Virtue alone, without external goods, is enough to secure eudaimonia.

But although all standard versions of virtue ethics insist on that conceptual link between virtue and eudaimonia, further links are matters of dispute and generate different versions. For Aristotle, virtue is necessary but not sufficient—what is also needed are external goods which are a matter of luck. For Plato and the Stoics, virtue is both necessary and sufficient for eudaimonia (Annas 1993).