Abstract

In his discussions of the Eucharist, Descartes gives prominent place to the notion of the “surfaces” of bodies. Given this context, it may seem that his account of surfaces is of limited interest. However, I hope to show that such an account is in fact linked to a philosophically significant medieval debate over whether certain mathematical “indivisibles”, including surfaces, really exist in nature. Moreover, the particular emphasis in Descartes on the fact that surfaces are modes rather than parts of bodies bespeaks the influence of the later scholastic Francisco Suárez. However, in his own contribution to the medieval debate, Suárez refrained from identifying surfaces with modes, holding instead that they are special “constituents” of bodies that differ from the parts of which these bodies are composed. Two main conclusions derive from the comparison of the views of Suárez and Descartes on surfaces. The first is that Descartes’s “modal realist” account is in fact superior to the “moderate realist” account that Suárez offers, for reasons internal to Suárez’s own system. The second is that Suárez’s reasons for refraining from adopting modal realism in this case serve to highlight a serious deficiency in Descartes’s version of this view. In this way, a consideration of the relevant Suárezian background allows us to better appreciate both the strengths and the weaknesses of Descartes’s stance on the metaphysics of surfaces.