In his “Two Kinds of Moral Reasoning; Ethical Egoism as a Moral Theory”, Jesse Kalin defines ethical egoism as “the position that a person ought, all things considered, to do an action if and only if that action is in his overall self-interest”, by which he means that each person is ‘rationally justified in’ or ‘has conclusive reasons for’ acting thus, and not that ‘it is good', or that ‘it is desirable', or that ‘it conduces to any intrinsically desirable state of affairs', for each to act only self-interestedly.
In this way, Kalin seeks to formulate an egoism which he takes to be rational, insofar as, in the interests of consistency, the egoist holds a principle applicable to all, and yet is not committed, ex hypothesi, to valuing collective goods or states of affairs which would tend to compromise his own interests (e.g. everyone's actually acting egoistically).