d explanation of the philosophy developed by Leucippus, for his ideas are known today only through the few surviving fragments. He apparently had no idea of the cause for the primal motion of the atoms, the motion which brought them into collision and formed larger aggregates over time:
Leucippus evidently did not consider any moving force to be a necessary hypothesis. . . Apparently the early cosmologists did not think of motion as requiring any explanation, and in the Atomist philosophy the eternal movement of the atoms is regarded as self-sufficient (Copleston 74).
Leucippus based his epistemology on sensory observation and the application of logic. He assumed the existence of atoms as a way of explaining the world as seen, and he postulated a void for the atoms to move through as they collided within one another:
These are the only basic realities, atoms an void, and the various universes, of which there may be many, and all individual things in them are simply produced by chance comings-together of atoms in their endless movement in the void (Armstrong 18).
For Leucippus, empty space and the atoms moving through it are the true reality. To arrive at this conclusion, Leucippus built on the ideas and structures created by earlier philosophers who were also attempting to create a comprehensive metaphysics. The approach of Leucippus differs primarily in being mechanistic in nature and in not having an explanation for how this mechanistic universe started.
Lucretius stated that it is not possible to create something out of nothing. We atomists were trying to reformulate pluralism in a way that would avoid the pitfalls that had plagued Empedocles and Anaxagoras. Lucretius also stated that nothing is destroyed. He further stated that there is such a thing as a void, an area of space that is completely empty. The void is indeed infinite. Matter, he stated, is made up of an infinite plurality of very small and ind...