Divine Activity and Motive Power in Descartes's Physics

Abstract

This paper is the second of a two-part reexamination of causation in Descartes's physics. Some prominent contemporary scholars, including Gary Hatfield and Daniel Garber, have argued that Descartes is an Occasionalist about natural motion. On their reading, Descartes holds that God alone causes the motions that are not caused by the free actions of finite minds. Hatfield and Garber offer similar, but independent arguments that Descartes's views about physics – in particular, his arguments that the laws of nature are grounded in God's immutability – entail Occasionalism about natural motion. In this paper I argue contra Hatfield and Garber that Descartes's natural philosophy does not entail Occasionalism. Descartes holds that God is a direct efficient cause of every natural motion. Yet he does not take this to imply that bodies lack genuine causal powers. According to Descartes, God concurs with bodies to cause natural motion in such a way that both God and bodies are genuine, efficient causes of motion. I conclude by presenting an account of how Descartes's theory of body is compatible with the thesis that bodies have intrinsic active causal powers.