Empedocles (fl. mid-5th century BC), regarded nature as composed of a small number of basic elements (earth, air, fire, and water) combining into temporarily stable mixtures.

Epicurus was a materialist, but not a determinist. He followed Democritus in believing that the world consists of atoms and the void; but he did not believe, as Democritus did, that the atoms are at all times completely controlled by natural laws.

The fundamental ideas of the common philosophy of Leucippus and Democritus were due to the former, but as regards the working out it is hardly possible to disentangle them, nor is it, for our purposes, important to make the attempt. Leucippus, if not Democritus, was led to atomism in the attempt to mediate between monism and pluralism, as

The metaphysics of Heraclitus are sufficiently dynamic to satisfy the most hustling of moderns: “This world, which is the same for all, no one of gods or men has made; but it was ever, is now, and ever shall be an ever-living Fire, with measures kindling and measures going out.” “The transformations of Fire are, first of all, sea; and half of the