Temperance is doing our own business.

This quote constitutes Charmides's first really consequential definition of temperance, and is in turn a quote from someone else (who turns out to be Critias). Thus, the line is significant partly because it is one of the few statements that ties all three debaters (Socrates, Charmides, and Critias) together in debate at the same time. Specifically, this theory of temperance as "doing our own business" becomes the occasion for Critias taking over from Charmides as Socrates's interlocutor; seeing Charmides unable to defend what is really his own definition, Critias can't help but jump in. As the transitional definition between Charmides and Critias, then, the theory also occupies an unusual place in the dialogue: neither entirely Critias's nor entirely Charmides's, this definition is also neither a cast-off, easily defeated suggestion (as are Charmides's earlier efforts) nor a theory that involves the dense, convoluted debates about "knowledge of knowledge" with which the rest of the dialogue is concerned.

It comes closest of any definition in the dialogue to the kind of received social commonplaces that are the usual candidates for Socratic debunking in the early dialogues. In the end, of course, this definition is defeated.