CHAPTER XVIII.

INFLUENCE OF DARWIN UPON HUXLEY.

[Sidenote: HUXLEY AND NATURAL SELECTION.]

It is of the utmost interest to trace the influence of Darwin upon Huxley, his great General in the numerous controversial battles which had to be fought before the new views were to secure a fair hearing and, at length, complete success. Now that we are quietly enjoying the fruit of his many victories, we are apt to forget how much we owe to Huxley, not only for evolution, but for that perfect freedom in the expression of thought and opinion which we enjoy. For Huxley fought on wider issues than those raised by evolution, wide as these are; and with a success so great that it is inconceivable that any new and equally illuminating thought which the future may hold in store for us, will meet with a reception like that accorded to the “Origin of Species.”

At first sight it seems a simple matter to describe the effect of the “Origin” upon Huxley, considering that he, more than any other man, expounded it, and defended it from the most weighty of the attacks made upon it. Hence, it is only natural to believe, as many have done, that he was in entire agreement with the conclusions of the book as regards natural selection as well as evolution. On the other hand, the opinion has often been expressed that Huxley, although agreeing with the “Origin” for some years after its first appearance, changed his mind in later years, and no longer supported Darwin’s views.

I shall give reasons for rejecting both these opinions about Huxley, although the first is far nearer the truth than the second. The latter is clearly untenable, and was probably merely an inference from the fact that after a time Huxley ceased to enter into Darwinian controversies. But this was because he had done his work with entire success, and therefore turned his attention in other directions. Whenever he was called on to write or speak about Darwinism, as he was on two occasions within a few months of his death, his writings and speeches left no doubt about his thoughts on the subject. Furthermore, in the Preface to “Darwiniana,” written in 1893, he expressly denied that he had recanted or changed his opinions about Darwin’s views.

In order to appreciate the influence of Darwin upon Huxley, we must find out the beliefs of the latter upon the “species question” before the appearance of the “Origin.” In his chapter “On the Reception of the ‘Origin of Species’” (“Life and Letters,” Vol. II.) Huxley says that, before 1858, he took up an agnostic position as regards evolution “... upon two grounds: firstly, that up to that time, the evidence in favour of transmutation was wholly insufficient; and, secondly, that no suggestion respecting the causes of the transmutation assumed, which had been made, was in any way adequate to explain the phenomena.” It is obvious that these two grounds are entirely distinct, and that the logical foundation of the first is far more secure than that of the second.

The effect of the “Origin” was completely to convince Huxley on the first ground: from that time he never doubted the truth of evolution, however it may have been brought about. With regard to the second ground, it is quite clear that Huxley had a very high opinion of natural selection: he thought it incomparably the best suggestion upon the subject that had ever been made, and he firmly believed that it accounted for something--that it may even have taken a dominant part in bringing about evolution. On the other hand, he never felt quite confident about the entire sufficiency of the evidence in its favour. It is probable that he was far more interested in the establishment of evolution as a fact than in natural selection as an explanation of it. He saw the vast amount of research in all kinds of new or almost neglected lines, which would be directly inspired by evolution. And his own investigations in some of these lines soon afforded some of the most weighty evidence in favour of the doctrine. Natural selection had not the same personal interest for him; no one has expounded it better or defended it more vigorously and successfully, but Huxley’s own researches never lay in directions which would have made them available as a test of the theory. Of natural selection he might have used the words of Mercutio--it may not be “so deep as a well, nor so wide as a church door,” to contain the whole explanation of evolution, “but ’tis enough ’twill serve”; it will, at any rate, prevent him from feeling the second ground on which he had maintained an agnostic position.

I believe that he maintained these views with inflexible consistency throughout his life, the only indications of change being in the last year, when the contrast between his certainty of evolution and his uncertainty of natural selection, as expressed in the two speeches quoted on pp. 140, 141, was, perhaps, more sharply marked than at any other period.

It is now proposed to support this conclusion by many extracts from Huxley’s writings, as well as from his speeches, which have been alluded to above. The deep interest of the subject, and the wide differences of opinion with regard to it, justify, and indeed demand, copious quotations selected from works and speeches, written and spoken at many different times during the years between 1858 and 1894.

It may not be out of place to emphasise the fact that the sole responsibility for the conclusions here drawn rests with the author of this volume, and that the evidence on which the conclusions rest is supplied in full.

About a month before the “Origin” was published, Darwin wrote to Professor Huxley asking for the names of foreigners to whom to send his book. This communication is of great interest as being the earliest letter, accessible to the public, which he wrote to Huxley. In it he says: “I shall be _intensely_ curious to hear what effect the book produces on you”; but he evidently thought that Huxley would disagree with much in it, and must have been surprised as well as gratified at the way in which it was received. In his chapter “On the Reception of the ‘Origin of Species’” (“Life and Letters,” Vol. II.), Huxley writes: “My reflection, when I first made myself master of the central idea of the ‘Origin,’ was, ‘How extremely stupid not to have thought of that.’”

Huxley replied on November 23rd, 1859--the day before the publication of the “Origin”--saying that he had finished the book on the previous day. His letter was a complete acceptance of evolution as apart from any theory which may account for it; and a thorough agreement with natural selection as a “true cause for the production of species.” At no time in his life did he state how far he considered natural selection to be a sufficient cause. He was only “prepared to go to the stake, if requisite, in support of” the chapters which marshal the evidence for evolution (ix., and most parts of x., xi., and xii.).

With regard to the earlier chapters, which propound the theory of natural selection, his exact words are:--

“As to the first four chapters, I agree thoroughly and fully with all the principles laid down in them. I think you have demonstrated a true cause for the production of species, and have thrown the _onus probandi_, that species did not arise in the way you suppose, on your adversaries.”

Darwin replied with much warmth, and expressed himself as “Now contented and able to sing my _Nunc Dimittis_.”

In the _Times_ of December 26th, 1859, appeared a masterly article upon the “Origin,” and, after a time, it became known that Huxley was its author. Volume II. of the “Life and Letters” explains the circumstances under which the review was written. The article is reprinted as the first essay (“The Darwinian Hypothesis,” I.) in “Darwiniana” (Vol. II. of the “Collected Essays of Professor Huxley,” London, 1893). The following quotation (pp. 19, 20) shows the attitude he took up with regard to natural selection:--

“That this most ingenious hypothesis enables us to give a reason for many apparent anomalies in the distribution of living beings in time and space, and that it is not contradicted by the main phenomena of life and organisation appear to us to be unquestionable; and, so far, it must be admitted to have an immense advantage over any of its predecessors. But it is quite another matter to affirm absolutely either the truth or falsehood of Mr. Darwin’s views at the present stage of the enquiry. Goethe has an excellent aphorism defining that state of mind which he calls “Thätige Skepsis”--active doubt. It is doubt which so loves truth that it neither dares rest in doubting, nor extinguish itself by unjustified belief; and we commend this state of mind to students of species, with respect to Mr. Darwin’s or any other hypothesis as to their origin. The combined investigations of another twenty years may, perhaps, enable naturalists to say whether the modifying causes and the selective power, which Mr. Darwin has satisfactorily shewn to exist in Nature, are competent to produce all the effects he ascribes to them; or whether, on the other hand, he has been led to over-estimate the value of the principle of natural selection, as greatly as Lamarck over-estimated his _vera causa_ of modification by exercise.”

Of all the statements about natural selection made by Huxley, this one seems to me the nearest to the spirit of the two speeches he made in 1894, in which it became evident that the intervening thirty-five years had not brought the increased confidence he had hoped for. Furthermore, in the Preface to “Darwiniana” (1893) he expressly stated that he had not changed his mind as regards this article and the next which will be considered (see p. 137, where the passage is quoted).

In 1860 Huxley wrote the article on “The Origin of Species” which appeared in the _Westminster Review_ for April, and is reprinted in “Darwiniana.” He here states the reasons for his doubts about natural selection in considerable detail. At the beginning of the essay (“Darwiniana,” p. 23) he asserts that--

“... all competent naturalists and physiologists, whatever their opinions as to the ultimate fate of the doctrines put forth, acknowledge that the work in which they are embodied is a solid contribution to knowledge and inaugurates a new epoch in natural history.”

