SUMMARY. — The account of Descartes' metaphysics given in the first part of Principia philosophiae cartesianae evolves as a rational reconstruction of the French philosopher's arguments, suggesting that Spinoza believed to have found some conceptual weaknesses in the work commented on. Spinoza seeks to provide an answer by calling on selected passages from Descartes himself. He again draws on Descartes in an attempt to articulate a rational theology based on the theory of the free creation of eternal truths.RÉSUMÉ. — L'exposé de la métaphysique cartésienne que Spinoza présente dans la première partie de ses Principia philosophiae cartesianae se développe suivant une reconstruction rationnelle des arguments de Descartes, qui révèle les faibl...