Abstract

Indifference, Necessity, and Descartes's Derivation of the Laws of Motion BLAKE D. DUTTON WHILE WORKING ON Le Monde, his first comprehensive scientific treatise, Des- cartes writes the following to Mersenne: "I think that all those to whom God has given the use of this reason have an obligation to employ it principally in the endeavor to know him and to know themselves. This is the task with which I began my studies; and I can say that I would not have been able to discover the foundations of physics if I had not looked for them along that road" . ' As the letter makes clear, knowl- edge of the foundations of Cartesian physics is inextricably linked to the knowledge of God. Unfortunately, Descartes never explains why this is the case, and the relation in which his theistic doctrine stands to his physics remains unspecified. In what follows I wish to clarify that relation by examining some of the problems surrounding Descartes's attempt to locate the metaphysical founda- tions of his physics in his doctrine of God. I begin my analysis with a discussion of the doctrine of divine indifference and argue that this doctrine is of great importance to any interpretation of the foundations of Cartesian physics, insofar as it provides Descartes with a rationale for dismissing the appeal to final causation in scientific explanation. Insofar as this is the case, it supplies an important piece of his justification for mechanism...