Amber Rose Carlson

When considering the nature of the human being, Descartes holds two main claims: he believes that the human being is a genuine unity and he also holds that it is comprised of two distinct substances, mind and body. These claims appear to be at odds with one another; it is not clear how the human being can be simultaneously two things and one thing. The details of Descartes' metaphysics of substance exacerbates this problem. Because of various theological and epistemological commitments, Descartes frames his metaphysics of substance in a way that ensures mind and body's real distinction from one another. Articulated from this perspective, the problem becomes one wherein it is not clear that two completely separate substances can come together to form one entity. The aim of this thesis is to show how Descartes can hold real distinction and true union without contradiction. To this end, I will first detail the problem and outline a variety of solutions that have already been presented. Then I will outline important concepts relating to Descartes' metaphysics of substance and attributes. This not only reveals the depth of the problem but also lays the groundwork for my proposed solution. I argue that the key to understanding how these two claims are consistent and in accord with Descartes' philosophy is through a comment Descartes makes to his contemporary Henricus Regius where he urges that the union of mind and body is achieved through a "mode of union." I substantiate this claim by arguing for the intelligibility of understanding union as a modal attribute within Descartes' framework. Finally, I show how Descartes can hold real distinction and true union with consistency. When union is understood as a mode, mind and body are able to exist apart from one another, ensuring real distinction. Moreover, union construed as a mode does not allow the complete separability of mind and body. Thus, when united, mind and body achieve the kind of unity Descartes desires for the human being