FREEDOM IN SCIENCE AND TEACHING. 

 FROM THE GERMAN OF ERNST HAECKEL. 

 _WITH A PREFATORY NOTE_ By T. H. HUXLEY, F. R. S. 

 DER TELEOLOG "Welche Verehrung verdient der Weltenschöpfer der gnädig. Als er den Korkbaum schuf, gleich auch die Stöpfel erfand. " XENIEN. 

 NEW YORK: D. APPLETON AND COMPANY, 549 AND 551 BROADWAY. 1879. 

PREFATORY NOTE. 

In complying with the wish of the publishers of Professor Haeckel'sreply to Professor Virchow, that I should furnish a prefatory noteexpressing my own opinion in respect of the subject-matter of thecontroversy, Gay's homely lines, prophetic of the fate of those "whoin quarrels interpose, " emerge from some brain-cupboard in which theyhave been hidden since my childish days. In fact, the hard-hittingwith which both the attack and the defence abound, makes me think witha shudder upon the probable sufferings of the unhappy man whoseintervention should lead two such gladiators to turn their weaponsfrom one another upon him. In my youth, I once attempted to stop astreet fight, and I have never forgotten the brief but impressivelesson on the value of the policy of non-intervention which I thenreceived. 

But there is, happily, no need for me to place myself in a positionwhich, besides being fraught with danger, would savour of presumption:Careful study of both the attack and the reply leaves me without theinclination to become either a partisan or a peacemaker: not apartisan, for there is a great deal with which I fully agree said onboth sides; not a peacemaker, because I think it is highly desirablethat the important questions which underlie the discussion, apart fromthe more personal phases of the dispute, should be thoroughlydiscussed. And if it were possible to have controversy withoutbitterness in human affairs, I should be disposed, for the generalgood, to use to both of the eminent antagonists the famous phrase of alate President of the French Chamber--"_Tape dessus. _"

No profound acquaintance with the history of science is needed toproduce the conviction, that the advancement of natural knowledge hasbeen effected by the successive or concurrent efforts of men, whoseminds are characterised by tendencies so opposite that they are forcedinto conflict with one another. The one intellect is imaginative andsynthetic; its chief aim is to arrive at a broad and coherentconception of the relations of phenomena; the other is positive, critical, analytic, and sets the highest value upon the exactdetermination and statement of the phenomena themselves. 

If the man of the critical school takes the pithy aphorism "Meliusautem est naturam secare quam abstrahere"[1] for his motto, thechampion of free speculation may retort with another from the samehand, "Citius enim emergit veritas e falsitate quam e confusione;"[2]and each may adduce abundant historical proof that his method hascontributed as much to the progress of knowledge as that of his rival. Every science has been largely indebted to bold, nay, even to wildhypotheses, for the power of ordering and grasping the endless detailsof natural fact which they confer; for the moral stimulus which arisesout of the desire to confirm or to confute them; and last, but notleast, for the suggestion of paths of fruitful inquiry, which, withoutthem, would never have been followed. From the days of Columbus andKepler to those of Oken, Lamarck, and Boucher de Perthes, Saul, who, seeking his father's asses, found a kingdom, is the prototype of manya renowned discoverer who has lighted upon verities while followingillusions, which, had they deluded lesser men, might possibly havebeen considered more or less asinine. 

On the other hand, there is no branch of science which does not owe atleast an equal obligation to those cool heads, which are not to beseduced into the acceptance of symmetrical formulæ and boldgeneralisations for solid truths because of their brilliancy andgrandeur; to the men who cannot overlook those small exceptions andinsignificant 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 bythe very conditions of thought, have warned mankind against fruitlessefforts to overstep those limits. 

Neither of the eminent men of science, whose opinions are at presentunder consideration, can be said to be a one-sided representativeeither of the synthetic or of the analytic school. Haeckel, no lessthan Virchow, is distinguished by the number, variety, and laboriousaccuracy of his contributions to positive knowledge; while Virchow, noless than Haeckel, has dealt in wide generalisations, and, until theobscurantists thought they could turn his recent utterances toaccount, no one was better abused by them as a typical free-thinkerand materialist. But, as happened to the two women grinding at thesame mill, one has been taken and the other left. Since thepublication of his famous oration, Virchow has been received into thebosom of orthodoxy and respectability, while Haeckel remains anoutcast!

To those who pay attention to the actual facts of the case, this is avery surprising event; and I confess that nothing has ever perplexedme more than the reception which Professor Virchow's oration has metwith, in his own and in this country; for it owes that reception, notto the undoubted literary and scientific merits which it possesses, but to an imputed righteousness for which, so far as I can discern, itoffers no foundation. It is supposed to be a recantation; I can findno word in it which, if strictly construed, is inconsistent with themost extreme of those opinions which are commonly attributed to itsauthor. It is supposed to be a deadly blow to the doctrine ofevolution; but, though I certainly hold by that doctrine with sometenacity, I am able, _ex animo_, to subscribe to every importantgeneral proposition which its author lays down. 

In commencing his address, Virchow adverts to the complete freedom ofinvestigation and publication in regard to scientific questions whichobtains in Germany; he points out the obligation which lies upon menof science, even if for no better reason than the maintenance of thisstate of things, to exhibit a due sense of the responsibility whichattaches to their speaking and writing, and he dwells on the necessityof drawing a clear line of demarcation between those propositionswhich they have a fair right to regard as established truths, andthose which they know to be only more or less well-foundedspeculations. Is any one prepared to deny that this is the first greatcommandment of the ethics of teaching? Would any responsiblescientific teacher like to admit that he had not done his best toseparate facts from hypotheses in the minds of his hearers; and thathe had not made it his chief business to enable those whom heinstructs to judge the latter by their knowledge of the former?

More particularly does this obligation weigh upon those who addressthe general public. It is indubitable, as Professor Virchow observes, that "he who speaks to, or writes for, the public is doubly bound totest the objective truth of that which he says. " There is a sect ofscientific pharisees who thank God that they are not as thosepublicans who address the public. If this sect includes anybody whohas attempted the business without failing in it, I suspect that hemust have given up keeping a conscience. For assuredly if a man ofscience, addressing the public, bethinks him, as he ought to do, thatthe obligation to be accurate--to say no more than he has warrantyfor, without clearly marking off so much as is hypothetical--is farheavier than if he were dealing with experts, he will find his task avery admirable mental exercise. For my own part, I am inclined todoubt whether there is any method of self-discipline better calculatedto clear up one's own ideas about a difficult subject, than that whicharises out of the effort to put them forth, with fulness andprecision, in language which all the world can understand. Sheridanis said to have replied to some one who remarked on the easy flow ofhis style, "Easy reading, sir, is--hard writing;" and any one who isabove the level of a scientific charlatan will know that easy speakingis "----hard thinking. "

Again, when Professor Virchow enlarges on the extreme incompletenessof every man's knowledge beyond those provinces which he has madehis own (and he might well have added within these also), and whenhe dilates on the inexpediency, in the interests of science, ofputting forth as ascertained truths propositions which the progressof knowledge soon upsets--who will be disposed to gainsay him? Norhave I, for one, anything but cordial assent to give to hisdeclaration, that the modern development of science is essentiallydue to the constant encroachment of experiment and observation onthe domain of hypothetical dogma; and that the most difficult, aswell as the most important, object of every honest worker is "_sichent-subjectiviren_"--to get rid of his preconceived notions, and tokeep his hypotheses well in hand, as the good servants and bad mastersthat they are. 

I do not think I have omitted any one of Professor Virchow's maintheses in this brief enumeration. I do not find that they are disputedby Haeckel, and I should be profoundly astonished if they were. What, then, is all the coil about, if we leave aside various irritatingsarcasms, which need not concern peaceable Englishmen? Certainly aboutnothing that touches the present main issues of scientific thought. The "plastidule-soul" and the potentialities of carbon may be soundscientific conceptions, or they may be the reverse, but they are nonecessary part of the doctrine of evolution, and I leave their defenceto Professor Haeckel. 

On the question of equivocal generation, I have been compelled, moreconspicuously and frequently than I could wish, during the last tenyears, to enunciate exactly the same views as those put forward byProfessor Virchow; so that, to my mind, at any rate, the denial thatany such process has as yet been proved to take place in the existingstate of nature, as little affects the general doctrine. [3]

With respect to another side issue, raised by Professor Virchow, heappears to me to be entirely in the wrong. He is careful to say thathe has no unwillingness to accept the descent of man from some lowerform of vertebrate life; but, reminding us of the special attentionwhich, of late years, he has given to anthropology, he affirms thatsuch evidence as exists is not only insufficient to support thathypothesis, but is contrary to it. "Every positive progress which wehave made in the region of prehistoric anthropology has removed usfurther from the demonstration of this relation. "

Well, I also have studied anthropological questions in my time; and Ifeel bound to remark, that this assertion of Professor Virchow'sappears to me to be a typical example of the kind of incautiousover-statement which he so justly reprehends. 

For, unless I greatly err, all the real knowledge which we possess ofthe fossil remains of man goes no farther back than the Quaternaryepoch; and the most that can be asserted on Professor Virchow's siderespecting these remains is, that none of them present us with moremarked pithecoid characters than such as are to be found among theexisting races of mankind. [4] But, if this be so, then the only justconclusion to be drawn from the evidence as it stands is, that the menof the Quaternary epoch may have proceeded from a lower type ofhumanity, though their remains hitherto discovered show no definiteapproach towards that type. The evidence is not inconsistent with thedoctrine of evolution, though it does not help it. If ProfessorVirchow had paid as much attention to comparative anatomy andpalæontology as he has to anthropology, he would, I doubt not, beaware that the equine quadrupeds of the Quaternary period do notdiffer from existing _Equidæ_ in any more important respect than theselast differ from one another; and he would know that it is, nevertheless, a well-established fact that, in the course of theTertiary period, the equine quadrupeds have undergone a series ofchanges exactly such as the doctrine of evolution requires. Hencesound analogical reasoning justifies the expectation that, when weobtain the remains of Pliocene, Miocene, and Eocene _Anthropidæ_, theywill present us with the like series of gradations, notwithstandingthe fact, if it be a fact, that the Quaternary men, like theQuaternary horses, differ in no essential respect from those which nowlive. 

I believe that the state of our knowledge on this question is stilljustly summed up in words written some seventeen years ago:--

"In conclusion, I may say, that the fossil remains of man hithertodiscovered do not seem to me to take us appreciably nearer to thatlower pithecoid form by the modification of which he has probablybecome what he is. And considering what is now known of the mostancient races of men; seeing that they fashioned flint axes, and flintknives, and bone skewers of much the same pattern as those fabricatedby the lowest savages at the present day, and that we have everyreason to believe the habits and modes of living of such people tohave remained the same from the time of the mammoth and the tichorhinerhinoceros till now, I do not know that the result is other than mightbe expected. "[5]

I have seen no reason to change the opinion here expressed, and so farfrom the fact being in the slightest degree opposed to a belief in theevolution of man, all that has been learned of late years respectingthe relation of the Recent and Quaternary to the Tertiary mammaliaappears to me to be in striking harmony with what we know respectingQuaternary man, supposing man to have followed the general law ofevolution. 

The only other collateral question of importance raised by ProfessorVirchow is, whether the doctrine of evolution should be generallytaught in schools or not. Now I cannot find that Professor Virchowanywhere distinctly repudiates the doctrine; all that he distinctlysays is that it is not proven, and that things which are not provenshould not be authoritatively instilled into the minds of youngpeople. 

If Professor Virchow will agree to make this excellent rule absolute, and applicable to all subjects that are taught in schools, I should bedisposed heartily to concur with him. 

But what will his orthodox allies say to this? If "not provenness" issusceptible of the comparative degree, by what factor must we multiplythe imperfection of the evidence for evolution in order to expressthat of the evidence for special creation; or to what fraction mustthe value of the evidence in favour of the uninterrupted succession oflife be reduced in order to express that in support of the deluge?Nay, surely even Professor Virchow's "dearest foes, " the "plastidulesoul" and "Carbon & Co. , " have more to say for themselves, than thelinguistic accomplishments of Balaam's ass and the obedience of thesun and moon to the commander of a horde of bloodthirsty Hebrews! Butthe high principles of which Professor Virchow is so admirable anexponent do not admit of the application of two weights and twomeasures in education; and it is surely to be regretted that a man ofscience of great eminence should advocate the stern bridling of thatteaching which, at any rate, never outrages common sense, nor refusesto submit to criticism, while he has no whisper of remonstrance tooffer to the authoritative propagation of the preposterous fables bywhich the minds of children are dazed and their sense of truth andfalsehood perverted. Professor Virchow solemnly warns us against thedanger of attempting to displace the Church by the religion ofevolution. 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 atpresent foisted upon the young in the name of the Church. 

I make these remarks simply in the interests of fair play. Far be itfrom me to suggest that it is desirable that the inculcation of thedoctrine of evolution should be made a prominent feature of generaleducation. I agree with Professor Virchow so far, but for verydifferent reasons. It is not that I think the evidence of thatdoctrine insufficient, but that I doubt whether it is the business ofa teacher to plunge the young mind into difficult problems concerningthe origin of the existing condition of things. I am disposed to thinkthat the brief period of school-life would be better spent inobtaining an acquaintance with nature, as it is; in fact, in laying afirm foundation for the further knowledge Which is needed for thecritical examination of the dogmas, whether scientific oranti-scientific, which are presented to the adult mind. At present, education proceeds in the reverse way; the teacher makes the mostconfident assertions on precisely those subjects of which he knowsleast; while the habit of weighing evidence is discouraged, and themeans of forming a sound judgment are carefully withheld from thepupil. 

 * * * * *

Professor Virchow is known to me only as he is known to the world ingeneral--by his high and well-earned scientific reputation. WithProfessor Haeckel, on the other hand, I have the good fortune to be onterms of personal friendship. But in making the precedingobservations, I should be sorry to have it supposed that I am holdinga brief for my friend, or that I am disposed to adopt all the opinionswhich he has expressed in his reply. Nevertheless, I do desire toexpress my hearty sympathy with his vigorous defence of the freedom oflearning and teaching; and I think I shall have all fair-minded menwith me when I also give vent to my reprobation of the introduction ofthe sinister arts of unscrupulous political warfare into scientificcontroversy, manifested in the attempt to connect the doctrines headvocates with those of a political party which is, at present, theobject of hatred and persecution in his native land. The one blot, sofar as I know, on the fair fame of Edmund Burke is his attempt toinvolve Price and Priestley in the furious hatred of the Englishmasses against the authors and favourers of the revolution of 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 considerwhat might be the effect of such an innovation as the discovery ofoxygen on the minds of members of the Jacobin Club. 

Professor Virchow is a politician--maybe a German Burke, for anythingthat I know to the contrary; at any rate, he knows the political valueof words; and, as a man of science, he is devoid of the excuses thatmight be made for Burke. Nevertheless, he gravely charges his hearersto "imagine what shape the theory of descent takes in the head of aSocialist. "

I have tried to comply with this request, but I have utterly failed tocall up the dread image; I suppose because I do not sufficientlysympathise with Socialists. All the greater is my regret thatProfessor Virchow did not himself unfold the links of the hidden bondswhich unite evolution with revolution, and bind together the communityof descent with the community of goods. 

Professor Virchow is, I doubt not, an accomplished English scholar. Let me commend the "Rejected Addresses" to his attention. For sincethe brothers Smith sang--

 "Who 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 to the attemptto frighten sober people by the suggestion that evolutionaryspeculations generate revolutionary schemes in Socialist brains. Butthen the authors of the "Rejected Addresses" were joking, whileProfessor Virchow is in grim earnest; and that makes a greatdifference in the moral aspect of the two achievements. 

FOOTNOTES:

[1] Novum Organon, li. 

[2] Partis instaurationis secundæ delineatio. 

[3] I may remark parenthetically that Professor Virchow's statement ofthe attitude of Harvey towards equivocal generation is strangelymisleading. For Harvey, as every student of his works knows, believed inequivocal generation; and, in the sense in which he uses the word ovum, "nempe substantiam quandam corpoream vitam habentem potentia, " the truthof the axiom "omne vivum ex ovo, " popularly ascribed to him, has in nowise been affected by the discoveries of later days in the mannerasserted by Professor Virchow. 

[4] I do not admit that so much can be said; for the like of theNeanderthal skull has yet to be produced from among the crania ofexisting men. 

[5] Man's Place in Nature, p. 159. 

PREFACE. 

When the address delivered by Rudolph Virchow on the 22d of Septemberlast year, at the fiftieth meeting of German Naturalists andPhysicians at Munich, on "Freedom of Science in the Modern State, "appeared in print in the following October, I was called upon, on manysides, to prepare a reply. And such a reply on my part seemed, infact, justified by the severe strictures which Virchow in hisdiscourse had directed against one delivered by me only four dayspreviously, before the same meeting, on "The Modern Doctrine ofEvolution in its Relation to General Science. " The general views whichVirchow then unfolded proved such a fundamental opposition in ourprinciples, and touched our dearest moral convictions so nearly, thatany reconciliation of such antagonistic views was no longer to bethought of. Nevertheless I forbore publishing the ready reply for tworeasons: one relating to the matter itself, the other a personal one. 

With regard to the matter itself, I believed I might confidently leaveit to futurity to decide in the contention that has declared itselfbetween us. For on one hand the doctrine of evolution which Virchowattacks has already so far become a sure basis of biological scienceand part of the most precious mental-stock of cultivated humanity, that neither the anathemas of the Church nor the contradiction of thegreatest scientific authority--and such an one is Virchow--can prevailagainst it; and on the other hand most of the arguments which hespecially adduces against the theory of descent have been so oftendiscussed and so thoroughly refuted that any renewed discussion seemsin fact superfluous. 

Personally, it was in the highest degree repugnant to me to comeforward as the opponent of a man whom I learned, a quarter of acentury ago, to acknowledge and to honour as the reformer of medicalscience; a man whose most ardent disciple and most enthusiasticfollower I at that time was, with whom I subsequently stood in theclosest relation as his assistant, and with whom I long aftercontinued in the most friendly intercourse. The more keenly I lamentedVirchow's position, for some years past, as the antagonist of ourmodern doctrine of evolution, and the more I felt myself challenged toa reply by his repeated attacks upon it, the less inclination I felt, nevertheless, to come forward publicly as the opponent of thisdistinguished and highly-honoured man. 

And if I find myself, after all, forced to reply, it is in thepersuasion that a longer silence will add to the erroneous conclusionswhich my hitherto resigned attitude has already given rise to; at thesame time I believe that, precisely by reason of the peculiar interestwith which I have throughout followed Virchow's scientificachievements, I am specially qualified to answer the question, ahundred times repeated by letter or by word of mouth--"How is itpossible that a man who so long stood at the head of a party ofprogress in science as in politics, who in political life indeed, hasoutwardly maintained this position, has in science become aninstrument of the most perilous reaction?"

A verbal answer, which I incidentally gave in March of last year atthe Concordia Banquet at Vienna, was reported in the daily papers insuch a different sense, and was in part so misunderstood or sointentionally misrepresented, that I am forced at last, on thataccount, to publish a clear and unambiguous reply. The "AugsburgerAllgemeine Zeitung, " which eagerly seizes every opportunity ofexpressing its unconquerable aversion to the evolution theory, accusedme, in one of its hostile articles, of a virulent and undignifiedattack on Virchow. In contradiction of this misrepresentation in theAugsburg paper--which was copied by other journals--I must expresslyassert that not Virchow but I myself am the person attacked, andthat, therefore, the matter in question is not an unjustifiable attackby me on a formerly revered friend, but a defence to which I amcompelled by repeated and sharp attacks on his part. 

