the latter takes it to be inalienable owing to the certainty of our mental apprehension. And virtue in itself they hold to be worthy of choice for its own sake. At all events we are ashamed of bad conduct as if we knew that nothing is really good but the morally beautiful. Moreover, they hold that it is in itself sufficient to ensure well-being : thus Zeno, and Chrysippus in the first book of his treatise On Ptrtues, and Hecato in the second book of his treatise On Goods: " For if magnanimity by itself alone can raise us far above everything, and if magnanimity is but a part of virtue, then too virtue as a whole will be sufficient in itself for well-being — despising all things that seem troublesome." Panaetius, however, and Posidonius deny that virtue is self-sufficing : on the contrary, health is necessary, and some means of living and strength. Another tenet of theirs is the perpetual exercise of virtue, as held by Cleanthes and his followers. For virtue can never be lost, and the good man is always exercising his mind, which is perfect. Again, they say that justice, as well as law and right reason, exists by nature and not by convention : so Chrysippus in his work On the Morally Beautiful. Neither do they think that the divergence of opinion between philosophers is any reason for abandoning the study of philosophy, since at that rate we should have to give up life altogether : so Posidonius in his Exhortations. Chrysippus allows that the ordinary Greek education is serviceable. It is their doctrine that there can be no question of right as between man and the lower animals, because of their unlikeness. Thus Chrysippus in the first book of his treatise On Justice, and Posi-