Abstract

Cartesian epistemology comprises three main divisions: an a priori theory, discussed in Chs. 1–3, a psychological theory of error explanations in judgment induced by features of our sense experience discussed in Chs. 4, 5 and 7, and a theory of natural reasons, discussed here. The theory of natural reasons, based on Descartes's notion of natural inclinations, is expressed here in terms of a series of warrant principles of which there are two main kinds: those that warrant action and those that warrant claims for what is true. This chapter traces Descartes's epistemically ambivalent attitude to cognitive dispositions from the early treatment in the Rules for the Direction of the Mind through to the final treatment in The Passions of the Soul. The chapter focuses special attention on the appearance of one kind of natural reason, reasons of truth, in the proof of the external world in Meditation VI and the striking absence of same in the proof of the external world in the Principles of Philosophy II. The chapter also considers whether natural reasons apply to particular aspects of corporeal things, concluding with a discussion of the Cartesian Circle.