In this paper I discuss Plato's conception of expertise as a part of the Platonic theory of a good, successful life (eudaimonia). In various Platonic dialogues, Socrates argues that the good life requires a certain kind of knowledge that guides all our good, beneficial actions: the “knowledge of the good and bad”, which is to be acquired by “questioning ourselves and examining our and others’ beliefs”. This knowledge encompasses the particular knowledge of how to recognize experts in a given technical (...) domain. The central element in Socrates’ account of an expert is what I call the truth-and-caring criterion: an expert has to make seeking the truth and avoiding (avoidable) error her supreme epistemic goal and she has to make caring for common goods the supreme goal of practising her expertise. (shrink)