Since it is one of Descartes' basic beliefs that any attempt to explain natural phenomena, as well as to discover natural laws, must be grounded in metaphysics, scholars have interpreted Descartes as if he intended logically to deduce physics, an empirical science, from metaphysics. Consequently, they maintain that Descartes' study of nature results in an a priori system, which is independent of experience and observation. It is the main thesis of this dissertation to reject that interpretation of Descartes' philosophy of nature. It is true that Descartes uses the term 'deduction' to describe the relation between physics and metaphysics. However, it will be argued here that Descartes does not interpret this term in the strict sense of logical deduction. He uses it, rather, in a looser sense to describe the foundational role of metaphysics. This role is to provide a general conceptual context within which principles of physics first arise as hypotheses. But these hypotheses can be confirmed only in the light of observations and well-constructed experiments. Thus, Descartes' conception of the foundational role of metaphysics does not commit him to treating physics as an a priori system
