One can argue that the problem posed by difference/identity in contemporary philosophy has its roots in the persistent epistemological imperative to be certain about what we know. We find this demand in Plato’s Theaetetus and Sophist. But beyond this demand, there is a sense in the earlier dialogue that difference is not a passive feature waiting to be identified. “Difference” points towards an active differentiating. In the Sophist, difference appears in the method of dividing and gathering deployed to hunt for the elusive “sophist.” Difference is also one of the great kinds that weaves together other kinds. Practically, difference enables the sophist’s expertise of appearance-making as he knowingly confuses things with words. This paper then quizzes the concept of difference in all these guises in the two dialogues.