Another reason which urges me at last to break silence consists in thecontinual and ample advantage that all the clerical and reactionaryorgans have been taking of Virchow's address, during the lastthree-quarters of a year, in favour of mental retrogression. Theshouts of triumph with which they at once hailed Virchow's "grandmoral action, " that is to say, his perversion from a Free-thinker tothe side of mental darkness, was the first signal for that persistentutilisation of his authority of which the pernicious consequences canby no means be escaped. Friedrich von Hellwald, in his discussion onthe speeches made at Munich, has already strikingly pointed out[6] thegrave danger that exists when just such an one as Virchow, standingunder the banner of political liberalism and wrapped in the mantle ofsevere science, decisively combats against the freedom of science andof its doctrines. This serious danger has never shown so threateningan aspect as at the present moment, when our political and religiouslife appears to be encountering such a reaction as has not occurredfor a long time. The two insane attempts which, within a few weeks, have been made by Social-democracy against the revered and reverendperson of the German Emperor have raised a storm of righteousindignation of such violence that calm judgment is entirelyoverthrown, and that many even of the most liberal of liberalpoliticians not only impetuously urge us to the severest measuresagainst the Utopian doctrines of social democracy but, farover-shooting the mark, demand that free-doctrine and free-thought, that freedom of the press and even freedom of conscience shall bethrown into the narrowest fetters. Can this reaction, lurking in thebackground, find any more welcome support than is afforded by the meredemand of such a man as Virchow for restriction of liberty inteaching? And if he makes our present doctrines of evolution ingeneral and the theory of descent in particular responsible for themad doctrines of social-democracy, it is but a natural and justconsequence when the famous New-Prussian "Kreuz-Zeitung" throws allthe blame of these treasonable attempts of the democrats Hödel andNobiling--as in fact it quite lately did--directly on the theory ofdescent, and especially on the hated doctrine of the "descent of manfrom apes. " And the danger which threatens us shows a still graveraspect when we consider how great an influence Virchow has at thepresent day as an advanced liberal, and how he is regarded in thePrussian diet as the highest practical authority, and at the same timeas the most liberal critic when educational questions are underconsideration. Now it is well known that one of the most importantproblems lying before the Prussian parliament is the consideration ofa new education-law, which will probably exercise its restrictinginfluence for a long time to come, not in Prussia only, but throughoutGermany; what can we expect of such an education-law if in the courseof the deliberations, among the small number of those specialists whoare generally listened to, Virchow raises his voice as a leadingauthority, and brings forward the principles that he proclaimed in hisspeech at Munich as the surest guarantees for the freedom of sciencein the modern polity? Article XX. Of the Prussian Charter, and § 152of the Code of the German Empire, say, "Science and its doctrines arefree. " And Virchow's first step, according to the principles he nowdeclares, must be a motion to abrogate this paragraph. 

In the face of this imminent danger, I dare no longer hesitate aboutmy answer. _Amicus Socrates, amicus Plato, magis amica Veritas. _ Anunreserved and public opposition can be no longer postponed. As amatter of fact, at the Munich meeting, neither did Virchow hear myspeech nor I his. I read my paper, as it is printed, on the 18thSeptember 1877, and left on the 19th. Virchow came to Munich only onthe 20th, and delivered his speech on the 22d. 

Bearing in mind the gratitude which I owe to Virchow as my formermaster and friend at Würzburg--a gratitude which I have at all timesstriven to prove by the further development of his mechanicaltheory--I shall confine myself, as far as possible, to an objectiveand special confutation of his assertions. Certainly the temptation onthis occasion was a strong one to pay the debt in like kind. In myMunich lecture, among the few names to which I alluded, I particularlymentioned that of Virchow as the distinguished founder ofcellular-pathology (p. 12). [7] Virchow's return for this was to heapscorn and ridicule on the doctrine of evolution in his usual manner. The critic in the "National-Zeitung, " Herr Isidor Kastan, says of thiswith particular satisfaction, "The ridicule with which Herr Virchowtreated this side of Haeckel's visions was indeed caustic enough, butthis is ever Virchow's way; only in this case, if in any, he was fullyjustified. "

I could less easily ignore Virchow's denunciation of me than hissatire--a denunciation which gibbeted me as a confederate in thesocial-democratic cause, and which made the theory of descentanswerable for the horrors of the Paris Commune. The opinion is nowwidely spread that by this intentional connection of the theory ofdescent with Social Democracy he has hit the hardest blow at thattheory, and that he aimed at nothing less than the removal of all"Darwinists" from their academic chairs and professorships. This isthe inevitable consequence of his demands; for if Virchow insists withthe utmost determination that the theory of descent must not be taught(because he does not regard it as true), what is to become of thesupporters of that theory who, like myself, regard it asincontrovertibly true, and teach it as a perfectly sound theory? Andat least nine-tenths of all the teachers of zoology and botany inEurope are among its supporters from immutable conviction of itstruth, as well as all morphologists without exception. Virchow cannotexpect that these teachers should collectively renounce that whichthey believe to be immutable truth, and in its place set up the dogmaof the Church as the basis of their teaching, in accordance with hiswish! Nothing 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 ifthey did not voluntarily renounce it. 

If this be indeed Virchow's purpose, as it is generally supposed tobe, with regard to me, at least, he may spare himself the trouble. Amongst us in Jena quite other ideas prevail as to the "Freedom ofscience 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. "[8]

The Jena students, on the contrary, sing the rhyme in its originalform--

 "Who knows the truth and speaks it not, A feeble wretch is he, God wot. "[9]

The Rector Magnificentissimus of the University of Jena, the GrandDuke of Saxony, who has proved himself the protector of the arts andsciences, has besides far more liberal views as to the liberty ofscientific investigation and teaching than the illustrious head of theparty of progress at Berlin. The enlightened and liberal Prince atWeimar, under whose particular protection we in Jena find ourselves, has never conceived it necessary to limit in any way the unboundedfreedom of my teaching and my writing; not even when in 1866 my"General Morphology, " and 1868 my "History of Creation" firstappeared, and when many people attempted to make the youthfulextravagances which were to be found in those works the ground of aserious accusation. And what farther mischief have these extravagancesdone, though I now sincerely lament them?

Faithful to the glorious traditions of a past extending over threecenturies, the little Thuringian university of Jena will find a way topreserve her perfect and unlimited freedom. She will ever bear in mindthat she is the first Protestant university of Germany, protestingagainst every strait-waistcoat which hierarchical obstinacy wouldforce upon human reason, against every dogma by which the arrogance ofthe learned may try to suppress all freedom of teaching. She willfreely seek and freely teach in accordance with her highestconvictions, untroubled by the fact that in the "great" university ofBerlin nothing may be taught, as Virchow insists, but what isobjectively ascertained, absolutely sure; that is to say, nothing thatrises above individual, indubitable, and intelligible facts; not anidea, not a conception, not a theory, in fact not any real science;mathematics, at most, excepted. It is our conviction that Jena willcontinue to be an independent city of refuge for free science and freeteaching as long as it remains under the faithful nurture and liberalprotection of the princely house of Sax Weimar, that enlightened racewhich is linked with the history of German intellect through thematchless traditions of its glorious past. What the Wartburg was toMartin Luther, what Weimar has been to the foremost heroes of Germanliterature, what Jena herself has been during three hundred years to avast number of illustrious investigators, that will the tried andtested Jena of to-day undoubtedly continue to be to the moderndoctrine of evolution, as to every other doctrine which asks freedevelopment; a strong-hold of free thought, free investigation, andfree doctrine. 

 ERNST HAECKEL. 

JENA, _June 24th_, 1878. 

FOOTNOTES:

[6] Kosmos, Vol. II. P. 172. 

[7] Of the German. 

[8]

 "Wer die Wahrheit kennet und saget sie frei, Der kommt in Berlin auf die Stadt-Vogtei. "

[9]

 "Wer die Wahrheit kennet und saget sie nicht Der ist für wahr ein erbärmlicher Wicht. "

CONTENTS. 

 PAGE

 PREFATORY NOTE v

 PREFACE xxi

 CHAP. 

 I. DEVELOPMENT AND CREATION 1

 II. CERTAIN PROOFS OF THE DOCTRINE OF DESCENT 10

 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

 VI. THE DOCTRINE OF DESCENT AND SOCIAL DEMOCRACY 88

 VII. IGNORABIMUS ET RESTRINGAMUR 99

FREEDOM IN SCIENCE AND TEACHING. 

CHAPTER I. 

DEVELOPMENT AND CREATION. 

Nothing is more helpful for the understanding of scientificcontroversies, or for the clearing of confused conceptions, than acontrasted statement, as defined and clear as possible, of thesimplest leading propositions of the contending doctrines. Hence it ishighly favourable to the victory of our modern doctrine of evolutionthat its chief problem, the question as to the origin of species, isbeing more and more pressed by these opposite alternatives: Either allorganisms are naturally evolved, and must in that case be alldescended from the simplest common parent-forms--or: That is not thecase, and the distinct species of organisms have originatedindependently of each other, and in that case can only have beencreated in a supernatural way, by a miracle. Natural evolution, orsupernatural creation of species--we must choose one of these twopossibilities, for a third there is not. 

But as Virchow, like many other opponents of the doctrine ofevolution, constantly confounds this latter proposition with thedoctrine of descent, and that again with Darwinism, it will not besuperfluous to indicate here, in a few words, the limitation andsubordination of these three great theories. 

I. The general doctrine of development, the progenesis-theory orevolution-hypothesis (in the widest sense), as a comprehensivephilosophical view of the universe, assumes that a vast, uniform, uninterrupted and eternal process of development obtains throughoutall nature; and that all natural phenomena without exception, from themotions of the heavenly bodies and the fall of a rolling stone to thegrowth of plants and the consciousness of men, obey one and the samegreat law of causation; that all may be ultimately referred to themechanics of atoms--the mechanical or mechanistic, homogeneous ormonistic view of the universe; in one word, Monism. 

II. The doctrine of derivation, or theory of descent, as acomprehensive theory of the natural origin of all organisms, assumesthat all compound organisms are derived from simple ones, allmany-celled animals and plants from single-celled ones, and these lastfrom quite simple primary organisms--from monads. As we see theorganic species, the multiform varieties of animals and plants, varyunder our eyes through adaptation, while the similarity of theirinternal structure is reasonably explicable only by inheritance fromcommon parent-forms, we are forced to assume common parent-forms forat least the great main divisions of the animal and vegetablekingdoms, and for the classes, orders, and so forth. Thus the numberof these will be very limited, and the primitive archigonianparent-forms can be nothing else than monads. Whether we finallyassume a single common parent-form (the monophyletic hypothesis), orseveral (the polyphyletic hypothesis), is wholly immaterial to theessence of the theory of descent; and it is equally immaterial to itsfundamental idea what mechanical causes are assumed for thetransformation of the varieties. This assumption of a transformationor metamorphosis of species is, however, indispensable, and the theoryof descent is very properly called also the "metamorphosishypothesis, " or "doctrine of transmutation;" as well as Lamarckism, after Jean Lamarck, who first founded it in 1809. 

III. The doctrine of elimination, or the selection theory, as thedoctrine especially of "choice of breed or selection, " assumes thatalmost all, or at any rate most, organic species have originated by aprocess of selection; the artificial varieties under conditions ofdomestication--as the races of domestic animals and cultivatedplants--through artificial choice of breeds; and the natural varietiesof 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 apurpose; in the second, it is effected in a purposeless way by the"struggle for existence. " In both cases the transformation of theorganic forms takes place through the reciprocal action of the laws ofinheritance and of adaptation; in both cases it depends on thesurvival or selection of the better-qualified minority. This theory ofelimination was first clearly recognised and appreciated in its fullsignificance by Charles Darwin in 1859, and the selection-hypothesiswhich he founded on it is Darwinism properly so called. 

The relation that these three great theories, which are frequentlyconfounded, bear to one another may, according to the present positionof science, be simply defined as follows:--I. Monism, the universaltheory of development, or the monistic progenesis-hypothesis, is theone only scientific theory which affords a rational interpretation ofthe whole universe and satisfies the craving of our human reason forcausality, by bringing all natural phenomena into a mechanicalcausal-connection as parts of a great uniform process of evolution. II. The theory of transmutation, or descent, is an essential andindispensable element in the monistic development hypothesis, becauseit is the one only scientific theory which rationally explains theorigin of organic species--that is to say, by transformation--andreduces it to mechanical principles. III. The theory of Selection orDarwinism is, up to the present time, the most important of thevarious theories which seek to explain the transformation of speciesby mechanical principles, but it is by no means the only one. If weassume that most species have originated through natural elimination, we also now know, on the other hand, that many forms distinguished asvarieties are hybrids between two different varieties, and can bepropagated as such; and it is equally well worthy of considerationthat other causes are in activity in the formation of species ofwhich, up to the present time, we have no conception. Thus it is leftto the judgment of individual naturalists to decide what share is tobe attributed to natural selection in the origin of species, and evenat the present day authorities differ widely on the subject. Some giveit a large share, and some a very small one in the result. MoritzWagner, for instance, would substitute his own migration-hypothesisfor Darwin's theory of selection; while I regard the action ofmigration, which acts as isolation or separation, as merely a specialmode of selection. But these differing estimates of Darwinism arequite independent of the absolute import of the doctrine of descentor of transformation, for the latter is as yet the only theory whichrationally explains the origin of species. If we discard it, nothingremains but the irrational assumption of a miracle, a supernaturalcreation. 

In this crucial and unavoidable dilemma, Virchow has declared himselfpublicly in favour of the latter, and against the former hypothesis. Every one who has attentively followed his occasional utterances onthe theory of descent during the last decade with an unprejudiced eyeand an unbiassed judgment, must be convinced that he fundamentallyrejects it. Still, his dissent has always been so obscured, and hisjudgment on Darwinism in particular so wrapped in ambiguities, that anopportune conversion to the opposite side seemed not impossible; andmany, even among those who stood near to Virchow--his friends anddisciples--did not know to what point he was in fact an opponent ofthe evolution hypothesis in general. Virchow took the last steptowards clearing up this matter at Munich; for after his Munichaddress there can be no farther doubt that he belongs to the mostdecided opponents of the whole theory of evolution, including those ofinheritance and selection. 

If any one still has doubts on the matter, let him read the jubilanthymns of triumph with which Virchow's friend and collaborator, AdolfBastian, greeted his Munich discourse. This "enfant terrible" of theschool--this well-nicknamed "Acting privy counsellor of the board ofconfusion"[10]--whose merits in involuntarily advancing the cause ofmetamorphism I have already done justice to in the preface to thethird edition of my "Natural History of Creation"[11]--expresseshimself in the "Zeitschrift für Ethnologie, " which is edited by himand Virchow (tenth yearly part, X. 1878, p. 66) as follows:--"At theMunich meeting of naturalists, Virchow by a few weighty words clearedthe atmosphere, which was heavy and stifling under the pressure of theincubus called Descent, and once more freed science from thatnightmare which it has so long--in many opinions so much toolong--allowed to weigh upon it; freed it, let us hope, once and forever. The forecasts of this storm were discernible many years since, and its whole course has been a strictly normal one. When the germsplanted by Darwin, and that promised so much, were forced into growthby 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 runtoo high under the pressure of a psychical storm, it is almost uselessto protest against it, for every ear is too much deafened by thenoise all round to hear the voice of individuals. It is best to leavethings to go their own way, deeper and deeper into the mire, till theycome to a stand-still there of their own accord; for 'Quos deus vultperdere prius dementat. ' Thus it is in this case. When theextravagances of the descent hypothesis, encouraged as they were bymutual incitement, had reached their highest pitch in the ravings thatwere uttered at Munich, the too pointed point broke in thissuperabundance of absurdity almost by its own pointedness, and so wewere quit of it with one blow. Now, happily, all is over with thetheory of descent, or ascent, but natural science will not on thataccount fare any the worse, for many of its adherents belong to herablest youth, and as they now need no longer waste their best time onromantic schemes, they will have it to use at the orders and for theadvancement of science, so as to enrich her through real and solidcontributions. "

Furthermore, Bastian quotes Virchow's maxim:--"The plan oforganisation is immutable within the limits of the species; species isnot produced from species. " The fundamental teleological idea of thatschool, that each species has its constant and specific plan ofstructure, certainly cannot be more emphatically expressed. Thus it isundoubtedly certain that Virchow has become a Dualist, and is asthoroughly penetrated by the truth of his principles as I, as aMonist, am of mine. This is undoubtedly the upshot of his Munichaddress, though he is throughout careful to avoid acknowledging hischief standpoint in all its nakedness. On the contrary, even now hestill veils his antagonism under the phrase, which is also a favouritewith the clerical papers, that the theory of descent is an "unprovedhypothesis. " Now it is clear that this theory never will be "proved"if the proofs that already lie before us are not sufficient. How oftenhas it been repeated that the scientific certainty of the hypothesisof descent is not grounded in this or that isolated experiment, but inthe collective sum of biological phenomena; in the causal nexus ofevolution. Then what are the new proofs of the theory of descent whichVirchow demands of us?

FOOTNOTES:

[10] "Wirkliche Geheime Ober-Confusionsrath. "

[11] Translated under the supervision of E. Ray Lankester. London: C. Kegan Paul & Co. 

CHAPTER II. 

CERTAIN PROOFS OF THE DOCTRINE OF DESCENT. 

All the common phenomena of Morphology and Physiology, of Chorologyand Oekology, of Ontology and Paleontology, can be explained by thetheory of descent, and referred to simple mechanical causes. It isprecisely in this, viz. , that the primary simple causes of all thesecomplex aggregates of phenomena are common to them all, and that othermechanical causes for them are unthinkable--it is in this that, to us, the guarantee of their certainty consists. For this reason all thesevast and manifold aggregates of facts are so many evidences of thedoctrine of descent. This fundamental relation of facts has been sooften 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 ofCreation, "[12] or "The Evolution of Man" (vol. I. P. 93). [13]

And where is yet farther proof of the truth of the theory of descentto be found? Neither Virchow, nor any one of the clerical opponentsand the dualistic philosophers who are perpetually reiterating thiscry for more certain evidence, anywhere indicate where possibly suchevidence is to be sought. Where in all the world can we discover"facts" which will speak more plainly or significantly for the truthof transmutation than the facts of comparative morphology andphysiology; than the facts of the rudimentary organs and of embryonicdevelopment; than the facts revealed by fossils and the geographicaldistribution of organisms--in short, than the collective recognisedfacts of the most diverse provinces of biological science?

But I am in error--the certain proof that Virchow demands in order tobe perfectly satisfied with the evidence, is to be supplied by"experiment, the test as well as the highest means of evidence. " Thisdemand, that the doctrine of descent should be grounded on experiment, is so perverse and shows such ignorance of the very essence of ourtheory, that though we have never been surprised at hearing itcontinually repeated by ignorant laymen, from the lips of a Virchow ithas positively astounded us. What can in this case be proved byexperiment, and what can experiment prove?

"The variability of species, the transformation of species, thetransition of a species into one or more new varieties, " is theanswer. Now, so far as these facts can be proved by experiment, theyactually have long since been experimentally proved in the completestmanner. For what are the numberless trials of artificial selection forbreeding purposes which men have practised for thousand of years inbreeding domestic animals and cultivated plants, but physiologicalexperiments which prove the transformation of species? As an examplewe may refer to the different races of horses and pigeons. The swiftrace-horse and the heavy pack-horse, the graceful carriage-horse andthe sturdy cart-horse, the huge dray-horse and the dwarfed pony--theseand many other "races" are so different from each other, that if wehad found them wild we should certainly have described them as quitedifferent varieties of one species, or even representatives ofdifferent species. Undoubtedly, these so-called "races" and "sports"of the horse tribe differ from each other in a much greater degreethan do the zebra, the quagga, the mountain horse, and the other wildvarieties of the horse, which every zoologist distinguishes as "bonæspecies. " And yet all these artificial varieties, which man hasdesignedly produced by selection, are descended from a single commonparent-form, from one wild "true variety. " The same is the case withthe numerous and highly differing varieties of pigeons. Domesticpigeons and carrier-pigeons, turbits and cropper-pigeons, fantailpigeons and owls, tumblers and pouters, trumpeters and laughingpigeons (or Indian doves), and the rest, are all, as Darwin hasconvincingly proved, descendants of a single wild variety, therock-pigeon (_Columba livia_). And how wonderfully various they are, not only in general form, size, and colouring, but in the particularform of the skull, the beak, the feet, and so forth! They differ muchmore in every respect each from the others than the numerous wildvarieties which, in systems of ornithology, are recognised as truevarieties, and even as true species. It is the same with the differentartificial varieties of apples, pears, pansies, dahlias, and so on; inshort, of almost all the domestic varieties of animals and plants. Wewould lay particular stress on the fact that these artificial specieswhich man has produced or created by artificial breeding and throughexperimental transformation out of one original species, differ farmore one from another in physiological as well as in morphologicalconditions than the natural species in a wild state. With these it isself-evident that any proof by experiment of a common origin is whollyimpossible. For, so soon as we subject any wild variety of animal orplant to such an experiment, we bring it under the conditions ofartificial breeding. 

