, and that in the case of these 
 infusoria one single cell is capable of all the various 
 vital functions — including soul - functions — which in 
 the zoophytes (plant-animals), as the hydra and the 
 sponges, are distributed among the cells of the two 
 germ-layers, and in all the higher animals among the 
 different tissues, organs, and apparatus of a highly 
 developed and constructed organism. The psychic 
 functions of sensation and voluntary motion, which 
 are here distributed to such very various organs and 
 tissues, are in. the infusoria fulfilled by the neutral 
 plasson material of the cell, by the protoplasma, and 
 possibly also by the nucleus (compare my treatise 
 *' The Morphology of the Infusoria." Jena, Zeitschrif- 
 ten, 1873, vol. vii. p. 5 1 6). And just as we must attri- 
 bute to these primary animal forms an independent 
 " soul," just as we must plainly be convinced that the 
 single independent cell has a " psyche," we must as 
 decidedly attribute a soul to every other cell ; for the 
 most important active constituent of the cell, the proto- 
 
58 THE CELL-SOUL 
 
 plasm, everywhere exhibits the same psychic proper- 
 ties of sensibility or irritability, and motive power or 
 will. The only difference is this, that in the organism 
 of the higher animals and plants the numerous collected 
 cells, to a great extent, give up their individual inde- 
 pendence, and are subject, like good citizens, to the 
 soul-polity which represents the unity of the will and 
 sensations in the cell community. "We here also must 
 distinguish clearly between the central soul of the 
 whole many- celled organism or the personal psyche 
 (the person-soul), and the particular individual soul or 
 elementary soul of the individual cells constituting 
 that organism (the cell-soul). Their relations are 
 strikingly illustrated in the instructive group of Sipho- 
 nophora, as I have briefly shown in my article on 
 " The Cell-soul and Soul-cells " (Deutsche Eundschau, 
 July 1878). Beyond a doubt the whole stock or 
 polity of Siphonophora has a very definite united will 
 and a united sensibility, and yet each of the indivi- 
 dual persons of which this stock (or Cormus) is com- 
 posed has its own personal will and its own particular 
 sensations. Each of these persons indeed was originally 
 a separate Medusa, and the individual Siphonophora 
 stock originated, by association and division of labour, 
 out of these united Medusa communities. 
 
 When I developed this theory of the cell-soul and 
 designated it in my Munich address as the " surest 
 
AND CELLULAR PSYCHOLOGY. 59 
 
 foundation of empirical psychology," I believed I was 
 drawing an inference quite to Yirchow's mind, from 
 his own views of mechanical and cellular-physiology ; 
 and for that reason I took the same occasion specially 
 to celebrate his very great services to the cell theory. 
 How astonished then was I when in his reply this very 
 theory was violently attacked and satirised as "mere 
 trifling with words." It never could have occurred to 
 me that Yirchow had long since become unfaithful to 
 his most important biological principles, and had de- 
 serted his own mechanical " theory of cells ; " it never 
 had occurred to me that Virchow could be in great 
 measure wanting in that zoological knowledge which 
 is requisite for a practical comprehension of the cell- 
 soul theory. He has never thoroughly studied either 
 the one-celled Protozoa, the Infusoria and Lobosa, 
 nor the Coelenterata, the highly instructive Sponges, 
 Hydroids, Medusae, or Siphonophora ; and thus he is 
 wanting in those genetic principles of comparative 
 zoology on which our theory rests. It is in no other 
 way conceivable that Virchow should contemn the 
 most important consequences of the ceU theory as 
 "mere trifling with words." 
 
 N"ext to the one-celled infusoria no phenomenon 
 throws such direct light on our cellular psychology as 
 the fact that the human ovum, like the ova of all 
 other animals, is a single, simple cell. In accordance 
 
6o THE CELL-SOUL, ETC. 
 
 with our monistic conception of the cell-soul, we must 
 conclude that the fertilised ovum-cell already virtually 
 possesses those psychical properties which, by the special 
 combination of the peculiarities inherited from both 
 parents, characterise the individual soul of the new 
 person ; in the course of the development of the germ, 
 the cell-soul of the fertilised ovum naturally is de- 
 veloped simultaneously with its material substratum, 
 , and. subsequently, after birth, it appears in full activity. 
 According to Yirchow's dualistic conception of the 
 psyche, we must, on the contrary, assume that this 
 immaterial essence at some period of its embryonic 
 development (apparently when the spine separates 
 itself from the external germ - layer) informs the 
 soulless germ. Of course, the bare miracle is thus 
 complete, and the natural and unbroken continuity of 
 development is superfluous. 
 
( 6i ) 
 
 CHAPTEE V. 
 
 THE GENETIC AND DOGMATIC METHODS OF TEACHING. 
 
 The very justifiable surprise which Virchow's Munich 
 address has excited in many circles is due only in part 
 to his opposition to the theory of descent ; for the rest, 
 and in much greater part, it is due to the astounding 
 arguments which he has connected with it, particularly 
 as to freedom for instruction. These arguments so 
 closely resemble those of the Jesuits that they might 
 have been inspired direct from the Vatican, or, which 
 is the same thing, the notorious " court-chaplain 
 party" in Berlin. No wonder, then, that these 
 prop*ositions, which would undermine the whole liberty 
 of science, have met with the loudest approbation from 
 the " Germania," the " New Evangelical Church Times " 
 ("Neue Evangelischen Kirchenzeitung "), and other 
 leading, equivocating organs of the Church militant. 
 On the other hand, these odious principles are 
 already so extensively discussed, and have been so 
 clearly laid down in all their indefensibility, that I 
 may here deal with them briefly, 
 
62 THE GENETIC AND 
 
 Yirchow's politics as a pedagogue reach their 
 highest pitch in this demand : " that in all schools, 
 from the poor schools to the universities, nothing shall 
 be taught that is not absolutely certain. None but 
 objective and absolutely ascertained knowledge is to be 
 imparted by the teacher to the learner; nothing sub- 
 jective, no knowledge that is open to correction, only 
 facts, no hypotheses." The investigation of such 
 problems as the whole nation may be interested in 
 must not be restricted ; that is liberty of inquiry ; 
 but the problem ought not, without anything 
 farther, to be the subject of teaching. " When we 
 teach we must restrict ourselves to the smaller, and 
 yet how great, departments which we are actually 
 masters of" 
 
 Earely indeed has such a treasonable attempt on 
 liberty of doctrine been made by a prominent repre- 
 sentative of science, and a leader of the intellectual 
 movement too, as this by Virchow. Only inquiry 
 is to be free and not teaching ! And where in the 
 whole history of science is there one single scientific 
 inquirer to be found who would not have felt himself 
 quite justified in teaching his own subjective convic- 
 tions with as much right as he had to construct them 
 from inquiry into objective facts. And where, gene- 
 rally speaking, is the limit to be found between objec- 
 
• DOGMATIC METHODS OF TEACHING. 63 
 
 tive and subjective knowledge ? Is there, in fact, any 
 , objective science ? 
 
 This question Virchow answers in the affirmative, 
 for he goes on to say : " We must not forget that there 
 is a boundary line between the speculative depart- 
 ments of natural science and those that are actually 
 conquered and firmly established " (p. 8). In my 
 opinion, there is no such boundary line; on the con- 
 trary, all human knowledge as such is subjective. An 
 objective science which consists merely of facts with- 
 out any subjective theories is inconceivable. For 
 evidence in favour of this view we must take a rapid 
 survey of the whole domain of human science, and test 
 the chief departments of it to see how far they contain, 
 on the one hand, objective knowledge and facts, and on 
 the other, subjective knowledge and hypotheses. We 
 may begin directly with Kant's assertion that in every 
 science only so much true — that is objective — know- 
 ledge is to be found as it contains of mathematics. 
 Unquestionably mathematics stand at the head of all 
 the sciences as regards the certainty of its teaching. 
 But how as to those deepest and simplest fundamental 
 axioms which constitute the firm basis on which the 
 proud edifice of mathematical teaching' rests ? Are 
 these certain and proved ? Certainly not. The bases of 
 its teaching are simply " axioms " which are incapable 
 
 of proof. To give only one example of how the very 
 5 
 
64 THE GENETIC AND 
 
 first principles of matliematics migM be attacked by 
 scepticism and shaken by philosophical speculation, 
 we may remember the recent discussions as to the 
 three dimensions of space and the possibility of a 
 fourth dimension ; disputes which are carried on even 
 at the present day by the most eminent mathe- 
 maticians, physicists, and philosophers. So much as 
 this is certain, that mathematics as little constitute 
 an absolutely objective science as any other, but by 
 the very nature of man are subjectively conditioned. 
 A man's subjective power of knowing can only discern 
 the objective facts of the outer world in general so far 
 as his organs of sense and his brain admit in his own 
 individual degree of cultivation. 
 
 However, granting that mathematics practically 
 constitute an absolutely certain and objective science, 
 how is it with the rest of the sciences ? Un- 
 doubtedly the most certain among them are those 
 " exact sciences " whose principles are to be directly 
 proved by mathematics ; thus, in the first place, a great 
 part of physics. We say, " a great part," for another 
 large part — to speak accurately, by far the greatest — - 
 is incapable of any exact mathematical proof. For 
 what do we know for certain of the essential nature 
 of matter, or the essential nature of force ? What do 
 we know for certain of gravitation, of the attraction of 
 mass, of its effects at great distances, and so on ? 
 
DOGMATIC METHODS OF TEACHING. 65 
 
 Newton's theory of gravitation is regarded as the most 
 important and certain theory of physics, and yet 
 gravitation itself is a hypothesis. Then, as to the 
 other branches of physics — electricity and magnetism. 
 The whole scheme of these important sciences rests on 
 the hypothesis of " electric fluidity," or of imponderable 
 matter of which the existence is nothing ]ess than 
 proved. Or optics ? Optics certainly appertain to 
 the most important and completest branch of physics, 
 and yet the nndiilatory theory of light, which we 
 accept now as the indispensable basis of optics, rests 
 on an unproved hypothesis, on the subjective assump- 
 tion of an ethereal medium, whose existence no one is 
 in a position to prove objectively in any way. Nay, 
 further, before Young set up the undulatory theory of 
 light, for a hundred years the emanation theory as 
 taught by Newton obtained exclusively in physics ; a 
 theory which at the present day is universally regarded 
 as untenable. In our opinion the mighty Newton 
 won the greatest honours in the development of the 
 science of optics, inasmuch as he was the first to 
 connect and explain the vast mass of objective optical 
 facts by a subjective and pregnant hypothesis. But, 
 according to Yirchow's view, Newton on the contrary 
 transgressed greatly by teaching this erroneous hypo- 
 thesis ; for even in " exact " physics none but " inde- 
 pendent and certain facts " are to be taught and 
 
66 THE GENETIC AND 
 
 established by " experiment as the highest means of 
 proof." Physics as a whole, as resting on mere un- 
 proved hypotheses, may be indeed an object of inquiry 
 but not of teaching. 
 
