In Nicomachean Ethics X 7-8, Aristotle distinguishes two kinds of eudaimonia, primary and secondary. The first corresponds to contemplation, the second to activity in accordance with moral virtue and practical reason. My task in this paper is to elucidate this distinction. Like Charles, I interpret it as one between paradigm and derivative cases; unlike him, I explain it in terms of similarity, not analogy. Furthermore, once the underlying nature of the distinction is understood, we can reconcile the claim that paradigm eudaimonia consists just in contemplation with a passage in the first book requiring eudaimonia to involve all intrinsic goods.