That the morphological conception of a Species is not a positive butonly a relative conception, and that it has no other absolute orpositive value than those other similar system-categories--sports, varieties, races, tribes, families, classes--is now acknowledged byevery systematiser who forms an honest and unprejudiced judgment ofthe practical systematic distinction of species. From the very natureof the case there are no limits to arbitrary discretion in thisdepartment, and there are no two systematists who are at one in everyinstance; this one separating forms as true varieties which that onedoes not. (Compare on this point "History of Creation, " vol. I. , p. 273. ) The conception of variety or species has a different value inevery small or large department of systematic Zoology and Botany. 

But the conception of species has just as little any fixedphysiological value. In respect to this we must especially insist thatthe question of hybrid offspring, the last corner of refuge of all thedefenders of the constancy of species, has at present lost allsignificance as bearing on the conception of species. For we know now, through numerous and reliable experiences and experiments, that twodifferent true varieties can frequently unite and produce fertilehybrids (as the hare and rabbit, lion and tiger, many different kindsof the carp and trout tribes, of willows, brambles, and others); andin the second place, the fact is equally certain that descendants ofone and the same species which, according to the dogma of the oldschools, could always effect a fertile union under certaincircumstances, either cannot effect such a union or produce onlybarren 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 asubjective abstraction and has a merely relative value--like theconception of genus, family, order, class, &c. --no class of animals isof so much importance as that of the Sponges. In it the fluctuatingforms vary with such unexampled indefiniteness and variability as tomake all distinction of species quite illusory. Oscar Schmidt hasalready pointed this out in the siliceous sponges and keratosesponges; and I, in my monograph, in three volumes, on the CalcareousSponges (the result of five years of most accurate investigations ofthis small animal group), have pointed out that we may at pleasuredistinguish 3, or 21, or 111, or 289, or 591 different species. I alsobelieve that I have thus convincingly demonstrated how all thesedifferent forms of the calcareous sponges may quite naturally, andwithout any forcing, be traced to a single common parent-form, thesimple--and not hypothetical, but existing at this present day--thesimple Olynthus. Hence I think I have here produced the most positiveanalytical evidence of the transformation of species, and of the unityof the derivation of all the species of a given group of animals, thatis generally possible. 

Properly, I might spare myself these disquisitions on the question ofspecies, for Virchow does not go into this main question of the theoryof descent--but this is very characteristic of his attitude. And justas he nowhere thoroughly discusses the doctrine of transformation, neither does he enter generally on the refutation of any of the othercertain proofs of the doctrine of descent which we in fact possess atthe present day. Neither the morphological nor the physiologicalarguments for the theory of descent, neither the rudimentary organsnor the embryonic forms, neither the paleontological nor thechronological argument are anywhere closely examined and tested as totheir worth or their worthlessness as "certain proofs. " On thecontrary, Virchow takes them quite easily, sets them aside, anddeclares that "certain proofs" of the doctrine of descent do notexist, but remain to be discovered. To be sure, he does not indicatewhere they are to be sought, nor can he indicate it. How is thisstrange conduct to be explained? How is it possible that adistinguished naturalist should resist the most important step forwardof modern natural science without in any way specially investigatingit, without even practically testing and refuting the most weightyarguments in its favour? To this question there is but one answer. Virchow is not generally intimate with the modern doctrine ofevolution, and does not possess that knowledge of natural sciencewhich is indispensable for any well-grounded judgment on it. 

After collecting and carefully reading all that Virchow, during manyyears, had written against evolution, I arrived at the conviction thathe had not thoroughly read either Darwin's great work on the Origin ofSpecies, nor any other work on the theory of descent, nor had hethought the matter out with such attention as so serious and intricatea subject absolutely demands. Virchow did with these works as it hasbeen his well-known custom to do with many others--he hastily turnedover the pages, caught at a few leading words, and without any farthertrouble he has discoursed upon them, and, which is worst of all, hasperpetuated these discourses through the press. 

To excuse this conduct, and to account for Virchow's enigmaticalposition in the battle of evolution, we must consider what changesthis highly-gifted and meritorious man has gone through in the courseof the last thirty years. The most important and fruitful part of hislife and labours was indisputably during the eight years when heresided in Würzburg, from 1848 to 1856. There Virchow, with all thekeenness of his youthful intellect, with a sacred enthusiasm forscientific truth, with indefatigable powers of work and the rarestinsight, worked out that glorious reform of scientific medicine whichwill shine through all time as a star of the first magnitude in thehistory of medical science. In Würzburg, Virchow elaborated thatcomprehensive application of the cellular theory to pathology whichculminates in the conception that the cell is an independent livingelementary organism, and that our human organism, like that of all thehigher animals, is merely a congeries of cells--a highly fertileconception, which Virchow now denies as resolutely as he thensupported it. In Würzburg, twenty-five years since, I sat devoutly athis feet, and received from him with enthusiasm that clear and simpledoctrine of the mechanics of all vital activity--a truly monisticdoctrine, which Virchow now undoubtedly opposes where formerly hedefended it. In Würzburg, finally, he wrote those incomparablecritical and historical leading articles which are the ornament of thefirst ten yearly series of his "Archives" of pathological anatomy. Allthat Virchow effected as the great pioneer of reform in medicine, andby which he won imperishable honour in the scientific treatment ofdisease, --all this was either carried out or preconceived in Würzburg;and even the celebrated "Cellular Pathology, " a course of lectureswhich he delivered during the first year and a half after quittingWürzburg for Berlin, consists only of the collected and matured fruitsof which the blossoms are due to Würzburg. 

In the autumn of 1856 Virchow left Würzburg to settle in Berlin. Theexchange of a narrow sphere of labours for a wider one, of small meansand appliances for greater ones, proved unfavourable in this case, asin many similar cases. Since he has been in Berlin, in a "greatInstitution, " and with luxurious appliances, all the scientificresults which Virchow has as yet brought to light are not to becompared, either as to quality or quantity, to the grand and immortalachievements which he himself effected in the little institute ofWürzburg with the scantiest means--a new proof of the maxim enunciatedby me, and hitherto never confuted, that "the scientific results of aninstitute are in inverse proportion to its size. " (See "The Aim andMethods of Modern Evolution. "[14])

Still more grave is the circumstance that, since settling in Berlin, Virchow has more and more exchanged his theoretical scientificactivity for practical political life. It is well known how prominenta part he plays there in the Prussian Chamber of Representatives, howhe raised himself to be the leader of the party of progress, and, togive this political position a broader basis, took part in therepresentation of the citizens of the capital; how he has taken a mostactive interest, as city commissioner, in all the petty anxieties andconcerns which the charge of such a city as Berlin entails. I am farfrom blaming, as many have blamed, the political and civic activity towhich Virchow has indefatigably devoted his best powers. If a manfeels in himself the inclination and vocation with strength and talentenough, to play a conspicuous political part, by all means let him doso; but verily I do not envy him; for the satisfaction which isderived from the most successful and fruitful political activity isnot, to my taste, to be compared with that pure and disinterestedsatisfaction of the mind which results from absorption in serious anddifficult scientific labours. In the turmoil of the political andsocial struggle, even the most splendid civic crown will be dulled bythe stifling dust of practical life, which never reaches the etherealheights of pure science and never rests on the laurels of thethoughtful investigator. However, as I have said, that is a matter oftaste. If Virchow really believes that he is doing a greater serviceto humanity by his practical political life in Berlin than heformerly did by his theoretical scientific work in Würzburg, that ishis affair; but for all that, in his former sphere he wasincomparable, and cannot be replaced; in the latter this is not thecase. 

If a distinguished man, be he never so remarkable for uncommon powerof work and universal gifts, passes the whole day in the friction ofpolitical party-struggles, and throws himself as well into all thepetty and wearisome details of daily civic life, it is impossible forhim to maintain the requisite feeling for the progress ofscience--particularly when it advances so rapidly and incessantly asis the case in our day. It is therefore quite intelligible thatVirchow should soon have lost this feeling, and in the course of thelast two decades have become more and more estranged from science. Andthis estrangement has at last led to so complete a change in hisfundamental views, to such a metapsychosis, that the present Virchowof 1878 is hardly in a position to understand the youthful Virchow of1848. 

We have seen a similar mental change occur contemporaneously in ourgreatest naturalist, Carl Ernst von Baer. This gifted and profoundthinker and biologist, whose name marks a new epoch in the history ofevolution, had in his later years become wholly incompetent even tounderstand those most important problems of his youthful labourswhich opened up new paths of inquiry. While in his early years he laiddown principles of the greatest value to our modern doctrine ofevolution, and even went very near to adopting this hypothesis intohis system, at a later period he utterly denied it, and by hiswritings on Darwinism proved that he was no longer generally capableof mastering this difficult problem. As I am one of Von Baer's warmestadmirers, and in my "Evolution of Man, " as well as in the "History ofCreation, " and in other places, have most emphatically expressed thatsincere esteem, I thought I might venture to forbear from callingattention to the discrepancy between the lucid, monistic principles ofVon Baer in his youth, and the confused dualistic views of his oldage. But as many opponents of Darwinism--and among them particularlythe Old Catholic philosopher of Munich, Huber, who has written aseries of articles in the "Augsburger Zeitung"--have made constantcapital out of the harmless talk of the feeble old Von Baer, I must inthis place explicitly declare that this dualistic prating of the oldman is quite incapable of shaking the monistic principles of the youngand enterprising pioneers of science, or of giving them the lie. 

In his autobiography Von Baer gives us the explanation of thisstriking contradiction. In 1834 he entirely and for ever abandonedthe province of the history of development, at which for twenty yearshe had laboured incessantly, and where he had earned splendid laurels. To escape from the haunting and importunate ideas of the science whichhad so wholly absorbed him, he fled from Königsberg to Petersburg, andsubsequently busied himself in scientific inquiries of a quitedifferent character. Twenty-five long years passed by, and whenDarwin's work appeared in 1859, Von Baer had too long undergone ametapsychosis to be able to understand it. In Von Baer, as in Virchow, the course of this remarkable metapsychosis is highly instructive, andwill itself afford to the thoughtful psychologist an interestingevidence of the doctrine of evolution. 

However, the lack of comprehension of our modern evolution-hypothesisis easier to explain in Virchow's case than in Von Baer's, for thisreason: morphological knowledge was greatly lacking to Virchow, whileVon Baer possessed it in the highest degree. Now morphology isprecisely that very department of inquiry in which our theory ofdescent has its deepest and strongest roots, and has matured the mostglorious fruits of knowledge. The study of organic forms, ormorphology, is thus, more than any other science, interested in thedoctrine of descent, because through this doctrine it first obtained apractical knowledge of effective causes, and was able to raise itselffrom the humble rank of a descriptive study of _forms_ to the highposition of an analytical science of _form_. It is true that by thebeginning of this century the most comprehensive branch ofmorphology--_i. E. _, comparative anatomy--which was founded by Cuvierand splendidly developed by Johannes Müller, had laid the foundationson which to build a truly philosophical science of form. The enormousmass of various empirical material, which had been accumulated bydescriptive systematists and by the dissections of zootomists sincethe time of Linnæus and Pallas, had already been abundantly maturedand utilised in many ways for philosophic purposes by the syntheticprinciples of comparative anatomy. But even the most importantuniversal laws of organisation--of which the old system of comparativeanatomy was one--had to take refuge in mystical ideas of a plan ofstructure and of creative final causes (_causæ finales_); they wereincapable of arriving at a true and clear perception of effectivemechanical causes (_causæ 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 yearsold, on a firm footing by his own theory of selection. By thishypothesis it was first made possible to fit together the richmaterials which had been previously amassed, into the splendidedifice of the mechanical science of form. (See my "GeneralMorphology, " vol. I. Chap. Iv. )

The immeasurable step which Darwin thus made in organic morphology canbe adequately appreciated only by those who, like myself, were broughtup in the school of the old teleological morphology, and whose eyeswere suddenly opened by the theory of selection to a comprehension ofthat greatest of all biological riddles, the creation of specificforms. The dogma of creation, the mystic and dualistic doctrine of theisolated creation of each separate variety, was annihilated at oneblow; the belief in transmutation has now for ever taken itsplace--the mechanistic and monistic doctrine of the metamorphosis oforganic forms, of the descent of all the species of one natural classfrom a common parent-form. How complete a change the science ofmechanical morphology has by this means been compelled to undergo, Ihave endeavoured to point out in my "General Morphology;" and any onewho wishes to convince himself clearly of what an enormous revolutionhas been brought about, particularly in comparative anatomy, maycompare the "Outlines of Comparative Anatomy" (Grundzüge dervergleichenden Anatomie), by Carl Gegenbaur, 1870, and the latestedition of his "Elements" (Grundrisses), with the old text-books ofthat science. 

Virchow has no suspicion even of all these immeasurable strides inmorphology, for this department always lay out of his ken. His greatreforms in pathology were founded in the province of physiology, andmore especially in cellular physiology. But within the last twentyyears these two main branches of biological inquiry have grown moreand more apart. The great Johannes Müller was the last biologist whowas able to keep these departments of organic inquiry together, andwho won equally immortal honours in both divisions of the subject. After Müller's death in 1858 they fell asunder. Physiology, as thescience especially of the functions or living activity of theorganism, addressed itself more and more to exact and experimentalmethods: morphology, on the contrary, as the science of the forms andstructure of animals and plants, could naturally make but very smalluse of this method; it must take refuge more and more in the historyof evolution, and so constitute an historical natural science. It wason this very historical and genetic method of morphology, incontradistinction to the exact and experimental method of physiology, that I based my Munich address; and if Virchow in his answer hadreally and thoroughly refuted this position, instead of fighting withmere phrases and denunciations, this radical opposition would havebeen well worthy of the fullest discussion. At the same time I haveno wish to reproach Virchow for being wholly fettered by the one-sidedviews of the modern school-physiology, nor because morphology lies sofar out of his ken that he has not been able to form an independentjudgment of its aims and methods; but when, in spite of all this, heon every occasion lets fall a disparaging judgment of it, we mustdispute his competence. It is true that in his Munich address heemphasises the statement, "That which graces me best is that I know myignorance, " by printing it in italics. I only regret that I am forcedto deny his possession of this very grace. Virchow does not know howignorant he is of morphology, else he would never have uttered hisannihilating verdict on it, else he would not continually designatethe study of the theory of descent as dilettanteism and vain dreaming, as "a fanciful private speculation which is now making its way inseveral departments of natural science. " In truth, Virchow does megreatly too much honour when he designates as my "personal crotchet"an idea which for the last ten years has been the most precious commonpossession of all morphological science. If Virchow were not sounfamiliar with the literature of morphology, he must have known thatit is penetrated throughout by this principle of descent, that everymorphological inquiry which conscientiously pursues a well-consideredproblem now assumes the doctrine of descent as granted andindisputable. Of all this he is ignorant, and so it is intelligiblethat he should continue to demand "certain proofs" of this hypothesis, although those proofs have long since been produced. 

FOOTNOTES:

[12] Vol. Ii. , p. 334 of translation. 

[13] London: C. Kegan Paul & Co. 1879. 

[14] Jena, Zeitschriften für Naturwissenschaft, 1875. Vol. X. Supplement. 

CHAPTER III. 

THE SKULL THEORY AND THE APE THEORY. 

Inasmuch as Virchow persists in treating the theory of descent as an"unproved hypothesis, " inasmuch as he ignores all the forcibleevidences of that hypothesis, he deprives himself of the right ofspeaking a decisive word in this, the most important scientificdispute of the present day. Virchow is, in fact, simply incompetent inthe great question of evolution, as he is deficient in the greaterpart of that knowledge--more especially morphological knowledge--whichis indispensable to forming a judgment upon it. Hence on theturning-point of the whole matter--viz. , the problem as to the originof species--he can have no opinion, as he has never turned hisattention to the systematic treatment of species: those transitions ofone species into another, which he asks to see, abound on all sides, as is well known to every systematic naturalist. Only consider, forexample, the genera of Rubus and Salix among the living plants of thepresent period, and the Ammonites and Brachiopoda among extinctanimals. Hence, too, Virchow can have no independent views as to thehistorical development of the higher from the lower animals, becausethe abundant living forms of the lower animals are almost unknown tohim, and because he has hardly any conception of the marvellousstrides which hundreds of industrious workers have made in this verydepartment within the last twenty years. But there can be no doubt, indeed it is already universally acknowledged, that it is preciselythe comparative anatomy of the lower--nay, of the very lowestanimals--that has solved the greatest riddles of life, and removed thegreatest obstacles from the path of the doctrine of descent. He simplyignores the fact that true Monads actually exist, and have beenpositively identified by many different observers as structureless"organisms without organs, " and he turns out the poor Bathybius with akick. And yet I believe that in "Kosmos"[15] I have conclusively provedthat Monads must retain their vast elementary importance whether theBathybius actually exists or not. 

But even as regards the higher animals--nay, even as to thecomparative anatomy of the highest next to man, the apes--Virchowstands apart, not understanding the views of modern morphology. 

We must here examine more closely into this, because it is preciselyin this department that Virchow's only morphological experiments havebeen made; viz. , his investigations as to the skulls of apes and ofmen. This is precisely the one only point on which he has sought acloser acquaintance with morphology, and precisely here it is mostclearly to be seen how little he is acquainted with the recentadvances our science has made, and that he has hardly any conceptionof the extraordinary importance to that science of the theory ofdescent. 

The skull theory, as is well known, has for a long time been a veryfavourite theme, not only with prominent naturalists, but also withtalented amateurs. Undoubtedly the skull, viewed as the bony capsulewhich encloses our most important organ of sense, our brain, has aspecial claim to morphological importance; for the generalconformation of the skull corresponds on the whole to the developmentof the brain, and its inner surface gives an approximate idea of theouter surface of the brain. In this correspondence lies the only soundkernel of the sickly, overgrown fancies of phrenology. The variousdevelopment of the skull allows of an approximate inference as to thevarious degrees of development of the brain and of the mentalfaculties. The comparative study of the skulls of the vertebrateanimals had excited the lively interest of morphologists by the end ofthe last century, when comparative anatomy was beginning toconstitute a special science; and the genetic inquiry as to themorphological significance and development of the skull soon grew outof it. It was no less a man than our greatest German poet who firstanswered this question, and propounded the theory that the skull wasneither more nor less than the modified foremost end of the vertebralcolumn, and that the separate groups of bones which lie behind oneanother in the human skull, as in that of all the higher vertebrata, answer to the separate modified vertebræ. This "vertebral theory" ofthe skull, which Von Goethe and Oken simultaneously and independentlyattempted to prove, aroused universal interest and maintained itsground for seventy years, while many attempts were made to improve andenlarge upon it in detail. 

A quite new light was thrown on this, as on every other morphologicalquestion, as soon as Darwin in 1859 had once more put into our handsthe torch of the doctrine of descent. The inquiry as to the origin ofthe skull now assumed a real and tangible form. Since all vertebrateanimals, from fishes up to man, agree so completely as to theiressential internal structure that they can be rationally conceived ofno otherwise than as branches of one stock and as descendants of oneparent-form, the distinctly formulated question as to the skulltheory which now started into prominence was this: "How, historically, has the skull of man and of the higher animals originated from that ofthe lower animals? How is the development of the bones of the skullfrom the vertebræ to be proved?" The answer to these difficultquestions was supplied by the first comparative anatomist of thepresent day, by Carl Gegenbaur. After Huxley had pointed out that theontogenesis or individual development of the skull by no meansfavoured the older hypothesis of Goethe and Oken, Gegenbaur broughtforward evidence that the fundamental idea of that theory was correct;that the skull does in fact correspond to a series of coalescentvertebræ, but that the separate bones of the skull are not to beregarded as representing parts of such modified vertebræ. Theskull-bones of all recent vertebrate animals are rather, for the mostpart, dermal bones, which have come into closer connection assupplementary to the cartilaginous primitive skull. We can even nowtrace the number and position of the original vertebræ, from whichthis primitive skull originated, by the number of the vertebral arches(gill-arches) which are attached to it, as well as by the number andposition of those vertebræ, from nine to ten. Of all the recentvertebrata, the cartilaginous fishes, or Selachians, have most nearlypreserved the form and structure of this primordial skull. TheseSelachians, the Rays and Sharks, are on the whole the creatures whichthrow the clearest light on the history of the lineage of thevertebrata and on the organisation of our primeval fish-naturedancestors. It is one of the particular merits of Gegenbaur that heclearly and firmly established the place in nature of the Selachiansas the common ancestors of all vertebrate animals from fish up to man. 

