Darwin, and After Darwin, Volumes 1 and 3 / An Exposition of the Darwinian Theory and a Discussion of Post-Darwinian Questions

by George John Romanes

Now, these traditional notions touching the severance between the facts of natural history and the philosophy of it, continued more or less to dominate the minds of naturalists until the publication of the Origin of Species, in 1859. Then it was that an epoch was marked in this respect, as in so many other respects where natural history is concerned. For, looking to the enormous results which followed from a deliberate disregard of such traditional canons by Darwin, it has long since become impossible for naturalists, even of the strictest sect, not to perceive that their previous bondage to the law of a mere ritual has been for ever superseded by what verily deserves to be regarded as a new dispensation. Yet it cannot be said, or even so much as suspected, that Darwin’s method in any way resembled that of pre-scientific days, the revolt against which led to the straight-laced—and for a long time most salutary—conceptions of method that we have just been noticing. Where, then, is the difference? To me it seems that the difference is as follows; and, if so, that not the least of our many obligations to Darwin as the great organizer of biological science arises from his having clearly displayed the true principle which ought to govern biological research.

To begin with, he nowhere loses sight of the primary distinction between fact and theory; so that, thus far, he loyally follows the spirit of revolt against subjective methods. But, while always holding this distinction clearly in view, his idea of the scientific use of facts is plainly that of furnishing legitimate material for the construction of theories. Natural history is not to him an affair of the herbarium or the cabinet. The collectors and the species-framers are, as it were, his diggers of clay and makers of bricks: even the skilled observers and the trained experimentalists are his mechanics. Valuable as the work of all these men is in itself, its principal value, as he has finally demonstrated, is that which it acquires in rendering possible the work of the architect. Therefore, although he has toiled in all the trades with his own hands, and in each has accomplished some of the best work that has ever been done, the great difference between him and most of his predecessors consists in this,—that while to them the discovery or accumulation of facts was an end, to him it is the means. In their eyes it was enough that the facts should be discovered and recorded. In his eyes the value of facts is due to their power of guiding the mind to a further discovery of principles. And the extraordinary success which attended his work in this respect of generalization immediately brought natural history into line with the other inductive sciences, behind which, in this most important of all respects, she has so seriously fallen. For it was the Origin of Species which first clearly revealed to naturalists as a class, that it was the duty of their science to take as its motto, what is really the motto of natural science in general,

Felix qui potuit rerum cognoscere causas.

Not facts, then, or phenomena, but causes or principles, are the ultimate objects of scientific quest. It remains to ask, How ought this quest to be prosecuted?

Well, in the second place, Darwin has shown that next only to the importance of clearly distinguishing between facts and theories on the one hand, and of clearly recognising the relation between them on the other, is the importance of not being scared by the Bugbear of Speculation. The spirit of speculation is the same as the spirit of science, namely, as we have just seen, a desire to know the causes of things. The hypotheses non fingo of Newton, if taken to mean what it is often understood as meaning, would express precisely the opposite spirit from that in which all scientific research must necessarily take its origin. For if it be causes or principles, as distinguished from facts or phenomena, that constitute the final aim of scientific research, obviously the advancement of such research can be attained only by the framing of hypotheses. And to frame hypotheses is to speculate.

Therefore, the difference between science and speculation is not a difference of spirit; nor, thus far, is it a difference of method. The only difference between them is in the subsequent process of verifying hypotheses. For while speculation, in its purest form, is satisfied to test her explanations only by the degree in which they accord with our subjective ideas of probability—or with the “Illative Sense” of Cardinal Newman,—science is not satisfied to rest in any explanation as final until it shall have been fully verified by an appeal to objective proof. This distinction is now so well and so generally appreciated that I need not dwell upon it. Nor need I wait to go into any details with regard to the so-called canons of verification. My only object is to make perfectly clear, first, that in order to have any question to put to the test of objective verification, science must already have so far employed the method of speculation as to have framed a question to be tested; and, secondly, that the point where science parts company with speculation is the point where this testing process begins.

Now, if these things are so, there can be no doubt that Darwin was following the truest method of inductive research in allowing any amount of latitude to his speculative thought in the direction of scientific theorizing. For it follows from the above distinctions that the danger of speculation does not reside in the width of its range, or even in the impetuosity of its vehemence. Indeed, the wider its reach, and the greater its energy, the better will it be for the interests of science. The only danger of speculation consists in its momentum being apt to carry away the mind from the more laborious work of adequate verification; and therefore a true scientific judgment consists in giving a free rein to speculation on the one hand, while holding ready the break of verification with the other. Now, it is just because Darwin did both these things with so admirable a judgment, that he gave the world of natural history so good a lesson as to the most effectual way of driving the chariot of science.

This lesson we have now all more or less learnt to profit by. Yet no other naturalist has proved himself so proficient in holding the balance true. For the most part, indeed, they have now all ceased to confound the process of speculation per se with the danger of inadequate verification; and therefore the old ideal of natural history as concerned merely with collecting species, classifying affinities, and, in general, tabulating Facts, has been well-nigh universally superseded. But this great gain has been attended by some measure of loss. For while not a few naturalists have since erred on the side of insufficiently distinguishing between fully verified principles of evolution and merely speculative deductions therefrom, a still larger number have formed for themselves a darwinian creed, and regard any further theorizing on the subject of evolution as ipso facto unorthodox.

Having occupied the best years of my life in closely studying the literature of Darwinism, I shall endeavour throughout the following pages to avoid both these extremes. No one in this generation is able to imitate Darwin, either as an observer or a generalizer. But this does not hinder that we should all so far endeavour to follow his method, as always to draw a clear distinction, not merely between observation and deduction, but also between degrees of verification. At all events, my own aim will everywhere be to avoid dogmatism on the one hand, and undue timidity as regards general reasoning on the other. For everything that is said justification will be given; and, as far as prolonged deliberation has enabled me to do so, the exact value of such justification will be rendered by a statement of at least the main grounds on which it rests. The somewhat extensive range of the present treatise, however, will not admit of my rendering more than a small percentage of the facts which in each case go to corroborate the conclusion. But although a great deal must thus be necessarily lost on the one side, I am disposed to think that more will be gained on the other, by presenting, in a terser form than would otherwise be possible, the whole theory of organic evolution as I believe that it will eventually stand. My endeavour, therefore, will be to exhibit the general structure of this theory in what I take to be its strictly logical form, rather than to encumber any of its parts by a lengthy citation of facts. Following this method, I shall in each case give only what I consider the main facts for and against the positions which have to be argued; and in most cases I shall arrange the facts in two divisions, namely, first those of largest generality, and next a few of the most special character that can be found.

As explained in the Preface, the present instalment of the treatise is concerned with the theory of evolution, from the appearance of the Origin of Species in 1859, to the death of its author in 1882; while the second part will be devoted to the sundry post-Darwinian questions which have arisen in the subsequent decade. To the possible criticism that a disproportionate amount of space will thus be allotted to a consideration of these post-Darwinian questions, I may furnish in advance the following reply.