Page:Aristotelous peri psuxes.djvu/221

CH. II.] the knowledge of natural causes; and he was thus led to adopt the hypothesis of indivisible and moving corpuscles, in order to account for the universal law of motion. "Several other philosophers had, before their time, matter as divisible into indefinitely small particles, but as they were the first who taught that these particles were originally destitute of all qualities except figure and motion, they may well be regarded as the founders of the atomic system of philosophy." Democritus maintained that nothing can ever be produced from nothing, and that "indivisible atoms (elementary corpuscles, that is) the essence of bodies." He adopted, as elements, the plenum and vacuum, making the former, in to the latter, to be entity, and the two to be, as matter, the causes of things; he maintained too, that they are equally distributed through all bodies. He agreed with Anaxagoras in believing that throughout all nature there is a principle of combination; and with his master Leucippus, in regarding form arrangement and position of particles, as causes of elementary distinctions among bodies. But in some of this reasoning he was mistaken, Aristotle observes, from not distinguishing the condition of from reality, since the same object may, when in potentiality, be and not be, although this cannot hold good of the same when in reality. Democritus also thought that, owing to the difference of sensation