None but those who have thoroughly studied the comparative morphologyof the vertebrata, who have sought the genetic issue from thatlabyrinth of intricate morphological problems at the hands of thetheory of descent, can duly value the immeasurable service whichGegenbaur has done by this and other "Investigations into theComparative Anatomy of the Vertebrata. " These investigations are asmuch distinguished by a profound knowledge and careful working out ofthe wonderfully-extensive empirical materials for the subject, as bytheir critical acumen and philosophic grasp. At the same time they setin the clearest light the immeasurable value of the theory of descentin the causal explanation of the most difficult morphologicalproblems. Gegenbaur might, therefore, with perfect right, enunciatethis axiom in the Introduction to his "Comparative Anatomy. " "Thetheory of descent will at once find a touchstone of proof incomparative anatomy. Up to this time no experience in comparativeanatomy has transpired which contradicts that theory; on thecontrary, they all lead up to it. Thus it will receive back fromscience that which it has given to scientific method: clearness andcertainty. " In point of fact we can adduce no morphologicalinvestigations which better support this declaration than those veryphylogenetic researches "as to the cranium of the Selachians, as abasis for the critical examination of the genesis of the cranium ofthe vertebrata, " 1872. As Virchow had formerly thoroughly studied theold skull-hypothesis, and in his admirable discourse on "Goethe as aNaturalist, " 1861, had given an excellent exposition of it; asmoreover he had produced most valuable contributions to the normal andpathological anatomy of the human skull, we might have expected thathe would have received Gegenbaur's grand reform of the theory of theskull, and historical solution of the skull-problem, with the greatestinterest, and have made it the clue to his own further researches. Butwe seek in vain through Virchow's latest contributions to the study ofthe human skull, for any indication of his knowing or appreciatingGegenbaur's investigations. On the contrary, we see him persistentlymoving, without any clear goal in view, on that trodden and deviouspath of investigation which finds the highest aim of craniologicalscience in the measuring of skulls, or craniometry. 

We are far from undervaluing the full significance of the results ofexact and careful descriptions and measurements of variousconformations of the skull as an empirical basis for a true andscientific study of the skull--_i. E. _, for comparative and geneticcraniology. But still we must say that the way and method by whichthis skull measurement has, for ten years now, been pursued bynumerous craniologists can never yield corresponding scientificresults; on the contrary, though it is cried up as the "exactmorphology" of the skull, it simply loses itself in the domains ofharmless trifling. A large amount of time has in the last ten yearsbeen squandered in disputes as to the best method of measuring skulls, while the craniologists concerned have not, in the first place, answered the obviously most important question: What end they proposeto gain by this specialist measuring, what proposition they mean toprove by it? Most of those numerous skull measurers know nothingbeyond the perfect human skull, or at most the skulls of a few othermammalia, while the comparative morphology and historical developmentof the crania of the lower vertebrata are wholly unknown to them; andyet these last contain the true key to the comprehension of theothers. One single month devoted by these "exact skull measurers" tothe study of Gegenbaur's theory of the skull, and to testing thehypothesis by the skulls of Selachians, would have yielded them morefruit and have given them more light than long years of describing andmeasuring human skulls, however various. 

Virchow himself affords the most striking example of the usual resultsof this so-called "exact method" of studying skulls. In his popularessay on "The Skulls of Men and Apes, " 1870, he concludes with thisnotable proposition:--"It is therefore self-evident that Man can neverby any progressive development have originated from the Apes. " Everyevolutionist who is familiar with the surprising facts of comparativemorphology will draw from them the opposite conclusion: "It isself-evident that Man could only have originated from the progressivedevelopment of the Ape (organism). "

This brings us to that question which, in the popular treatment of thetheory of descent, is justly considered as its most important outcomeand as the keystone of the evolutionist edifice--to the well-knownproposition, "Man is descended from the Ape. " While we simply ignoreall the misrepresentation, distortion, and misinterpretation whichthis ape, or pithecoid hypothesis, has met with on all sides, we willonly remark that this fundamental proposition, in the sense of ourmodern doctrine of evolution, can rationally have only this plainmeaning: that the human species as a whole was long since developedfrom the order of apes, indeed actually from one (or perhaps more)long since extinct form of ape; the immediate progenitors of man inthe long series of his vertebrate ancestry were apes or ape-likeanimals. Of course none of the now surviving species of apes is to beregarded as the unaltered posterity of that primeval parent-form. Virchow, however, understanding the "ape question" in this sense, answers it, as Bastian also does, with the most positivecontradiction. "We cannot teach the doctrine that man is descendedfrom apes or from any other animal, for we cannot regard it as a realacquisition of science" (p. 31). Although I myself, in directopposition to this view, and in agreement with almost all myprofessional colleagues, look upon the descent of man from apes as oneof the surest of phylogenetic hypotheses, I will here expressly admitthat the _relative_ certainty of this, as of all other historicalhypotheses of descent, is not comparable with the _absolute_ certaintyof the general theory of descent. It is now ten years since I firstexplicitly stated (in my "Natural History of Creation, " vol. Ii. P. 358): "The pedigree of the human race, like that of every animal orplant, remains in detail a more or less approximate generalhypothesis. This, however, in no way affects the application of thetheory of descent to man. In this, as in all researches into thederivation of our organism, we must distinguish between the _generaltheory_ of descent and the _specific hypothesis_ of descent. Thegeneral theory of descent claims full and permanent value, because itis inductively based on the whole range of common biological phenomenaand on their internal causal connection. Each special hypothesis ofdescent, on the other hand, is conditional as to its specific value onthe existing state of our biological information, and on the extent ofthose objective empirical grounds on which we deductively found thehypothesis, by our subjective inferences. " And I must hereemphatically add that I have on every opportunity repeated thatreservation, and have always insisted on the difference which existsbetween the absolute certainty of transmutation in general and therelative certainty of each individual specific pedigree. So that whenSemper and others of my opponents assert that I teach my specificgenealogies as "infallible dogmas, " it is simply false. I have, on thecontrary, pointed out on all occasions that I regard them only as_heuristic or provisional hypotheses_, and as a means of investigatingthe actual relations of cognate races of organic forms more and moreapproximately. 

Since the conception of the natural animal system as a hypotheticalgenealogical tree, and the phylogenetic interpretation ofmorphological affinity which that conception involves, afford in factthe only rational interpretation of that affinity in general, my firstgenealogical attempts soon found many imitators, and at the presenttime numerous industrious labourers in the different departments ofsystematic zoology are endeavouring to find in the construction ofsuch hypothetical genealogies the shortest and completest expressionof the modern conception of structural affinity. If Virchow had notbeen as ignorant of the true significance and method of systematicmorphology as he is of its progress and scientific contents, he mustcertainly have known this, and then he would surely have withheld hismockery of all these grave phylogenetic studies as "personalcrotchets" and worthless dreams. 

What mighty strides towards a mechanical morphology we have made bythis phylogenetic working out of the system, and how much light andlife it has at once thrown into the system that before was dead andcold, can only be known to those who have long and deeply studiedspecific systematisation and the grouping of species; Virchow has notthe remotest suspicion of it. Moreover, these attempts have nowproceeded so far, that a large proportion of the phylogenetichypotheses are regarded as very nearly certain, and can hardlyundergo any further essential modifications; while the greater numberof them are still in an unfixed state, and one systematist tries toimprove them in this direction, and another in that. 

The following phylogenetic hypotheses are held to be almostcertain:----The descent of many-celled animals from single-celled, ofthe Medusæ from the hydroid Polyps, of the jointed from the unjointedworms, of the sucking from the gnawing insects, of amphibious animalsfrom fishes, of birds from reptiles, of the placental mammalia fromthe marsupials, and so forth. I personally consider the descent of manfrom the apes as equally certain; nay, I regard this most importantand pregnant genealogical hypothesis as one of those which, up to thepresent time, rest on the best empirical basis. 

Huxley, in particular, fifteen years ago, in his celebrated "Man'sPlace in Nature, " 1863, so admirably proved the undoubted "descent ofman from apes, " and so clearly discussed all the relations that had tobe taken into consideration, that very little was left to others todo. The result of his comparative morphological investigations iscontained in this proposition----" If we take up a system of organs, be it which we will, the comparison of its modifications throughoutthe series of apes leads us to the same conclusion: that in everysingle visible character man differs less from the higher apes thanthese do from the lower members of the same order. " It is thereforeimpossible for any objective zoologist, according to the principles ofcomparative systematisation, to ascribe to man any other place in theanimal world than in the order of apes; and it is quite immaterialwhether we designate this individual group as the Order of Apes, or, with Linnæus, as the Primates. For the phylogenetic construction ofthe system, the common descent of man and of apes from one commonparent-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 andapes may have been, very different views might probably be brought onopposite sides; but any one who knows the collected facts that bearupon the matter, and estimates them impartially, must, in conclusion, arrive at the certain conviction that that hypothetical and long-sinceextinct parent-form can only have been genuine apes; that is to say, of the placental mammalian type, such as when we see them now livingbefore our eyes we unhesitatingly class, on the ground of theirzoological characters, as true apes, in the order of Apes or Primates. 

In this, and all other sound phylogenetic hypotheses, we may mosteasily attain to a conviction of their truth by taking intoconsideration and comparison the other possible hypotheses. But infact no single opponent of the ape-hypothesis has been able to combatit with any other phylogenetic hypothesis that has the faintestglimmer of probability. Not one opponent has suggested, or cansuggest, any other animal form that can serve as our nearest ancestorthan the ape. No one has ever reproached me by saying that MotherNature has endowed me with too little imagination; on the contrary, Iam often accused of having a superfluity of that gift of the gods; butI have often and repeatedly exerted my imagination to picture tomyself any known or unknown animal-form as the nearest parent-form toman in the place of the apes, and have always found myself under thenecessity of falling back upon the stock of apes. Let me conceive ofthe outward conformation and the internal structure of the nearestmammalian ancestors of men as I will, I am always forced toacknowledge that this hypothetical parent-form ranges under thezoologically-conceived order of apes, and cannot possibly be separatedfrom the Simiadoe or Primates. If, in spite of this, any one chooses, out of a "personal crotchet, " to accept some other series of unknownanimal ancestors of man that have nothing to do with apes, that is buta mere empty hypothesis floating in the air. Our ape-hypothesis, onthe other hand, is objectively and thoroughly proved by the essentialagreement of the internal bodily structure of man and of apes, and bythe identity of their embryonic development, as I have fully shown inmy "Evolution of Man" (chaps. Xix. And xxvi. ) The mode and manner inwhich he here puts palæontology in the foreground, and throws on thetheory of descent the task of producing an unbroken gradation offossil transitional forms between the apes and man, is very indicativeof Virchow's ignorance of this zoological question--in which I, as aprofessional zoologist, must decisively declare his incompetence. Thereasons why such a solution of the problem is not to be expected, theextraordinary imperfection of the palæontological record, the naturalimpediments to the palæontological evidence of the genealogical table, have been so lucidly unfolded by Darwin himself (chaps. Ix. And x. Ofthe "Origin of Species") that I am obliged once more to come to theconclusion that Virchow has never read it with any attention. 

Besides, long before Darwin, the gifted Lyell, the great originator ofmodern geology, showed clearly and convincingly how, for many reasons, the greater part of the fossil series must remain most imperfect, andthese reasons were at a later period so often and so fully discussed(by myself among others, in chap. Xv. Of the "History of Creation, "vol. Ii. Pp. 24-32) that it is wholly superfluous once more and inthis place to state these well-known and time-worn questions. It onlyshows how little Virchow was acquainted with geology and palæontology, and what a limited judgment he can form of these historical causalrelations. 

FOOTNOTES:

[15] Vol. I. P. 293. 

CHAPTER IV. 

THE CELL-SOUL AND CELLULAR PSYCHOLOGY. 

No attack in Virchow's Munich address surprised me so much, and noneso plainly betrayed the subversion of his most important scientificviews, as that which he directed against my observations on psychologyand cellular physiology. A mystic dualism in his fundamental views ishere revealed, which stands in the sharpest contrast to the mechanicalmonism formerly upheld by the famous pathologist of Würzburg. 

In my Munich discourse (p. 12), I had alluded to the "grand andfruitful application which Virchow had made, in his system of cellularpathology, of the cell-theory to the general province of theoreticmedicine;" and as a logical amplification of that idea, I assertedemphatically that we must ascribe an independent soul-life to everyindividual organic cell. "This conception is validly proved by thestudy of infusoria, amoebæ, and other one-celled organisms; for, inthese individual, isolated, living cells we find the samemanifestations of soul-life--feelings, and ideas (mental images), will and motion, as is in the higher animals compounded of many cells"(p. 13). Virchow now rises up in the strongest protest against thistheory of a cellular sensibility, which I regard as the inevitableconsequence of his early views of cellular physiology; it is to him"mere trifling with words. " He combats with equal decisiveness "thescientific necessity of extending the province of psychical processesbeyond the circle of those bodies in and by which we actually see themexhibited. " He further says, "If I explain attraction and repulsion aspsychical phenomena, I simply throw the psyche out of the window; thepsyche ceases to be a psyche. " Finally he says, "I assert without anyhesitation that for us the sum total of psychical phenomena isconnected with certain animals only, and not with the collective massof all organic beings; nay, not even with all animals in general. Wehave no ground as yet for speaking of the lowest animals as possessingpsychical properties; we find such properties only in the highergrades, and with perfect certainty only in the very highest. "

When I first read this and other astounding statements in Virchow'spaper, I involuntarily asked myself, "Can this be the same Virchowfrom whom, twenty-five years ago, I learnt in Würzburg that thesoul-functions of man and animals depend on mechanical processes inthe soul-organs; that these organs are, like all other organs, composed of cells, and that the functional activity of an organ isnothing more than the sum of the activity of all the cells whichcompose it? Is this the same Virchow whose most vital doctrine it wasthat all the physical and psychical processes of the human organismwere to be referred to the mechanics of cell life; who supported theview of the unity of all the phenomena of life with the same emphasiswith which we are now obliged to defend it against his attacks?"

In fact, and beyond a doubt, we have here a new proof of Virchow'scomplete change in all fundamental scientific principles. For thecellular psychology which I advance is only a necessary consequence ofthe cellular physiology promulgated by Virchow. His present oppositionto the former is either a renunciation of the latter or an untenableand inconsequent position. To explain this astonishing metapsychosis, we shall do well first to glance at the soul in general, and then giveparticular consideration to the cell-soul. 

What is the Soul or Psyche? The innumerable different answers whichhave been given to this crowning question of psychology, maycollectively, when freed from all extraneous matter, be broughtunder two groups which we may shortly designate as the dualistic andthe monistic soul-hypothesis. According to the monistic (orrealistic) soul-hypothesis, the "soul" is nothing more than the sumor aggregate of a multitude of special cell-activities, among whichsensation and volition--sensual perception and voluntarymovement--are the most important, the most common, and the mostwidely diffused; associated with these in the higher animals and inman, we find the more developed activities of the ganglionic cellswhich are included under the conceptions of Thought, Consciousness, Intellect, and Reason. Like all the other functional-activities ofthe organic cells, these soul-functions depend ultimately onmaterial phenomena of motion, and more particularly on the motionsof the plasson-molecules or plastidules, the ultimate atoms of theprotoplasma, and perhaps of the nucleus also; therefore we should beable actually to grasp and explain them, as well as every othercognisable natural process, if we were in a position to refer themto the mechanics of atoms. This monistic soul-hypothesis, then, isat bottom mechanistic. If psychical mechanics--psychophysics--werenot so infinitely complex and involved, if we were in a position totake a complete view of the historical evolution of the psychicfunctions, we could reduce the whole of them (includingconsciousness) to a mathematical "soul-formula. "

According to the opposite, or dualistic (or spiritualistic)soul-hypothesis, the soul is, on the contrary, a 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, andstands in only a temporary connection with certain organs of thatbody--the soul-, or mental-organs. It has been imagined that thissoul-matter, which resembles that imponderable ether which is themedium of light, is diffused between the ponderable molecules of thesoul-organs and especially of the nerve-cells, and that thisconnection of the imponderable "soul" with the ponderable bodysubsists only so long as the individual life lasts. At the instant ofthe first beginning of the individual organism, at the moment ofgeneration, this imponderable "soul" passes into the body, and at theinstant of death, at the annihilation of the living individual, itagain quits the body. This mystical or dualistic soul-hypothesis, which, as is well known, is to this day universally accepted, isfundamentally vitalistic, inasmuch as it regards the force which isbound up with the soul-substance, like the "vital force" of a pasttime, as a peculiar force quite independent of mechanical forces. Thisforce does not depend on the material phenomena of motion, and isquite independent of the mechanics of atoms. The highest law of modernnatural science, the law of the conservation of force, has, therefore, no application in the region of soul-life, and thatmechanical causality which prevails throughout all the processes ofnature does not exist for the soul. The Psyche, in a word, is asupernatural phenomenon, and the supernatural department of thespiritual world stands free and independent of the natural departmentof the material world. 

If we now compare the psychological views of the youthful andunprejudiced Virchow of Würzburg with those of the older and mysticalVirchow of Berlin, there can be no doubt in the minds of the impartialthat the former, a quarter of a century ago, was as decided andlogical a monist as the latter is at present a confessed and convicteddualist. The distinguished position which Virchow, twenty-five yearssince, won by his natural conception of the nature of man, and thegreat fame which he then earned in the fight for the truth, restprecisely on this, that on every occasion he maintained with hisutmost vigour the unity of all vital phenomena, and asserted theirmechanical character. All organic life, even the soul-life, rests onmechanical principles, on that causal mechanism of which Kant saidthat "it alone contained a practical interpretation of nature, " andthat "without it no natural science can exist. " On this point Virchowsays well in his discourse on "Efforts at Unity in ScientificMedicine, " 1849:--"Life is only a peculiar sort of mechanics, thoughit is indeed the most complex form of mechanics; that in which theusual mechanical laws fall under the most unusual and manifoldconditions. Thus life, compared with the universal processes of motionin nature, is a thing peculiar in itself; but it does not constitute adiametrical, dualistic opposition to those laws; it is only a peculiarspecies of motion. The motion itself is a mechanical one, for howshould we become cognisant of it if it were not based on the sensibleproperties of bodies? The media of the motion are certain chemicalmatters, for we recognise none but chemical matter in bodies. Theindividual acts of motion reduce themselves to mechanical, orphysico-chemical, modifications of the constituent elements of theorganic unities, the cells and their equivalents. " These and manysimilar utterances in Virchow's earlier writings, and especially inthe essay I have mentioned, "On the Mechanical Conception of Life, "leave no doubt that he formerly supported, with a clear conscience andhis utmost energy, in psychology as in the other collected departmentsof physiology, that very mechanical standpoint which we to-day acceptas the essential basis of our monism, and which stands inirreconcilable antagonism to the dualism of the vitalistic doctrine. To none of my teachers am I so deeply indebted for my emancipationfrom all the prejudices of the dualistic doctrine, and for myconversion to the monistic, as to Rudolf Virchow; for it was hissuperior guidance which most firmly convinced me, and many others, ofthe exclusive importance of the mechanical view of nature. He led meto a clear recognition of the fact that the nature of man, like everyother organism, can only be rightly understood as a united whole, thatthis spiritual and corporeal being are inseparable, and that thephenomena of the soul-life depend, like all other vital phenomena, onmaterial motion only--on mechanical (or physico-chemical)modifications of cells. And it was in perfect agreement with my mosthonoured master that I subscribed then, and at this day stillsubscribe, to the proposition with which he, in September 1849, closedthe preface to the above-mentioned "Efforts at Unity. " "It is possiblethat I may have erred in details; in the future I shall be ready andwilling to acknowledge my mistakes and to rectify them, but I enjoythis conviction, that I shall never find myself in the position ofdenying the principle of the unity of the human nature with all itsconsequences!"

