But is the analogy more than superficial? Is it relevant to our present argument? Can it explain either the spread of higher moral ideals or their development? Let us consider for a moment some examples of this psychological “struggle for existence.” Take, as a simple case, the competition between rival inventions—between the spinning-jenny and the hand-loom, the breech-loader and the muzzle-loader, pre-Listerian and post-Listerian methods of surgery. Unless the environment be strongly charged with prejudice, ignorance, or sinister interests, the “fittest” in such cases is that which best serves its purpose. Measurable efficiency is the quality which wins. But this supplies us with no useful analogy when we are dealing with ethics. Morality, as I have already insisted, is not an invention designed to serve an external purpose. The “struggle for existence” between higher and lower ethical ideals has no resemblance to the struggle between the spinning-jenny and the hand-loom. It is a struggle between ends, not between means. Efficiency is not in question. A like observation applies to that quality of our beliefs which might be described as “argumentative plausibility.” This is to abstract theorising what efficiency is to practical invention. It has survival value. Both, of course, are relative terms, whose application varies with circumstances. An invention is only efficient while the commodity it produces is in demand. A theory is only plausible while it hits off the intellectual temper of the day. But if efficiency and plausibility be thus understood, the more efficient invention and the more plausible doctrine will oust their less favoured rivals. They are the “fittest.” But as morality is not a means, so neither is it a conclusion. Whatever be its relation to Reason, _reasoning_ can never determine the essential nature of its contents. Plausibility, therefore, is no more in question than efficiency. I do not, of course, deny that ethics are always under discussion, or that the basis of moral rules and their application are themes of unending controversy. This is plainly true. But it is also true that there is no argumentative method of shaking any man’s allegiance to an end which he deems intrinsically worthy, except by showing it to be inconsistent with some other end which _he_ (not you) deems more worthy still. Dialectic can bring into clear consciousness the implicit beliefs which underlie action, but it cannot either prove them or refute them. It is as untrue to say that there is no disputing about morals as to say that there is no disputing about tastes. But also it is as true; and the truth, properly understood, is fundamental.