Towards the end of the essay, after vindicating the logical method followed by Darwin, he continues (pp. 73–75):--

“There is no fault to be found with Mr. Darwin’s method, then; but it is another question whether he has fulfilled all the conditions imposed by that method. Is it satisfactorily proved, in fact, that species may be originated by selection? that there is such a thing as natural selection? that none of the phœnomena exhibited by species are inconsistent with the origin of species in this way? If these questions can be answered in the affirmative, Mr. Darwin’s view steps out of the ranks of hypotheses into those of proved theories; but, so long as the evidence at present adduced falls short of enforcing that affirmation, so long, to our minds, must the new doctrine be content to remain among the former--an extremely valuable, and in the highest degree probable, doctrine, indeed the only extant hypothesis which is worth anything in a scientific point of view; but still a hypothesis, and not yet the theory of species.

“After much consideration, and with assuredly no bias against Mr. Darwin’s views, it is our clear conviction that, as the evidence stands, it is not absolutely proven that a group of animals, having all the characters exhibited by species in Nature, has ever been originated by selection, whether artificial or natural. Groups having the morphological character of species, distinct and permanent races in fact, have been so produced over and over again; but there is no positive evidence, at present, that any group of animals has, by variation and selective breeding, given rise to another group which was even in the least degree infertile with the first. Mr. Darwin is perfectly aware of this weak point, and brings forward a multitude of ingenious and important arguments to diminish the force of the objection. We admit the value of these arguments to their fullest extent; nay, we will go so far as to express our belief that experiments, conducted by a skilful physiologist, would very probably obtain the desired production of mutually more or less infertile breeds from a common stock, in a comparatively few years; but still, as the case stands at present, this ‘little rift within the lute’ is not to be disguised nor overlooked.”

He concludes with a summary of the results of his argument. The sentences which bear on the present question are as follows (pp. 77, 78):--

“Our object has been attained if we have given an intelligible, however brief, account of the established facts connected with species, and of the relation of the explanation of those facts offered by Mr. Darwin to the theoretical views held by his predecessors and his contemporaries, and, above all, to the requirements of scientific logic. We have ventured to point out that it does not, as yet, satisfy all those requirements; but we do not hesitate to assert that it was superior to any preceding or contemporary hypothesis, in the extent of observational and experimental basis on which it rests, in its rigorously scientific method, and in its power of explaining biological phenomena, as was the hypothesis of Copernicus to the speculations of Ptolemy. But the planetary orbits turned out to be not quite circular after all, and, grand as was the service Copernicus rendered to science, Kepler and Newton had to come after him. What if the orbit of Darwinism should be a little too circular? what if species should offer residual phenomena, here and there, not explicable by natural selection? Twenty years hence naturalists may be in a position to say whether this is, or is not, the case; but in either event they will owe the author of ‘The Origin of Species’ an immense debt of gratitude. We should leave a very wrong impression on the reader’s mind if we permitted him to suppose that the value of that work depends wholly on the ultimate justification of the theoretical views which it contains. On the contrary, if they were disproved to-morrow, the book would still be the best of its kind--the most compendious statements of well-sifted facts bearing on the doctrine of species that has ever appeared.”

It is clear that two very distinct points are urged in this criticism of natural selection--(1) the difficulty that selective methods applied by man have not as yet produced all the characteristics of true species; (2) supposing the latter difficulty to be surmounted or sufficiently explained, the uncertainty as to how much or how little of the process of evolution has been due to natural selection.

Later in the same year Darwin seems to have been a little disappointed that Huxley’s confidence did not increase. Thus, he wrote on December 2nd, 1860:--

“I entirely agree with you that the difficulties on my notions are terrific; yet having seen what all the _Reviews_ have said against me, I have far more confidence in the _general_ truth of the doctrine than I formerly had. Another thing gives me confidence--viz. that some who went half an inch with me now go further, and some who were bitterly opposed are now less bitterly opposed. And this makes me feel a little disappointed that you are not inclined to think the general view in some slight degree more probable than you did at first. This I consider rather ominous. Otherwise I should be more contented with your degree of belief. I can pretty plainly see that if my view is ever to be generally adopted, it will be by young men growing up and replacing the old workers, and then young ones finding that they can group facts and search out new lines of investigation better on the notion of descent than on that of creation.”

In 1863 Huxley delivered a course of lectures to working men on “The Causes of the Phenomena of Organic Nature”; here, too, he expressed his opinions about natural selection with great clearness and force. These lectures are reprinted as the concluding part of “Darwiniana,” and the references are to the pages of that volume of his collected essays.

