essential what the Stoic regards as accidental—this difference of opinion in regard to happiness is founded on a difference of opinion in regard to the nature of man, and it leads at once to a difference of opinion in regard to virtue and in regard to the practical conduct of life. Let me speak of these in their order; and, first, in regard to the difference of opinion between the Stoics and the Epicureans as to the nature of man, and as to the life which is conformable to that nature.
33. According to the Epicureans, the essential staple of man's nature consists of sensations, appetites, passions, and desires. These constitute man's proper nature. They do not deny that thought and reason are also a part of man's nature, but these they regard as accidental and secondary; and accordingly a life prudently conformable to these impulses is a life of nature. It is a life according to nature, because it is a life which leads to the end for which nature designed us, to that happiness, namely, which springs from a prudent indulgence in the passions.
34. On the other hand, according to the Stoics, the essential staple of man's nature consists, not of his sensations, appetites, passions, and desires, but of thought and reason; in other words, of the limits by which these are held in check. It is the limit, and not the passion, which constitutes man's proper and peculiar nature; and accordingly a life conformable,
