 Descartes’ many hypotheses concerning space and body are best appreciated when viewed as a continuation of a long debate within Medieval/Renaissance philosophy centered upon the Aristotelian dictum that whatever possessed dimensionality was body (see, Grant 1981). While some philosophers, such as Telesio, Campanella, and Bruno, held space to be always filled with matter (i.e., a plenum) yet somehow independent of matter, others, like Patrizi and Gassendi, endorsed a more absolutist notion that allowed spaces totally devoid of matter (i.e., vacuum). Rejecting these anti-Aristotelian ideas of empty space, Descartes equated the defining property, or “essence”, of material substance with three-dimensional spatial extension: “the extension in length, breadth, and depth which constitutes the space occupied by a body, is exactly the same as that which constitutes the body” (Pr II 10). Consequently, there cannot exist a space separate from body (Pr II 16), since all spatial extension simply is body (and he rejects the possibility of a vacuum that is not extended). If, for example, God removed the matter within a vessel (such that nothing remained), then the sides of the vessel would immediately become contiguous (but not through motion; Pr II 18). It is important to note that Descartes’ claim, that the vessel’s sides must become contiguos, was a fairly common view among the Scholastics, since they also accepted the idea that spatial extension required a substance to ground extension (see, Grant 1981, 122). Descartes argues that, with respect to the empty vessel, that “nothingness cannot possess any extension”, since “all distance is a mode of extension, and therefore cannot exist without an extended substance” (Pr II 18). While Descartes accepts a substance-property metaphysics, the rejection of the empty vessel scenario seems more motivated by his nominalism, which is the view that only particulars exist, whereas universals are only names and abstractions from particluar things. As he states in an earlier section of the Principles as regards numbers, “when number is not being considered in any created things, but only in the abstract or in general, it is merely a mode of thought” (Pr I 58).