On page 464 we read--

“Here are the phenomena of Hybridism staring you in the face, and you cannot say, ‘I can, by selective modification, produce these same results.’ Now, it is admitted on all hands, at present, so far as experiments have gone, it has not been found possible to produce this complete physiological divergence by selective breeding.... If we were shewn that this must be the necessary and inevitable results of all experiments, I hold that Mr. Darwin’s hypothesis would be utterly shattered.”

He then goes on to show that this is very far from proved, and concludes (page 466)--

“that though Mr. Darwin’s hypothesis does not completely extricate us from this difficulty at present, we have not the least right to say it will not do so.”

A passage on page 467 shows that Huxley placed natural selection infinitely higher than any other attempt to account for evolution, and indeed that he regarded all other attempts with scorn.

“I really believe that the alternative is either Darwinism or nothing, for I do not know of any rational conception or theory of the Organic universe which has any scientific position at all beside Mr. Darwin’s.... Whatever may be the objections to his views, certainly all other theories are absolutely out of court.”

On page 468 he continues--

“But you must recollect that when I say I think it is either Mr. Darwin’s hypothesis or nothing; that either we must take his view, or look upon the whole of organic nature as an enigma, the meaning of which is wholly hidden from us; you must understand that I mean that I accept it provisionally, in exactly the same way as I accept any other hypothesis.”

He concludes the lectures and the volume in which they are now reproduced by the following eloquent testimony to the unique value of the “Origin of Species”:--

“I believe that if you strip it of its theoretical part it still remains one of the greatest encyclopædias of biological doctrine that any one man ever brought forth, and I believe that, if you take it as the embodiment of an hypothesis, it is destined to be the guide of biological and psychological speculation for the next three or four generations.”

The next essay from which I quote was written in 1871. At the beginning of “Mr. Darwin’s Critics” (“Darwiniana,” p. 120) he uses words which, if they stood alone, might be interpreted as an indication of a stronger conviction.

“Whatever may be thought or said about Mr. Darwin’s doctrines, or the manner in which he has propounded them, this much is certain, that, in a dozen years, the ‘Origin of Species’ has worked as complete a revolution in biological science as the ‘Principia’ did in astronomy--and it has done so, because, in the words of Helmholtz, it contains an ‘essentially new creative thought.’”

This last quotation, and the following one, from “Evolution in Biology,” written in 1878, are, I think, among the strongest utterances in favour of natural selection to be found in the Collected Essays. At the conclusion of the above-named essay (_l. c._, p. 223) he states that it was clearly seen that--

“if the explanation would apply to species, it would not only solve the problem of their evolution, but that it would account for the facts of teleology, as well as for those of morphology;...”

“How far ‘natural selection’ suffices for the production of species remains to be seen. Few can doubt that, if not the whole cause, it is a very important factor in that operation; and that it must play a great part in the sorting out of varieties into those which are transitory and those which are permanent.”

The seventh essay, “The Coming of Age of ‘The Origin of Species,’” was written in 1880. His complete confidence in evolution, as shown in this essay, may be contrasted with his cautious statements about natural selection. He boldly affirms evolution to be the fundamental doctrine of the “Origin of Species,” while natural selection is, I believe, neither mentioned nor even alluded to. On this great occasion he thus emphasised the immense debt we owe to Darwin in that he was the first to produce adequate evidence in favour of the ancient doctrine of evolution, a benefit quite distinct from that which he conferred in the theory of natural selection (see pp. 100–102).

The following are among the most confident statements about evolution to be found in this essay. Speaking of the “Origin,” he says (p. 229):--

“... the general doctrine of evolution, to one side of which it gives expression, obtains, in the phenomena of biology, a firm base of operations whence it may conduct its conquest of the whole realm of nature.”

And again, on page 332:--

“The fundamental doctrine of the ‘Origin of Species,’ as of all forms of the theory of evolution applied to biology, is ‘that the innumerable species, genera, and families of organic beings with which the world is peopled have all descended, each within its own class or group, from common parents, and have all been modified in the course of descent.’”

Furthermore, on page 242 we read:--

“I venture to repeat what I have said before, that so far as the animal world is concerned, evolution is no longer a speculation, but a statement of historical fact. It takes its place alongside of those accepted truths which must be reckoned with by philosophers of all schools.”