 Of course the same is true of chemistry ; nay, this 
 stands on much weaker feet, and is even less proved 
 than physics. The whole theoretical side of chemistry 
 is an airy structure of hypotheses such as does not 
 exist in any other science. In the last three decades 
 we have seen a whole series of the most different theories 
 rapidly succeed each other, none of which can be posi- 
 tively proved, though at least one of them is taught by 
 every professor of chemistry. But what is worst of all, 
 the common basis of all the most dissimilar chemical 
 theories, viz., the atomic theory, is as unproved and 
 unprovable as any hypothesis can be. ISTo chemist 
 has ever seen an atom, but he nevertheless considers 
 the mechanism of atoms as the highest term of his 
 science, he nevertheless describes and constructs the 
 connection of atoms in their various combinations as 
 though he had them before him on the dissecting- 
 table ! All the conceptions which we possess as to 
 chemical structure and the affinities of matter, are 
 subjective hypotheses, mere conceptions as to the 
 position and changes of position of the various atoms, 
 whose very existence is incapable of proof. Away, 
 
DOGMATIC METHODS OF TEACHING, 67 
 
 then, with chemistry from our schools ! The chemist 
 must only describe the properties of the different 
 elements and those combinations which can be put 
 before the pupil as ascertained facts founded in experi- 
 ment, " the highest means of proof." Everything that 
 goes beyond this is mischievous, particularly every 
 suggestion as to the essence and chemical constituents 
 of bodies ; matters as to which, in the nature of 
 things, we can only form uncertain hypotheses. For 
 as all chemistry, viewed as a system of doctrine, rests 
 solely on such hypotheses, it may be indeed a subject 
 of investic^ation but not of teachinoj. 
 
 Having thus convinced ourselves that chemistry as 
 well as physics, those " exact sciences," those " mechani- 
 cal " bases of all other sciences, rest on mere unproved 
 hypotheses, and so must not be taught, we may make 
 short work of the other faculties. For they collectively 
 are more or less historical sciences and dispense wholly 
 or in part with even those half-exact, fundamental prin- 
 ciples on which physics and chemistry are based. In 
 the first place, there is that grand, historical, natural 
 science, geology ; the great doctrine of the structure 
 and conxposition, the origin and development of our 
 globe. According to Virchow this too must be limited 
 to the description of ascertained facts, such as the struc- 
 ture of mountain masses, the character of the fossils 
 
68 THE GENETIC AND 
 
 they contain, tlie formation of crystals, and so forth. 
 But not for the world must anything be taught as to 
 the evolution of this globe ; for this rests from begin- 
 ning to end on unproved hypotheses. For even to the 
 present day the Plutonic and J^ep tunic theories are 
 disputing the field, and to this day we know not as to 
 many of the most important rocks, whether they ori- 
 ginated by the agency of fire or of water. The new 
 and remarkable discoveries of the great Challenger- 
 expedition threaten to subvert a great many geological 
 notions which had long been regarded as certain. 
 Then again, as to fossils. Who can prove with any 
 certainty that these petrifactions are in truth the 
 fossilised remains of extinct organisms ? They may 
 be — as many distinguished naturalists of even the last 
 century maintained — marvellous sports of nature, mys- 
 terious "Lusus naturse," or mere rough, inorganic models 
 of the labouring Creator into which He subsequently 
 " breathed the breath of life ; " or perhaps " stone- 
 flesh "(caro fossilis) brought into existence, on the dead 
 rocks by the " fertilising air " (aura semiaalis), and so 
 forth. 
 
 But I am wrong ! for with regard to petrifactions, 
 Yirchow is in the highest degree speculative, and 
 accepts without any hesitation the rash hypothesis 
 that fossils are actually the remains of extinct or- 
 
DOGMATIC METHODS OF TEACHING, 69 
 
 ganisms, althougli no " certain proof " whatever can 
 be offered in its favour, and altliough experiment, the 
 " highest means of proof/' has never yet produced a single 
 fossil. According to him these are actual "objective, 
 material evidences," only here we must go no further 
 than certain experience teaches us, and base no subjec- 
 tive conclusions on these objective facts. Thus, for 
 instance, in the long series of the mesozoic formations, 
 in the different strata of the Trias, Jurassic, and Chalk 
 formations, for the deposition of which a lapse of many 
 millions of years has been required, we find absolutely 
 no remains of fossil mammalia beyond lower jaws ; seek 
 where we will, nothing is anywhere to be found but 
 lower jaws, and no other bones whatever. The simple 
 reasons of this striking imperfection of the palseontolo- 
 gical record have been clearly expounded by Lyell, 
 Huxley, and others. (Comp. my " History of Creation," 
 vol. ii. p. 32.) These great investigators, in accordance 
 with all other palaeontologists, have demonstrated that 
 these jaw-bones of the mesozoic period are the remains 
 of mammalia, accurately speaking of marsupials, on 
 the simple ground that the nether jaws of the extant 
 recent marsupials show a similar characteristic form 
 with the fossil ones. They therefore unhesitatingly 
 assume that the rest of the bones in the bodies of these 
 extinct animals corresponded to those of living mam- 
 
10 THE GENETIC AND 
 
 mals. 'But this is a quite inadmissible hypothesis 
 devoid of any " certain proof ! " Where, then, are the 
 other bones ? Let ns see them ! till then we decline 
 to believe in them. Accordino^ to Yirchow, we onerht 
 rather to assume that the lower jaw was the only bone 
 in the body of these extraordinary beasts. Are there 
 not, in fact, snails, in which an upper jaw is the only 
 representation of a skeleton. 
 
 We cannot omit taking this opportunity of casting 
 a side glance at the very hazardous position which 
 Virchow, in total opposition to his boasted cool scepti- 
 cism, has taken up in anthropology as it is called, now 
 his favourite branch of science. In his Munich address 
 he tells us that he is pursuing the study of anthropology 
 with delight, and then asserts that " the quarternary 
 man " is an uuiversally-accepted fact. Quite apart 
 from this statement, we have seen that Virchow can 
 never attain to a profound and really scientific study 
 of anthropology simply for this reason, that he is lack- 
 ing in that comprehensive knowledge of comparative 
 morphology which is indispensable to it; nay, com- 
 parative anatomy and ontogenesis must be, according to 
 him, unpermitted speculations and the phylogenesis of 
 man, the key to all the most important questions of 
 anthropology, being based upon these, is devoid of all 
 certain proof. All the more must we wonder at the 
 
DOGMATIC METHODS OF TEACHING. 71 
 
 speculative levity with which even the sceptic Yirchow 
 in the " Primeval History of Man " and " Fossil Anthro- 
 pology," embarks in the most hazardous conjectures, and 
 gives out uncertain, subjective hypotheses as certain, 
 objective facts. 
 
 There is, in fact, at the present day no department of 
 science in which the wildest and most untenable hypo- 
 theses have blossomed- out so freely as in anthropology 
 and ethnology, so-called. All the phylogenetic hypo- 
 theses which I myself have put forward in my " Evolu- 
 tion of Man " as to the animal ancestry of man, Or in 
 my " I^atural History of Creation " as to the affinities 
 of animal races — all the other genealogical hypotheses 
 which are now advanced by numerous zoologists and 
 botanists as to the phylogenetic evolution of the animal 
 and plant worlds — all these hypotheses together, which 
 Yirchow rejects in a lump, are, critically considered as 
 hypotheses, far better grounded in facts, far better 
 supported by facts, than the majority of those innumer- 
 able airy and fanciful hypotheses with which, for the 
 last twelve years, the " Archiv fiir Anthropologic " and 
 " Zeitschrift fiir Ethnologic," edited by Yirchow and 
 Bastian, have filled their columns. This last perio- 
 dical has at least the merit of being a tolerably 
 consistent opponent of the doctrine of evolution, 
 while in the former, during twelve years, essays on 
 both sides have been mixed up in cheerful confusion. 
 
72 THE GENETIC AND 
 
 And how fanciful are the short-sighted hypotheses 
 which there blossom forth from the mixed mass of 
 facts, chaotically flung together. Only think of the 
 disputes over the stone age, bronze age, and iron age ; 
 think of the motley discussions as to the varieties of 
 skull-conformation and their significance ; on the races 
 of man, the migrations of peoples and the like. Most 
 of these very intricate historical problems are far more 
 buried in obscurity, and the hypotheses to explain 
 them dispense far more largely with any basis of facts, 
 than is the case with our phylogenetic hypotheses ; for 
 these are more or less " objectively " based on the facts 
 of comparative anatomy and ontogenesis. 
 
 But no one of these historical hypotheses is so daring, 
 so little " certainly proved," as the group of very vari- 
 ous and contradictory hypotheses which have been put 
 forward as to the antiquity and first appearance of the 
 human species ; and Yirchow asserts positively " The 
 pleistocene man is an universally accepted fact. The 
 tertiary man is, on the other hand, a problem, though 
 indeed a problem which is already under substantial 
 discussion ! " As if the distinction between the 
 tertiary and quarternary periods were not itself a 
 geological hypothesis, and as if the significance of 
 the fossil animal-remains, which play the largest 
 part in it, did not also rest on mere hypotheses 
 which escape all certain proof! Where, then, is the 
 
DOGMATIC METHODS OF TEACHING. 73 
 
 actual experiment " as the highest means of proof," 
 which gives evidence for these " certain facts " ? The 
 whole discussion in general about pre-historic man, 
 which Yirchow has mixed up with his Munich address 
 (pp. 30, 31), is the clearest evidence of the uncritical 
 spirit in which he deals with these historical problems 
 as " exact natural sciences." He assures us that " not 
 one single ape's skull, nor skull of an anthropoid ape, 
 has ever been found which could actually have belonged 
 to a human owner ! and he adds this sentence, in italics, 
 " We cannot teach, for we cannot regard it as a real 
 acquisition of science, that man is descended from the 
 ape or from any other animal ! " Then evidently no 
 alternative remains but that he is descended from a 
 god, or from a clod ! 
 
