But now let us hear what Mr Spencer says about the application of Evolution to Ethics. (§ 31 ¶ 1)

I recur, he says, to the main proposition set forth in these two chapters, which has, I think, been fully justified. Guided by the truth that as the conduct with which Ethics deals is part of conduct at large, conduct at large must be generally understood before this part can be specially understood; and guided by the further truth that to understand conduct at large we must understand the evolution of conduct; we have been led to see that Ethics has for its subject-matter, that form which universal conduct assumes during the last stages of its evolution. We have also concluded that these last stages in the evolution of conduct are those displayed by the highest type of being when he is forced, by increase of numbers, to live more and more in presence of his fellows. And there has followed the corollary that conduct gains ethical sanction in proportion as the activities, becoming less and less militant and more and more industrial, are such as do not necessitate mutual injury or hindrance, but consist with, and are furthered by, co-operation and mutual aid. (§ 31 ¶ 2)

These implications of the Evolution-Hypothesis, we shall now see harmonize with the leading moral ideas men have otherwise reached. (§ 31 ¶ 3)

Now, if we are to take the last sentence strictly—if the propositions which precede it are really thought by Mr Spencer to be implications of the Evolution-Hypothesis—there can be no doubt that Mr Spencer has committed the naturalistic fallacy. All that the Evolution-Hypothesis tells us is that certain kinds of conduct are more evolved than others; and this is, in fact, all that Mr Spencer has attempted to prove in the two chapters concerned. Yet he tells us that one of the things it has proved is that conduct gains ethical sanction in proportion as it displays certain characteristics. What he has tried to prove is only that, in proportion as it displays those characteristics, it is more evolved. It is plain, then, that Mr Spencer identifies the gaining of ethical sanction with the being more evolved: this follows strictly from his words. But Mr Spencer’s language is extremely loose; and we shall presently see that he seems to regard the view it here implies as false. We cannot, therefore, take it as Mr Spencer’s definite view that better means nothing but more evolved; or even that what is more evolved is therefore better. But we are entitled to urge that he is influenced by these views, and therefore by the naturalistic fallacy. It is only by the assumption of such influence that we can explain his confusion as to what he has really proved, and the absence of any attempt to prove, what he says he has proved, that conduct which is more evolved is better. We shall look in vain for any attempt to shew that ethical sanction is in proportion to evolution, or that it is the highest type of being which displays the most evolved conduct; yet Mr Spencer concludes that this is the case. It is only fair to assume that he is not sufficiently conscious how much these propositions stand in need of proof—what a very different thing is being more evolved from being higher or better. It may, of course, be true that what is more evolved is also higher and better. But Mr Spencer does not seem aware that to assert the one is in any case not the same thing as to assert the other. He argues at length that certain kinds of conduct are more evolved, and then informs us that he has proved them to gain ethical sanction in proportion, without any warning that he has omitted the most essential step in such a proof. Surely this is sufficient evidence that he does not see how essential that step is. (§ 31 ¶ 4)