 If Descartes holds that when doing strict metaphysics we ought not speak of what we do not clearly and distinctly perceive, a general Cartesian theory of modality should not be sensitive to claims about possibilities or necessities that Descartes himself would identify as wholly confused. There are modal claims that seem intuitive and obvious, Descartes might say, and modal claims that actually are intuitive and obvious, and he would want his account of modality to accommodate only the latter. 