And on the same page he quotes with approval the statement by M. Filhol of the results to which he had been led by his palæontological investigations:--

“Under the influence of natural conditions of which we have no exact knowledge, though traces of them are discoverable, species have been modified in a thousand ways: species have arisen which, becoming fixed, have thus produced a corresponding number of secondary species.”

Similarly, in the Obituary notice in _Nature_ (1882), Huxley speaks of the secure position in which Darwin had placed the doctrine of evolution as his great achievement. The following eloquent passage occurs on page 247 of “Darwiniana”:--

“None have fought better, and none have been more fortunate, than Charles Darwin. He found a great truth trodden underfoot, reviled by bigots, and ridiculed by all the world; he lived long enough to see it, chiefly by his own efforts, irrefragibly established in science,...”

In the impressive speech in which Huxley handed over the statue of Darwin to the Prince of Wales, as representative of the Trustees of the British Museum, on June 9th, 1885 (“Darwiniana,” p. 248), the references to Darwin are most consistent with the view that the support to evolution was held by the speaker to be the great work of his life. Natural selection is not mentioned.

The next publication on this subject by Huxley is the celebrated chapter “On the Reception of the ‘Origin of Species,’” in the second volume of the great “Life and Letters.” In this chapter he speaks rather more confidently about natural selection than in some of the earlier essays and in the later speeches:--

“The reality and the importance of the natural processes on which Darwin founds his deductions are no more doubted than those of growth and multiplication; and, whether the full potency attributed to them is admitted or not, no one doubts their vast and far-reaching significance.”

But of evolution he speaks far more strongly:--

“To any one who studies the signs of the times, the emergence of the philosophy of Evolution, [“bound hand and foot and cast into utter darkness during the millennium of theological scholasticism”] in the attitude of claimant to the throne of the world of thought, from the limbo of hated and, as many hoped, forgotten things, is the most portentous event of the nineteenth century.”

And for this he gives Darwin the credit.

Later on he indicates the sense in which his keen appreciation of natural selection is to be understood. Thus, such strong statements as--

“... the publication of the Darwin and Wallace papers in 1858, and still more that of the ‘Origin’ in 1859, had the effect ... of the flash of light, which to a man who has lost himself in a dark night, suddenly reveals a road which, whether it takes him straight home or not, certainly goes his way”;

and--

“The facts of variability, of the struggle for existence, of adaptation to conditions, were notorious enough; but none of us had suspected that the road to the heart of the species problem lay through them, until Darwin and Wallace dispelled the darkness, and the beacon-fire of the ‘Origin’ guided the benighted,”

if they stood alone, might naturally be interpreted as an unqualified testimony to the permanent truth of natural selection. But this interpretation is expressly excluded:--

“Whether the particular shape which the doctrine of evolution, as applied to the organic world, took in Darwin’s hands, would prove to be final or not, was, to me, a matter of indifference. In my earliest criticisms of the ‘Origin’ I ventured to point that its logical foundation was insecure ...; and that insecurity remains.”

Its value for Huxley was that it was “incomparably more probable than the creation hypothesis”; that it was “a hypothesis respecting the origin of known organic forms, which assumed the operation of no causes but such as could be proved to be actually at work”; that it provided “clear and definite conceptions which could be brought face to face with facts and have their validity tested”; that it freed us “for ever from the dilemma--refuse to accept the creation hypothesis, and what have you to propose that can be accepted by any cautious reasoner?” Indeed, the hypothesis did away with this dilemma, even if it were itself to disappear; for “if we had none of us been able to discern the paramount significance of some of the most patent and notorious of natural facts, until they were, so to speak, thrust under our noses, what force remained in the dilemma--creation or nothing? It was obvious that, hereafter, the probability would be immensely greater, that the links of natural causation were hidden from our purblind eyes, than that natural causation should be incompetent to produce all the phenomena of nature.”

Therefore, “the only rational course for those who had no other object than the attainment of truth, was to accept ‘Darwinism’ as a working hypothesis, and see what could be made of it.” Furthermore, “Whatever may be the ultimate fate of the particular theory put forth by Darwin, ... all the ingenuity and all the learning of hostile critics has not enabled them to adduce a solitary fact, of which it can be said, this is irreconcilable with the Darwinian theory.”

Taking this argument as a whole, it seems to me to amount to the words of Mercutio quoted at the beginning of this chapter.

