 The Atomists’ theory is, however, in the spirit of an important strain of the seventeenth century division of qualities. The ancients hold that reality is grasped solely by intellect. They accept two of Parmenides’ intelligibility constraints on change—that one thing cannot come from many things and many cannot come from one; they aim to construct a metaphysical system in which change under these constraints is possible and the experience of non-conforming change is explained (Taylor 1999: 160–4). Anaxagoras and Empedocles share a strategy for explaining a sort of change under these constraints: basic things, conceived either as the four elements or as stuffs and qualities, do not begin or cease to exist strictly speaking; but states or relations of substances, conceived as either mixtures or separations, have a qualified, or relative, being. Leucippus and Democritus take a somewhat similar line: atoms moving in the void always exist; they are indivisible, and never fuse along a common boundary, but bitter, sweet and the like are aggregates of atoms that come to be by convention, or relatively (Taylor 1999: 160–175). Atoms and the void are an a priori solution to a problem of intelligibility. Some later advocates of the P/SQ distinction, e.g., Galileo and Descartes, hold that intellect provides a priori knowledge of the essences of things. But although variants of the later distinction offer to explain the potentiality inherent in matter and the means by which change is regulated, the issues are not presented as a Parmenidian challenge to intelligibility. The target is rather the Aristotelian view that matter is potentiality and the bifurcated theory of accidental and substantial change. The influence of Parmenides on metaphysics in the modern era is complex, but advocates of the doctrine of P/SQs as a group show little of it beyond adherence to ex nihilo nihil fit. Although atomism is prevalent in the early seventeenth century, it is often coupled with the Aristotelian theory of elements (Kargon 1964). LoLordo (2011) argues that Gassendi’s adaptation of Epicurean atomism makes no distinction between PQs and SQs.