The attitude of the sociological school towards the systems of moral belief that they find current in various ages and races is a curiously inconsistent one. On the one hand we are urged to accept an existing code as something analogous to an existing law of nature, something not to be questioned or criticized but to be accepted and conformed to as part of the given scheme of things; and on this side the school is able sincerely to proclaim itself conservative of moral values, and is indeed conservative to the point of advocating the acceptance in full of conventional morality. On the other hand, by showing that any given code is the product partly of bygone superstitions and partly of out-of-date utilities, it is bound to create in the mind of any one who accepts its teaching (as it presupposes in the mind of the teacher) a sceptical attitude towards any and every given code. In fact the analogy which it draws between a moral code and a natural system like the human body (a favourite comparison) is an entirely fallacious one. By analysing the constituents of the human body you do nothing to diminish the reality of the human body as a given fact, and you learn much which will enable you to deal effectively with its diseases. But beliefs have the characteristics which bodies have not, of being true or false, of resting on knowledge or of being the product of wishes, hopes, and fears; and in so far as you can exhibit them as being the product of purely psychological and non-logical causes of this sort, while you leave intact the fact that many people hold such opinions you remove their authority and their claim to be carried out in practice.

W. D. Ross, The Right and the Good, Oxford, 1930, p. 13