§2.

With such opinion in the air all around him, it must be with much misgiving that one who has no prophetic utterance to offer in regard to conduct, but who still believes in the necessity of a philosophy of morals which no adaptation of natural science can supply, undertakes to make good his position. He will gain nothing, however, by trying to sail under false colours, or by disguising his recognition of an antithesis between the natural and the moral, which can alone justify his claim to have something to say that lies beyond the limits of the man of science. It is better that he should make it clear at the outset why and in what sense he holds that there is a subject-matter of enquiry which does not consist of matters of fact, ascertainable by experiment and observation, and what place he assigns to morals in this subject-matter. In other words, at the risk of repelling readers by presenting them first with the most difficult and least plausible part of his doctrine, he should begin with explaining why he holds a metaphysic of morals to be possible and necessary; the proper foundation, though not the whole, of every system of Ethics. (§2 ¶1)

This has not been the method commonly pursued by English writers on the subject, and, in the face of present tendencies, is likely to seem something of an anachronism. To any one who by idiosyncrasy, or by the accident of his position, is led to occupy himself with Moral Philosophy, the temptation to treat his subject as a part of natural science is certainly a strong one. In so doing he can plead the authority of eminent names and is sure of intelligent acceptance; nor can he fail by patient enquiry to arrive at a theory of some phenomena of human life, which, though it may leave certain primary problems untouched, shall be not only plausible but true so far as it goes. He can reckon securely on having more to show for his life’s work, when it comes to an end, than if he spent himself on questions which he may recognise as of real interest, but to which he will also be aware that experiment and observation, strictly so called, cannot afford an answer. It thus would not be wonderful that, with most enquirers and teachers, the interest once taken in Moral Philosophy should be mainly transferred to the physical science conveniently called Anthropology, even if the insufficiency of the latter to deal with the most important questions of Moral Philosophy were admitted. (§2 ¶2)

This admission, however, has of late been fast coming to be thought unnecessary. That a physical science of Ethics is not intrinsically impossible, however difficult it may be rendered by the complexity, and inaccessibility to direct experiment, of its subject-matter; that there are no intelligible questions—no questions worth asking—as to human life which would not be beyond the reach of such a science; this would seem to be the general opinion of modern English culture, so far as it is independent of theological prepossessions. And it is natural that it should be so. The questions raised for us by the Moral Philosophy which in England we have inherited, are just such as to invite a physical treatment. If it is the chief business of the moralist to distinguish the nature and origin of the pleasures and pains which are supposed to be the sole objects of human desire and aversion, to trace the effect upon the conduct of the impulses so constituted, and to ascertain the several degrees in which different courses of action, determined by anticipation of pleasure and pain, are actually productive of the desired result; then the sooner the methods of scientific experiment and observation are substituted for vague guessing and an arbitrary interpretation by each man of his own consciousness, the better it will be. Ethics, so understood, becomes to all intents and purposes a science of health, and the true moralist will be the physiologist who, making the human physique his specialty, takes a sufficiently wide view of his subject; who traces the influence of historical and political factors, or of what it is now the fashion to call the social medium, in giving a specific character to those susceptibilities of pleasure and pain on which, according to the theory supposed, the phenomena of human action depend. (§2 ¶3)