 But let us go over the rest of the sciences to see 
 what, according to Yirchow, may be taught in each 
 without endangering the safety of science. In the 
 whole department of biology, as well as in zoology 
 — including anthropology — and in botany, instruction 
 must be limited to imparting those trifling fragments 
 of knowledge which either consist of mere descriptions 
 of dry facts, or which supply an explanation of them 
 by mathematical formulas. Morphology must be taught 
 as mere descriptive anatomy and systematising, the 
 history of development as mere descriptive ontogenesis. 
 Comparative anatomy and phylogenesis, which by their 
 
74 THE GENETIC AND 
 
 explanatory hypotheses raise those dead masses of facts 
 to the place of true and livmg sciences — these must 
 not be taught at all. And how then do matters stand 
 with regard to the cell- theory, that fundamental theory 
 on which every element of our morphology and physio- 
 logy depends, and by applying which Yirchow himself 
 reached his grandest results ? 
 
 Since Schleiden in Jena, forty years ago, first put 
 forward the cell-theory, and Schwann immediately 
 after applied it to the animal kingdom and so 
 to - the whole organic world, this fundamental doc- 
 trine has undergone very important modifications, for 
 it is indeed a biological theory, but not a fact. We 
 may recollect under what different aspects its main 
 principles have appeared in the course of these four 
 decades : what changes have taken place in the con- 
 cej)tion of the • cell itself. After the organic cell had 
 originally been conceived of as a vesicle, consisting of a 
 firm capsule and a fluid content, we subsequently dis- 
 cerned it to be composed of a glutinous semi-fluid cell- 
 substance, the protoplasm, and convinced ourselves that 
 this protoplasm and the cell- core or nucleus enclosed in 
 it are the most important and indispensable constituent 
 parts of the cell, while the external firm capsule, the 
 cell-membrane, is not essential and very frequently 
 wanting. But even now opinions widely differ as to 
 how the conception of a cell should be precisely defined, 
 
DOGMATIC METHODS OF TEACHING. 75 
 
 and what consequences mnst be inferred from the cell- 
 theory, and attempts have not been wanting to upset 
 it altogether and to treat it as worthless. The anato- 
 mist Henle, of Gottingen, in particular, has repeatedly 
 made such an attempt, that "gifted" anatomist who, in 
 the preface to his bulky text-book of human anatomy, 
 declared that scientific ideas are mere worthless paper 
 money, and that the noble metal of facts, on the con- 
 trary, is the only genuine article. jN'ot long since a 
 bulky volume in quarto appeared, by one Herr ISTathu- 
 sius-Konigsborn, in which the cell is explained to be 
 a subordinate plastic element, and the cell-theory is 
 eliminated as superfluous ; and this monstrous volume, 
 full of the most amusing nonsense, is dedicated to 
 Herr Henle. Yirchow formerly was one of the vic- 
 torious opponents of the Gottingen physician, and wrote 
 brilliant articles against the " rational pathology " of 
 " irrational Herr Henle ; " now apparently he agrees 
 with him that the paper money of ideas is worthless 
 as compared with the noble metal of facts. Of course 
 the cell-theory then loses all its value, and cannot be 
 a subject of instruction ; for the cell itself is not a 
 certain and undoubted fact, but only an abstraction, a 
 philosophical idea. 
 
 Nothing more clearly shows what a coinplete change 
 Yirchow has undergone in his most important principles, 
 and what an utter metapsychosis in this special pro- 
 
76 THE GENETIC AND 
 
 vince, than his famous axiom, uttered in 1855 — 
 " Omnis cellula e cellula." That is unquestionably 
 the boldest generalisation to which the youthful, inde- 
 pendent Yirchow ever attained, and one on which he 
 justly prided himself not a little. He himself re- 
 peatedly compared it with Harvey's saying, which 
 marked an epoch — " Omne vivum ex ovo." But 
 neither of these axioms is universally correct. On 
 the contrary, we now know that every cell does not 
 necessarily originate from a cell, any more than that 
 every organic individual originates from an ovum. In 
 many cases true nucleated cells proceed from un-nu- 
 cleated cytods, as in the Gregarinae, Myxomycetee and 
 others. N'ay more, the primordial organic cells could 
 only have originated in the first instance from non- 
 cellular plastides or monads by their homogeneous 
 plasson resolving itself into an internal nucleus and an 
 external protoplasm. Thus, as we subsequently learnt 
 to know most of the exceptions to this generalisation 
 of Yirchow, it appeared all the bolder; the more 
 so as we were at that time far from being able to 
 refer all the different tissues of the higher animals 
 with any certainty to cells, and as not a few experi- 
 ments seemed to point to the hypothesis of free cell- 
 formation. That guiding axiom, which so powerfully 
 furthered the cell -theory, Yirchow, from his present 
 standpoint, must wholly condemn as a crime against 
 
DOGMATIC METHODS OF TEACHING. 77 
 
 exact science, and he surely can never forgive himself 
 for having propounded this hypothesis — which was 
 afterwards found to be not universally true — as an- 
 important doctrinal axiom. . 
 
 We shall indeed find much worse sins against his 
 own principles of to-day if we turn to Virchow's own 
 special department of science, namely, pathological 
 anatomy and physiology, the most important division 
 of theoretic medicine. The great and incomparable 
 services which Virchow here effected do not depend 
 on the numerous independent new facts which he 
 discovered, but on the theories and hypotheses by 
 which, like an inspired pioneer, he sought to open 
 a way through the dead waste of pathological know- 
 ledge and to form it into a living science. These new 
 theories and the hypotheses on which they were 
 founded, Yirchow then propounded to us, his disciples, 
 with such incisive assurance that every one of us was 
 convinced of their truth; and yet later experience has 
 shown that they were in part insufi&ciently proved and 
 in part wholly false. For example, I will only here 
 recall his famous theory of the connective-tissue, for 
 which I myself in several of my early works (1856 to 
 1858) broke a lance. His theory seemed to explain 
 a host of the most important physiological and patho- 
 logical phenomena in the simplest manner, and yet 
 it was afterwards proved to be false. In spite of 
 
78 THE GENETIC AND 
 
 this, I declare to this day that it was of the greatest 
 service for the development of our acquaintance with 
 the formation of the connective-tissue ; as a guiding 
 hypothesis and as a provisional clue to our investi- 
 gations. Virchow, on the contrary, if he impartially 
 reflects on the part he took in the diffusion of this 
 misleading doctrine, must reproach himself severely 
 for it. For "we must draw a hard and fast line 
 between what we are to teach and what we are to 
 investigate. What we investigate are problems," but 
 "the problem ought not to be the subject of teach- 
 ing." That Yirchow, in his course of instruction, 
 every day belied this, his present view of teaching, 
 that he every hour taught his disciples some un- 
 proved theory and problematical hypothesis, every one 
 knows who, like myself, for years and with the deepest 
 interest, enjoyed his distinguished instruction. Still 
 the captivating charm of this instruction — -in spite of 
 the defective method of unprepared lectures— lay pre- 
 cisely in this, that Virchow as a teacher constantly let 
 us, his pupils, enter into those problems with which 
 he himself at the moment was occupied ; that he pro- 
 pounded to us his personal hypothesis for the eluci- 
 dation of the given facts. And what really gifted 
 teacher who lives in his science would not do the same ? 
 Where is there, or where has there ever been, a great 
 master who in his teaching has confined himself to 
 
DOGMATIC METHODS OF TEACHING, 79 
 
 only imparting certain and undoubtedly ascertained 
 facts ? Who has not, on the contrary, found that the 
 charm and value of his instruction lay precisely in 
 propounding the problems which link themselves 
 with those facts, and in teaching the uncertain theories 
 and fluctuating hypotheses which may serve to solve 
 these problems ? Or is there for the young and strug- 
 gling mind anything better, or more conducive to cul- 
 ture, than to exercise the intelligence in problems of *• 
 investigation ? ^ 
 
 How unpractical and how absurd is Virchow's 
 demand — that only ascertained facts and no problematic 
 theories shall be admitted in teaching — will be still 
 more strikingly shown by a glance over the remaining 
 provinces of human knowledge. What, indeed, will 
 be left of history, of philology, of political science, of 
 jurisprudence, if we restrict the teaching of them to 
 absolutely- ascertained and established facts. What of 
 " science " will remain to them if the idea which en- 
 deavours to discern the causes of the facts is banished ? 
 if the problems, the theories, the hypotheses, which 
 seek these causes may not be generally taught ? And 
 that philosophy — the science of knowing^by which 
 all the common results of human knowledge are to be 
 bound up into one grand and harmonious whole — that 
 philosophy, I say, must not be generally taught, is, 
 according to Virchow, quite self-evident. 
 
8o THE GENETIC AND 
 
 Finally, there remains nothing but theology. Theo- 
 logy alone is the one true science, and its dogmas alone 
 may be taught as certain. Of course ! for it proceeds 
 directly from revelation, and only divine revelation can 
 be " quite certain ; " it alone can never err. Yes, incre- 
 dible as it sounds, Yirchow, the sceptical, opponent of 
 dogma, the leader of the fight for "liberty of science," 
 Yirchow now finds the only sure basis for instruction 
 in the dogmas of the Church. After all that has gone 
 before, the following memorable sentence leaves no 
 doubt on this score : — " Every attempt to transform 
 our problems into dogmas, to introduce our conjectures 
 as a basis of instruction, particularly any attempt 
 simply to dispossess the Church and to supplant her 
 dogma by a creed of descent — ay, gentlemen — this 
 attempt must fail, and in its ruin will entail the 
 greatest peril on the position of science in general." 
 
 The shouts of triumph of the whole clerical press 
 over Yirchow's Munich address is thus rendered per- 
 fectly intelligible, for it is well known that " there is 
 more joy in heaven over one sinner that repenteth 
 than over ten just men." When Rudolf Yirchow, the 
 " notorious materialist," the " advanced radical," the 
 " great supporter of the atheism of science," is so sud- 
 denly converted, when he proclaims loudly and publicly 
 that the dogmas of the Church are the only sure basis 
 of instruction, then the Church militant may well sing 
 
DOGMATIC METHODS OF TEACHING. 8l 
 
 " Hosanna in the highest ! " Only one thing is to be 
 regretted, that Yirchow has not more clearly defined 
 which of the many different church-religions is the 
 only true one, and which of the innumerable and con- 
 tradictory dogmas are to form the sure basis of 
 instruction. We all know that each Church regards 
 itself as the only truly saving one, and her own dogma 
 as the only true one. But as to whether it is to be 
 Protestantism or Catholicism, the Eeformed or the 
 Lutheran confession, whether the Anglican or the 
 Presbyterian dogma, whether the Eoman or the Greek 
 Church, the Mosaic or the Mohammedan dispensation, 
 whether Buddhism or Brahmanism, whether, finally, 
 it is to be one of the many fetish-religions of the 
 Indians and Negroes that is to form the permanent 
 and sure basis of instruction, let us hope that Virchow 
 will at the next meeting of German naturalists and 
 physicians divulge his opinion. 
 
