First Philosophy, Metaphysics and Physics. The Implications of order in Cartesian Philosophy and in Philosophy of Enlightenment

The Philosophes’ relationships with Descartes’ philosophy constitutes one of the most interesting chapters in the history of metaphysics. Their rejection of Cartesian metaphysics is in fact radical; according to the "Philosophes" of the Eighteenth century, the Cartesian theory of the soul is "a roman de l’âme" based on chimeric innate ideas to which Locke had happily replaced "the true histoire de l’âme"; the Cartesian demonstrations of the existence of God drawn from innate ideas are to abstract and less convincing that the metaphycisical proofs by Clarke and “the proofs of the general laws of nature”. But the "Philosophes"’ critique of the Cartesian metaphysical system from the point of view of the new logic of experience, founded on the English philosophy of Newton and Locke, is non a refusal of all metaphysics: it is rather the a reform of metaphysics and a foundation of a new metaphysics. For the "Philosophes", metaphysics is not indeed “the science of first truths, or the first principles of things” but is “the experimental physics of the soul”, which now is limited to the theory of knowledge: the search for the first principles now goes hand in hand with the mind’s reflection on its own history.