In Plato's Euthydemus, Socrates claims that the possession of epistēmē (usually construed as knowledge or understanding) suffices for practical success. Several recent treatments suggest that we may make sense of this claim and render it plausible by drawing a distinction between so-called “outcome-success” and “internal-success” and supposing that epistēmē only guarantees internal-success. In this paper, I raise several objections to such treatments and suggest that the relevant cognitive state should be construed along less than purely intellectual lines: as a cognitive state constituted at least in part by ability. I argue that we may better explain Socrates' claims that epistēmē suffices for successful action by attending to the nature of abilities, what it is that we attempt to do when acting, and what successful action amounts to in the relevant contexts. These considerations suggest that, contrary to several recent treatments, the success in question is not always internal-success.