Prudence (phronēsis) is found to be all or part of virtue (aretē). Given that this has followed from the hypothesis that virtue is teachable, it would seem that phronēsis does not come to people by nature. Socrates supports this conclusion with compelling evidence. Naturally good children are not kept under guard in the acropolis until they are of an age to benefit cities, and this indicates that there are no naturally good children.
