text: "But it is folly," they retort, "to prescribe what a sick man ought to do, just as if he were well, when you should really restore his health; for without health precepts are not worth a jot." But have not sick men and sound men something in common, concerning which they need continual advice? For example, not to grasp greedily after food, and to avoid getting over-tired. Poor and rich have certain precepts which fit them both. "Cure their greed, then," people say, "and you will not need to lecture either the poor or the rich, provided that in the case of each of them the craving has subsided." But is it not one thing to be free from lust for money, and another thing to know how to use this money? Misers do not know the proper limits in money matters, but even those who are not misers fail to comprehend its use. Then comes the reply: "Do away with error, and your precepts become unnecessary." That is wrong; for suppose that avarice is slackened, that luxury is confined, that rashness is reined in, and that laziness is pricked by the spur; even after vices are removed, we must continue to learn what we ought to do, and how we ought to do it.