Recent Cartesian scholarship postulates two Descartes, separating Descartes into a scientist and a metaphysician. The purpose varies, but one has been to show that the metaphysical Descartes, of the Meditations, is less genuine than the scientific Descartes. Accordingly, discussion of God and the soul, the evil demon, and the non-deceiving God were elements of rhetorical strategy to please theologians, not of serious philosophical argumentation. I agree in finding two Descartes, but the two I identify are not scientist and philosopher, but (...) practitioner and methodologist of the mathematical sciences on the one hand, and metaphysician of a new, general science of nature on the other. This chapter examines the transition to the second Descartes, and especially the metaphysical turn. It proposes that although Descartes' doubt was methodological and he felt no serious threat from skepticism and absolute certainty was not his primary goal. Rather, the doubt was used to reform the intellect, or to teach the use of the pure intellect (and to obtain certainty in that domain). Further, Descartes' metaphysics was primarily in the service of his natural philosophy (where in the main he did not claim absolute certainty). He did not talk about God and the soul in order to fool the theologians. His discussion of the relation between God and human reason was part of a metaphysical strategy in which, through his doctrine on the eternal truths, he separated knowledge of the first principles of natural philosophy (gained by the natural light) from theological cognition (through the light of grace), thereby seeking to render his metaphysics distinct from the proper domain of theology. (shrink)