Darwin himself to be based on inadequate information or erroneous conception, and therefore futile), is that which says:--Evolution, if true, can only be proved so by an actual observation of the process, and as no one pretends to have witnessed the trans.m.u.tation of species, it follows that evolution has not been proved.

Now, it is perfectly right to draw a clear distinction between a theory and a demonstration; but it is a great mistake to suppose that a theory may then only be admitted by science when it has been demonstrated.

Bishop Butler tells us that "Probability is the guide of life," and not less true is it that probability is likewise the guide of science. The business of science, as of common life, is to estimate correctly the relative degrees of probability presented by this and that theory or hypothesis; when once a theory or hypothesis is demonstrated it ceases to be a matter of scientific inquiry, and becomes a matter of scientific fact. Thus received, we have to consider the doctrine of evolution as certainly standing in the first rank of scientific theories in respect of probability sustained by evidence, although no less certainly not demonstrated as a matter of scientific fact. But when a theory has been raised to such a level of probability as this, it is, for all practical purposes, as good as a demonstration. Thus, in the particular instance before us, even if the sceptical demand for evidence, which from the nature of the case is clearly impossible, were granted, and if we could actually observe the trans.m.u.tation of species, the fact would not exert any further influence on the progress of science than is now exerted by the large and converging bodies of evidence which leave no other rational theory open to us than that such trans.m.u.tation has taken place.

Therefore, it seems to me, the hypercritical objection which we are considering is really founded on a misconception of scientific method, and of what it is that justifies a scientific doctrine. a.s.suredly, in the case of every theory, as distinguished from a demonstration, there must always be a proportion between the evidence of and the warrant for the proposition which the theory states; and if gauged by this simple rule the warrant for accepting the theory of evolution is now estimated by the judgment of all scientifically trained minds as so high, that by no additional evidence could it be placed higher without becoming a full demonstration. Or, otherwise stated, as a theory the doctrine of descent is now in the topmost position of probability, so that by no amount of additional evidence could it be raised higher without ceasing to be a probability and becoming a certainty. That is to say, we do not need any more evidence in any of the lines of evidence to add to the strength of our belief in, as distinguished from our knowledge of, the truth of evolution. For the strength of our conviction could not be increased by the discovery of any additional number of connecting links among fossil species, further facts relating to geographical distribution, to morphology, cla.s.sification, embryology, or any of the other lines of evidence which have been mentioned; no further evidence the same in kind is now competent to raise in degree the probability which has already been raised, as far as from its very nature as a probability it can be raised.

I have no doubt, however, that the princ.i.p.al obstacle which the doctrine of evolution encounters in the popular mind is not one of reason, but of sentiment. It is thought that the conception of man being a lineal descendant of the monkey is a conception which is degrading to the dignity of the former animal. Now this obstacle being, as I have said, a matter of feeling or sentiment, as such I am not able to meet it. If you think that man is shown to be any less human because his origin is now shown to have been derivative, I cannot change that decision on your part; I can only express dissent from it on my own. But although I cannot affect your sentiments in this matter, I may be permitted to point out that, as they are only sentiments, they are quite worthless as arguments or guides to truth. I have yet to learn that the "dignity of man" is a matter of any concern to our Mother Nature, who in all her dealings appears, to say the least, to treat us in rather a matter-of-fact sort of way. Indeed, so far is she from respecting our ideas of "dignity," that whenever these ideas have been applied to any of her processes, the progress of science has been destined rudely to dispel them. Thus, for instance, when the sun-spots were first observed they were indignantly denied by the Aristotelians, on the ground of its being "impossible that the eye of the universe could suffer from ophthalmia;" and when Kepler made his great discovery of the accelerated and r.e.t.a.r.ded motion of the planets in different parts of their orbits, many persons refused to entertain the conception, on the ground that it was "undignified" for heavenly bodies to hurry and slacken their pace in accordance with Kepler's law. This now seems most absurd to us; but to posterity it will not seem nearly so much so as that, notwithstanding such precedents, persons should still be found to object to Darwin's discovery, not because they were anxious to maintain the dignity of the heavenly bodies, but because they were so ludicrously anxious to maintain the dignity of their own! Good it is for man, puffed up with such silly pride, that Nature teaches him humility.

But, before leaving this subject, I should like further to point out that those who advance this preposterous objection from dignity appear to forget one all-important point, viz., that whether or not the monkey is the parent of the man, the man is certainly made in every way to _look like_ a child of the monkey. For it is a matter of anatomical demonstration, that in all the features of our bodily structure--even up to our brains--we more closely resemble the man-like apes than the man-like apes resemble the lower quadrumana. And I beg it to be remembered that the tremendous significance of this fact can only be duly appreciated by those who know the astounding complexity of our bodily structure. Those who are ignorant of human anatomy cannot form any adequate--probably not even an approximate--conception of its intricacy. Yet we find that this terrifically intricate organisation is repeated down to all the minute bones and muscles, blood-vessels, nerves and viscera, in the bodies of the higher apes. Here, then, I say, we have a fact--or rather let me say a hundred thousand facts--which cannot possibly be attributed to chance. As reasonable beings we must conclude that there has been some definite cause for this extraordinary imitation by the most highly organised being in creation of the next most highly organised. And if we reject the natural explanation of hereditary descent from a common ancestry, we can only suppose that the Deity, in creating man, took the most scrupulous pains to make him in the image of the ape. This, I say, is a matter of undeniable fact--supposing the creation theory true--and as a matter of fact, therefore, it calls for explanation. Why should G.o.d have thus conditioned man as an elaborate copy of the ape, when we know from the rest of creation how endless are His resources in the invention of types?

I present the matter thus to show that even the weight of sentiment is not all on the side of special creation. Look on this picture and on this:--

The Creator has exhibited the extraordinary and unaccountable design of casting the complex structure of man in the same mould that He had just previously used to cast the complex structure of the ape.

"When I view all beings, not as special creations, but as the lineal descendants of some few beings which lived long before the first bed of the Cambrian system was deposited, they seem to me to become enn.o.bled.... There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one; and that, whilst this planet has gone cycling on according to the first law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved."

THE END.