Nature

The Epicurean understanding of nature is, to speak anachronistically, somewhat Darwinian: nature was not designed at its "beginning", nor is it continuously run by divine agency; much that happens by nature happens essentially by random chance and accident.

The lasting value of Epicurean naturalism is its cheerful acceptance of chance: it is not vengeful or vindictive (as the gods were believed to be at times), nor is there some inexorable Fate, by whose decree each and every natural process must unfold (as the Stoics believed). Chance and accident in nature, according to Epicurus and his followers, simply happens; the Sage learns to live with whatever is dealt him by this random, but entirely unpurposed process.

Epicureans believed, however, that the workings of nature were not entirely random, but that they followed specific, specifically natural (i.e. and not divine/metaphysical) laws, such as heredity and natural selection.