 At any rate, the " instruction of the future, accord- 
 ing to Yirchow," will be greatly simplified if he will do 
 this. Por the dogma of the Trinity in Unity as a basis 
 of mathematics, the dogma of the resurrection of the 
 body as a basis of medicine, the dogma of infallibility 
 as a basis of psychology, the dogma of the immaculate 
 conception as a basis of genetic science, the dogma of 
 the staying of the sun as a basis of astronomy, the 
 dogma of the creation of the earth, animals, and plants 
 
82 THE GENETIC AND 
 
 as a basis of geology and phylogenesis — -these or any 
 other dogma, at pleasure, from any other church will 
 make all other doctrine quite superfluous. Yirchow, 
 " that critical spirit," knows as well as I, and as every 
 other naturalist, that these dogmas are not true, and 
 nevertheless, in his opinion, they are not to be sup- 
 planted as the "basis of instruction" by those theories 
 and hypotheses of modern natural science of which 
 Virchow himself says that they may be true, that in 
 a great measure they probably are true, but are not 
 yet " quite certainly proved." 
 
 At pages 15, 24, 26, 28, and elsewhere in his 
 Munich address, Virchow strongly insists that only 
 that objective knowledge may be taught which we 
 possess as absolutely certain fact ! and then at page 
 29 he requires us to conclude that the basis of instruc- 
 tion shall continue to be the purely subjective dogmas 
 of the Church ; revelations and dogmas which not only 
 are not proved by any facts whatever, but on the con- 
 trary, stand in the most trenchant contradiction to the 
 most obvious facts of natural experience and fly in the 
 'face of all human reason. These contradictions, to be 
 sure, are no greater than some others which stand out 
 conspicuous and incomprehensible in Yirchow's dis- 
 course. Thus at the beginning of his address he 
 glorifies Lorenz Oken and deeply laments "that he, 
 that highly-valued and honoured master, that ornament 
 
DOGMATIC METHODS OF TEACHING. 83 
 
 of the high school of Munich, had been forced to die 
 in exile ! That cruel exile which oppressed Oken's 
 latter years, which left him to perish far from those 
 cities to which he had sacriJSced the best powers of 
 his life, that exile will be remembered as the note 
 of the time which we have passed through. And so 
 long as there continue to be meetings of German 
 naturalists, so long may we gratefully remember that 
 this man to his death bore upon him all the signs of 
 a martyr, so long shall we point to him as one of the 
 witnesses who have fought for us and for the liberty 
 of science." Verily these words from Virchow's lips 
 sound like the bitterest irony; for was not Lorenz 
 Oken one of the foremost and most zealous champions 
 of that monistic doctrine of development against which 
 Eudolf Virchow at this day is most violently striving ? 
 Did not Oken himself proceed farther in the construc- 
 tion of bold hypotheses and comprehensive theories 
 than any supporter of the doctrine of evolution at the 
 present time ? Is not Oken justly considered as the 
 one typical representative of that older period of 
 natural philosophy who rose to much higher and bolder 
 flights of fancy, and left the solid ground of facts much 
 farther behind him than any tyro of the new philo- 
 sophy ? And this makes the irony seem all the greater 
 with which Virchow at the beginning of his address 
 
84 THE GENETIC AND 
 
 glorifies Oken the free teacher, as a martyr to the 
 freedom of science, and at the end of it insists that 
 this freedom applies only to inquiry and not to teach- 
 ing, and that the master must teach no problem, no 
 theory, no hypothesis. 
 
 While this unheard-of demand sets Virchow's views 
 of teaching in the most extraordinary light, and while 
 every unprejudiced and experienced teacher must 
 most emphatically protest against this strait-waist- 
 coat for instruction, he will feel no less bound to resist 
 Virchow's other strange demand, that every ascertained 
 truth shall forthwith be taught in all schools, down 
 to the elementary schools. I myself, in my Munich 
 address, sought the instructional value of our monistic 
 evolution theory above all in the genetic method, in 
 the inquiry, that is to say, for the effective causes of 
 the facts taught; and I added these words — "How 
 far the principles of the doctrine of universal evolution 
 ought to be at once introduced into our schools, and in 
 what succession its most important branches ought to 
 be taught in the different classes — cosmogony, geology, 
 the phylogenesis of animals and plants,. ^nd anthro- 
 pology — this we must leave to practical teachers to 
 settle. But we believe that an extensive reform of 
 instruction in this direction is inevitable, and will be 
 crowned by the fairest results." I purposely avoided 
 
DOGMATIC METHODS OF TEACHING. 85 
 
 any closer discussion of tliis specialist question, as I 
 felt not even approximately capable of solving it, and 
 I believe, in fact, that none but skilled and experienced 
 practical teachers can undertake the solution of it with 
 any success. 
 
 Eor Virchow these specialist difficulties seem not to 
 exist ; he regards my reticence as a mere " postponement 
 of the task," and he answers in the following astonish- 
 ing sentences : — " If the theory of descent is as certain 
 as Herr Haeckel assumes, then we must demand — 
 for it is a necessary consequence — that it shall be 
 taught in schools. How is it conceivable that a 
 doctrine of such importance, which must effect such a 
 total revolution in all our mental consciousness, which 
 directly tends to create a new kind of religion, should 
 not be included in the school scheme of instruc- 
 tion ? How is it possible that such a — revelation, 
 shall I say — should be in any measure suppressed, 
 or that the promulgation of the greatest and most im- 
 portant advance which has been made in our views 
 during the present century should be left to the dis- 
 cretion of schoolmasters ? Ay, gentlemen, that would 
 indeed be a renunciation of the hardest kind, and 
 practically it could never be carried out ! Every 
 schoolmaster who assumes this doctrine for himself 
 will involuntarily teach it, how can it be otherwise ? " 
 
86 THE GENETIC AND 
 
 I must here be permitted to take Yirchow exactly 
 at his word. I endorse alrdost all that he has said in 
 these and the following sentences. ■ The only difference 
 in our views is this, that Yirchow regards the theory 
 of descent as an unproved and unproveable hypothesis; 
 I, on the contrary, as a fully established and indispen- 
 sable theory. How then will it be if the teachers of 
 whom Yirchow speaks agree with my views, if — apart, 
 of course, from all special theories -of descent — they, 
 like me, consider the general theory of descent as the 
 indispensable basis of all biological teaching ? And 
 that that is actually the case Yirchow may easily 
 convince himself if he looks over the recent literature 
 of zoology and botany ! Our whole morphological 
 literature in particular is already so deeply and com- 
 pletely penetrated by the doctrine of descent, phylo- 
 genetic principles already prevail so universally as a 
 certain and indispensable instrument of inquiry, that 
 no man for the future would deprive himself of their 
 help. As Oscar Schmidt justly observes — " Perhaps 
 ninety-nine per cent, of all living, or rather of all work- 
 ing zoologists, are convinced by inductive methods of 
 the truth of the doctrine of descent." And Yirchow 
 with his magisterial requirements will attain only the 
 very reverse of what he aims at. How often has it 
 not been said already that science must either have 
 perfect freedom or else none at all ? This is as true 
 
DOGMATIC METHODS OF TEACHING. 87 
 
 of teaching as it is of inquiry, for the two are intrinsi- 
 cally and inseparably connected. And so it is not in 
 vain that it is written in section i 5 2 of the German 
 Code, and in section 20 of the Prussian Charter, 
 " Science and her teaching shall be free ! " 
 
( 88 ) 
 
 CHAPTEE VI 
 
 THE DOCTRINE OF DESCENT AND SOCIAL DEMOCRACY. 
 
 Every great and comprelieiisive theory which affects 
 the foundations of human science, and which, conse- 
 quently, influences the systems of philosophy, will, in 
 the first place, not only further our theoretical views of 
 the universe, but will also react on practical philosophy 
 ethics, and the correlated provinces of religion and 
 politics. In my paper read at Munich I only briefly 
 pointed out the happy results which, in my opinion, 
 the modern doctrine of evolution will entail when the 
 true, natural religion, founded on reason, takes the place 
 of the dogmatic religion of the Church, and its leading 
 principle derives the human sense of duty from the 
 social instincts of animals. 
 
 The references to the social instincts which I, in 
 common with Darwin and many others, regard as the 
 proper source and origin of all moral development, 
 appear to have afforded Virchow an opportunity in his 
 reply for designating the doctrine of inheritance as a 
 " socialist theory," and for attributing to it the most 
 
THE DOCTRINE OF DESCENT, ETC. 89 
 
 dangerous and objectionable character which, at the 
 present time, any political theory can have ; and these 
 startling denunciations so soon as they were known 
 called forth such just indignation and such compre- 
 hensive refutation that I might very properly pass 
 them over here. Still we must at least shortly examine 
 them, in so far as they supply a further proof that 
 Virchow is unacquainted with the most important prin- 
 ciples of the development-theory of the day, and there- 
 fore is incompetent to judge it. Moreover, Yirchow, as 
 a politician, manifestly attributed special importance 
 to this political application of his paper, for he gave it 
 the title, which otherwise would have been hardly 
 suitable, of " The Freedom of Science in the Modern 
 Polity." Unfortunately he forgot to add to this title 
 the two words in which the special tendency of his 
 discourse culminates ; the two pregnant words, " must 
 cease ! " 
 
 The surprising disclosures in which Yirchow de- 
 nounces the doctrine of evolution, and particularly the 
 doctrine of descent, as socialist theories and dangerous 
 to the community, run as follows : — " Now, picture to 
 yourself the theory of descent as it already exists in 
 the brain of a socialist. Ay, gentlemen, it may seem 
 laughable to many, but it is in truth very serious, and 
 I only hope that the theory of descent may not entail 
 on us all the horrors which similar theories have 
 
90 THE DOCTRINE OF DESCENT 
 
 actually brought upon neighbouring countries. At all 
 times this theory, if it is logically carried out to the 
 end, has an uncommonly suspicious aspect, and the 
 fact that it has gained the sympathy of socialism has 
 not, it is to be hoped, escaped your notice. We must 
 make that quite clear to ourselves." 
 