To err is human! Who can say to what diametrical contradiction to hisfirmest convictions man may not in the future be driven by hisadaptation to new relations in life? If we compare these stoutmonistic declarations of 1849 and 1858 with the equally decideddualistic utterances in Virchow's Munich address of 1877, we perceivethat he could not give the lie more fiercely to his former fundamentalopinions than he has there done. Not quite twenty years have passedby, and yet, in the course of that time, in Virchow's views of theuniverse, in his conception of human nature, and of the soul-life, achange has been effected than which we can conceive of no greater. Welearn to our surprise that psychical and corporeal processes arewholly different phenomena; that no scientific necessity whateverexists for extending the province of psychical processes beyond thecircle of those bodies in which, and by which, we see them actuallyexhibited. "We may ultimately explain the processes of the human mindas chemical, but at any rate, it is not yet our business to amalgamatethese two subjects!"

From the whole psychological discussion which is involved in Virchow'sMunich address, it is made clear that at the present time he regardsthe "soul" in a purely dualistic sense as a substance, an immaterialessence which only temporarily takes up its abode in the body. Highlycharacteristic of this is the remarkable sentence, "If I explainattraction and repulsion as psychical phenomena, I simply throw thepsyche out of the window; the psyche ceases to be a psyche. " If wesubstitute for the word "psyche" the word which corresponds toVirchow's earlier mechanistic view--the word "motion" (or peculiarmode of motion)--the sentence runs thus: "If I explain attraction andrepulsion as phenomena of motion, I simply throw motion out of thewindow. "

Almost more remarkable is Virchow's assertion that the lowest animalshave no psychic properties; that, on the contrary, "these are only tobe found in the higher, and, with perfect certainty, only in thehighest animals. " It is only to be regretted that Virchow has not herestated what he understands by the higher and the highest animals;where that remarkable dividing line is, beyond which the soul suddenlyappears in the hitherto soulless body. Every zoologist who is in somedegree familiar with the results of comparative morphology andphysiology will here clasp his hands in astonishment, for by thisproposition Virchow seems to mean that we must ascribe a soul-lifeonly to those animals in which special soul-organs, in the form of acentral and peripheral nerve-system, are developed from sense-organsand muscles. But it is admitted that all these different soul-organswith their characteristic properties have originated from single cellsthrough the division of labour (differentiation); and the nerves andmuscles especially have been developed by differentiation from theneuro-muscular cells. The cells from which all these differentnerve-cells, muscle-cells, mind-cells, and so forth, are derived, areoriginally the simple neutral cells of the epithelium of the ectodermor exterior germ-layer, and these cells, again, like all the cells ofmany-celled animal bodies, originated in the repeated division of onesingle original cell, the ovum-cell. 

The individual development or ontogenesis of each of these many-celledanimal-forms, brings this histological process of development soclearly and evidently before our eyes that we can but directly inferfrom it the truth of the phylogenesis, or gradual historical evolutionof the soul-organs. The association of cells and the division oflabour among them are the modes by which, in the first instance, thecompound many-celled organism has originated, historically, from thesimple one-celled organism. And an impartial comparative considerationteaches us in the clearest way that a functional-activity of thesoul-cells exists in the lowest one-celled animals as well as in thehighest and many-celled; in the infusoria as well as in man. Volitionand sensation, the universal and unmistakable signs of soul-life, maybe observed among the former as well as in the latter. Voluntarymotion and conscious sensation (of pressure, light, warmth, &c. ) comeunder our observation so undoubtedly in the commonest forms ofinfusorial animals--for instance the Ciliata, that one of their mostpersevering observers, Ehrenberg, asserted undeviatingly to the day ofhis death that all Infusoria must possess nerves and muscles, organsof sense and of soul, as well as the higher animals. 

It is well known that the enormous advance which our science has latelymade in the natural history of these lowest organisms culminates in thestatement--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 ofall the various vital functions--including soul-functions--which in thezoophytes (plant-animals), as the hydra and the sponges, are distributedamong the cells of the two germ-layers, and in all the higher animalsamong the different tissues, organs, and apparatus of a highly developedand constructed organism. The psychic functions of sensation andvoluntary motion, which are here distributed to such very various organsand tissues, are in the infusoria fulfilled by the neutral plassonmaterial of the cell, by the protoplasma, and possibly also by thenucleus (compare my treatise "The Morphology of the Infusoria. " Jena, Zeitschriften, 1873, vol. Vii. P. 516). And just as we must attribute tothese primary animal forms an independent "soul, " just as we mustplainly be convinced that the single independent cell has a "psyche, " wemust as decidedly attribute a soul to every other cell; for the mostimportant active constituent of the cell, the protoplasm, everywhereexhibits the same psychic properties of sensibility or irritability, andmotive power or will. The only difference is this, that in the organismof the higher animals and plants the numerous collected cells, to agreat extent, give up their individual independence, and are subject, like good citizens, to the soul-polity which represents the unity of thewill and sensations in the cell community. We here also must distinguishclearly between the central soul of the whole many-celled organism orthe personal psyche (the person-soul), and the particular individualsoul or elementary soul of the individual cells constituting thatorganism (the cell-soul). Their relations are strikingly illustrated inthe instructive group of Siphonophora, as I have briefly shown in myarticle on "The Cell-soul and Soul-cells" (Deutsche Rundschau, July1878). Beyond a doubt the whole stock or polity of Siphonophora has avery definite united will and a united sensibility, and yet each of theindividual persons of which this stock (or Cormus) is composed has itsown personal will and its own particular sensations. Each of thesepersons indeed was originally a separate Medusa, and the individualSiphonophora 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 myMunich address as the "surest foundation of empirical psychology, " Ibelieved I was drawing an inference quite to Virchow's mind, from hisown views of mechanical and cellular-physiology; and for that reason Itook the same occasion specially to celebrate his very great servicesto the cell theory. How astonished then was I when in his reply thisvery theory was violently attacked and satirised as "mere triflingwith words. " It never could have occurred to me that Virchow had longsince become unfaithful to his most important biological principles, and had deserted his own mechanical "theory of cells;" it never hadoccurred to me that Virchow could be in great measure wanting in thatzoological knowledge which is requisite for a practical comprehensionof the cell-soul theory. He has never thoroughly studied either theone-celled Protozoa, the Infusoria and Lobosa, nor the Coelenterata, the highly instructive Sponges, Hydroids, Medusæ, or Siphonophora; andthus he is wanting in those genetic principles of comparative zoologyon which our theory rests. It is in no other way conceivable thatVirchow should contemn the most important consequences of the celltheory as "mere trifling with words. "

Next to the one-celled infusoria no phenomenon throws such directlight on our cellular psychology as the fact that the human ovum, likethe ova of all other animals, is a single, simple cell. In accordancewith our monistic conception of the cell-soul, we must conclude thatthe fertilised ovum-cell already virtually possesses those psychicalproperties which, by the special combination of the peculiaritiesinherited from both parents, characterise the individual soul of thenew person; in the course of the development of the germ, thecell-soul of the fertilised ovum naturally is developed simultaneouslywith its material substratum, and subsequently, after birth, itappears in full activity. 

According to Virchow's dualistic conception of the psyche, we must, onthe contrary, assume that this immaterial essence at some period ofits embryonic development (apparently when the spine separates itselffrom the external germ-layer) informs the soulless germ. Of course, the bare miracle is thus complete, and the natural and unbrokencontinuity of development is superfluous. 

CHAPTER V. 

THE GENETIC AND DOGMATIC METHODS OF TEACHING. 

The very justifiable surprise which Virchow's Munich address hasexcited in many circles is due only in part to his opposition to thetheory of descent; for the rest, and in much greater part, it is dueto the astounding arguments which he has connected with it, particularly as to freedom for instruction. These arguments so closelyresemble those of the Jesuits that they might have been inspireddirect from the Vatican, or, which is the same thing, the notorious"court-chaplain party" in Berlin. No wonder, then, that thesepropositions, which would undermine the whole liberty of science, havemet with the loudest approbation from the "Germania, " the "NewEvangelical Church Times" ("Neue Evangelischen Kirchenzeitung"), andother leading, equivocating organs of the Church militant. On theother hand, these odious principles are already so extensivelydiscussed, and have been so clearly laid down in all theirindefensibility, that I may here deal with them briefly. 

Virchow's politics as a pedagogue reach their highest pitch in thisdemand: "that in all schools, from the poor schools to theuniversities, nothing shall be taught that is not absolutely certain. None but objective and absolutely ascertained knowledge is to beimparted by the teacher to the learner; nothing subjective, noknowledge that is open to correction, only facts, no hypotheses. " Theinvestigation of such problems as the whole nation may be interestedin must not be restricted; that is liberty of inquiry; but the problemought not, without anything farther, to be the subject of _teaching_. "When we teach we must restrict ourselves to the smaller, and yet howgreat, departments which we are actually masters of. "

Rarely indeed has such a treasonable attempt on liberty of doctrinebeen made by a prominent representative of science, and a leader ofthe intellectual movement too, as this by Virchow. Only inquiry is tobe free and not teaching! And where in the whole history of science isthere one single scientific inquirer to be found who would not havefelt himself quite justified in teaching his own subjectiveconvictions with as much right as he had to construct them frominquiry into objective facts. And where, generally speaking, is thelimit to be found between objective and subjective knowledge? Isthere, in fact, any objective science?

This question Virchow answers in the affirmative, for he goes on tosay: "We must not forget that there is a boundary line between thespeculative departments of natural science and those that are actuallyconquered and firmly established" (p. 8). In my opinion, there is nosuch boundary line; on the contrary, all human knowledge as such issubjective. An objective science which consists merely of factswithout any subjective theories is inconceivable. For evidence infavour of this view we must take a rapid survey of the whole domain ofhuman science, and test the chief departments of it to see how farthey contain, on the one hand, objective knowledge and facts, and onthe other, subjective knowledge and hypotheses. We may begin directlywith Kant's assertion that in every science only so much true--that isobjective--knowledge is to be found as it contains of mathematics. Unquestionably mathematics stand at the head of all the sciences asregards the certainty of its teaching. But how as to those deepest andsimplest fundamental axioms which constitute the firm basis on whichthe proud edifice of mathematical teaching rests? Are these certainand proved? Certainly not. The bases of its teaching are simply"axioms" which are incapable of proof. To give only one example of howthe very first principles of mathematics might be attacked byscepticism and shaken by philosophical speculation, we may rememberthe recent discussions as to the three dimensions of space and thepossibility of a fourth dimension; disputes which are carried on evenat the present day by the most eminent mathematicians, physicists, andphilosophers. So much as this is certain, that mathematics as littleconstitute an absolutely objective science as any other, but by thevery nature of man are subjectively conditioned. A man's subjectivepower of knowing can only discern the objective facts of the outerworld in general so far as his organs of sense and his brain admit inhis own individual degree of cultivation. 

However, granting that mathematics practically constitute anabsolutely certain and objective science, how is it with the rest ofthe sciences? Undoubtedly the most certain among them are those "exactsciences" whose principles are to be directly proved by mathematics;thus, in the first place, a great part of physics. We say, "a greatpart, " for another large part--to speak accurately, by far thegreatest--is incapable of any exact mathematical proof. For what do weknow for certain of the essential nature of matter, or the essentialnature of force? What do we know for certain of gravitation, of theattraction of mass, of its effects at great distances, and so on?Newton's theory of gravitation is regarded as the most important andcertain 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 hypothesisof "electric fluidity, " or of imponderable matter of which theexistence is nothing less than proved. Or optics? Optics certainlyappertain to the most important and completest branch of physics, andyet the undulatory theory of light, which we accept now as theindispensable basis of optics, rests on an unproved hypothesis, on thesubjective assumption of an ethereal medium, whose existence no one isin a position to prove objectively in any way. Nay, further, beforeYoung set up the undulatory theory of light, for a hundred years theemanation theory as taught by Newton obtained exclusively in physics;a theory which at the present day is universally regarded asuntenable. In our opinion the mighty Newton won the greatest honoursin the development of the science of optics, inasmuch as he was thefirst to connect and explain the vast mass of objective optical factsby a subjective and pregnant hypothesis. But, according to Virchow'sview, Newton on the contrary transgressed greatly by teaching thiserroneous hypothesis; for even in "exact" physics none but"independent and certain facts" are to be taught and established by"experiment as the highest means of proof. " Physics as a whole, asresting on mere unproved hypotheses, may be indeed an object ofinquiry but not of teaching. 

Of course the same is true of chemistry; nay, this stands on muchweaker feet, and is even less proved than physics. The wholetheoretical side of chemistry is an airy structure of hypotheses suchas does not exist in any other science. In the last three decades wehave seen a whole series of the most different theories rapidlysucceed each other, none of which can be positively proved, though atleast one of them is taught by every professor of chemistry. But whatis worst of all, the common basis of all the most dissimilar chemicaltheories, viz. , the atomic theory, is as unproved and unprovable asany hypothesis can be. No chemist has ever seen an atom, but henevertheless considers the mechanism of atoms as the highest term ofhis science, he nevertheless describes and constructs the connectionof atoms in their various combinations as though he had them beforehim on the dissecting-table! All the conceptions which we possess asto chemical structure and the affinities of matter, are subjectivehypotheses, mere conceptions as to the position and changes ofposition of the various atoms, whose very existence is incapable ofproof. Away, then, with chemistry from our schools! The chemist mustonly describe the properties of the different elements and thosecombinations which can be put before the pupil as ascertained factsfounded in experiment, "the highest means of proof. " Everything thatgoes beyond this is mischievous, particularly every suggestion as tothe essence and chemical constituents of bodies; matters as to which, in the nature of things, we can only form uncertain hypotheses. For asall chemistry, viewed as a system of doctrine, rests solely on suchhypotheses, it may be indeed a subject of investigation but not ofteaching. 

Having thus convinced ourselves that chemistry as well as physics, those "exact sciences, " those "mechanical" bases of all othersciences, rest on mere unproved hypotheses, and so must not be taught, we may make short work of the other faculties. For they collectivelyare more or less historical sciences and dispense wholly or in partwith even those half-exact, fundamental principles on which physicsand chemistry are based. In the first place, there is that grand, historical, natural science, geology; the great doctrine of thestructure and composition, the origin and development of our globe. According to Virchow this too must be limited to the description ofascertained facts, such as the structure of mountain masses, thecharacter of the fossils they contain, the formation of crystals, andso forth. But not for the world must anything be taught as to theevolution of this globe; for this rests from beginning to end onunproved hypotheses. For even to the present day the Plutonic andNeptunic theories are disputing the field, and to this day we know notas to many of the most important rocks, whether they originated by theagency of fire or of water. The new and remarkable discoveries of thegreat Challenger-expedition threaten to subvert a great manygeological notions which had long been regarded as certain. Thenagain, as to fossils. Who can prove with any certainty that thesepetrifactions are in truth the fossilised remains of extinctorganisms? They may be--as many distinguished naturalists of even thelast century maintained--marvellous sports of nature, mysterious"Lusus naturæ, " or mere rough, inorganic models of the labouringCreator into which He subsequently "breathed the breath of life;" orperhaps "stone-flesh" (caro fossilis) brought into existence, on thedead rocks by the "fertilising air" (aura seminalis), and so forth. 

But I am wrong! for with regard to petrifactions, Virchow is in thehighest degree speculative, and accepts without any hesitation therash hypothesis that fossils are actually the remains of extinctorganisms, although no "certain proof" whatever can be offered in itsfavour, and although experiment, the "highest means of proof, " hasnever yet produced a single fossil. According to him these are actual"objective, material evidences, " only here we must go no further thancertain experience teaches us, and base no subjective conclusions onthese objective facts. Thus, for instance, in the long series of themesozoic formations, in the different strata of the Trias, Jurassic, and Chalk formations, for the deposition of which a lapse of manymillions of years has been required, we find absolutely no remains offossil mammalia beyond lower jaws; seek where we will, nothing isanywhere to be found but lower jaws, and no other bones whatever. Thesimple reasons of this striking imperfection of the palæontologicalrecord have been clearly expounded by Lyell, Huxley, and others. (Comp. My "History of Creation, " vol. Ii. P. 32. ) These greatinvestigators, in accordance with all other palæontologists, havedemonstrated that these jaw-bones of the mesozoic period are theremains of mammalia, accurately speaking of marsupials, on the simpleground that the nether jaws of the extant recent marsupials show asimilar characteristic form with the fossil ones. They thereforeunhesitatingly assume that the rest of the bones in the bodies ofthese extinct animals corresponded to those of living mammals. Butthis is a quite inadmissible hypothesis devoid of any "certain proof!"Where, then, are the other bones? Let us see them! till then wedecline to believe in them. According to Virchow, we ought rather toassume that the lower jaw was the only bone in the body of theseextraordinary beasts. Are there not, in fact, snails, in which anupper jaw is the only representation of a skeleton. 

We cannot omit taking this opportunity of casting a side glance at thevery hazardous position which Virchow, in total opposition to hisboasted cool scepticism, has taken up in anthropology as it is called, now his favourite branch of science. In his Munich address he tells usthat he is pursuing the study of anthropology with delight, and thenasserts that "the quarternary man" is an universally-accepted fact. Quite apart from this statement, we have seen that Virchow can neverattain to a profound and really scientific study of anthropologysimply for this reason, that he is lacking in that comprehensiveknowledge of comparative morphology which is indispensable to it; nay, comparative anatomy and ontogenesis must be, according to him, unpermitted speculations and the phylogenesis of man, the key to allthe most important questions of anthropology, being based upon these, is devoid of all certain proof. All the more must we wonder at thespeculative levity with which even the sceptic Virchow in the"Primeval History of Man" and "Fossil Anthropology, " embarks in themost hazardous conjectures, and gives out uncertain, subjectivehypotheses as certain, objective facts. 

There is, in fact, at the present day no department of science inwhich the wildest and most untenable hypotheses have blossomed out sofreely as in anthropology and ethnology, so-called. All thephylogenetic hypotheses which I myself have put forward in my"Evolution of Man" as to the animal ancestry of man, or in my "NaturalHistory of Creation" as to the affinities of animal races--all theother genealogical hypotheses which are now advanced by numerouszoologists and botanists as to the phylogenetic evolution of theanimal and plant worlds--all these hypotheses together, which Virchowrejects in a lump, are, critically considered as hypotheses, farbetter grounded in facts, far better supported by facts, than themajority of those innumerable airy and fanciful hypotheses with which, for the last twelve years, the "Archiv für Anthropologie" and"Zeitschrift für Ethnologie, " edited by Virchow and Bastian, havefilled their columns. This last periodical has at least the merit ofbeing a tolerably consistent opponent of the doctrine of evolution, while in the former, during twelve years, essays on both sides havebeen mixed up in cheerful confusion. And how fanciful are theshort-sighted hypotheses which there blossom forth from the mixed massof facts, chaotically flung together. Only think of the disputes overthe stone age, bronze age, and iron age; think of the motleydiscussions as to the varieties of skull-conformation and theirsignificance; on the races of man, the migrations of peoples and thelike. Most of these very intricate historical problems are far moreburied in obscurity, and the hypotheses to explain them dispense farmore largely with any basis of facts, than is the case with ourphylogenetic 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 various and contradictoryhypotheses which have been put forward as to the antiquity and firstappearance of the human species; and Virchow asserts positively "Thepleistocene man is an universally accepted fact. The tertiary man is, on the other hand, a problem, though indeed a problem which is alreadyunder substantial discussion!" As if the distinction between thetertiary and quarternary periods were not itself a geologicalhypothesis, and as if the significance of the fossil animal-remains, which play the largest part in it, did not also rest on merehypotheses which escape all certain proof! Where, then, is the actualexperiment "as the highest means of proof, " which gives evidence forthese "certain facts"? The whole discussion in general aboutprehistoric man, which Virchow has mixed up with his Munich address(pp. 30, 31), is the clearest evidence of the uncritical spirit inwhich he deals with these historical problems as "exact naturalsciences. " He assures us that "not one single ape's skull, nor skullof an anthropoid ape, has ever been found which could actually havebelonged to a human owner!" and he adds this sentence, in italics, "Wecannot teach, for we cannot regard it as a real acquisition ofscience, that man is descended from the ape or from any other animal!"Then evidently no alternative remains but that he is descended from agod, or from a clod!

