[Footnote 14: Gompertz, Opus citum, Pages 333-334. Authorized English translation, from the German edition of 1896, by Laurie Magnus, M. A. (Oxon.), London, 1906.] CHAPTER III THE ELEATIC VIEW One of the problems that early perplexed the human mind was that of motion. Parmenides, of the Eleatic school, could not conceive of movement of bodies without vacuous space, and for him there could be no vacuum, since the universe is a _plenum_--the All, the One. Hence there could be no motion, movement of bodies and physical changes being mere delusive appearances. Leucippus granted that he, likewise, could not conceive of the motion of bodies unless there was empty space for them to move in. But motion he recognized as a fact of nature, as a reality. The Eleatics must, therefore, he said, be in error in supporting the premise that “there is no vacuum.” Given empty space, motion followed. Neither Parmenides nor Leucippus introduced the conception of the vacuum. It was a pre-existing doctrine fervently attacked by Parmenides and supported on logical grounds by Leucippus. “Nor,” says Professor Gompertz of Leucippus, “did he do more than to refine and to raise to the dignity of a self-sustained system the atomic theory which existed before him, though in a rude, rudimentary and imperfect shape.” Given atoms of various sizes and forms, their movement in vacuous space was taken as much for granted as their existence. Just as matter itself had no beginning, and can have no ending, so the natural and original condition of atoms was a state of motion. The state of rest was no more “natural” to the Atomists than was the state of motion. They knew nothing of the doctrine which regards matter as an “inert mass.” Matter for them was essentially active and non-quiescent, as it was centuries later for Bruno, Bacon, Leibnitz, Spinoza, and as it is in our own times for all physicists. For _energy_ is synonymous with _motion_, and matter itself is but a collection of _energy units_ (in constant motion). DEMOCRITUS’ THEORY According to Democritus the atoms fall with varying degrees of rapidity, the heavier particles faster, the lighter with less speed, the heavier overtaking and striking against the lighter ones. To quote Lange’s succinct statement: