 One might object to that this analogy is not clearly persuasive. Shifts of temperature lead to a thaw only because bodies—ice crystals and aggregates thereof—melt as temperature rises, and their boundaries recede along the backdrop of a very bodily landscape. Indeed, to thaw is just to pass from a solid to a liquid state, and solidity is a benchmark of the bodily. If we excise these bodily aspects of the analogy, it is unclear how much of its explanatory force remains. But then it is unclear just how well qualitative variations of fields can explain the appearance of bodies. Perhaps if we knew more about this quality, the sense in which such continuous paths of patterns of it could appear as or constitute bodies would be clearer. Garrett (1994) adopts Bennett's field metaphysic, and attempts to fill in the explanatory gap by providing definite senses to the PI's uses of the terms “motion” and “rest”. Relying on Spinoza's remark, following PCP IIp22, that “by force of moving bodies, we understand a quantity of motion …. In bodies at rest, we understand by force of resisting a quantity of rest”, Garrett claims that by “motion” and “rest” in the PI, Spinoza means a quantity of force that moves a thing and a quantity of force resisting such imposed movement, respectively. Furthermore, these quantities can be ascribed, he says, to the regions of extension themselves, rather than to bodies, thus overcoming the circularity problem we found in Descartes. But it is unclear that Spinoza's text can support this interpretation. PCP IIp22 speaks of the force or motion “in” a body. Spinoza elaborates: “By force in moving bodies, we understand a quantity of motion, which must be greater, in bodies of equal size, as the speed of motion is greater … . But in bodies at rest we understand by force of resisting a quantity of rest” (emphasis added). In each mention, the force or resistance is attributed to a body. This strongly suggests that quantity of motion and rest, as force and resistance, are features of  bodies.[9]  Moreover, even supposing that it makes interpretive sense to ascribe force and resistance directly to regions, what is being attributed to these regions seems to be a power to move bodies or to slow bodies down. Rather than showing how bodies could just be, or arise from, fields of such forces, the forces themselves seem to be characterized in ways that presuppose body; the circularity, then, remains.