But let us go over the rest of the sciences to see what, according toVirchow, may be taught in each without endangering the safety ofscience. In the whole department of biology, as well as inzoology--including anthropology--and in botany, instruction must belimited to imparting those trifling fragments of knowledge whicheither consist of mere descriptions of dry facts, or which supply anexplanation of them by mathematical formulas. Morphology must betaught as mere descriptive anatomy and systematising, the history ofdevelopment as mere descriptive ontogenesis. Comparative anatomy andphylogenesis, which by their explanatory hypotheses raise those deadmasses of facts to the place of true and living sciences--these mustnot be taught at all. And how then do matters stand with regard to thecell-theory, that fundamental theory on which every element of ourmorphology and physiology depends, and by applying which Virchowhimself reached his grandest results?

Since Schleiden in Jena, forty years ago, first put forward thecell-theory, and Schwann immediately after applied it to the animalkingdom and so to the whole organic world, this fundamental doctrinehas undergone very important modifications, for it is indeed abiological theory, but not a fact. We may recollect under whatdifferent aspects its main principles have appeared in the course ofthese four decades: what changes have taken place in the conception ofthe cell itself. After the organic cell had originally been conceivedof as a vesicle, consisting of a firm capsule and a fluid content, wesubsequently discerned it to be composed of a glutinous semi-fluidcell-substance, the protoplasm, and convinced ourselves that thisprotoplasm and the cell-core or nucleus enclosed in it are the mostimportant and indispensable constituent parts of the cell, while theexternal firm capsule, the cell-membrane, is not essential and veryfrequently wanting. But even now opinions widely differ as to how theconception of a cell should be precisely defined, and whatconsequences must be inferred from the cell-theory, and attempts havenot been wanting to upset it altogether and to treat it as worthless. The anatomist Henle, of Göttingen, in particular, has repeatedly madesuch an attempt, that "gifted" anatomist who, in the preface to hisbulky text-book of human anatomy, declared that scientific ideas aremere worthless paper money, and that the noble metal of facts, on thecontrary, is the only genuine article. Not long since a bulky volumein quarto appeared, by one Herr Nathusius-Königsborn, in which thecell is explained to be a subordinate plastic element, and thecell-theory is eliminated as superfluous; and this monstrous volume, full of the most amusing nonsense, is dedicated to Herr Henle. Virchowformerly was one of the victorious opponents of the Göttingenphysician, and wrote brilliant articles against the "rationalpathology" of "irrational Herr Henle;" now apparently he agrees withhim that the paper money of ideas is worthless as compared with thenoble metal of facts. Of course the cell-theory then loses all itsvalue, and cannot be a subject of instruction; for the cell itself isnot a certain and undoubted fact, but only an abstraction, aphilosophical idea. 

Nothing more clearly shows what a complete change Virchow hasundergone in his most important principles, and what an uttermetapsychosis in this special province, than his famous axiom, uttered in 1855--"Omnis cellula e cellula. " That is unquestionably theboldest generalisation to which the youthful, independent Virchow everattained, and one on which he justly prided himself not a little. Hehimself repeatedly compared it with Harvey's saying, which marked anepoch--"Omne vivum ex ovo. " But neither of these axioms is universallycorrect. On the contrary, we now know that every cell does notnecessarily originate from a cell, any more than that every organicindividual originates from an ovum. In many cases true nucleated cellsproceed from un-nucleated cytods, as in the Gregarinæ, Myxomycetæ andothers. Nay more, the primordial organic cells could only haveoriginated in the first instance from non-cellular plastides or monadsby their homogeneous plasson resolving itself into an internal nucleusand an external protoplasm. Thus, as we subsequently learnt to knowmost of the exceptions to this generalisation of Virchow, it appearedall the bolder; the more so as we were at that time far from beingable to refer all the different tissues of the higher animals with anycertainty to cells, and as not a few experiments seemed to point tothe hypothesis of free cell-formation. That guiding axiom, which sopowerfully furthered the cell-theory, Virchow, from his presentstandpoint, must wholly condemn as a crime against exact science, andhe surely can never forgive himself for having propounded thishypothesis--which was afterwards found to be not universally true--asan important doctrinal axiom. 

We shall indeed find much worse sins against his own principles ofto-day if we turn to Virchow's own special department of science, namely, pathological anatomy and physiology, the most importantdivision of theoretic medicine. The great and incomparable serviceswhich Virchow here effected do not depend on the numerous independentnew facts which he discovered, but on the theories and hypotheses bywhich, like an inspired pioneer, he sought to open a way through thedead waste of pathological knowledge and to form it into a livingscience. These new theories and the hypotheses on which they werefounded, Virchow then propounded to us, his disciples, with suchincisive assurance that every one of us was convinced of their truth;and yet later experience has shown that they were in partinsufficiently proved and in part wholly false. For example, I willonly here recall his famous theory of the connective-tissue, for whichI myself in several of my early works (1856 to 1858) broke a lance. His theory seemed to explain a host of the most importantphysiological and pathological phenomena in the simplest manner, andyet it was afterwards proved to be false. In spite of this, I declareto this day that it was of the greatest service for the development ofour acquaintance with the formation of the connective-tissue; as aguiding hypothesis and as a provisional clue to our investigations. Virchow, on the contrary, if he impartially reflects on the part hetook in the diffusion of this misleading doctrine, must reproachhimself severely for it. For "we must draw a hard and fast linebetween what we are to teach and what we are to investigate. What weinvestigate are problems, " but "the problem ought not to be thesubject of teaching. " That Virchow, in his course of instruction, every day belied this, his present view of teaching, that he everyhour taught his disciples some unproved theory and problematicalhypothesis, every one knows who, like myself, for years and with thedeepest interest, enjoyed his distinguished instruction. Still thecaptivating charm of this instruction--in spite of the defectivemethod of unprepared lectures--lay precisely in this, that Virchow asa teacher constantly let us, his pupils, enter into those problemswith which he himself at the moment was occupied; that he propoundedto us his personal hypothesis for the elucidation of the given facts. And what really gifted teacher who lives in his science would not dothe same? Where is there, or where has there ever been, a great masterwho in his teaching has confined himself to only imparting certainand undoubtedly ascertained facts? Who has not, on the contrary, foundthat the charm and value of his instruction lay precisely inpropounding the problems which link themselves with those facts, andin teaching the uncertain theories and fluctuating hypotheses whichmay serve to solve these problems? Or is there for the young andstruggling mind anything better, or more conducive to culture, than toexercise the intelligence in problems of investigation?

How unpractical and how absurd is Virchow's demand--that onlyascertained facts and no problematic theories shall be admitted inteaching--will be still more strikingly shown by a glance over theremaining provinces of human knowledge. What, indeed, will be left ofhistory, of philology, of political science, of jurisprudence, if werestrict the teaching of them to absolutely-ascertained andestablished facts. What of "science" will remain to them if the ideawhich endeavours to discern the causes of the facts is banished? ifthe problems, the theories, the hypotheses, which seek these causesmay not be generally taught? And that philosophy--the science ofknowing--by which all the common results of human knowledge are to bebound up into one grand and harmonious whole--that philosophy, I say, must not be generally taught, is, according to Virchow, quiteself-evident. 

Finally, there remains nothing but theology. Theology alone is the onetrue science, and its dogmas alone may be taught as certain. Ofcourse! for it proceeds directly from revelation, and only divinerevelation can be "quite certain;" it alone can never err. Yes, incredible as it sounds, Virchow, the sceptical opponent of dogma, theleader of the fight for "liberty of science, " Virchow now finds theonly sure basis for instruction in the dogmas of the Church. After allthat has gone before, the following memorable sentence leaves no doubton this score:--"Every attempt to transform our problems into dogmas, to introduce our conjectures as a basis of instruction, particularlyany attempt simply to dispossess the Church and to supplant her dogmaby a creed of descent--ay, gentlemen--this attempt must fail, and inits ruin will entail the greatest peril on the position of science ingeneral. "

The shouts of triumph of the whole clerical press over Virchow'sMunich address is thus rendered perfectly intelligible, for it is wellknown that "there is more joy in heaven over one sinner that repenteththan over ten just men. " When Rudolf Virchow, the "notoriousmaterialist, " the "advanced radical, " the "great supporter of theatheism of science, " is so suddenly converted, when he proclaimsloudly and publicly that the dogmas of the Church are the only surebasis of instruction, then the Church militant may well sing "Hosannain the highest!" Only one thing is to be regretted, that Virchow hasnot more clearly defined which of the many different church-religionsis the only true one, and which of the innumerable and contradictorydogmas are to form the sure basis of instruction. We all know thateach Church regards itself as the only truly saving one, and her owndogma as the only true one. But as to whether it is to beProtestantism or Catholicism, the Reformed or the Lutheran confession, whether the Anglican or the Presbyterian dogma, whether the Roman orthe Greek Church, the Mosaic or the Mohammedan dispensation, whetherBuddhism or Brahmanism, whether, finally, it is to be one of the manyfetish-religions of the Indians and Negroes that is to form thepermanent and sure basis of instruction, let us hope that Virchow willat the next meeting of German naturalists and physicians divulge hisopinion. 

At any rate, the "instruction of the future, according to Virchow, " willbe greatly simplified if he will do this. For the dogma of the Trinityin Unity as a basis of mathematics, the dogma of the resurrection of thebody as a basis of medicine, the dogma of infallibility as a basis ofpsychology, the dogma of the immaculate conception as a basis of geneticscience, the dogma of the staying of the sun as a basis of astronomy, thedogma of the creation of the earth, animals, and plants as a basis ofgeology and phylogenesis--these or any other dogma, at pleasure, from anyother church will make all other doctrine quite superfluous. Virchow, "that critical spirit, " knows as well as I, and as every other naturalist, that these dogmas are not true, and nevertheless, in his opinion, theyare not to be supplanted as the "basis of instruction" by those theoriesand hypotheses of modern natural science of which Virchow himself saysthat 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, Virchowstrongly insists that only that objective knowledge may be taughtwhich we possess as absolutely certain fact! and then at page 29 herequires us to conclude that the basis of instruction shall continueto be the purely subjective dogmas of the Church; revelations anddogmas which not only are not proved by any facts whatever, but on thecontrary, stand in the most trenchant contradiction to the mostobvious facts of natural experience and fly in the face of all humanreason. These contradictions, to be sure, are no greater than someothers which stand out conspicuous and incomprehensible in Virchow'sdiscourse. Thus at the beginning of his address he glorifies LorenzOken and deeply laments "that he, that highly-valued and honouredmaster, that ornament of the high school of Munich, had been forcedto die in exile! That cruel exile which oppressed Oken's latter years, which left him to perish far from those cities to which he hadsacrificed the best powers of his life, that exile will be rememberedas the note of the time which we have passed through. And so long asthere continue to be meetings of German naturalists, so long may wegratefully remember that this man to his death bore upon him all thesigns of a martyr, so long shall we point to him as one of thewitnesses 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 championsof that monistic doctrine of development against which Rudolf Virchowat this day is most violently striving? Did not Oken himself proceedfarther in the construction of bold hypotheses and comprehensivetheories than any supporter of the doctrine of evolution at thepresent time? Is not Oken justly considered as the one typicalrepresentative of that older period of natural philosophy who rose tomuch higher and bolder flights of fancy, and left the solid ground offacts much farther behind him than any tyro of the new philosophy? Andthis makes the irony seem all the greater with which Virchow at thebeginning of his address glorifies Oken the free teacher, as a martyrto the freedom of science, and at the end of it insists that thisfreedom applies only to inquiry and not to teaching, and that themaster must teach no problem, no theory, no hypothesis. 

While this unheard-of demand sets Virchow's views of teaching in themost extraordinary light, and while every unprejudiced and experiencedteacher must most emphatically protest against this strait-waistcoatfor instruction, he will feel no less bound to resist Virchow's otherstrange demand, that every ascertained truth shall forthwith be taughtin all schools, down to the elementary schools. I myself, in my Munichaddress, sought the instructional value of our monistic evolutiontheory above all in the genetic method, in the inquiry, that is tosay, for the effective causes of the facts taught; and I added thesewords--"How far the principles of the doctrine of universal evolutionought to be at once introduced into our schools, and in whatsuccession its most important branches ought to be taught in thedifferent classes--cosmogony, geology, the phylogenesis of animals andplants, and anthropology--this we must leave to practical teachers tosettle. But we believe that an extensive reform of instruction in thisdirection is inevitable, and will be crowned by the fairest results. "I purposely avoided any closer discussion of this specialistquestion, as I felt not even approximately capable of solving it, andI believe, in fact, that none but skilled and experienced practicalteachers can undertake the solution of it with any success. 

For Virchow these specialist difficulties seem not to exist; heregards my reticence as a mere "postponement of the task, " and heanswers in the following astonishing sentences:--"If the theory ofdescent is as certain as Herr Haeckel assumes, then we mustdemand--for it is a necessary consequence--that it shall be taught inschools. How is it conceivable that a doctrine of such importance, which must effect such a total revolution in all our mentalconsciousness, which directly tends to create a new kind of religion, should not be included in the school scheme of instruction? How is itpossible that such a--revelation, shall I say--should be in anymeasure suppressed, or that the promulgation of the greatest and mostimportant advance which has been made in our views during the presentcentury should be left to the discretion of schoolmasters? Ay, gentlemen, that would indeed be a renunciation of the hardest kind, and practically it could never be carried out! Every schoolmaster whoassumes this doctrine for himself will involuntarily teach it, how canit be otherwise?"

I must here be permitted to take Virchow exactly at his word. Iendorse almost all that he has said in these and the followingsentences. The only difference in our views is this, that Virchowregards the theory of descent as an unproved and unproveablehypothesis; I, on the contrary, as a fully established andindispensable theory. How then will it be if the teachers of whomVirchow speaks agree with my views, if--apart, of course, from allspecial theories of descent--they, like me, consider the generaltheory of descent as the indispensable basis of all biologicalteaching? And that that is actually the case Virchow may easilyconvince himself if he looks over the recent literature of zoology andbotany! Our whole morphological literature in particular is already sodeeply and completely penetrated by the doctrine of descent, phylogenetic principles already prevail so universally as a certainand indispensable instrument of inquiry, that no man for the futurewould deprive himself of their help. As Oscar Schmidt justlyobserves--"Perhaps ninety-nine per cent. Of all living, or rather ofall working zoologists, are convinced by inductive methods of thetruth of the doctrine of descent. " And Virchow with his magisterialrequirements will attain only the very reverse of what he aims at. Howoften has it not been said already that science must either haveperfect freedom or else none at all? This is as true of teaching asit is of inquiry, for the two are intrinsically and inseparablyconnected. And so it is not in vain that it is written in section 152of the German Code, and in section 20 of the Prussian Charter, "Science and her teaching shall be free!"

CHAPTER VI. 

THE DOCTRINE OF DESCENT AND SOCIAL DEMOCRACY. 

Every great and comprehensive theory which affects the foundations ofhuman science, and which, consequently, influences the systems ofphilosophy, will, in the first place, not only further our theoreticalviews of the universe, but will also react on practical philosophy, ethics, and the correlated provinces of religion and politics. In mypaper read at Munich I only briefly pointed out the happy resultswhich, in my opinion, the modern doctrine of evolution will entailwhen the true, natural religion, founded on reason, takes the place ofthe dogmatic religion of the Church, and its leading principle derivesthe human sense of duty from the social instincts of animals. 

The references to the social instincts which I, in common with Darwinand many others, regard as the proper source and origin of all moraldevelopment, appear to have afforded Virchow an opportunity in hisreply for designating the doctrine of inheritance as a "socialisttheory, " and for attributing to it the most dangerous andobjectionable character which, at the present time, any politicaltheory can have; and these startling denunciations so soon as theywere known called forth such just indignation and such comprehensiverefutation that I might very properly pass them over here. Still wemust at least shortly examine them, in so far as they supply a furtherproof that Virchow is unacquainted with the most important principlesof the development-theory of the day, and therefore is incompetent tojudge it. Moreover, Virchow, as a politician, manifestly attributedspecial importance to this political application of his paper, for hegave it the title, which otherwise would have been hardly suitable, of"The Freedom of Science in the Modern Polity. " Unfortunately he forgotto add to this title the two words in which the special tendency ofhis discourse culminates; the two pregnant words, "must cease!"

The surprising disclosures in which Virchow denounces the doctrine ofevolution, and particularly the doctrine of descent, as socialisttheories and dangerous to the community, run as follows:--"Now, picture to yourself the theory of descent as it already exists in thebrain 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 ofdescent may not entail on us all the horrors which similar theorieshave actually brought upon neighbouring countries. At all times thistheory, if it is logically carried out to the end, has an uncommonlysuspicious aspect, and the fact that it has gained the sympathy ofsocialism has not, it is to be hoped, escaped your notice. We mustmake that quite clear to ourselves. "

On reading this statement, which seems extracted from the Berlin"Kreuz-Zeitung, " or the Vienna "Vaterland, " 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 wouldthink clearly they would feel that they must do all they can to chokethe doctrine of descent, for it declares with express distinctnessthat socialist ideas are impracticable. " And he proceeds to add, "Andwhy has not Virchow made the gentle doctrines of Christianityresponsible for the excesses of socialism? That would have had somesense. His denunciation flung so mysteriously and so confidentlybefore the great public, as though it concerned 'a sure and attestedscientific truth, ' is, at the same time, so hollow that it cannot bebrought into harmony with the dignity of science. "

With all these empty accusations, as with all the empty reproaches andgroundless objections which Virchow brings against the doctrine ofevolution, he takes good care in no way to touch the kernel of thematter. How, indeed, would it have been possible without arriving atconclusions wholly opposed to those which he has declared? For thetheory of descent proclaims more clearly than any other scientifictheory, that that equality of individuals which socialism strivesafter is an impossibility, that it stands, in fact, in irreconcilablecontradiction to the inevitable inequality of individuals whichactually and everywhere subsists. Socialism demands equal rights, equal duties, equal possessions, equal enjoyments for every citizenalike; the theory of descent proves, in exact opposition to this, that the realisation of this demand is a pure impossibility, andthat in the constitutionally organised communities of men, as ofthe lower animals, neither rights nor duties, neither possessionsnor enjoyments have ever been equal for all the members alike norever can be. Throughout the evolutionist theory, as in its biologicalbranch, the theory of descent--the great law of specialisation ordifferentiation--teaches us that a multiplicity of phenomena isdeveloped from original unity, heterogeneity from original similarity, and the composite organism from original simplicity. The conditions ofexistence are dissimilar for each individual from the beginning of itsexistence; even the inherited qualities, the natural "disposition, "are more or less unlike; how, then, can the problems of life andtheir solution be alike for all? The more highly political life isorganised, the more prominent is the great principle of the divisionof labour, and the more requisite it becomes for the lasting securityof the whole state that its members should be variously distributed inthe manifold tasks of life; and as the work to be performed bydifferent individuals is of the most various kind, as well as thecorresponding outlay of strength, skill, property, &c. , the reward ofthe work must naturally be also extremely various. These are suchsimple and tangible facts that one would suppose that every reasonableand unprejudiced politician would recommend the theory of descent, andthe evolution hypothesis in general, as the best antidote to thefathomless absurdity of extravagant socialist levelling. 