 On reading this statement, which seems extracted 
 from the Berlin " Kreuz-Zeitung," or the Vienna 
 " Yaterland," I ask myself in surprise, " What in the 
 world has the doctrine of descent to do with socialism ? " 
 It has already been abundantly proved on many sides, 
 and long since, that these two theories are about as 
 compatible as fire and water. Oscar Schmidt might 
 with justice retort, " If the socialists would tliink 
 clearly they would feel that they must do all they can 
 to choke the doctrine of descent, for it declares with 
 express distinctness that socialist ideas are im- 
 practicable." And he proceeds to add, " And why has 
 not Yirchow made the gentle doctrines of Christianity 
 responsible for the excesses of socialism ? That would 
 have had some sense. His denunciation flung so 
 mysteriously and so confidently before the great public, 
 as though it concerned ' a sure and attested scientific 
 truth,' is, at the same time, so hollow that- it cannot 
 be brought into harmony with the dignity of science." 
 
 With all these empty accusations, as with all the 
 empty reproaches and groundless objections which 
 
AND SOCIAL DEMOCRACY. 91 
 
 Virchow brings again&t tlie doctrine of evolution, lie 
 takes good care in no way to touch the kernel of the 
 matter. How, indeed, would it have been possible 
 without arriving at conclusions wholly opposed to 
 those which he has declared ? For the theory of 
 descent proclaims more clearly than any other scientific 
 theory, that that equality of individuals which socialism 
 strives after is an impossibility, that it stands, in fact, 
 in irreconcilable contradiction to the inevitable in- 
 equality of individuals which actually and everywhere 
 subsists. Socialism demands equal rights, equal duties, 
 equal possessions, equal enjoyments for every citizen 
 alike ; the theory of descent proves, in exact opposition 
 to this, that the realisation of this demand is a pure 
 impossibility, and that in the constitutionally organised 
 communities of men, as of the lower animals, neither 
 rights nor duties, neither possessions nor enjoyments 
 have ever been equal for all the members alike nor 
 ever can be. Throughout the evolutionist theory, as 
 in its biological branch, the theory of descent — the 
 great law of specialisation or differentiation — teaches 
 us that a multiplicity of phenomena is developed from 
 original unity, heterogeneity from original similarity, 
 and the composite organism from original simplicity. 
 The conditions of existence are dissimilar for each 
 individual from the beginning of its existence ; even 
 the inherited qualities, the natural " disposition," are 
 
92 THE DOCTRINE OF DESCENT 
 
 more or less unlike ; how, then, can the problems 
 of life and their solution be alike for all ? The 
 more highly political life is organised, the more 
 prominent is the great principle of the division of 
 labour, and the more requisite it becomes for the 
 lasting security of the whole state that its members 
 should be variously distributed in the manifold tasks 
 of life ; and as the work to be performed by different 
 individuals is of the most various kind, as well as the 
 corresponding outlay of strength, skill, property, &c., 
 the reward of the work must naturally be also ex- 
 tremely various. These are such simple and tangible 
 facts that one would suppose that every reasonable and 
 unprejudiced politician would recommend the theory 
 . of descent, and the evolution hypothesis in general, as 
 the best antidote to the fathomless absurdity of ex- 
 travagant socialist levelling. 
 
 Besides, Darwinism, the theory of natural selection 
 — which Virchow aimed at in his denunciation, much 
 more especially than at transformation, the theory of 
 descent — which is often confounded with it — Darwin- 
 ism, I say, is anything rather than socialist ! If this 
 English hypothesis is to be compared to any definite 
 political tendency — as is, no doubt, possible — that 
 tendency can only be aristocratic, certainly not demo- 
 cratic, and least of all socialist. The theory of selec- 
 tion teaches that in human life, as in animal and plant 
 
AND SOCIAL DEMOCRACY, 93 
 
 life everywhere, and at all times, only a small and 
 chosen minority can exist and flourish, while the 
 enormous majority starve and perish miserably and 
 more or less prematurely. The germs of every 
 species of animal and plant and the young individuals 
 which spring from them are innumerable, while the 
 number of those fortunate individuals which develop 
 to maturity and actually reach their hardly- won life's 
 goal is out of all proportion trifling. The cruel and 
 merciless struggle for existence which rages throughout 
 all living nature, and in the course of nature must 
 rage, this unceasing and inexorable competition of all 
 living creatures, is an incontestable fact ; only the 
 picked minority of the qualified " fittest " is in a posi- 
 tion to resist it successfully, while the great majority 
 of the competitors must necessarily perish miserably. 
 We may profoundly lament this tragical state of 
 things, but we can neither controvert it nor alter it. 
 " Many are called but few are chosen." The selection, 
 the picking out of these '' chosen ones," is inevitably 
 connected with the arrest and destruction of the 
 remaining majority. Another English naturalist, 
 therefore, designates the kernel of Darwinism very 
 frankly as the " survival of the fittest," as the " victory 
 of the best." At any rate> this principle of selection is 
 nothing less than democratic, on the contrary, it is 
 aristocratic in the strictest sense of the word. If, there- 
 
94 THE DOCTRINE OF DESCENT 
 
 fore, Darwinism, logically carried out, has, according to 
 Vircliow, " an uncommonly suspicious aspect," this can 
 only be found in the idea that it offers a helping hand 
 to the efforts of the aristocrats. But how the social- 
 ism of the day can find any encouragement in these 
 efforts, and how the horrors of the Paris Commune 
 can he traced to them, is to me, I must frankly confess, 
 absolutely incomprehensible. 
 
 Moreover, we must not omit this opportunity of 
 pointing out how dangerous such a direct and un- 
 qualified transfer of the theories of natural science to • 
 the domain of practical politics must be. The highly 
 elaborate conditions of our modern civilised life require 
 from the practical politician such circumspect and 
 impartial consideration, such thorough historical train- 
 ing and powers of critical comparison, that he will not 
 venture to make such an application of a " natural 
 law " to the practice of civilised life, but with the 
 greatest caution and reserve. How, then, is it possible 
 that Virchow, the experienced and skilled politician, 
 who, above all things, preaches caution and reserve in 
 theory, suddenly makes just such an application of 
 transformation and Darwinism — an application so 
 radically perverse that it actually flies in the face of 
 the fundamental ideas of these doctrines ? I myself 
 am nothing less than a politician. In direct contrast 
 with Yu'chow, I lack alike the gift and the training for 
 
AND SOCIAL DEMOCRACY. 95 
 
 it, as well as taste and * vocation. Hence I neither 
 shall play any political part in the future, nor have I 
 hitherto made any attempt of the kind. Though here 
 and there I have occasionally uttered a political 
 opinion, or have made a political application of some 
 theory of natural science, these subjective opinions 
 have no objective value. In point of fact I have by 
 so doing overstepped the limits of my competence, just 
 as Virchow has by going into questions of zoology and 
 particularly that of the transformation of apes : I am 
 a layman in political practice, as Virchow is in the 
 province of zoological hypothesis. Moreover, such 
 success as Virchow has attained during the twenty 
 years of his painful, wearisome, and exhausting acti- 
 vity as a politician does not, in truth, make me pine 
 for such laurels. 
 
 But this at least I, as a theoretical naturalist, may 
 demand of practical politicians, that in utilising our 
 theories for political ends they should first make them- 
 selves exactly acquainted with them ; they then, for 
 the future, would forbear drawing conclusions from 
 them, the very opposite to those which ought reasonably 
 to be inferred. Misunderstandings would never thus 
 be wholly avoided, it is true, but what doctrine is 
 universally secure against misunderstanding ? And 
 from what theory, however sound and true, may not 
 the most unsound and frantic inferences''be drawn ? 
 
96 THE DOCTRINE OF DESCENT 
 
 ISTotMng, perhaps, shows so plainly as the history of 
 Christianity how little theory and practice harmonise 
 in human life ; how little pains are taken, even by 
 those whose calling it is to uphold established doc- 
 trines, to apply their natural consequences to practical 
 life. The Christian religion, no doubt, as well as the 
 Buddhist, when stripped of all dogmatic and fabulous 
 nonsense, contains an admirable human kernel, and 
 precisely that human portion of Christian teaching — 
 in the best sense social-democratic — which preaches 
 the equality of all men before God, the loving of your 
 neighbour as yourself, love in general in the noblest 
 sense, a fellow-feeling with the poor and wretched, and 
 so forth — precisely, those truly human sides of the 
 Christian doctrine are so natural, so noble, so pure, 
 that we unhesitatingly adopt them into the moral doc- 
 trine of our monistic natural religion. Nay, the social 
 instincts of the higher animals on which we found this 
 religion (for instance the marvellous sense of duty of 
 ants, &c.) are in this best sense strictly Christian. 
 
 And what — we may ask — what have the professed 
 supporters, the " learned divines " of this religion of 
 love done ? Their deeds are written in letters of blood 
 in the history of the civilisation of mankind during - 
 the last 1800 years. All else that differing church- 
 religions have accomplished for the forcible extension 
 of their doctrfties and for the extirpation of heretics of 
 
AND SOCIAL DEMOCRACY. 97 
 
 other creeds, aril that the Jews have been guilty of 
 towards the heathen, the Eoman emperors towards the 
 Christians, the Mohammedans towards Christians and 
 Jews alike — all this is outdone by the hecatombs of 
 human victims which Christianity has demanded for 
 the spread of her doctrines. And these were Christians 
 against Christians — orthodox Christians against hetero- 
 dox Christians ! think only of the Inquisition in the 
 Middle Ages, of the inconceivable and inhuman bar- 
 barities committed by the " most Christian kings " of 
 Spain, by their worthy colleagues in Prankfort, in Italy, 
 and elsewhere. Hundreds of thousands then died 
 that most horrible death by fire, simply because they 
 would not bend their reason to pass under the yoke of 
 the grossest superstition, and because their loyalty to 
 their convictions forbade them to deny the natural 
 truth that they clearly discerned. There are no deeds 
 more hideous, base, and inhuman than those that at 
 that time were committed — nay, are still committed — 
 in the name and on account of " true Christianity." 
 
