  Ethical egoism claims that I morally ought to perform some action if and only if, and because, performing that action maximizes my self-interest.  (There are possibilities other than maximization. One might, for example, claim that one ought to achieve a certain level of welfare, but that there is no requirement to achieve more. Ethical egoism might also apply to things other than acts, such as rules or character traits. Since these variants are uncommon, and the arguments for and against them are largely the same as those concerning the standard version, I set them aside.)