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.”