Again, all or most men in whom the moral consciousness is strongly developed find themselves from time to time in conflict with the commonly received morality of the society to which they belong: and thus—as was before said—have a crucial experience proving that duty does not mean to them what other men will disapprove of them for not doing.
(Henry Sidgwick, The Methods of Ethics, 7th ed. [Indianapolis: Hackett Publishing Company, 1981], bk. I, chap. III, sec. 2, p. 30 [italics in original] [first published in 1907; 1st ed. published in 1874])