On Metaphysics and Method in Newton

Descartes begins his philosophy with metaphysics; immediately after the cogito, with God, upon whom, he maintains, all of his physics rests (and by whose guarantee it is true beyond a doubt). Newton introduces into the beginning of his natural philosophy only just that part of what I have called his metaphysics that he regards as (a) adequately supported by prior evidence, and (b) necessary for the development of physics. The rest, in so far as it appears at all in his scientific work, does so at the end of his works