In the following year (1888) Huxley wrote the Obituary Notice of Darwin for the Proceedings of the Royal Society: it is reprinted in “Darwiniana” (pp. 253 _et seq._). In this admirable essay the author recognises that Darwin evidently accepted evolution before he could offer any explanation of the motive cause by which that process took place. The theory of descent with modification had often been thought of before, “but in the eyes of the naturalist of the ‘Beagle’ (and, probably, in those of most sober thinkers), the advocates of transmutation had done the doctrine they expounded more harm than good.” Huxley speaks of the “Origin” as “one of the hardest books to master,” in this agreeing with Hooker (see p. 111).

In this essay Huxley gives a clear and excellent statement of natural selection, prefaced by these words (p. 287):--

“Although, then, the present occasion is not suitable for any detailed criticism of the theory, or of the objections which have been brought against it, it may not be out of place to endeavour to separate the substance of the theory from its accidents; and to shew that a variety not only of hostile comments, but of friendly would-be improvements, lose their _raison d’être_ to the careful student.”

Then follows a brief but epigrammatic description, such as only Huxley could have written, of the theory, and some of the chief arguments which have revolved round it. Occasionally he speaks as if he were stating his own opinion as well as Darwin’s, but throughout it seems to me that his object is not to give his own views but to write a fair and clear account of Darwin’s theory, and to defend it from a number of criticisms and modifications which have been, from time to time, brought forward.

“Darwiniana” was published in 1893, and this is the date of the Preface, in which Huxley speaks of--

“... the ancient doctrine of Evolution, rehabilitated and placed upon a sound scientific foundation, since, and in consequence of, the publication of the ‘Origin of Species....’”

He thinks that readers will admit that in the first two essays (see pages 124–128 of the present volume)--

“... my zeal to secure fair play for Mr. Darwin, did not drive me into the position of a mere advocate; and that, while doing justice to the greatness of the argument, I did not fail to indicate its weak points. I have never seen any reason for departing from the position which I took up in these two essays; and the assertion which I sometimes meet with nowadays, that I have ‘recanted’ or changed my opinions about Mr. Darwin’s views, is quite unintelligible to me.”

“As I have said in the seventh essay, [see pages 131, 132 of the present volume] the fact of evolution is to my mind sufficiently evidenced by palæontology; and I remain of the opinion expressed in the second, that until selective breeding is definitely proved to give rise to varieties infertile with one another, the logical foundation of the theory of natural selection is incomplete.”

It is therefore clear, as I have before stated, that Huxley, in 1893, re-stated his criticisms and qualifications of thirty years before, and expressed his conviction anew of the validity of the objections which he then raised against a full and complete acceptance of natural selection.

We now come to the last and most significant of all Huxley’s utterances on evolution and natural selection, made on two great occasions in the last year of his life. Lord Salisbury, in his eloquent and interesting Presidential Address to the British Association at Oxford (August 8th, 1894), had said of Darwin:--

“He has, as a matter of fact, disposed of the doctrine of the immutability of species.... Few now are found to doubt that animals separated by differences far exceeding those that distinguish what we know as species have yet descended from common ancestors.”

While thus completely admitting evolution in the organic world, Lord Salisbury attacked natural selection on two grounds--first, on the insufficiency of the time allowed by physicists for a process which is, of necessity, extremely slow in its operation; secondly, on the ground that “we cannot demonstrate the process of natural selection in detail; we cannot even, with more or less ease, imagine it.” And his main objection under this head was the supposed difficulty in securing the union of successful variations. The actual words have been already quoted on page 83, where it was shown that the criticism does not apply to natural selection, but to a theory mistaken by the speaker for that of Darwin. Curiously enough, the first objection of the insufficiency of time was the indirect cause of a subsequent trenchant criticism by Professor Perry of the line of mathematical reasoning on which the limit had been fixed.

Huxley was called on to second the vote of thanks, and his speech had evidently been considered with the greatest care. I quote the passages which bear on evolution and natural selection from the _Times_ of August 9th, 1894, in which a _verbatim_ report is furnished:--

“... As one of those persons who for many years past had made a pretty free use of the comfortable word ‘evolution,’ let him remind them that 34 years ago a considerable discussion, to which the President had referred, took place in one of their sectional meetings upon what people frequently called the ‘Darwinism question,’ but which on that occasion was not the Darwinism question, but the very much deeper question which lay beneath the Darwinism question--he meant the question of evolution.... The two doctrines, the two main points, for which these men [Sir John Lubbock, Sir J. Hooker, and the speaker] fought were that species were mutable, and that the great variety of animal forms had proceeded from gradual and natural modification of the comparatively few primitive forms....”

