The Argument for Cartesian Dualism
Today we only had time to look at a small but important part of Part IV of the Discourse, where Descartes tries to pull Cartesian dualism out of the cogito: the ‘I’ in the ‘I think’ is essentially a thinking thing, and distinct from the body.
If you found this topic interesting, you probably should read Descartes’s more developed exposition of this idea in Meditation Two of the Meditations on First Philosophy. You might also find interesting Louise Derksen’s paper on Anne Conway’s Critique of Cartesian Dualism (Conway is an early modern philosopher who had a number of interesting and unusual ideas). The argument against Cartesian dualism that is most often accepted is usually regarded as the same as one given by Princess Elisabeth of Bohemia in her correspondence with Descartes (she, however, did not propose it as an objection but as a puzzle that she was hoping Descartes could solve). The correspondence is online in French, but, unfortunately, not in English. However, this paper by Deborah Tollefsen is an excellent overview of Elisabeth’s argument (Tollefsen also argues that Elisabeth’s primary argument is different from the one usually attributed to her, which I think is correct.) Bruce Hauptli’s lecture supplement is a simpler, shorter summary of the basic points.
