 According to Desgabets, it is undeniable that man is a being who reasons, draws consequences, does not see things indivisibly, who has thoughts in succession which begin, continue, and finish, and who often experiences doubt and conjecture. Such doubting, discursive reasoning and succession of thought prove that all thought is tied to the body since duration and successive extension are nothing but the local movements of the body (OPD 7: 299). A pure thought, the kind that Descartes (and Malebranche after him) envisioned for metaphysical reasoning, would have no beginning, duration, end, or succession. In short, such a thought would be indivisible, and hence unthinkable by the human mind. Both Descartes and Malebranche rejected the empiricist thesis because they erroneously thought that it would commit them to the materialist thesis that thoughts and the soul are material.  This led them to adopt the intellectualist thesis regarding the mind’s perception of metaphysical essences. However, Desgabets saw a third option, one which is founded on the mind-body union and the sensory basis of all knowledge, and one which founds the proper sense of the empiricist motto, that all ideas originate by the senses.