The second and more extensive doctrine I will call, for the same reason, the Wallacean doctrine. This is, as already stated, that it follows deductively from the theory of natural selection, that not only all species, but even all the distinctive characters of every species, must necessarily be due to natural selection; and, therefore, can never be other than themselves useful, or, at the least, correlated with some other distinctive characters which are so. Here, however, I should like to remark parenthetically, that in choosing Professor Huxley and Mr. Wallace as severally representative of the doctrines in question, I earnestly desire to avoid any appearance of discourtesy towards such high authorities. I am persuaded--as I shall hereafter seek to show Darwin was persuaded--that the doctrine of utility as universal where species are concerned, is, in both the above forms, unsound. But it is less detrimental in its Huxleyan than in its Wallacean form, because it does not carry the erroneous deduction to so extreme a point. Therefore let us first consider the doctrine in its more restricted form, and then proceed, at considerably greater length, to deal with it in its more extended form. * * * * * The doctrine that all _species_ must necessarily be due to natural selection, and therefore must severally present at least one adaptive character, appears to me doubly erroneous. In the first place, it is drawn from what I have just shown to be a false premiss; and, in the second place, the conclusion does not follow even from this premiss. That the premiss--or definition of the theory as primarily a theory of the origin of species--is false, I need not wait again to argue. That the conclusion does not follow even from this erroneous premiss, a very few words will suffice to prove. For, even if it were true that natural selection is primarily a theory of the origin of species, it would not follow that it must therefore be a theory of the origin of _all_ species. This would only follow if it were first shown that the theory is not merely _a_ theory of the origin of species, but _the_ theory of the origin of species--i.e. that there can be no further theory upon this subject, or any cause other than natural selection which is capable of transforming any single specific type. Needless to say, this cannot be shown by way of deduction from the theory of natural selection itself--which, nevertheless, is the only way whereby it is alleged that the doctrine is arrived at[86]. [86] For a full treatment of Professor Huxley's views upon this subject, see Appendix II. * * * * *