 And finally, how do matters stand with regard to 
 the morality of the priests who announce themselves 
 as the ministers of God's Word, and whose duty is 
 therefore above all others to carry out the saving 
 doctrines of Christianity in their own lives ? The long, 
 unbroken, and horrible series of crimes of every kind 
 which is offered by the history of the Eoman Popes is 
 
98 THE DOCTRINE OF DESCENT, ETC. 
 
 the best answer to this question. And just as* these 
 "Vicars of God on earth" did, so did their subordi- 
 nates and accomplices, so, too, have the orthodox priests 
 of other sects done ; never failing to set the practice of 
 their own course of life in the strongest possible con- 
 trast to those noble doctrines of Christian love which 
 were constantly on their lips. 
 
 And as with Christianity so it is with every other 
 religious and moral doctrine which ought to have 
 proved its power in the wide domain of practical 
 philosophy, in the education of youth, in the civilisa- 
 tion of nations. The theoretic kernel of this doctrine 
 may always and everywhere stand in the most glaring 
 contradiction to its practical working-out, testifying to 
 the endless inconsistency of human nature : but what 
 can all this matter to the scientific inquirer? His 
 sole and only task is to seek for truth and to teach 
 what he has discerned to be the truth, indifferent as 
 to what consequences the various parties of state or 
 church may happen to draw from it. 
 
( 99 ) 
 
 CHAPTEE VII. 
 
 IGNOEABIMUS ET RESTKINGAMUR. 
 
 The dangerous attempt which Yirchow made in 
 Munich against the freedom of science is not the 
 first of its kind. On the contrary, five years before, it 
 experienced a similar attack which is most intimately 
 connected with this later one, so that, in conclusion, 
 we must here add a few words on the subject. Un- 
 doubtedly the famous " Ignorabimus-speech " of Du 
 Bois-Eeymond, which he delivered in 1872 at the 
 forty-fifth meeting of German naturalists and physicians 
 in Leipzig, forms only the first portion of that same 
 crusade against the freedom of science of which Vir- 
 chow's " Eestringamur speech " of 1877, at the fiftieth 
 meeting of the same society, forms the second part. 
 
 That brilHant and powerful essay by Du Bois-Eey- 
 mond " on the Limitation of Natural Knowledge " has 
 already been discussed so often, and from such different 
 sides, that it might seem superfluous to say another 
 word about it. It seems to me, nevertheless, that by 
 most people the centre-of-gravity of its contents was 
 
loo IGNORABIMUS ET RESTRINGAMUR. 
 
 overlooked in admiration of the brilliant accessories of 
 the essay. Indeed this frequently happens with Du 
 Bois-Eeymond's articles, for he knows too well how to 
 conceal the weakness of his argument and evidence, 
 and the shallowness of his thought, by striking images 
 and flowery metaphors, and by all the phraseology of 
 rhetoric in which the versatile French nature is so 
 superior to our sober German one. It is all the more 
 important that we should not let ourselves be dazzled 
 by these seductive tricks, and particularly by adduced 
 facts which bear upon the most important and funda- 
 mental questions of human science, but that we should 
 extract the hard kernel from the savoury and fragrant 
 fruit. In the preface to my " Evolution of Man," and 
 in the notes 2 2 and 2 3 of my Munich address, I have 
 already incidentally alluded to the chief weaknesses 
 of the " Ignorabimus-speech ; " but I must here return 
 somewhat more fully to the subject. 
 
 There are, as is well known, two problems which Du 
 Bois-Eeymond propounds as the impassable boundary 
 of human knowledge of nature ; limits which indeed 
 the human mind is not only incapable of passing at 
 the present stage of its development, but which it 
 never can be capable of passing in any more advanced 
 stage. The first problem is the nature and connection 
 of matter and force ; the second is human conscious- 
 ness. ISTow, first of all, as has already been said in 
 
IGNORABIMUS ET RESTRINGAMUR. loi 
 
 the preface to the "Evohition of Man," we must 
 raise a decided protest against the air of infalli- 
 bility with which Du Bois-Eeymond pronounces 
 that these two problems are insoluble, not only at 
 the present time but to all futurity. The power of 
 development inherent in science and knowledge is 
 hereby simply swept away with a word. Almost 
 every great and difficult problem of knowledge seems 
 to most or all contemporary thinkers insoluble, and 
 every path to the solution of it seems closed, till at 
 last the ])old genius appears whose clear sight detects 
 the right path which till then was hidden, and which 
 leads to the required knowledge. We need only call 
 to mind our present doctrine of evolution. The pro- 
 blem of creation — the question as to the origin of 
 animal and vegetable species — was universally looked 
 upon as transcendental and perfectly insoluble, till the 
 genius of Lamarck established the . principles of the 
 theory of descent in his admirable " Philosophie Zoo- 
 logique" in 1809. Nay, even then most — and among 
 them the most distinguished — biologists thought the 
 problem of creation a quite insoluble mystery, and 
 Darwin was the first to solve it, fifty years later, by 
 his theory of selection in 1859. Hence we venture to 
 assert that there is no scientific problem of which we 
 may dare to say that the mind of man will never solve 
 it even in the remotest future. Well does Darwin 
 
I02 IGNORABIMUS ET RESTRINGAMUR. 
 
 say, in the introduction to his " Descent of Man/* 
 "Ignorance more frequently begets confidence than 
 does knowledge : it is those who know little and not 
 those who know much who so positively assert that 
 this or that problem will never be solved by science." 
 As far as concerns the two separate limits which Du 
 Bois-Eeymond fixes for human knowledge, in my 
 opinion they are undoubtedly identical. The pro- 
 blem of the origin and nature of consciousness is 
 only a special case of the general problem of the 
 connection of matter and force. Du Bois-Eeymond 
 himself indicates that this is possible at the close of 
 his paper ; for he says, " Finally, the question arises 
 whether the two limitations to our natural knowledge 
 may not perhaps be identical ; that is to say, whether 
 if we could conceive of the true essence of matter and 
 force, we should not also understand how the substance 
 which lies at their root can, under certain given con- 
 ditions, feel, desire, and think.. This conception is, no 
 doubt, the simplest, and according to admitted principles 
 of inquiry it is to be preferred to that other which it 
 confutes, and according to which, as has been said, the 
 world appears doubly incomprehensible. But it is in 
 the very nature of things that we cannot on this point 
 come to any clear conclusion, and all further words on 
 the subject are idle — and so, " Ignorabimus." 
 
 The light way in which Du Bois-Eeymond here 
 
IGNORABIMUS ET RESTRINGAMUR. 103 
 
 passes over the most important part of Ms subject is 
 truly surprising; as if it were ultimately indifferent 
 whether we have before us one single insoluble funda- 
 mental problem or two quite different ones ; and as if 
 mature reflection did not lead to the conviction that, 
 in fact, the second problem is only a special case of the 
 first general problem. I, for my part, cannot conceive 
 of them in any other relation ; I think, too, that all 
 further words are by no means superfluous, but on the 
 contrary conduce to a very strong conviction of the 
 unity of the problem. That Du Bois-Eeymond also 
 has not come to any clear conclusion on this point 
 lies, not alone in the " nature of things," but, as in 
 Virchow's case, in the nature of the investigator him- 
 self; in his lack of knowledge of the history of 
 evolution, and in his neglect of those comparative 
 and genetic methods of study, without which, in my 
 opinion, not even an approximate solution of this 
 highest and most difi&cult question is to be looked 
 for. 
 
 Nothing appears to me to be of more importance 
 for the mechanical explanation of consciousness than 
 the comparative consideration of its development. We 
 know that a new-born child has no consciousness, but 
 that it is slowly and gradually acquired and developed. 
 We perceive for ourselves how unconscious actions 
 become conscious, and vice versa. Innumerable actions 
 
I04 IGNORABIMUS ET RESTRINGAMUR. 
 
 whicli at first are troublesome and have to be learnt 
 with consciousness and reflection — as for instance 
 walking, swimming, singing, and so fortb-^become 
 unconscious only by repetition, practice, and the habit 
 of using the organs. On the contrary, unconscious 
 actions become conscious as soon as we direct our 
 attention to them or our self-observation is attracted to 
 them ; as for instance when we miss a step in going up 
 stairs or touch a wrong note on the piano ; and beyond 
 a doubt, conscious and unconscious actions pass into 
 each other without any distinct line of demarcation. 
 Finally, we see no less plainly by a comparative con- 
 sideration of the soul-life of animals, that their con- 
 sciousness is slowly, gradually, and serially developed, 
 and that a long unbroken series of steps leads from 
 unconscious to conscious existence. From these com- 
 parative and genetic experiences we may draw the 
 conclusion that consciousness, like sensation ' and voli- 
 tion, like all the other soul-activities, is a function of 
 the organism, a mechanical activity of the cells ; and, as 
 such, is referable to chemical and physical processes. 
 Hence, if we were in a position to understand force as 
 a necessary function of matter, we could explain con- 
 sciousness, as well as the soul in general, as a neces- 
 sary function of certain cells. 
 
 How little Du Bois-Eeymond is acquainted with the 
 facts of comparative and genetic psychology, nothing 
 
IGNORABIMUS ET RESTRINGAMUR. 105 
 
 shows more strikingly than the following astounding 
 proposition in the " Ignorabimus-speech : " — " Where 
 the material conditions for psychical activity, in the 
 form of a nervous system, are wanting, as in plants, 
 the naturalist cannot recognise a soul-life, and, on this 
 point, he but seldom meets with contradiction." Beg- 
 ging your pardon ! Every naturalist who is familiar 
 with the comparative morphology and physiology of 
 the lower animals will here put in a decided contradic- 
 tion, for he can no more refuse to admit the undoubted 
 sensation and voluntary motion of the one-celled 
 Infusoria than of the many-celled hydroid polyps. 
 The body of the true Infusoria (Ciliata, Acineta, &c.), 
 and many other Protista, remain throughout life one 
 single cell, and, nevertheless, this cell is as fully fur- 
 nished with all the most important attributes of the 
 soul, with sensation and volition, as any one of the 
 higher animals with a nervous system. The same 
 obtains of the Hydra and the related hydroid polyps, 
 in which the neuro-muscular cells, or other distributed 
 cells of the outer germ-layer, fulfil the soul-func- 
 tions. But as these cells, besides this, exercise motor 
 and other functions as well, we cannot as yet designate 
 them as nerve- cells, at any rate there can be no idea 
 of a special nervous-system. The characteristic soul- 
 organs of the higher animals, which we include under 
 the conception of a nervous-system, in fact originated 
 
io6 IGNORABIMUS ET RESTRINGAMUR. 
 
 by the division of labour of the cells out of those 
 neutral cell-groups in their lower-typed ancestors. 
 