Besides, Darwinism, the theory of natural selection--which Virchowaimed at in his denunciation, much more especially than attransformation, the theory of descent--which is often confounded withit--Darwinism, I say, is anything rather than socialist! If thisEnglish hypothesis is to be compared to any definite politicaltendency--as is, no doubt, possible--that tendency can only bearistocratic, certainly not democratic, and least of all socialist. The theory of selection teaches that in human life, as in animal andplant life everywhere, and at all times, only a small and chosenminority can exist and flourish, while the enormous majority starveand perish miserably and more or less prematurely. The germs of everyspecies of animal and plant and the young individuals which springfrom them are innumerable, while the number of those fortunateindividuals which develop to maturity and actually reach theirhardly-won life's goal is out of all proportion trifling. The crueland merciless struggle for existence which rages throughout all livingnature, and in the course of nature _must_ rage, this unceasing andinexorable competition of all living creatures, is an incontestablefact; only the picked minority of the qualified "fittest" is in aposition to resist it successfully, while the great majority of thecompetitors must necessarily perish miserably. We may profoundlylament this tragical state of things, but we can neither controvert itnor alter it. "Many are called but few are chosen. " The selection, thepicking out of these "chosen ones, " is inevitably connected with thearrest and destruction of the remaining majority. Another Englishnaturalist, therefore, designates the kernel of Darwinism very franklyas the "survival of the fittest, " as the "victory of the best. " At anyrate, this principle of selection is nothing less than democratic, onthe contrary, it is aristocratic in the strictest sense of the word. If, therefore, Darwinism, logically carried out, has, according toVirchow, "an uncommonly suspicious aspect, " this can only be found inthe idea that it offers a helping hand to the efforts of thearistocrats. But how the socialism of the day can find anyencouragement in these efforts, and how the horrors of the ParisCommune can be traced to them, is to me, I must frankly confess, absolutely incomprehensible. 

Moreover, we must not omit this opportunity of pointing out howdangerous such a direct and unqualified transfer of the theories ofnatural science to the domain of practical politics must be. Thehighly elaborate conditions of our modern civilised life require fromthe practical politician such circumspect and impartial consideration, such thorough historical training and powers of critical comparison, that he will not venture to make such an application of a "naturallaw" to the practice of civilised life, but with the greatest cautionand reserve. How, then, is it possible that Virchow, the experiencedand skilled politician, who, above all things, preaches caution andreserve in theory, suddenly makes just such an application oftransformation and Darwinism--an application so radically perversethat it actually flies in the face of the fundamental ideas of thesedoctrines? I myself am nothing less than a politician. In directcontrast with Virchow, I lack alike the gift and the training for it, as well as taste and vocation. Hence I neither shall play anypolitical part in the future, nor have I hitherto made any attempt ofthe kind. Though here and there I have occasionally uttered apolitical opinion, or have made a political application of some theoryof natural science, these subjective opinions have no objective value. In point of fact I have by so doing overstepped the limits of mycompetence, just as Virchow has by going into questions of zoology andparticularly that of the transformation of apes: I am a layman inpolitical practice, as Virchow is in the province of zoologicalhypothesis. Moreover, such success as Virchow has attained during thetwenty years of his painful, wearisome, and exhausting activity as apolitician does not, in truth, make me pine for such laurels. 

But this at least I, as a theoretical naturalist, may demand ofpractical politicians, that in utilising our theories for politicalends they should first make themselves exactly acquainted with them;they then, for the future, would forbear drawing conclusions fromthem, the very opposite to those which ought reasonably to beinferred. Misunderstandings would never thus be wholly avoided, it is true, but what doctrine is universally secure againstmisunderstanding? And from what theory, however sound and true, maynot the most unsound and frantic inferences be drawn?

Nothing, perhaps, shows so plainly as the history of Christianity howlittle theory and practice harmonise in human life; how little painsare taken, even by those whose calling it is to uphold establisheddoctrines, to apply their natural consequences to practical life. TheChristian religion, no doubt, as well as the Buddhist, when strippedof all dogmatic and fabulous nonsense, contains an admirable humankernel, and precisely that human portion of Christian teaching--in thebest sense social-democratic--which preaches the equality of all menbefore God, the loving of your neighbour as yourself, love in generalin the noblest sense, a fellow-feeling with the poor and wretched, andso forth--precisely, those truly human sides of the Christian doctrineare so natural, so noble, so pure, that we unhesitatingly adopt theminto the moral doctrine of our monistic natural religion. Nay, thesocial instincts of the higher animals on which we found this religion(for instance the marvellous sense of duty of ants, &c. ) are in thisbest sense strictly Christian. 

And what--we may ask--what have the professed supporters, the "learneddivines" of this religion of love done? Their deeds are written inletters of blood in the history of the civilisation of mankind duringthe last 1800 years. All else that differing church-religions haveaccomplished for the forcible extension of their doctrines and for theextirpation of heretics of other creeds, all that the Jews have beenguilty of towards the heathen, the Roman emperors towards theChristians, the Mohammedans towards Christians and Jews alike--allthis is outdone by the hecatombs of human victims which Christianityhas demanded for the spread of her doctrines. And these wereChristians against Christians--orthodox Christians against heterodoxChristians! think only of the Inquisition in the Middle Ages, of theinconceivable and inhuman barbarities committed by the "most Christiankings" of Spain, by their worthy colleagues in Frankfort, in Italy, and elsewhere. Hundreds of thousands then died that most horribledeath by fire, simply because they would not bend their reason to passunder the yoke of the grossest superstition, and because their loyaltyto their convictions forbade them to deny the natural truth that theyclearly discerned. There are no deeds more hideous, base, and inhumanthan those that at that time were committed--nay, are stillcommitted--in the name and on account of "true Christianity. "

And finally, how do matters stand with regard to the morality of thepriests who announce themselves as the ministers of God's Word, andwhose duty is therefore above all others to carry out the savingdoctrines of Christianity in their own lives? The long, unbroken, andhorrible series of crimes of every kind which is offered by thehistory of the Roman Popes is the best answer to this question. Andjust as these "Vicars of God on earth" did, so did their subordinatesand accomplices, so, too, have the orthodox priests of other sectsdone; never failing to set the practice of their own course of life inthe strongest possible contrast to those noble doctrines of Christianlove which were constantly on their lips. 

And as with Christianity so it is with every other religious and moraldoctrine which ought to have proved its power in the wide domain ofpractical philosophy, in the education of youth, in the civilisationof nations. The theoretic kernel of this doctrine may always andeverywhere stand in the most glaring contradiction to its practicalworking-out, testifying to the endless inconsistency of human nature:but what can all this matter to the scientific inquirer? His sole andonly task is to seek for truth and to teach what he has discerned tobe the truth, indifferent as to what consequences the various partiesof state or church may happen to draw from it. 

CHAPTER VII. 

IGNORABIMUS ET RESTRINGAMUR. 

The dangerous attempt which Virchow made in Munich against thefreedom of science is not the first of its kind. On the contrary, five years before, it experienced a similar attack which is mostintimately connected with this later one, so that, in conclusion, we must here add a few words on the subject. Undoubtedly the famous"Ignorabimus-speech" of Du Bois-Reymond, which he delivered in 1872 atthe forty-fifth meeting of German naturalists and physicians inLeipzig, forms only the first portion of that same crusade against thefreedom of science of which Virchow's "Restringamur speech" of 1877, at the fiftieth meeting of the same society, forms the second part. 

That brilliant and powerful essay by Du Bois-Reymond "on theLimitation of Natural Knowledge" has already been discussed so often, and from such different sides, that it might seem superfluous to sayanother word about it. It seems to me, nevertheless, that by mostpeople the centre-of-gravity of its contents was overlooked inadmiration of the brilliant accessories of the essay. Indeed thisfrequently happens with Du Bois-Reymond's articles, for he knows toowell how to conceal the weakness of his argument and evidence, and theshallowness of his thought, by striking images and flowery metaphors, and by all the phraseology of rhetoric in which the versatile Frenchnature is so superior to our sober German one. It is all the moreimportant that we should not let ourselves be dazzled by theseseductive tricks, and particularly by adduced facts which bear uponthe most important and fundamental questions of human science, butthat we should extract the hard kernel from the savoury and fragrantfruit. In the preface to my "Evolution of Man, " and in the notes 22and 23 of my Munich address, I have already incidentally alluded tothe chief weaknesses of the "Ignorabimus-speech;" but I must herereturn somewhat more fully to the subject. 

There are, as is well known, two problems which Du Bois-Reymondpropounds as the impassable boundary of human knowledge of nature;limits which indeed the human mind is not only incapable of passing atthe present stage of its development, but which it never can becapable of passing in any more advanced stage. The first problem isthe nature and connection of matter and force; the second is humanconsciousness. Now, first of all, as has already been said in thepreface to the "Evolution of Man, " we must raise a decided protestagainst the air of infallibility with which Du Bois-Reymond pronouncesthat these two problems are insoluble, not only at the present timebut to all futurity. The power of development inherent in science andknowledge is hereby simply swept away with a word. Almost every greatand difficult problem of knowledge seems to most or all contemporarythinkers insoluble, and every path to the solution of it seems closed, till at last the bold genius appears whose clear sight detects theright path which till then was hidden, and which leads to the requiredknowledge. We need only call to mind our present doctrine ofevolution. The problem of creation--the question as to the origin ofanimal and vegetable species--was universally looked upon astranscendental and perfectly insoluble, till the genius of Lamarckestablished the principles of the theory of descent in his admirable"Philosophie Zoologique" in 1809. Nay, even then most--and among themthe most distinguished--biologists thought the problem of creation aquite insoluble mystery, and Darwin was the first to solve it, fiftyyears later, by his theory of selection in 1859. Hence we venture toassert that there is no scientific problem of which we may dare to saythat the mind of man will never solve it even in the remotest future. Well does Darwin say, in the introduction to his "Descent of Man, ""Ignorance more frequently begets confidence than does knowledge: itis those who know little and not those who know much who so positivelyassert that this or that problem will never be solved by science. " Asfar as concerns the two separate limits which Du Bois-Reymond fixesfor human knowledge, in my opinion they are undoubtedly identical. Theproblem of the origin and nature of consciousness is only a specialcase of the general problem of the connection of matter and force. DuBois-Reymond himself indicates that this is possible at the close ofhis paper; for he says, "Finally, the question arises whether the twolimitations to our natural knowledge may not perhaps be identical;that is to say, whether if we could conceive of the true essence ofmatter and force, we should not also understand how the substancewhich lies at their root can, under certain given conditions, feel, desire, and think. This conception is, no doubt, the simplest, andaccording to admitted principles of inquiry it is to be preferred tothat other which it confutes, and according to which, as has beensaid, the world appears doubly incomprehensible. But it is in the verynature of things that we cannot on this point come to any clearconclusion, and all further words on the subject are idle--and so, 'Ignorabimus. '"

The light way in which Du Bois-Reymond here passes over the mostimportant part of his subject is truly surprising; as if it wereultimately indifferent whether we have before us one single insolublefundamental problem or two quite different ones; and as if maturereflection did not lead to the conviction that, in fact, the secondproblem is only a special case of the first general problem. I, for mypart, cannot conceive of them in any other relation; I think, too, that all further words are by no means superfluous, but on thecontrary conduce to a very strong conviction of the unity of theproblem. That Du Bois-Reymond also has not come to any clearconclusion on this point lies, not alone in the "nature of things, "but, as in Virchow's case, in the nature of the investigator himself;in his lack of knowledge of the history of evolution, and in hisneglect of those comparative and genetic methods of study, withoutwhich, in my opinion, not even an approximate solution of this highestand most difficult question is to be looked for. 

Nothing appears to me to be of more importance for the mechanicalexplanation of consciousness than the comparative consideration of itsdevelopment. We know that a new-born child has no consciousness, butthat it is slowly and gradually acquired and developed. We perceivefor ourselves how unconscious actions become conscious, and _viceversa_. Innumerable actions which at first are troublesome and haveto be learnt with consciousness and reflection--as for instancewalking, swimming, singing, and so forth--become unconscious only byrepetition, practice, and the habit of using the organs. On thecontrary, unconscious actions become conscious as soon as we directour attention to them or our self-observation is attracted to them; asfor instance when we miss a step in going up stairs or touch a wrongnote on the piano; and beyond a doubt, conscious and unconsciousactions pass into each other without any distinct line of demarcation. Finally, we see no less plainly by a comparative consideration of thesoul-life of animals, that their consciousness is slowly, gradually, and serially developed, and that a long unbroken series of steps leadsfrom unconscious to conscious existence. From these comparative andgenetic experiences we may draw the conclusion that consciousness, like sensation and volition, like all the other soul-activities, is afunction of the organism, a mechanical activity of the cells; and, assuch, is referable to chemical and physical processes. Hence, if wewere in a position to understand force as a necessary function ofmatter, we could explain consciousness, as well as the soul ingeneral, as a necessary function of certain cells. 

How little Du Bois-Reymond is acquainted with the facts of comparativeand genetic psychology, nothing shows more strikingly than thefollowing astounding proposition in the "Ignorabimus-speech:"--"Wherethe material conditions for psychical activity, in the form of anervous system, are wanting, as in plants, the naturalist cannotrecognise a soul-life, and, on this point, he but seldom meets withcontradiction. " Begging your pardon! Every naturalist who is familiarwith the comparative morphology and physiology of the lower animalswill here put in a decided contradiction, for he can no more refuse toadmit the undoubted sensation and voluntary motion of the one-celledInfusoria than of the many-celled hydroid polyps. The body of the trueInfusoria (Ciliata, Acineta, &c. ), and many other Protista, remainthroughout life one single cell, and, nevertheless, this cell is asfully furnished with all the most important attributes of the soul, with sensation and volition, as any one of the higher animals with anervous system. The same obtains of the Hydra and the related hydroidpolyps, in which the neuro-muscular cells, or other distributed cellsof the outer germ-layer, fulfil the soul-functions. But as thesecells, besides this, exercise motor and other functions as well, wecannot as yet designate them as nerve-cells, at any rate there can beno idea of a special nervous-system. The characteristic soul-organs ofthe higher animals, which we include under the conception of anervous-system, in fact originated by the division of labour of thecells out of those neutral cell-groups in their lower-typed ancestors. 

In the great Soul-question Du Bois-Reymond, like Virchow, still keepshis position on the standpoint of neural-psychology, according towhich no personal soul-life is conceivable without a nervous system. We look upon this standpoint as left far behind, and set up inopposition to it Cellular-psychology, the doctrine that every animalcell has a soul; that is to say, that its protoplasm is endowed withsensation and motion. In the one-celled Infusoria, which are so highlysensitive and have such an energetic will, this conception will beclear without any farther explanation. But we cannot refuse to allowthat plant-cells as well as animal-cells have psychic functions, sincewe know that the phenomena of irritability, and of "automatic motion, "are the universal attributes of all protoplasm. No doubt the specificmechanism, the cause of motion, in the irritable Mimosa and other"sensitive" plants, is quite different from the muscular motions ofanimals; but these, like those, are only specifically different formsof development of the "cell-soul, " and both proceed from the"mechanical energy of the protoplasm. " The sensibility of theirritable protoplasm is the same in the vegetable-cell of the Mimosaas in the animal-cell of the Hydra. How far Du Bois-Reymond is fromdiscerning this, and how deeply he is still entangled inneuro-psychological views is shown most clearly in the astonishingsentence which he has thought good to append to his above-quoted, erroneous assertion. "And what could we reply to the naturalist if, before he could agree to the assumption of a World-soul he requiredthat we should show him--bedded in neuroglia and nourished by warmarterial blood--anywhere in the world a convolution of ganglioniccentres co-extensive with the psychic capacity of such a Soul" (!)

In other respects we will not deny that Du Bois-Reymond stands farnearer to our recent evolution-theory than Virchow; nay, that fromyear to year he has always pronounced more and more emphatically infavour of the theory of descent as the one possible explanation ofmorphological phenomena; indeed, Du Bois-Reymond has lately countedhimself as one of those naturalists who were convinced of the truth ofevolution even before Darwin! Then it is only to be wondered why soacute and gifted an inquirer, who is certainly not lacking inscientific ambition, left it to Charles Darwin to place the egg ofColumbus on the ring and to point out to biological science a newmethod of unlimited capacity by giving the theory of descent adefinite and reliable basis!

It is clear from some remarks in his discourse bearing the title"Darwin versus Galiani" (1876), that Du Bois-Reymond is still farfrom understanding the full significance of transmutation as affordinga mechanical explanation of morphological problems. In this paper the"History of Creation" is treated simply as a romance, and thegenealogies of phylogenesis are in his eyes "of about as much value asthe pedigrees of the Homeric heroes are in the eyes of historicalcritics. " Geologists may be extremely grateful for this estimate oftheir science, for undoubtedly geology, as a structure of hypotheses, is neither more nor less justifiable than phylogenesis, as I havealready pointed out in my Munich address: "Our phylogenetic hypothesesmay claim to have equal value with the universally-admitted hypothesesof geology; the only difference is this, that the mighty structure ofhypotheses called geology is incomparably more complete, simpler, andeasier to grasp than that more youthful one called phylogenesis. " Butas to the much-talked-of "genealogies, " though they are nothing morethan the simplest, barest, and most superficial expression of thehypotheses of phylogenesis, as provisional hypotheses they are just asindispensable to specific phylogenesis as the theoreticalsection-tables of the strata of the earth's crust are to geology. 

If Du Bois-Reymond is so convinced of the truth of transmutation as hehas lately given himself out to be, why does not he make at least oneearnest attempt to test the interpreting power of the theory ofdescent in physiology--his own most special province of inquiry? Whydoes he not labour at that hitherto quite unworked-out branch, physiogenesis, at the history of the evolution of functions, at theontogenesis and phylogenesis of vital processes? The one idea whichhas lately been often spoken of as an important discovery of DuBois-Reymond's--[the idea which had already been anticipated byLeibnitz, that the "innate ideas, "--intuitions _à priori_--haveoriginated by transmission from primordial experience, _i. E. _, empirical, _à posteriori_ convictions], was distinctly enunciated byme long before Du Bois-Reymond (as he omits to mention), in 1866, inmy "General Morphology" (vol. Ii. P. 446), and in 1868 in the "Historyof Creation" (vol. I. P. 31, vol. Ii. P. 344). If Du Bois-Reymond hadpractically busied himself with these problems he would certainly havethought a little about the development of consciousness, and not haveset down as an eternally insoluble problem, "How is it possible thatmatter can think?"--a form of words, be it observed, which has aboutas much sense as "how matter runs, " or "how matter strikes the hours. "Surely he would have guarded himself in that case from uttering theponderous "Ignorabimus. "

The question has been repeatedly asked why two such prominent Berlinbiologists as Virchow and Du Bois-Reymond availed themselves of theparticularly solemn occasions of the fiftieth anniversary and of thefiftieth meeting of the German naturalists and physicians to lay lancein rest against the progress and freedom of science. The eagerapprobation which they both promptly met with from the party of theclergy and of all other enemies of free thought--Virchow, indeed, inmuch greater measure than Du Bois-Reymond--appears to justify thisinquiry. I believe I can contribute something towards answering it, and as I am not fettered by any reverence for the Berlin tribunal ofscience 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 andfrankest manner, not troubling myself about the wrath which may beroused in many actual--and not actual--officials in Berlin at thisexposition of the unvarnished truth. 

The primary cause of their "misunderstanding, " and the best excusethat can be offered for it, in Virchow and Du Bois-Reymond alike, liesin their unacquaintance with the advance of modern morphology. As hasbeen repeatedly stated, no natural science is so directly to bereferred to the doctrine of evolution--and more particularly to thetheory of descent--as morphology. It is because we morphologists canneither explain nor comprehend all the manifold and infinitely complexform-phenomena of the animal and plant worlds without this theory, because to us transmutation contains the only possible, rationalexplanation of organic types, that we all regard it as theindispensable basis of the scientific doctrine of form, and asdemanding no further proofs of its certainty than those which now liein abundance before us. 

