ABSTRACT
This chapter examines Rene Descartes' and Issac Newton's matter theory with an eye toward assessing the novelty of new materialism's claims and how best to understand present theory in relation to the past. "Cartesian–Newtonian" suggests, when new materialists discuss seventeenth-century ideas about matter, they tend to lump Descartes and Newton together, assuming that their purported thinking about matter's inertness is interchangeable. Descartes explains that strictly speaking, motion's cause is twofold: God and the ongoing transfer of action between particular colliding bodies. Newton's critique of Descartes can be read as an attempt to save physics from the threat of materialism. Newton argued against Descartes that eternal space and extension were distinct from finite, created bodies, and that to assert otherwise had troubling theological implications. Newton's initial presentation of vis inertiae in the Principia is much closer to Descartes' first law than his adoption of the term "inertia".