 In the great Soul-question Du Bois-Reymond, like 
 Virchow, still keeps his position on the standpoint of 
 neural-psychology, according to which no personal 
 soul-life is conceivable without a nervous system. We 
 look upon this standpoint as left far behind, and set 
 up in opposition to it Cellular-psychology, the doctrine 
 that every animal cell has a soul ; that is to say, that 
 its protoplasm is endowed with sensation and motion. 
 In the one-celled infusoria, which are so highly sensi- 
 tive and have such an energetic will, this conception 
 will be clear without any farther explanation. But 
 we cannot refuse to allow that plant-cells as well as 
 animal-cells have psychic functions, since we know 
 that the phenomena of irritability, and of " automatic 
 motion," are the universal attributes of all protoplasm. 
 No doubt the specific mechanism, the cause of motion, 
 in the irritable Mimosa and other " sensitive " plants, 
 is quite different, from the muscular motions of ani- 
 mals; but these, like those, are only specifically 
 different forms of development of the " cell-soul," and 
 both proceed from the " mechanical energy of the 
 protoplasm." The sensibility of the irritable proto- 
 plasm is the same in the vegetable-cell of the Mimosa 
 as in the animal- cell of the Hydra. How far Du Bois- 
 Eeymond is from discerning this, and how deeply he 
 
IGNORABIMUS ET RES TRING AMUR. 107 
 
 is still entangled in nenro-psy ecological views is shown 
 most clearly in the astonishing sentence which he has 
 thought good to append to his above-quoted, erroneous 
 assertion. " And what could we reply to the natura- 
 list if, before he could agree to the assumption of a 
 World-soul he required that we should show him — 
 bedded in neuroglia and nourished by warm arterial 
 blood — anywhere in the world a convolution of gan- 
 glionic centres co-extensive with the psychic capacity 
 of such a Soul " (!) 
 
 In other respects we will not deny that Du Bois- 
 Eeymond stands far nearer to our recent evolution- 
 theory than Yirchow; nay, that from year to year 
 he has always pronounced more and more emphati- 
 cally in favour of the theory of descent as the one 
 possible explanation of morphological phenomena; 
 indeed, Du Bois-Eeymond has lately counted himself 
 as one of those naturalists who were convinced of 
 the truth of evolution even before Darwin ! Then 
 it is only to be wondered why so acute and gifted an 
 inquirer, who is certainly not lacking in scientific 
 ambition, left it to Charles Darwin to place the Qgg of 
 Columbus on the ring and to point out to biological 
 science a new method of unlimited capacity by giving 
 the theory of descent a definite and reliable basis ! 
 
 It is clear from some remarks in his discourse bear- 
 ing the title " Darwin versus Galiani " (1876), that Du 
 
io8 IGNORABIMUS ET RESTRINGAMUR. 
 
 Bois-Eeymond is still far from -understanding the full 
 significance of transmutation as affording a mecha- 
 nical explanation of morphological problems. In this 
 paper the " History of Creation " is treated simply as 
 a romance, and the genealogies of phylogenesis are in 
 his eyes " of about as much value as the pedigrees of 
 the Homeric heroes are in the eyes of historical critics." 
 Geologists may be extremely grateful for this estimate 
 of their science, for undoubtedly geology, as a structure 
 of hypotheses, is neither more nor less justifiable than 
 phylogenesis, as I have already pointed out in my 
 Munich address : " Our phylogenetic hypotheses may 
 claim to have equal value with the universally-admitted 
 hypotheses of geology ; the only difference is this, that 
 the mighty structure of hypotheses called geology is 
 incomparably more complete, simpler, and easier to 
 grasp than that more youthful one called phylogenesis." 
 But as to the much-talked-of " genealogies," though 
 they are nothing more than the simplest, barest, and 
 most superficial expression of the hypotheses of 
 phylogenesis, as provisional hypotheses they are just 
 as indispensable to specific phylogenesis as the theo- 
 retical section-tables of the strata of the earth's crust 
 are to geology. 
 
 If Du Bois-Eeymond is so convinced of the truth 
 of transmutation as he has lately given himself out 
 to be, why does not he make at least one earnest 
 
IGNORABIMUS ET RESTRINGAMUR. 109 
 
 attempt to test the interpreting power of the theory of 
 descent in physiology — his own most special province 
 of inquiry ? ' Why does he not labour at that hitherto 
 quite unworked-out branch, physiogenesis, at the his- 
 tory of the evolution of functions, at the ontogenesis 
 and phylogenesis of vital processes ? The one idea 
 which has lately been often spoken of as an important 
 discovery of Du Bois-Eeymond's — [the idea which had 
 already been anticipated by Leibnitz, that the " innate 
 ideas," — intuitions a 'priori — have originated by trans- 
 mission from primordial experience, i.e., empirical, db 
 posteriori convictions], was distinctly enunciated by me 
 long before Du Bois-Eeymond (as he omits to mention), 
 in I Z66, in my " General Morphology " (vol. ii. p. 446), 
 and in 1868 in the "History of Creation" (vol. i. p. 
 31, vol. ii. p. 344). If Du Bois-Eeymond had prac- 
 tically busied himself with these problems he would 
 certainly have thought a little about the development 
 of consciousness, and not have set down as an eternally 
 insoluble problem, " How is it possible that matter can 
 think ? " — a form of words, be it observed, which has 
 about as much sense as " how matter runs," or " how 
 matter strikes the hours." Surely he would have 
 guarded himself in that case from uttering the pon- 
 derous " Tgnorabimus." 
 
 ,-The question has been repeatedly asked why two 
 such prominent Berlin biologists as Yirchow and Du 
 
no IGNORABIMUS ET RESTRINGAMUR. 
 
 Bois-Eeymond availed themselves of the particularly 
 solemn occasions of the fiftieth anniversary and of the 
 fiftieth meeting of the German naturalists and physi- 
 cians to lay lance in rest against the progress and free- 
 dom of science. The eager approbation which they 
 both promptly met with from the party of the clergy 
 and of all other enemies of free thought — Virchow, in- 
 deed, in much greater measure than Du Bois-Eeymond 
 — appears to justify this inquiry. I believe I can con- 
 tribute something towards answering it, and as I am 
 not fettered by any reverence for the Berlin tribunal 
 of science or by any anxiety as to vexing influential 
 Berlin connections, as most of my colleagues are who 
 think as I do, I do not hesitate, here as elsewhere, to 
 express my honest conviction in the freest and frankest 
 manner, not troubling myself about the wrath which 
 may be roused in many actual — and not actual — offi- 
 cials in Berlin at this exposition of the unvarnished 
 truth. 
 
 The primary cause of their " misunderstanding," and 
 the best excuse that can be offered for it, in Virchow 
 and Du Bois-Eeymond alike, lies in their unacquaint- 
 ance with the advance of modern morphology. As 
 has been repeatedly stated, no natural science is so 
 directly to be referred to the doctrine of evolution — 
 and more particularly to the theory of descent — as 
 morphology. It is because we morphologists can 
 
IGNORABIMUS ET RESTRINGAMUR. in 
 
 neither explain nor comprehend all the manifold and 
 infinitely complex form-phenomena of the animal 
 and plant worlds without this theory, because to us 
 transmutation contains the only possible, rational ex- 
 planation of organic types, that we all regard it as the 
 indispensable basis of the scientific doctrine of form, 
 and as demanding no further proofs of its certainty 
 than those which now lie in abundance before us. 
 
 Du Bois-Eeymond, and still more Virchow, ignore 
 these proofs, because they are to a great extent ignorant 
 alike of the inquiries and results, of the methods 
 and the aims of our modern morphology, and this 
 ignorance may be accounted for partly by the one- 
 sided direction which their biological studies have 
 taken, partly by the fact tfiat there are few univer- 
 sities where the study of morphology is so behindhand 
 as at the University of BerKn. Fully twenty years 
 have now elapsed since the great Johannes Miiller 
 died, the last naturalist who could command all the 
 departments of biology. The three great provinces of 
 science which had been reunited into a triime king- 
 dom under his powerful sceptre, were then divided 
 among three professors' chairs : Du Bois - Eeymond 
 took that of physiology, Yirchow, theoretical pathology 
 (pathological anatomy and physiology), and the third, 
 and most important chair, that of morphology (human 
 
 and comparative anatomy, including the history of 
 7 
 
112 IGNORABIMUS ET RESTRINGAMUR. 
 
 evolution) fell to Boguslaus Eeichert. This choice 
 was, as is now universally admitted, an incomprehen- 
 sible mistake. Instead of calling Carl Gegenbaur, or 
 Max Schultze, or some one else of youthful capacity 
 and vigour to the chair of morphology — a science 
 which is the first foundation of zoology as well as of 
 medicine — in Eeichert they selected an elderly school 
 anatomist cramped hy strong old-fashioned notions, 
 who had done some good and useful specialist work, 
 but whose general views had developed all awry, and 
 who for the unexampled obscurity of his conceptions 
 and the confusion of his ideas, was outdone by none 
 save only Adolf Bastian. For twenty years this man 
 has represented animal morphology in the second 
 university of Germany, and in these twenty years 
 hardly any work worth mentioning has been done 
 there in the whole of this vast department — neither 
 by the master nor by his pupils. We have only to 
 compare the many worthless anatomical productions 
 t)f Berlin during these two decades (for instance, the 
 recent confused work by Tritsch on the brain of 
 fishes) with the rich mine of invaluable work produced 
 during the preceding twenty years by Johannes Miiller 
 and his crowd of disciples. 
 
 But, as if this were not enough, Eeichert took 
 advantage of his influential position to hinder as far 
 as possible all scientific study of morphology. For 
 
IGNORABIMUS E f RESTRINGAMUR. 1 1 3 
 
 example, he, with the co-operation of his colleagues, 
 carried through that pretended " reform " of medical 
 examination which puts the so-called Tentamen pliy- 
 sicum in the place of the philosophicum ; philosophy 
 was entirely eKminated. Zoology and botany, which 
 for centuries have been very justly regarded as the 
 indispensable foundation of all instruction in natural 
 science for the young , medical student, disappeared 
 from the curriculum. Only, as if in scorn of these 
 sciences, in each examination a small place was 
 reserved for comparative anatomy — for that most 
 difficult and philosophical part of animal morphology 
 which cannot be at all understood without some pre- 
 vious knowledge of the other branches of zoology. 
 And yet comparative anatomy and the history of 
 development are the indispensable preliminary steps 
 to a true scientific comprehension of human anatomy, 
 that most essential foundation of all medical laiow- 
 ledge. Without the vivifying idea of development, 
 mere anatomical knowledge is an empty and lifeless 
 cramming of the memory. 
 
