It was also fashionable in Butler's time to deny the possibility of disinterested action. This doctrine, which was a speculative principle with Hobbes, has always had a certain vogue. It is not without a certain superficial plausibility, and it has naturally been popular both with vicious persons who wanted a philosophical excuse for their own selfishness and with decent people who felt slightly ashamed of their own virtues and wished to be taken for men of the world. One of Butler's great merits is to have pointed out dearly and conclusively the ambiguities of language which make it plausible. As a psychological theory it was killed by Butler; but it still flourishes, I believe, among bookmakers and smart young business men whose claim to know the world is based on an intimate acquaintance with the shadier side of it. In Butler's day the theory moved in higher social and intellectual circles, and it had to be treated more seriously than any philosopher would trouble to treat it now. This change is very largely the result of Butler's work; he killed the theory so thoroughly that he sometimes seems to the modern reader to be flogging dead horses. Still, all good fallacies go to America when they die, and rise again as the latest discoveries of the local professors. So it will always be useful to have Butler's refutation at hand.
(C. D. Broad, Five Types of Ethical Theory [London and Henley: Routledge & Kegan Paul, 1930], 54-5)
Note from KBJ: I wrote the entry on psychological egoism for the forthcoming Encyclopedia of Utilitarianism. It may be false that all action is interested, but nobody can deny that very much of it is.
Keith Burgess-Jackson, J.D., Ph.D. 