The article examines the place and nature of morals in Descartes's works, from the « provisional morals » of the Discourse to the conception of morals as wisdom in the letter-preface to the French edition of the Principles. Descartes's elaboration of his metaphysics, with the separation of the truth from the good, allows him to assume his later view of morals as wisdom as definitive and perfect despite the epistemic doubt intrinsic to this morals.