ABSTRACT
In Chapter 6, Joel Archer and C. P. Ragland explore a tension in Descartes’ writings. The tension is generated by two views: (i) that the total amount of motion in the universe is constant and (ii) that the soul produces motion in the human body. Has Descartes put forward incompatible positions? There are two prominent solutions to this tension in the literature, each involving a different interpretation of Descartes. The first interpretation is traditionally attributed to Leibniz. In this view, Descartes affirmed that the soul did not add motion to the body but merely redirected the motion that is already present in it. According to another interpretation, recently defended by Daniel Garber, Descartes intended his conservation principle to apply only to inanimate bodies but not to animate ones such as the human body. Archer and Ragland argue that each of these interpretations is ultimately problematic. They argue, however, that Descartes has the internal resources to offer a different answer. In this solution, prior to creation, God has providential knowledge of all the decisions regarding bodily movements that free creatures will make. God then sets up the laws of nature governing bodies in such a way that the total amount of motion in the universe will remain constant even as bodies begin or cease to move in accord with the intentions of free agents. This proposal is independently motivated by Descartes’ own views regarding divine providence and human freedom and reveals in his thought a trace of the “pre-established harmony” later made famous by Leibniz.
