  The ethical theory the Republic offers is best characterized as eudaimonist, according to which a person should act for the sake of his or her own success or happiness (eudaimonia). Socrates does not argue for this as opposed to other approaches to ethics. Rather, he simply assumes that a person’s success gives him or her conclusive reasons to act, and he argues that success requires acting virtuously. This eudaimonism is widely thought to be an egoistic kind of consequentialism: one should act so as to bring about states of affairs in which one is happy or successful. But there is no reason to suppose that the Republic rejects the identity of eudaimonia and  good activity (eu prattein, eupragia) which  Socrates often assumes in Plato’s Socratic dialogues  (Charmides 171e–172a, Crito 48b,  Euthydemus 278e–282d, Gorgias 507c). If the Republic takes this identity seriously, as the function argument of Book One does (354a), it says that virtuous activity is good not because it brings about success, but because it is success. This is also the explicit view of Aristotle and the Stoics, who had considered Plato’s work carefully.