Abstract

Aristotle and Theophrastus are the two major sources for our knowledge of the atomist theory of weight.In theDe generatione et corruptioneAristotle argues that one atom may be hotter than another and that therefore the atoms cannot be impassible, since an atom which is only slightly hot could not fail to be acted upon by an atom that was very much hotter. The premiss to the argument Aristotle derives in part from a comparison with weight. It would be ridiculous, he claims, to suppose that hotness and coldness belong to the atoms, but that heaviness and lightness, hardness and softness do not belong to them. And in fact, he continues, Democritus does claim that each of the ‘indivisibles’ is βαρύτερον…κατὰ τὴν ὑπεροχήν. Aristotle has already supposed that one kind of atom, a round atom, may be accounted as hot. The use of the comparative for weight Aristotle now takes to justify the use of the comparative for heat : from this there follows the argument that the atoms cannot be impassible.