Summary : Although nothing shows at first sight that the Metaphysical meditations are built in accordance with a mathematical model, Des- cartes’ claim to have followed the « mos geometricus » invites us to pass over that first impression and to reconsider the Cartesian art of medita- tion. Descartes’ main letters of 1640 (where he describes and also criti- cizes his metaphysical method) along with the last pages of the Second replies of 1641 reveal indeed a mathematical pattern of argumentation based on the classical notion of geometrical analysis. But, if analysis plays an active role in the realization of the « order of reasons » within the context of hyperbolic doubt, its is deeply transformed by Descartes and amounts to a combination o...