Principia Ethica

may be shown in the following way. We have seen, in considering the possible bearing of Metaphysics upon Practical Ethics, that, since what exists eternally cannot possibly be affected by our actions, no practical maxim can possibly be true, if the sole reality is eternal. This fact, as I said, is commonly neglected by metaphysical writers: they assert both of the two contradictory propositions that the sole reality is eternal and that its realisation in the future is a good too. Prof. Mackenzie, we saw, asserts that we ought to aim at the realisation of “the true self” or “the rational universe”: and yet Prof. Mackenzie holds, as the word “true” plainly implies, that both “the true self” and “the rational universe” are eternally real. Here we have already a contradiction in the supposition that what is eternally real can be realised in the future; and it is comparatively unimportant whether or not we add to this the further contradiction involved in the supposition that the eternal is the sole reality. That such a contradiction should be supposed valid can only be explained by a neglect of the distinction between a real subject and the character which that real subject possesses. What is eternally real may, indeed, be realised in the future, if by this be only meant the sort of thing which is eternally real. But when we assert that a thing is good, what we mean is that its existence or reality is good; and the eternal existence of a thing cannot possibly be the same good as the existence in time of what, in a necessary sense, is nevertheless the same thing. When, therefore, we are told that the future realisation of the true self is good, this can at most only mean that the future realisation of a self exactly like the self, which is true and exists eternally, is good. If this fact were clearly stated, instead of consistently ignored, by those who advocate the view that the Supreme Good can be defined in these metaphysical terms, it seems probable that the view that a knowledge of reality is necessary to a knowledge of the Supreme Good would lose part of its plausibility. That that at which we ought to aim cannot possibly be that which is eternally real, even if it be exactly like it; and that the eternal reality cannot possibly be the sole good⁠—these two propositions seem sensibly to diminish the probability that Ethics must be based on Metaphysics. It is not very plausible to maintain that because one thing is real, therefore something like it, which is not real, would be good. It seems, therefore, that some of the plausibility of Metaphysical Ethics may be reasonably attributed to the failure to observe that verbal ambiguity, whereby “This is good” may mean either “This real thing is good” or “The existence of this thing (whether it exists or not) would be good.”

71. By exposing this ambiguity, then, we are enabled to see more clearly what must be meant by the question: Can Ethics be based on Metaphysics? and we are, therefore, more likely to find the correct answer. It is now plain that a metaphysical principle of Ethics which says “This eternal reality is the Supreme Good” can only mean “Something like this eternal reality would be the Supreme Good.” We are now to understand such principles as having the only meaning which they can consistently have, namely, as describing the kind of thing which ought to exist in the future, and which we ought to try to bring about. And, when this is clearly recognised, it seems more evident that the knowledge that such a kind of thing is also eternally real, cannot help us at all towards deciding the properly ethical question: Is the existence of that kind of thing good? If we can see that an eternal reality is good, we can see, equally easily, once the idea of such a thing has been suggested to us, that it would be good. The metaphysical construction of Reality would therefore be quite as useful, for the purposes of Ethics, if it were a mere construction of an imaginary Utopia: provided the kind of thing suggested is the same, fiction is as useful as truth, for giving us matter, upon which to exercise the judgment of value. Though, therefore, we admit that Metaphysics may serve an ethical purpose, in suggesting things, which would not otherwise have occurred to us, but which, when they are suggested, we see to be good; yet, it is not as Metaphysics⁠—as professing to tell us what is real⁠—that it has this use. And, in fact, the pursuit of truth must limit the usefulness of Metaphysics in this respect. Wild and extravagant as are the assertions which metaphysicians have made about reality, it is not to be supposed but that they have been partially deterred from making them wilder still, by the idea that it was their business to tell nothing but the truth. But the wilder they are, and the less useful for Metaphysics, the more useful will they be for Ethics; since, in order to be sure that we have neglected nothing in the description of our ideal, we should have had before us as wide a field as possible of suggested goods. It is probable that this utility of Metaphysics, in suggesting possible ideals, may sometimes be what is meant by the assertion that Ethics should be based on Metaphysics. It is not uncommon to find that which suggests a truth confused with that on which it logically depends; and I have already pointed out that Metaphysical have, in general, this superiority over Naturalistic systems, that they conceive the Supreme Good as something differing more widely from what exists here and now. But, if it be recognised that, in this sense, Ethics should, far more emphatically, be based on fiction, metaphysicians will, I think, admit that a connection of this kind between