The virtues, 20 then, come neither by nature nor against nature, but nature gives the capacity for acquiring them, and this is developed by training.

Again, where we do things by nature we get the power first, and put this power forth in act afterwards: as we plainly see in the case of the senses; for it is not by constantly seeing and hearing that we acquire those faculties, but, on the contrary, we had the power first and then used it, instead of acquiring the power by the use. But the virtues we acquire by doing the acts, as is the case with the arts too. We learn an art by doing that which we wish to do when we have learned it; we become builders by building, and harpers by harping. And so by doing just acts we become just, and by doing acts of temperance and courage we become temperate and courageous.