Lives and Opinions of Eminent Philosophers

​Therefore Zeno was the first to say in his On the Nature of Man that the end is to live in agreement with nature, which is to live according to virtue; for nature leads us toward this. Likewise Cleanthes also says in his On Pleasure, and Posidonius and Hecato in their books On Ends. Furthermore, to live according to virtue is equivalent to living according to experience of the things that happen by nature, as Chrysippus says in the first book of On Ends; for our natures are parts of the nature of the whole.

​Therefore the end becomes to live in accordance with nature, which is according to one's own nature and according to that of the universe, doing nothing of what the common law is accustomed to forbid, which is the right reason pervading all things, being the same as Zeus, who is this director of the administration of all things; and that this very thing is the virtue of the happy man and the smooth flow of life, whenever all things are done according to the harmony of the spirit within each with the will of the governor of the whole. Diogenes, then, expressly says that the end is to reason well in the selection of things according to nature; while Archedemus says it is to live completing all appropriate acts.

​And Chrysippus understands the nature, in accordance with which one must live, to be both the common nature and specifically human nature; but Cleanthes accepts only the common nature as that which one must follow, and no longer the particular nature as well. And virtue is a state of agreement; and it is choiceworthy for its own sake, not through any fear or hope or any of external things; and in it is happiness, since it is a soul fashioned for the agreement of the whole of life. But the rational animal is perverted, at times through the persuasiveness of external affairs, and at other times through the instruction of companions; since nature gives unperverted starting points.

​And of virtue, one kind is, broadly speaking, the perfection in anything, as of a statue; and there is non-intellectual virtue, such as health; and theoretical virtue, as prudence. For Hecato says in the first book of On Virtues that scientific and theoretical virtues are those having their constitution from theorems, as prudence and justice; while non-intellectual virtues are those observed as extending alongside those constituted from theorems, such as health and strength. For when temperance exists as theorized, it happens that health follows and extends alongside it, just as strength supervenes upon the building of an arch.

​And they are called non-intellectual because they do not have assents, but supervene and occur even around base persons, as health and courage. And as proof that virtue has real existence, Posidonius says in the first book of his Ethical Discourse the fact that Socrates, Diogenes, and Antisthenes and their circles were in progress. And vice also has real existence because it is opposite to virtue. And that it—I mean virtue—is teachable, Chrysippus says in the first book of On the End, and Cleanthes, and Posidonius in his Exhortations, and Hecato; and that it is teachable is evident from good men coming to be from base ones.

​Panaetius, then, says that virtues are two, theoretical and practical; others say logical, physical, and ethical; those around Posidonius say four; and those around Cleanthes, Chrysippus, and Antipater say more. Apollophanes, on his part, says there is one, namely prudence. And of the virtues, some are primary, and others are subordinate to these. Primary are the following: prudence, courage, justice, temperance; and as species of these: magnanimity, continence, endurance, quick-wittedness, good counsel. And prudence is the knowledge of things bad, good, and neither; and courage is the knowledge of things to be chosen, things to be avoided, and neither;