Freedom in Science and Teaching. / from the German of Ernst Haeckel

by Ernst Haeckel

To those who pay attention to the actual facts of the case, this is a very surprising event; and I confess that nothing has ever perplexed me more than the reception which Professor Virchow's oration has met with, in his own and in this country; for it owes that reception, not to the undoubted literary and scientific merits which it possesses, but to an imputed righteousness for which, so far as I can discern, it offers no foundation. It is supposed to be a recantation; I can find no word in it which, if strictly construed, is inconsistent with the most extreme of those opinions which are commonly attributed to its author. It is supposed to be a deadly blow to the doctrine of evolution; but, though I certainly hold by that doctrine with some tenacity, I am able, ex animo, to subscribe to every important general proposition which its author lays down.

In commencing his address, Virchow adverts to the complete freedom of investigation and publication in regard to scientific questions which obtains in Germany; he points out the obligation which lies upon men of science, even if for no better reason than the maintenance of this state of things, to exhibit a due sense of the responsibility which attaches to their speaking and writing, and he dwells on the necessity of drawing a clear line of demarcation between those propositions which they have a fair right to regard as established truths, and those which they know to be only more or less well-founded speculations. Is any one prepared to deny that this is the first great commandment of the ethics of teaching? Would any responsible scientific teacher like to admit that he had not done his best to separate facts from hypotheses in the minds of his hearers; and that he had not made it his chief business to enable those whom he instructs to judge the latter by their knowledge of the former?

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

Again, when Professor Virchow enlarges on the extreme incompleteness of every man's knowledge beyond those provinces which he has made his own (and he might well have added within these also), and when he dilates on the inexpediency, in the interests of science, of putting forth as ascertained truths propositions which the progress of knowledge soon upsets—who will be disposed to gainsay him? Nor have I, for one, anything but cordial assent to give to his declaration, that the modern development of science is essentially due to the constant encroachment of experiment and observation on the domain of hypothetical dogma; and that the most difficult, as well as the most important, object of every honest worker is "sich ent-subjectiviren"—to get rid of his preconceived notions, and to keep his hypotheses well in hand, as the good servants and bad masters that they are.

I do not think I have omitted any one of Professor Virchow's main theses in this brief enumeration. I do not find that they are disputed by Haeckel, and I should be profoundly astonished if they were. What, then, is all the coil about, if we leave aside various irritating sarcasms, which need not concern peaceable Englishmen? Certainly about nothing that touches the present main issues of scientific thought. The "plastidule-soul" and the potentialities of carbon may be sound scientific conceptions, or they may be the reverse, but they are no necessary part of the doctrine of evolution, and I leave their defence to Professor Haeckel.

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

With respect to another side issue, raised by Professor Virchow, he appears to me to be entirely in the wrong. He is careful to say that he has no unwillingness to accept the descent of man from some lower form of vertebrate life; but, reminding us of the special attention which, of late years, he has given to anthropology, he affirms that such evidence as exists is not only insufficient to support that hypothesis, but is contrary to it. "Every positive progress which we have made in the region of prehistoric anthropology has removed us further from the demonstration of this relation."

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

For, unless I greatly err, all the real knowledge which we possess of the fossil remains of man goes no farther back than the Quaternary epoch; and the most that can be asserted on Professor Virchow's side respecting these remains is, that none of them present us with more marked pithecoid characters than such as are to be found among the existing races of mankind.[4] But, if this be so, then the only just conclusion to be drawn from the evidence as it stands is, that the men of the Quaternary epoch may have proceeded from a lower type of humanity, though their remains hitherto discovered show no definite approach towards that type. The evidence is not inconsistent with the doctrine of evolution, though it does not help it. If Professor Virchow had paid as much attention to comparative anatomy and palæontology as he has to anthropology, he would, I doubt not, be aware that the equine quadrupeds of the Quaternary period do not differ from existing Equidæ in any more important respect than these last differ from one another; and he would know that it is, nevertheless, a well-established fact that, in the course of the Tertiary period, the equine quadrupeds have undergone a series of changes exactly such as the doctrine of evolution requires. Hence sound analogical reasoning justifies the expectation that, when we obtain the remains of Pliocene, Miocene, and Eocene Anthropidæ, they will present us with the like series of gradations, notwithstanding the fact, if it be a fact, that the Quaternary men, like the Quaternary horses, differ in no essential respect from those which now live.

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