This is a talk about the foundations of physics and classical mechanics in the 18th century, and more specifically the problem of bodies and the theory of constrained motions. At the beginning of the 18th century, physics and rational mechanics were distinct disciplines but they shared a common object of theorizing: bodies. I argue that the search for an adequate theory of bodies in motion was a foundational problem for both, one whose solution demanded a “philosophical mechanics”. The first half of the 18th century was dominated by constructive approaches to this problem, as exemplified by Du Châtelet in her Foundations of Physics. However, new work on constrained motion mid century changed the problem space: I explain why, and with what consequences. Within this context, I present d’Alembert’s Treatise on Dynamics as offering a principle approach to the problem. This serves two philosophical purposes: it opens up new questions about d’Alembert’s attempted axiomatization of mechanics, and it shows the significance of his Treatise for the problem of bodies.
Philosophy of Physics Seminar Convenor for HT22: Oliver Pooley | Philosophy of Physics Group Website