 Epicurus is a materialist in his metaphysics. For Epicurus, the two entities that exist per se are bodies and the empty space (the void) that they move in. The bodies that we see are aggregates of atoms, which are minute, uncuttable bodies. Anything else that exists—such as colors, time, or justice—depends for its existence on the existence of bodies and void. And so, everything that occurs depends ultimately on the motions of atoms through the void, with atomic motions caused by things like the atoms’ past motions and their collisions and entanglements with other atoms. Epicurus’ predecessor Democritus, one of the original inventors of atomism, thought that these were the only causes of atomic motion. The Epicureans believe that Democritus’ position would imply that the future is predetermined in a way that would make action and deliberation futile (Diogenes of Oinoanda, (inscription) 32.1.14—3.14, LS 20G), and Epicurus wants to avoid being 