Ethical egoism is the view that one ought to do what is in one's own self-interest, if necessary to the exclusion of what is (or seems to be) in other people's interests. This can be contrasted with both altruism and psychological egoism. A philosophy holding that one should be honest, just, benevolent etc., because those virtues serve one's self-interest is egoistic; one holding that one should practice those virtues for reasons other than self-interest is not egoistic.

There have been only a few ethical egoists among professional philosophers. The consensus among professional philosophers seems to be that the view is implausible to begin with and that those who advocate it seriously (as "enlightened egoists") do so only at the expense of redefining what self-interest amounts to (including, as it is made to do, the interests of some other people or all other people at some times).

Among philosophers of note who might be called ethical egoists are Friedrich Nietzsche, Max Stirner, Robert Nozick. Some, such as Thomas Hobbes and David Gauthier, have thought that the conflicts which arise when people each pursue their own ends be resolved the best for each individual only if they all voluntarily forgo some of their aims--that is, egoism within a society is often best pursued by being (partly) altruistic.

As Nietzsche (in Beyond Good and Evil) and Alasdair Macintyre (in After Virtue) are famous for pointing out, the ancient Greeks did not associate morality with altruism in the way that post-Christian Western civilization has done. Consequently, it is sometimes said that Greeks like Aristotle (for whom pride was a virtue) were ethical egoists. It would be more accurate, perhaps, to say that the issue of altruism vs. egoism simply did not arise for them in the way that it does for us, or for some of us. Aristotle's view, for example, is that we have duties ourselves as well as to other people (e.g., friends) and the polis as a whole.