Throughout the history of moral ideas, in spite of constant change, we may nevertheless trace a certain persistent content. In each modification the new stage is not entirely new; it brings out more fully something that was already suggested at an earlier stage. It is a permanent characteristic of the moral consciousness to find value in certain kinds of experience rather than in other kinds. At every critical turn the moral judgment pronounces for the superiority of the spiritual to the material in life, and recognises the importance of social ends when confronted by the interests or apparent interests of the self-seeking individual. The higher life and the wider life—the life of spirit and the life for others—these the moral judgment approves with a constancy which is almost uniform. Perhaps it is entirely uniform. The valuation has indeed been rejected by individuals from time to time—as it was by Thrasymachus in the Republic, as it is at the present day by the followers of Nietzsche. But this rejection is not so much a different interpretation of the moral consciousness as a revolt against morality. It is a substitution of new values for old, like the magician's offer of new lamps for old in the Arabian tale. The new lamps did not fulfil the same function as the old lamp; nor do the new values serve instead of the old. For, when we examine them, we find that they are only measurements of strength—physical standards, therefore—and not criteria of value or moral standards. In spite of the contrasts which we may discover between the ways in which different men and times express these values, their essential nature remains the same. They cannot be understood if we start by denying in toto the validity of the moral consciousness. And a sane criticism will find both unity of spirit and a principle of growth in its varied manifestations.
W. R. Sorley, Moral Values and the Idea of God, Chapter 4.