Value of this Evidence.

That is what I mean, ladies and gentlemen, by demonstrative evidence of Evolution an inductive hypothesis is said to be demonstrated when the facts are shown to be in entire accordance with it. If that is not scientific proof, there are no inductive conclusions which can be said to be scientific. And the doctrine of Evolution at the present time rests upon exactly as secure a foundation as the Copernican theory of the motions of the heavenly bodies. Its basis is precisely of the same character—the coincidence of the observed facts with theoretical requirements. As I mentioned just now, the only way of escape, if it be a way of escape, from the conclusions which I have just indicated, is the supposition that all these different forms have been created separately at separate epochs of time, and I repeat, as I said before, that of such a hypothesis as this there neither is nor can be any scientific evidence, and assuredly, so far as I know, there is none which is supported or pretends to be supported by evidence or authority of any other kind. I can but think that the time will come when such suggestions a these, such obvious attempts to escape the force of demonstration, will be put upon the same footing as the supposition by some writers, who are, I believe, not completely extinct at present, that fossils are not real existences, are no indications of the existence of the animals to which they seem to belong; but that they are either sports of nature or special creations, intended—as I heard suggested the other day—to test our faith. In fact, the whole evidence is in favour of Evolution, and there is none against it. And I say that, although perfectly well aware of the seeming difficulties which have been adduced from what appears to the uninformed to be a scientitic foundation. I meet constantly with the argument that this doctrine of Evolution cannot be correct, because it requires the lapse of a period of time in which duration of life upon the earth is inconsistent with the conclusions arrived at by the astronomer and the physicist. I may venture to say that I am familiar with those conclusions, inasmuch as some years ago, when President of the Geological Society of London, I took the liberty of criticising them, and of showing in what respects, as it appeared to me, they lacked complete and thorough demonstration. But putting that point aside altogether, suppose that, as the astronomers, or some of them, and some physical philosophers tell us, it is impossible that, life could have endured upon the earth for as long a period as is required by the doctrine of Evolution—supposing that to be proved. What I want to know is, what is the foundation for the statement that evolution does require so great a time? The biologist knows nothing whatever of the amount of time which may be required for the process of Evolution. It is a matter of fact that those forms which I have described to you occur in the order which I have described to you in the tertiary formation. But I have not the slightest means of guessing whether it took a million of years, or ten millions, or a hundred million of years, or a page 36 thousand millions of years to give rise to that series of changes. As a matter of fact, the biologist has no means of arriving at any conclusion as to the amount of time which may be needed for a certain quantity of organic change. He takes his facts as to time from the geologist. The geologist, taking into consideration the rate at which deposits are formed and the rate at which denudation goes on upon the surface of the earth, arrives at certain conclusions more or less justifiable as to the time which is required for the deposit of a certain amount of rocks, and if he tells me that the tertiary formation required 500,000,000 years for its deposit, I suppose he has good ground for what he says, and I take that as the measure of the duration of the Evolution of the horse from the orohippus up to its present condition, and if he is right, undoubtedly Evolution is a very slow process and requires a great deal of time. But suppose now that the astronomer—or for instance, my friend Sir Wiliiam Thompson—comes to me and tells me that my Geological friend is quite wrong, and that he has capital evidence to show that life could not possibly have existed upon the surface of the earth 500,000,000years ago, because the earth would have been too hot to allow of life. My reply is, "That is not my affair; settle that with the geologist, and when you settle that between yourselves I will agree with any conclusion." We take our time from the geologist, and it is monstrous that, having taken our time from the physical philosopher's clock, the physical philosopher should turn round upon us and say we are going too fast. What we desire to prove is, is it a fact that evolution took place? As to the amount of time it took for that, we are in the hands of the physicist and the astronomer, whose business it is to deal with those questions.