In the Atomists, we see pluralism taken as far as it could possibly go. We see Democritus and Epicurus divide all the world, as well as the universe, into two categories; atoms and empty space. Everything else is merely thought to exist. The atoms are eternal, infinite in size and number and they are moving through the empty space. There is no motion without empty space. Both Democritus and Epicurus agreed that motion was impossible in a plenum, but it is here that their theories diverge. In the cause of the motion, we begin to see a variety of opinions.
Both Democritus and Epicurus agreed that the "qualitative world of sense perception arises from the motion of qualitatively neutral atoms. They believe that the immense qualitative variety results from the 'jostling' of atoms...as they collide and bounce apart, and so, constantly form new groupings" (Jones 84). They believe it to be a mechanical process occurring completely by chance.
Furthermore, although new groupings are constantly being formed, only the few that can survive are considered the "right" combinations. These are the combinations we recognize through our senses as being "real", although they are not. However, the way in which this complex motion begins is a source of controversy and disagreement amongst the Atomists.
Democritus assumes that the atoms' motion is perpetual. The atoms are never at rest. He presumes that their nature is to move, thereby avoiding "the problem of explaining the origin of the complex motion of atoms by simply affirming that it is in their nature to move so" (Jones 85). He believes that atoms are born along with the whole universe in a vortex. The vortex is not an outside influence, but rather the motion of the atoms themselves. He never accounts for the initiation of...