 In the place of morphology, thus degraded from its 
 office, a detailed study of physiology was introduced, 
 but always in a one-sided direction. N'ow these two 
 great branches of biology, which are equally important 
 and have an equal claim on our attention, are so 
 dependent the one on the other, that a real scientific 
 
114 IGNORABIMUS ET RESTRINGAMUR. 
 
 understanding of organic life can never be obtained 
 without due relative study of both. The masterly 
 and incomparable teaching of Johannes Miiller owed 
 a great part of its captivating charm to his equitable 
 regard for morphology and physiology, as well as to 
 his comprehensive treatment, from the broadest point 
 of view, of the enormous mass of details to be dealt 
 with. I therefore have not the smallest doubt that 
 the morphological training of medical students, as at 
 present conducted at Berlin under the influence of 
 Eeichert and his colleagues, is as far behind that of 
 Miiller's day, twenty or thirty years ago, in all general 
 comprehension of the typical organism, as it is in 
 advance of it in specialist acquirements. 
 
 In medical, as in all other scientific learning, the 
 highest aim does not consist in seeking to accumu- 
 late a vast chaotic mass of isolated items of knowledge, 
 but in a general comprehension of the science, its aims 
 and problems. The teacher should, above everything, 
 guide the pupil to this general knowledge, and then it 
 will be easy to him, by the aid of proper methods, to 
 acquire mastery in each individual and special branch. 
 Thus in medicine, as in every other science, he is not 
 the best qualified who, on Bastian's method, has loaded 
 his memory with a confused mass of undigested facts, 
 and has flung them all together into his brain without 
 any order ; but, on the contrary, he who lias practically 
 
IGNORABIMUS ET RESTRINGAMUR. 115 
 
 digested a considerable number of the most important 
 facts, and has critically co-ordinated them to a harmo- 
 nious whole. It is precisely under this aspect that 
 transmutation is of such inestimable value to mor- 
 phology; it enables us to rise from the bare empirical 
 knowledge of numberless isolated facts to a philoso- 
 phical conception of their efficient causes. 
 
 The aversion and contempt which the theories of 
 descent and selection have met with at Berlin, more 
 than in any other place, is in great measure to be 
 explained by the circumstance that, during the last 
 two decades, morphological studies have been more 
 neglected in that university than any others. In 
 no other city of Germany has evolution in general, 
 as well as Darwinism in particular, been so little 
 valued, so utterly misunderstood, and treated with 
 such sovereign disdain as in Berlin. ISTay, Adolf 
 Bastian, the most zealous of all the Berlin opponents 
 of our doctrines, has insisted on these facts with pecu- 
 liar satisfaction. Of all the conspicuous naturalists of 
 Berlin only one accepted the doctrine of transmutation 
 from the beginning with sincere warmth and full convic- 
 tion, being, indeed, persuaded of its truth even before 
 Darwin himself. This was the gifted botanist Alex- 
 ander Braun, who is lately dead — a morphologist who 
 was equally distinguished by the extent of his com- 
 prehensive knowledge of details, as by his philosophical 
 
ii6 IGNORABIMUS ET RESTRINGAMUR, 
 
 mastery over them. His firm conviction of the truth 
 of the theory of descent is all the more remarkable 
 because he was at the same time a spotless character, 
 a pious Christian in the best sense of the word, and 
 an extremely conservative politician ; a striking ex- 
 ample that these convictions can dwell side by side 
 with the principles of the recent doctrines of evolution 
 in one and the same person. But in comparison with 
 the powerful influence of the rest of the Berlin natur- 
 alists who, for the most part, are decided opponents 
 of transmutation, and who have only lately — a few of 
 them, to follow the fashion — become converts to it, 
 a man like Alexander Braun could have no effect in 
 procuring that it should be taught. 
 
 However, this is not the first time that this very 
 Berlin society of learned men has set itself with 
 remarkable firmness against the most important 
 advances of science. Yirchow's former colleague, the 
 deceased Stahl, with a similar purpose and with great 
 success, preached this principle : " Science must turn 
 back again." Just as at the present day the Berlin 
 biologists have opposed the most obstinate and pertina- 
 cious resistance to the greatest scientific stride of 
 this century, so did it happen in former times with 
 regard to other doctrines of progress. We have only 
 to recall Caspar Friedrich Wolff, the great inquirer. 
 
IGNORABIMUS ET RESTRINGAMUR. 117 
 
 who in 1759 first detected the nature of the individual 
 processes of development in the animal ovum, and 
 founded on it his observations in his " Theoria Genera- 
 tiones," which marked an epoch in biological science. 
 The Berlin savants, full of the prevailing prejudices, 
 so contrived at that time that Wolff never once could 
 obtain the permission which he craved, to lecture 
 publicly, and in consequence found himself compelled 
 to retire to St. Petersburg for the sake of peace. And 
 yet in that instance there was no question of a 
 "theory" properly so-called. For the fundamental 
 theory of generation — the " theory of epigenesis " — as 
 propounded by Wolff was nothing more than a simple, 
 general exposition of embryological facts which he had 
 been the first to recognise, and of whose truth every, 
 one might convince himself by direct observation. In 
 spite of this, for another half century, the predominant 
 error of the '* Preformation-theory " continued to be 
 universally accepted — the ludicrous and nonsensical 
 doctrine, supported by the authority of Haller, that all 
 the successive generations of animals exist pre-con- 
 ceived and enclosed one within the other, and that no 
 individual development ever takes place ! Nulla est 
 epigenesis ! (Compare my " Evolution of Man," vol. i. 
 
 P-3I-) 
 
 But it would appear that it is the fate of that most 
 
1 1 8 IGNORABIMUS ET RESTRINGAMUR, 
 
 interesting of all sciences, the history of evolution, 
 to find its most important steps and its greatest 
 discoveries met by the firmest and most persistent 
 opposition. For while Wolff's fundamental theory of 
 epigenesis, which was promulgated in 1759, was not 
 recognised until 18 12, Lamarck's theory of descent, 
 founded in 1809, had to wait fully fifty years before 
 Darwin, in 1859, showed it to be the greatest acquisi- 
 tion of modern science ; and during that period, in 
 spite of all the progress made in empirical science, 
 how persistently this most comprehensive of all bio- 
 logical theories was combated. We need only re- 
 collect how, in 1830, the celebrated George Cuvier 
 silenced its most eloquent supporter, Geoffrey St. 
 Hilaire, in the midst of the Paris Academy, and how 
 almost at the same time its founder, the great Lamarck, 
 ended his life in blindness, misery and want, while 
 his opponent Cuvier was enjoying the highest honours 
 and the greatest splendour. And yet we know now 
 that the despised and contemned Lamarck and Geof- 
 frey had already grasped truths of the highest signifi- 
 cance, whUe Cuvier's much-admired and universally- 
 accepted theory of creation is now on all hands 
 neglected as an absurd and untenable delusion. But 
 as neither Haller as against Wolff, nor Cuvier as 
 against Lamarck, could permanently hinder the 
 
IGNORABIMUS ET RESTRINGAMUR. 119 
 
 progress of free inquiry, neither will Virchow succeed 
 in turning back the course of Darwin's admirable 
 achievement; no, not even when he is supported by 
 the discourses of his friend Bastian. 
 
 While we cannot but earnestly lament Virchow's ini- 
 mical attitude in this great struggle for truth, we must 
 not overlook the effects of his well-founded authority in 
 a yet wider sphere. For instance, the hostile attitude 
 which the greater part of the Berlin press persistently 
 maintains towards the doctrine of development (parti- 
 cularly the Liberal "ISTational-Zeitung") is to be referred 
 to the influence of his authority. But much as this 
 reactionary vein, in this and in other intelligent circles 
 at Berlin, must be regretted on the one hand, on the other 
 we must observe that by this evil we have been pre- 
 served from a far greater one. This greater evil— the 
 greatest, in fact, which German science could have to 
 encounter — would be the monopoly of knowledge at 
 Berlin ; a Centralisation of Science. The injurious fruits 
 of this system of centralisation in France, for instance, 
 the continual deterioration of French science through 
 the Parisian " Monopoly of Knowledge," and its steady 
 decline during half a century from the sublimest 
 heights — these are all well known. From such a 
 centralisation of German science — which would be 
 especially dangerous if it occurred in the capital, 
 
I20 IGNORABIMUS ET RESTRINGAMUR, 
 
 Berlin — we may hope to be preserved ; in the first 
 place by the manifold differences and the many-sided 
 individuality of the German national spirit, the much- 
 abused German provincialism (Particularismus). While 
 these provincial modes of thought can never have any 
 permanent political value, nor be productive of a desir- 
 able form of government, it is beyond a doubt that 
 their outcome has been fruitful and happy for German 
 science. For it owes its splendid pre-eminence over 
 that of other countries precisely to the many centres 
 of culture which were offered by those numerous petty 
 capitals of the minor German States which strove to 
 outdo each other in eager emulation. It is to be 
 hoped that this happy decentralisation of science in 
 our politically united fatherland may continue to 
 subsist ! 
 
 And next to this centrifugal tendency of our German 
 national mind nothing will so greatly contribute to 
 it as a vigorous opposition to the free advance of 
 science, such as is just now declaring itself in the 
 metropolis. For by just so much as Berlin is dragged 
 back by it in the mighty onward stream of free intel- 
 lectual movement, by so much will it see itself 
 outstripped by the other seats of culture in Germany, 
 which follow the stream with enthusiasm, or at least 
 without resistance. If Emil du Bois-Eeymond raises 
 
IGNORABIMUS ET RESTRINGAMUR. 121 
 
 the cry of " Ignorabimus," and Eudolf Vircliow his 
 still more audacious one of " Eestringamnr," as the 
 watchwords of science, then, from Jena, let the 
 shout be raised and echoed from a hundred other 
 universities — "Impavidi progrediamur ! " 
 
 lUTr?J^-Jf2.3^ (3',/3,^: 
 
 THE END. 
 
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17867( 
 
 i 
 
 Date Due 
 
 DeC-3'5'i 
 
 m>. 
 
 J UN 22 
 
 JUN 29 
 
 OCT 
 
 4m 
 
 1997 
 
 b 7 
 
BOSTON COLLEGE 
 
 3 9031 01652361 5 
 
 1 
 
 ^ 
 
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