Page:Popular Science Monthly Volume 5.djvu/477

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THE CHAIN OF SPECIES.
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not to be jumped at by mere speculation, nor by hasty inference from the sparse and ill-digested facts of natural history now in our possession. The full solution of the mystery still lies in the future, and is to be reached only after the collection and comparison of a mass of data overwhelming to contemplate. In the mean time, confusion of ideas and differences about words characterize all our controversies. How men will misunderstand one another!

"We have an idea, make a word,
Too false t' unite us, or control;
And for the word itself we fight
In bitterness of soul."—Wordsworth.

It is usual to state that there are two theories of the origin of species, of the production of organic forms, namely, the theory of special creations, and the theory of natural selection. But the statement stands in need of criticism. The supposition of a special genesis, whether by some assumed ab extra influence, in other words, miraculous interference, or by some influence working ab intra, is a virtual begging of the question, a virtual admission that we never can follow the chain of causation. And this, because at some stage of the process the battle is to be stopped; at some step of the argument our mouths are to be shut, if not with a miracle after the manner of the Sunday-school teachers, which has at least the merit of piety about it, then with the more formidable obstruction of an inexplicable fact or property. And we are actually told, by one of this turn of thinking, that "to bother ourselves about these inexplicable facts is as irrational as to discuss the politics of the moon."

But, leaving special genesis aside, let us consider a little more closely the doctrine of natural selection. This, in fact, is not a theory of the origin—of the genesis of species. As M. Quatrefages has remarked, it is not a theory at all, for it explains nothing, accounts for nothing, and is not therefore truly an hypothesis in philosophy. Natural selection is not a cause, but the discussion of it draws attention to the chain of causes at the bottom of which we must look for the solution of our problem. As we all know, it is a notion taken from the selection exercised by the hand of man in the rearing of domestic plants and animals. Man, by the conscious or unconscious selection of that which best suited his wants or caprices, has educed and displayed many varieties of living creatures; and in like manner it is suggested that Nature, by holding on to the fittest in the struggle for life, has herself made selection of the innumerable forms we see. In a general way, this principle has always been recognized; and in past ages it has been always remarked that the varieties discovered are well adapted to exist, and that, if they were not so adapted, they would perish. But we have yet to see that these variations are always the fittest, or that the fittest comparatively always survive.