Abstract

Descartes spent over 30 years commenting on the phenomenon of gravity. His attempts to explain gravity in his early private notes, his early letters up to the writing of Le Monde are subject to a clear development. This development is not merely of interest in the history of science, but also promises to shed light on those reasons that led him to reject the scholastic terminology on which he had based his early explanations. This is especially true of the concept of real quality, which is central in this context. It will be seen that Descartes justified his rejection of this concept at different times with quite different arguments. In doing so, I would like to correct a view that is sometimes suggested, if not explicitly put forward, in studies of Descartes' relationship to the scholastic vocabulary: Descartes rejected this vocabulary because of ontological reservations. This misinterpretation also seems to me to underlie Gilson's investigation. To illustrate the development of Descartes' attitude towards traditional ontological terminology, I will first consider the early statements in which Descartes conceives of gravity as a real quality. In a second step, I will examine the period around 1630, when Descartes arrived at a mechanistic conception of gravity. What were the reasons for Descartes abandoning his old conception? In a third step, I will look at the statements from the 1940s in which Descartes discusses gravity as an example of a real quality, a category that no longer has a place in his ontological considerations.