Du Bois-Reymond, and still more Virchow, ignore these proofs, becausethey are to a great extent ignorant alike of the inquiries andresults, of the methods and the aims of our modern morphology, andthis ignorance may be accounted for partly by the one-sided directionwhich their biological studies have taken, partly by the fact thatthere are few universities where the study of morphology is sobehindhand as at the University of Berlin. Fully twenty years have nowelapsed since the great Johannes Müller died, the last naturalist whocould command all the departments of biology. The three greatprovinces of science which had been reunited into a triune kingdomunder his powerful sceptre, were then divided among three professors'chairs: Du Bois-Reymond took that of physiology, Virchow, theoreticalpathology (pathological anatomy and physiology), and the third, andmost important chair, that of morphology (human and comparativeanatomy, including the history of evolution) fell to BoguslausReichert. This choice was, as is now universally admitted, anincomprehensible mistake. Instead of calling Carl Gegenbaur, or MaxSchultze, or some one else of youthful capacity and vigour to thechair of morphology--a science which is the first foundation ofzoology as well as of medicine--in Reichert they selected an elderlyschool anatomist cramped by strong old-fashioned notions, who had donesome good and useful specialist work, but whose general views haddeveloped all awry, and who for the unexampled obscurity of hisconceptions and the confusion of his ideas, was outdone by none saveonly Adolf Bastian. For twenty years this man has represented animalmorphology in the second university of Germany, and in these twentyyears hardly any work worth mentioning has been done there in thewhole of this vast department--neither by the master nor by hispupils. We have only to compare the many worthless anatomicalproductions of Berlin during these two decades (for instance, therecent confused work by Fritsch on the brain of fishes) with the richmine of invaluable work produced during the preceding twenty years byJohannes Müller and his crowd of disciples. 

But, as if this were not enough, Reichert took advantage of hisinfluential position to hinder as far as possible all scientific studyof morphology. For example, he, with the co-operation of hiscolleagues, carried through that pretended "reform" of medicalexamination which puts the so-called _Tentamen physicum_ in the placeof the _philosophicum_; philosophy was entirely eliminated. Zoologyand botany, which for centuries have been very justly regarded as theindispensable foundation of all instruction in natural science for theyoung medical student, disappeared from the curriculum. Only, as if inscorn of these sciences, in each examination a small place wasreserved for comparative anatomy--for that most difficult andphilosophical part of animal morphology which cannot be at allunderstood without some previous knowledge of the other branches ofzoology. And yet comparative anatomy and the history of developmentare the indispensable preliminary steps to a true scientificcomprehension of human anatomy, that most essential foundation of allmedical knowledge. Without the vivifying idea of development, mereanatomical knowledge is an empty and lifeless cramming of the memory. 

In the place of morphology, thus degraded from its office, a detailedstudy of physiology was introduced, but always in a one-sideddirection. Now these two great branches of biology, which are equallyimportant and have an equal claim on our attention, are so dependentthe one on the other, that a real scientific understanding of organiclife can never be obtained without due relative study of both. Themasterly and incomparable teaching of Johannes Müller owed a greatpart of its captivating charm to his equitable regard for morphologyand physiology, as well as to his comprehensive treatment, from thebroadest point of view, of the enormous mass of details to be dealtwith. I therefore have not the smallest doubt that the morphologicaltraining of medical students, as at present conducted at Berlin underthe influence of Reichert and his colleagues, is as far behind that ofMüller's day, twenty or thirty years ago, in all general comprehensionof the typical organism, as it is in advance of it in specialistacquirements. 

In medical, as in all other scientific learning, the highest aim doesnot consist in seeking to accumulate a vast chaotic mass of isolateditems of knowledge, but in a general comprehension of the science, itsaims and problems. The teacher should, above everything, guide thepupil to this general knowledge, and then it will be easy to him, bythe aid of proper methods, to acquire mastery in each individual andspecial branch. Thus in medicine, as in every other science, he is notthe best qualified who, on Bastian's method, has loaded his memorywith a confused mass of undigested facts, and has flung them alltogether into his brain without any order; but, on the contrary, hewho has practically digested a considerable number of the mostimportant facts, and has critically co-ordinated them to a harmoniouswhole. It is precisely under this aspect that transmutation is of suchinestimable value to morphology; it enables us to rise from the bareempirical knowledge of numberless isolated facts to a philosophicalconception of their efficient causes. 

The aversion and contempt which the theories of descent and selectionhave met with at Berlin, more than in any other place, is in greatmeasure to be explained by the circumstance that, during the last twodecades, morphological studies have been more neglected in thatuniversity than any others. In no other city of Germany has evolutionin general, as well as Darwinism in particular, been so little valued, so utterly misunderstood, and treated with such sovereign disdain asin Berlin. Nay, Adolf Bastian, the most zealous of all the Berlinopponents of our doctrines, has insisted on these facts with peculiarsatisfaction. Of all the conspicuous naturalists of Berlin only oneaccepted the doctrine of transmutation from the beginning with sincerewarmth and full conviction, being, indeed, persuaded of its truth evenbefore Darwin himself. This was the gifted botanist Alexander Braun, who is lately dead--a morphologist who was equally distinguished bythe extent of his comprehensive knowledge of details, as by hisphilosophical mastery over them. His firm conviction of the truth ofthe theory of descent is all the more remarkable because he was at thesame time a spotless character, a pious Christian in the best sense ofthe word, and an extremely conservative politician; a striking examplethat these convictions can dwell side by side with the principles ofthe recent doctrines of evolution in one and the same person. But incomparison with the powerful influence of the rest of the Berlinnaturalists who, for the most part, are decided opponents oftransmutation, and who have only lately--a few of them, to follow thefashion--become converts to it, a man like Alexander Braun could haveno effect in procuring that it should be taught. 

However, this is not the first time that this very Berlin society oflearned men has set itself with remarkable firmness against the mostimportant advances of science. Virchow's former colleague, thedeceased Stahl, with a similar purpose and with great success, preached this principle: "Science must turn back again. " Just as atthe present day the Berlin biologists have opposed the most obstinateand pertinacious resistance to the greatest scientific stride of thiscentury, so did it happen in former times with regard to otherdoctrines of progress. We have only to recall Caspar Friedrich Wolff, the great inquirer, who in 1759 first detected the nature of theindividual processes of development in the animal ovum, and foundedon it his observations in his "Theoria Generationes, " which markedan epoch in biological science. The Berlin savants, full of theprevailing prejudices, so contrived at that time that Wolff never oncecould obtain the permission which he craved, to lecture publicly, andin consequence found himself compelled to retire to St. Petersburg forthe sake of peace. And yet in that instance there was no questionof a "theory" properly so-called. For the fundamental theory ofgeneration--the "theory of epigenesis"--as propounded by Wolff wasnothing more than a simple, general exposition of embryological factswhich he had been the first to recognise, and of whose truth every onemight convince himself by direct observation. In spite of this, foranother half century, the predominant error of the "Preformation-theory"continued to be universally accepted--the ludicrous and nonsensicaldoctrine, supported by the authority of Haller, that all the successivegenerations of animals exist preconceived and enclosed one within theother, and that no individual development ever takes place! _Nulla estepigenesis!_ (Compare my "Evolution of Man, " vol. I. P. 31. )

But it would appear that it is the fate of that most interesting ofall sciences, the history of evolution, to find its most importantsteps and its greatest discoveries met by the firmest and mostpersistent opposition. For while Wolff's fundamental theory ofepigenesis, which was promulgated in 1759, was not recognised until1812, Lamarck's theory of descent, founded in 1809, had to wait fullyfifty years before Darwin, in 1859, showed it to be the greatestacquisition of modern science; and during that period, in spite of allthe progress made in empirical science, how persistently this mostcomprehensive of all biological theories was combated. We need onlyrecollect how, in 1830, the celebrated George Cuvier silenced its mosteloquent supporter, Geoffroy St. Hilaire, in the midst of the ParisAcademy, and how almost at the same time its founder, the greatLamarck, ended his life in blindness, misery and want, while hisopponent Cuvier was enjoying the highest honours and the greatestsplendour. And yet we know now that the despised and contemned Lamarckand Geoffroy had already grasped truths of the highest significance, while Cuvier's much-admired and universally-accepted theory ofcreation is now on all hands neglected as an absurd and untenabledelusion. But as neither Haller as against Wolff, nor Cuvier asagainst Lamarck, could permanently hinder the progress of freeinquiry, neither will Virchow succeed in turning back the course ofDarwin's admirable achievement; no, not even when he is supported bythe discourses of his friend Bastian. 

While we cannot but earnestly lament Virchow's inimical attitude inthis great struggle for truth, we must not overlook the effects of hiswell-founded authority in a yet wider sphere. For instance, thehostile attitude which the greater part of the Berlin presspersistently maintains towards the doctrine of development(particularly the Liberal "National-Zeitung") is to be referred to theinfluence of his authority. But much as this reactionary vein, in thisand in other intelligent circles at Berlin, must be regretted on theone hand, on the other we must observe that by this evil we have beenpreserved from a far greater one. This greater evil--the greatest, infact, which German science could have to encounter--would be themonopoly of knowledge at Berlin; a Centralisation of Science. Theinjurious fruits of this system of centralisation in France, forinstance, the continual deterioration of French science through theParisian "Monopoly of Knowledge, " and its steady decline during half acentury from the sublimest heights--these are all well known. Fromsuch a centralisation of German science--which would be especiallydangerous if it occurred in the capital, Berlin--we may hope to bepreserved; in the first place by the manifold differences and themany-sided individuality of the German national spirit, themuch-abused German provincialism (Particularismus). While theseprovincial modes of thought can never have any permanent politicalvalue, nor be productive of a desirable form of government, it isbeyond a doubt that their outcome has been fruitful and happy forGerman science. For it owes its splendid pre-eminence over that ofother countries precisely to the many centres of culture which wereoffered by those numerous petty capitals of the minor German Stateswhich strove to outdo each other in eager emulation. It is to be hopedthat this happy decentralisation of science in our politically unitedfatherland may continue to subsist!

And next to this centrifugal tendency of our German national mindnothing will so greatly contribute to it as a vigorous opposition tothe free advance of science, such as is just now declaring itself inthe metropolis. For by just so much as Berlin is dragged back by it inthe mighty onward stream of free intellectual movement, by so muchwill it see itself outstripped by the other seats of culture inGermany, which follow the stream with enthusiasm, or at least withoutresistance. If Emil du Bois-Reymond raises the cry of "Ignorabimus, "and Rudolf Virchow his still more audacious one of "Restringamur, " asthe watchwords of science, then, from Jena, let the shout be raisedand echoed from a hundred other universities--"Impavidi progrediamur!"

THE END. 

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A SHORT HISTORY

OF

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"The ease of her style, the charm of her illustrations, and theclearness with which she explains what is abstruse, are no doubt theresult of much labor; but there is nothing labored in her pages, andthe reader must be dull indeed who takes up this volume withoutfinding much to attract attention and to stimulate inquiry. "--_PallMall Gazette. _

"So interesting that having once opened it we do not know how to leaveoff reading. "--_Saturday Review. _

"We are compelled to admit that there is indeed a fairy-land ofscience. This is the fairy-land upon which Miss Arabella Buckleylectured last year, and upon which she has now produced a child'sreading-book, which is most charmingly illustrated, and which is inevery way rendered especially interesting to the juvenilereader. "--_London Athenæum. _

 * * * * *

THE EXPERIMENTAL SCIENCE SERIES. 

In neat 12mo volumes, bound in cloth, fully illustrated. Price pervolume, $1. 00. 

This series of scientific books for boys, girls, and students of everyage, was designed by Prof. Alfred M. Mayer, Ph. D. , at the StevensInstitute of Technology, Hoboken, New Jersey. Every book is addresseddirectly to the young student, and he is taught to construct his ownapparatus out of the cheapest and most common materials to be found. Should the reader make all the apparatus described in the first bookof this series, he will spend only $12. 40. 

NOW READY:

I. --LIGHT. 

A Series of Simple, Entertaining, and Inexpensive Experiments in thePhenomena of Light, for Students of every Age. 

_By ALFRED M. MAYER and CHARLES BARNARD. _

II. --SOUND:

A Series of Simple, Entertaining, and Inexpensive Experiments in thePhenomena of Sound, for the Use of Students of every Age. 

_By ALFRED MARSHALL MAYER_, Professor of Physics in the Stevens Institute of Technology; Member ofthe National Academy of Sciences; of the American PhilosophicalSociety, Philadelphia; of the American Academy of Arts and Sciences, Boston; of the New York Academy of Sciences; of the GermanAstronomical Society; of the American Otological Society; and HonoraryMember of the New York Ophthalmological Society. 

IN ACTIVE PREPARATION:

III. Vision and the Nature of Light. 

IV. Electricity and Magnetism. 

V. Heat. 

VI. Mechanics. 

VII. Chemistry. 

VIII. The Art of experimenting with Cheap and Simple Instruments. 

 * * * * *

LIGHT:

_A Series of Simple, Entertaining, and Inexpensive Experiments in thePhenomena of Light, for the Use of Students of Every Age. _

BY ALFRED M. MAYER and CHARLES BARNARD. 

NEAT 12MO VOLUME, FULLY ILLUSTRATED. CLOTH, PRICE, $1. 00. 

"Professor Mayer has invented a series of experiments in Light whichare described by Mr. Barnard. Nothing is more necessary forsound-teaching than experiments made by the pupil, and this book, byconsidering the difficulty of costly apparatus, has rendered animportant service to teacher and student alike. It deals with thesources of light, reflection, refraction, and decomposition of light. The experiments are extremely simple and well suited to youngpeople. "--_Westminster Review. _

"This work describes, in simple language, a number of experimentsillustrating the principal properties of light, by means of a beam ofsunlight admitted into a dark room, and various contrivances. Theexperiments are highly ingenious, and the young student can not failto learn a great deal from the book. As an example of the effectiveexperimental method employed, we may specially mention the device forillustrating the refraction of light. This book is specially designed'to give to every teacher and scholar the knowledge of the art ofexperimenting. '"--_The Quarterly Journal of Science_ (London). 

"A singularly excellent little hand-book for the use of teachers, parents, and children. The book is admirable both in design andexecution. The experiments for which it provides are so simple that anintelligent boy or girl can easily make them, and so beautiful andinteresting that even the youngest children must enjoy the exhibition. The experiments here described are abundantly worth all that they costin money and time in any family where there are boys and girls to beentertained. "--_New York Evening Post. _

"The experiments are capitally selected, and equally as welldescribed. The book is conspicuously free from the multiplicity ofconfusing directions with which works of the kind too often abound. There is an abundance of excellent illustrations. "--_New YorkScientific American. _

"The experiments are for the most part new, and have the merit ofcombining precision in the methods with extreme simplicity andelegance of design. The value of the book is further enhanced by thenumerous carefully-drawn cuts, which add greatly to itsbeauty. "--_American Journal of Science and Arts. _

 * * * * *

SOUND:

_A Series of Simple, Entertaining, and Inexpensive Experiments in thePhenomena of Sound, for the Use of Students of Every Age. _

By ALFRED MARSHALL MAYER, Professor of Physics in the Stevens Institute of Technology; Member ofthe National Academy of Sciences, etc. 

Uniform with "LIGHT, " first volume of the Series. 

Neat 12mo volume, fully illustrated. Cloth, price, $1. 00. 

"It would be difficult to find a better example of a series which isexcellent throughout. This little work is accurate in detail, popularin style, and lucid in arrangement. Every statement is accompaniedwith ample illustrations. We can heartily recommend it, either as anintroduction to the subject or as a satisfactory manual for those whohave no time for perusing a larger work. It contains an excellentdescription, with diagrams, of Faber's Talking Machine and of Edison'sTalking Phonograph, which can not fail to be interesting to any readerwho takes an interest in the marvelous progress of naturalscience. "--_British Quarterly. _

"The style of the book is very clear, and the experiments interesting. It can not fail to have an important educational influence. "--_WestminsterReview. _

"It would really be difficult to exaggerate the merit, in the sense ofconsummate adaptation to its modest end, of this little treatise on'Sound. ' It teaches the youthful student how to make experiments forhimself, without the help of a trained operator, and at very littleexpense. These hand-books of Professor Mayer should be in the hands ofevery teacher of the young. "--_New York Sun. _

"An admirably clear and interesting collection of experiments, described with just the right amount of abstract information and nomore, and placed in progressive order. The recent inventions of thephonograph and microphone lend an extraordinary interest to this wholefield of experiment, which makes Professor Mayer's manual especiallyopportune. "--_Boston Courier. _

 * * * * *

The Works of Professor E. L. YOUMANS, M. D. 

_Class-book of Chemistry. _

New edition. 12mo. Cloth, $1. 50. 

_The Hand-book of Household Science. _

A Popular Account of Heat, Light, Air, Aliment, and Cleansing, intheir Scientific Principles and Domestic Applications. 12mo. Illustrated. Cloth, $1. 75. 

_The Culture demanded by Modern Life. _

A Series of Addresses and Arguments on the Claims of ScientificEducation. Edited, with an Introduction on Mental Discipline inEducation. 1 vol. , 12mo. Cloth, $2. 00. 

_Correlation and Conservation of Forces. _

A Series of Expositions by Professor Grove, Professor Helmholtz, Dr. Mayer, Dr. Faraday, Professor Liebig, and Dr. Carpenter. Edited, withan Introduction and Brief Biographical Notices of the Chief Promotersof the New Views, by EDWARD L. YOUMANS, M. D. 1 vol. , 12mo. Cloth, $2. 00. 

 * * * * *

_The Popular Science Monthly. _

Conducted by E. L. And W. J. YOUMANS. 

Containing instructive and interesting articles and abstracts ofarticles, original, selected, and illustrated, from the pens of theleading scientific men of different countries;

Accounts of important scientific discoveries;

The application of science to the practical arts;

The latest views put forth concerning natural phenomena, by savants ofthe highest authority. 

TERMS: Five dollars per annum; or fifty cents per number. A Club offive will be sent to any address for $20. 00 per annum. 

The volumes begin May and November of each year. Subscriptions maybegin at any time. 

THE POPULAR SCIENCE MONTHLY and APPLETONS' JOURNAL, together, for$7. 00 per annum, postage prepaid. 

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_A New and Valuable Work for the Practical Mechanic and Engineer. _

APPLETONS' CYCLOPÆDIA OF APPLIED MECHANICS. 

A DICTIONARY OF

MECHANICAL ENGINEERING AND THE MECHANICAL ARTS. 

ILLUSTRATED BY 5, 000 ENGRAVINGS. 

Edited by PARK BENJAMIN, Ph. D. 

CONTRIBUTORS. 

 T. A. EDISON, PH. D. RICHARD H. BULL, C. E. SAMUEL WEBBER, C. E. PROF. DE VOLSON WOOD. CHARLES E. EMERY, C. E. JOSHUA ROSE, M. E. PIERRE DE P. RICKETTS, PH. D. HON. ORESTES CLEVELAND. W. T. J. KRAJEWSKI, C. E. S. W. GREEN, ESQ. JOHN BIRKINBINE, C. E. HENRY L. BREVOORT, C. E. LIEUT. A. A. BOYD, U. S. N. ABRAM L. HOLLEY, C. E. COLEMAN SELLERS, M. E. PROF. C. W. McCORD. IRVING M. SCOTT, ESQ. F. A. MCDOWELL, C. E. H. A. MOTT, JR. , PH. D. W. H. PAYNE, C. E. GEORGE H. BENJAMIN, M. D. THERON SKELL, C. E. WILLIAM KENT, C. E. W. E. KELLY, ESQ. F. T. THURSTON, C. E. JOHN HOLLINGSWORTH, ESQ. 

APPLETONS' CYCLOPÆDIA OF APPLIED MECHANICS of 1879 is a new work, andnot a revision of the former Dictionary of Mechanics of 1850. It aimsto present the best and latest American practice in the mechanicalarts, and to compare the same with that of other nations. It alsoexhibits the extent to which American invention and discovery havecontributed to the world's progress during the last quarter century. Its production is deemed timely in view of the existing popularinterest in the labors of the mechanic and inventor which has beenawakened by the great International Expositions of the last decade, and by the wonderful discoveries made by American inventors during thepast three years. 

The CONTRIBUTORS whose names are given above number many of the mosteminent American mechanical experts and engineers. Several of theircontributions contain the results of original research and thought, never before published. Their efforts have in all cases tended tosimplify the subjects treated, to avoid technicalities, and so torender all that is presented easily understood by the general readeras well as by the mechanical student. Examples are appended to allrules, explanations to all tables, and in such matters as the uses oftools and management of machines the instructions are unusually minuteand accurate. 

In semi-monthly Parts, 50 cents each. 

Subscriptions received only for the entire work of Twenty-four Parts. 

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D. APPLETON & CO. , PUBLISHERS, 549 & 551 BROADWAY, NEW YORK.