[T]he egoist is often portrayed as being authorized to do any act which advances his interests even if that act transgresses others' rights. Usually this is taken as showing egoism to be immoral. Just as plausibly, however, it could be taken as showing that to portray egoism as allowing such action is to portray it incorrectly.
(Edward Regis, Jr, "Ethical Egoism and Moral Responsibility," American Philosophical Quarterly 16 [January 1979]: 45-52, at 50-1)
Note from KBJ: The typical criticism of ethical egoism is that it has false or unacceptable implications. The argument goes like this:
1. If ethical egoism is true, then it is right to do X (transgress rights, for example).
2. It is not right to do X.
Therefore,
3. It is not the case that ethical egoism is true.
An ethical egoist can reply to this sort of criticism in either of two ways: first, by denying the first premise (this is known as grasping the bull by the horn); second, by denying the second premise (this is known as biting the bullet). Regis is grasping the bull by the horn. He is saying that, because 2 is true and 3 is false, 1 cannot be true. (No valid argument, by definition, has true premises and a false conclusion.) In other words, ethical egoism is not correctly formulated if it implies that it is right to do X. When it is correctly formulated, it will not imply that it is right to do X. I might add that many utilitarians make the same move. They say that their theory, correctly understood and correctly formulated, does not have the implication that its critics say it has.
Keith Burgess-Jackson, J.D., Ph.D. 