Imágenes de páginas
PDF
EPUB

other hand, the advocates of the traditional view had no thought of altering their standpoint. They stuck to their authorised version of the world's history, and could substitute no other. If they yielded, of course they would have to yield to their opponents. The result was a great advantage to the advocates of Natural Selection. So far as their opponents were concerned, the theory sufficed to prove that the transmutation of species was a fact in nature; and the easily learned formula of Natural Selection, embodying as it seemed the most obvious facts, gave to this teaching a power which no other, at that time, could have wielded.

But while this victory was being won, the triumphant theory was itself undergoing modification. The more absolute and, as it seems to me, the more logical theory of Pure Darwinism, was taking the place of Mixed Darwinism. This conviction was steadily growing, in consequence of the depreciatory language used by Mr. Darwin with respect to transforming influences; of the introduction by Dr. Weismann of his theory of the germ plasm; of the growing tendency of Mr. Wallace to the more exclusive doctrine; and of the powerful advocacy of writers like Dr. Ray Lankester. Pure Darwinism thus became the accepted view of the majority of the advocates of Natural Selection; and hence the identification of the arguments for the process of Organic Evolution, and for the one only law which was supposed to have brought about that process, seemed perfectly fair.

For these reasons, the arguments for the process of Organic Evolution have been treated as identical with the arguments for the particular law or method of Natural Selection. But while the historical development of the doctrine of Natural Selection has more or less justified this treatment of the subject, we must remember that for

the clear and logical conception of the subject it is necessary for us to bear in mind that Natural Selection is not necessarily identical with Organic Evolution, and that the arguments for the latter are not necessarily proofs of the former.

CHAPTER II.

ORGANIC EVOLUTION NOT PROVED BY NATURAL

SELECTION.

"It is possible to have a complete faith in the general doctrine of evolution, and yet to hesitate in accepting the Darwinian theory." -HUXLEY.

It was shown in the preceding chapter that the arguments for Organic Evolution were the common property of all those who believe in Organic Evolution; that they could be, and actually had been, urged by one who never heard of Natural Selection, no less than by those who are the convinced believers in that theory. Hence we infer that evidence to show that a certain process has taken place is not necessarily evidence as to the particular law of nature by which that process has been dominated. We have now to consider how far the doctrine of Organic Evolution has been confirmed by the theory of Natural Selection.

Mr. Romanes contends that "the evidences which he (Mr. Darwin) adduced in favour of Natural Selection as a method have constituted some of the strongest reasons which scientific men have felt for accepting evolution as a fact."* But in the context he makes admissions which tend to weaken this assertion. He says: "I have made the evidences of evolution as a fact to stand independently on their own feet-feet which, in my opinion, are amply strong enough to bear any weight of adverse criticism that

* Darwin and After Darwin. p. 252.

can be placed upon them." He fully admits that "the evidence in favour of this fact has gone on steadily growing, quite independently of the assistance which was thus so largely lent to it by the distinctively Darwinian theory of its method." He feels that "we must have some reasonable assurance that a fact is a fact before we endeavour to explain it." But if we are perfectly convinced that Organic Evolution is a fact, I fail to see how any argument as to the law which dominated the process can strengthen a conviction which is already strong enough "to stand upon its own feet" in face of the most adverse criticism.

It is true, historically, that it was this theoretical explanation of the method which first set him (Darwin) seriously to enquire into the evidences of evolution as a fact; but it is scarcely true to say that "the evidence of evolution as a fact has from the first been largely derived from testing Darwin's theory concerning its method"; for, as we have already shown, the arguments for Organic Evolution were stated by Mr. Robert Chambers fifteen years before the appearance of The Origin of Species, and, therefore Mr. Fiske is not justified in saying that Mr. Darwin "was the first to marshal the arguments from classification, embryology, morphology, and distribution, and thus fairly to establish the fact that there has been a derivation of higher forms from lower." *

It is true that the battle for Organic Evolution was fought and won by those who held Darwinian opinions. The special Darwinian hypothesis may have aided in this conflict without being on that account necessarily true. I am inclined to think that the simplicity of the theory, and the possibility of stating it in language which could be

*Cosmic Philosophy. vol. ii., pp. 7.8.

easily understood, and the adoption of its salient principles as household words, have largely contributed to the acceptance and popularity of the doctrine.

And this brings me to the consideration of another point. Is the ready acceptance of a theory a proof of its truth? Mr. Wallace declares that "in less than eight years The Origin of Species has produced conviction in the minds of a majority of the most eminent living men of science."* And he goes on to say that "new facts, new problems, new difficulties, as they arise, are accepted, solved, or removed by this theory." But, in the same chapter, he himself shows that it is possible that a false theory may meet with a speedy acceptance, though it may not be able to stand the test of time; and he gives as an illustration the Circular and Quinarian System of classification propounded by MacLeay and developed by Swainson. Yet it quite died out in a few short years. In cases which are not susceptible of mathematical proof, it is quite possible that a false theory may be accepted as soon as propounded. It would not be too much to say that a false theory which takes a superficial view and offers an easy explanation, may triumph over the complicated statement of a congeries of scientific truths.

But while a false theory may enjoy a temporary triumph more or less protracted, it does not follow by any manner of means that a true theory will be at once accepted, even when it is susceptible of mathematical proof. Mr. Fiske says:—

"Newton's law of gravitation, though proved by the strictest mathematical proof, received from many eminent men but a slow and grudging acquiescence. Even Leibnitz, who, as a mathematician hardly inferior to Newton himself, might have been expected to be convinced on simple inspection of the theory, was prevented from

* Contributions. pp. 46-7.

« AnteriorContinuar »