 Viewing Desgabets’s work as a whole, there is no doubt that what he viewed as a revision or perfection of the Cartesian philosophy others have viewed as a fundamental departure. In his favor, he never strayed from the Cartesian metaphysics, i.e., its substance dualism of mind and matter, substance-mode ontology, mind-body union and interaction, and the view that extension is the essence of matter and thought the essence of mind; and he remained loyal to the Cartesian physics against the atomists. However, heretically to some, he strongly rejected the rationalist epistemology which often dominates in Descartes, and argued that Descartes’s own principles favor a sensory foundation for knowledge.