and it happens that good health usually follows it, and is marshalled as it were beside it; in the same way as strength follows the proper structure of an arch.—And the unspeculative virtues derive their name from the fact of their not proceeding from any acquiescence reflected by intelligence; but they are derived from others, are only accessories, and are found even in worthless people, as in the case of good health, or courage. And Posidonius, in the first book of his treaties on Ethics, says that the great proof of the reality of virtue is that Socrates, and Diogenes, and Antisthenes, made great improvement; and the great proof of the reality of vice may be found in the fact of its being opposed to virtue.
Again, Chrysippus, in the first book of his treatise on the Chief Good, and Cleanthes, and also Posidonius in his Exhortations, and Hecaton, all agree that virtue may be taught. And that they are right, and that it may be taught, is plain from men becoming good after having been bad. On this account Panætius teaches that there are two virtues, one speculative and the other practical; but others make three kinds, the logical, the natural, and the ethical. Posidonius divides virtue into four divisions; and Cleanthes, Chrysippus, and Antipater make the divisions more numerous still; for Apollophanes asserts that there is but one virtue, namely, prudence.
Among the virtues some are primitive and some are derived. The primitive ones are prudence, manly courage, justice, and temperance. And subordinate to these, as a kind of species contained in them, are magnanimity, continence, endurance, presence of mind, wisdom in council. And the Stoics define prudence as a knowledge of what is good, and bad, and indifferent; justice as a knowledge of what ought to be chosen, what ought to be avoided, and what is indifferent; magnanimity as a knowledge of engendering a lofty habit, superior to all such accidents as happen to all men indifferently, whether they