 Since “body or individual” is here defined in terms of the relations among a plurality of bodies, PID5, to the extent it is meant to cover all bodies, is at best an inductive step of an inductive definition of body. The obvious candidates for the base case are what Spinoza calls “the simplest bodies”, but the description and differentiation of these is likewise in terms of their motion and rest. Indeed, they “are distinguished from one another only by motion and rest” (PIL7s, italics added).[7] Spinoza, then, appears to accord with Descartes in taking bodies to be distinguished by their respective motion and rest. But motion and rest seem in the first instance to be determinations of bodies. So the motion of bodies seems to presuppose a prior ground of their individuation.