After alluding to the revolution in thought which had taken place in thirty-four years, he said:--

“As he noted in the presidential address to which they had just listened with such well-deserved interest, he found it stated on that which was then and at this time the highest authority for them, that as a matter of fact the doctrine of the immutability of species was disposed of and gone. He found that few were now found to doubt that animals separated by differences far exceeding those which they knew as species were yet descended from a common ancestry. Those were their propositions; those were the fundamental principles of the doctrine of evolution. Darwinism was not evolution, nor Spencerism, nor Hæckelism, nor Weismannism, but all these were built on the fundamental doctrine which was evolution, which they maintained so many years, and which was that upon which their President had put the seal of his authority that evening....”

Huxley thus hailed the statements of the President in favour of evolution, while the attacks on natural selection he merely met by saying that the address would have made a good subject for discussion in one of the sections, and by insisting with impressive solemnity that evolution was a very different thing from natural selection, thereby implying that the former would be unaffected by the fate of the latter.

The second occasion was between three and four months later, when Huxley spoke at the Anniversary Dinner of the Royal Society, November 30th, 1894, after having been awarded the Darwin Medal at the afternoon meeting. I quote his words from the _verbatim_ report of the _Times_ for December 1st:--

“... I am as much convinced now as I was 34 years ago that the theory propounded by Mr. Darwin, I mean that which he propounded--not that which has been reported to be his by too many ill-instructed, both friends and foes--has never yet been shewn to be inconsistent with any positive observations, and if I may use a phrase which I know has been objected to and which I use in a totally different sense from that in which it was first proposed by its first propounder, I do believe that on all grounds of pure science it ‘holds the field,’ as the only hypothesis at present before us which has a sound scientific foundation.... I am sincerely of opinion that the views which were propounded by Mr. Darwin 34 years ago may be understood hereafter as constituting an epoch in the intellectual history of the human race. They will modify the whole system of our thought and opinion, our most intimate convictions. But I do not know, I do not think anybody knows, whether the particular views which he held will be hereafter fortified by the experience of the ages which come after us; ... whether the particular form in which he has put them before us (the Darwinian doctrines) may be such as is finally destined to survive or not is more, I venture to think, than anybody is capable at this present moment of saying.”

It is unnecessary to say anything about this passage, which fitly sums up and sets the seal on the long series of quotations I have felt obliged to make.

It may not be out of place, however, to state in a few words why many naturalists, including the present writer, are not inclined to accept the extremely cautious and guarded language of one upon whom, with regard to so many other subjects, they have ever looked as their teacher and guide. Concerning the verification of a hypothesis, Huxley said in his lectures to working men (“Darwiniana,” pages 367, 368)--

“... that the more extensive verifications are,--that the more frequently experiments have been made, and results of the same kind arrived at,--that the more varied the conditions under which the same results are attained, the more certain is the ultimate conclusion....”

And again--

“In scientific enquiry it becomes a matter of duty to expose a supposed law to every possible kind of verification, and to take care, moreover, that this is done intentionally, and not left to a mere accident....”

It may well be that the length of time required before an artificially-selected race will exhibit, when interbred with the parent species, phenomena of hybridism similar to those which are witnessed when distinct natural species are interbred--will be fatal to the production of this important line of evidence. But there is nothing to hinder us from holding the reasonable belief that such evidence might be obtained if we had command of the necessary conditions; and in the meantime other evidence of the most satisfactory kind is accumulating, and on a vast scale. Whenever a naturalist approaches a problem in the light of the theory of natural selection, and is able, by its aid, to predict a conclusion which subsequent investigation proves to be correct, he is helping in the production of evidence in favour of the theory. When a naturalist has found the formula “if natural selection be true so-and-so ought to happen” the safest of all guides into the unknown, when it has brought him success many times and in very different directions, when he knows that many other workers in other fields of biological inquiry have had a similarly happy experience, he gradually comes to feel a profound confidence in the permanent truth and the far-reaching importance of the great theory which has served him so well.