For this reason Pericles and men who resemble him are considered prudent, because they are able to see what is good for themselves and for men; and this we take to be the character of those who are able to manage a household or a state.

This, too, is the reason why we call temperance σωφροσύνη , signifying thereby that it is the virtue which preserves prudence. But what temperance preserves is this particular kind of judgment. For it is not any kind of judgment that is destroyed or perverted by the presentation of pleasant or painful objects (not such a judgment, for instance, as that the angles of a triangle are equal to two right angles), but only judgments about matters of practice. For the principles of practice [or the causes which originate action] 145 are the ends for the sake of which acts are done; but when a man is corrupted by pleasure or pain, he straightway loses sight of the principle, and no longer sees that this is the end for the sake of which, and as a means to which, each particular act should be chosen and done; for vice is apt to obliterate the principle.