Émilie du Châtelet: Balancing the Plenum and the Void

Ruth Hagengruber ()

Abstract: The struggle to grasp the metaphysical foundation of the natural world was most intense when Émilie du Châtelet (1706–1749) entered the philosophical scene. Voltaire derided Descartes’ mechanist view of the world, which was filled with vortices, and Newton posited occult forces that moved the planets in the void. The explanation of motion, from where it came and how it could be explained, stoked the debate while advancing the limits of our knowledge of the natural world.

Rejecting the ill-conceived ideas of Cartesian intuitionism and criticizing John Locke’s “muddled” ontology, du Châtelet presented in her discussion of the foundations of physics a model of constructive reasoning, which provided an understanding of how the notion of space emerged and how matter related to processes of abstraction. Furthermore, she argued that her model was compatible with the claim of the invariability of force in the universe.

This talk introduces the work of du Châtelet and focusses on the metaphysical debates surrounding the possible ground of natural philosophy as well as the nature of movement. During her lifetime, the Foundation of Physics was translated into several languages and was included in the canon of the most important books of her age. Kant wrote his first publication on her dispute with the secretary of the French Academy on the vis viva. Her definitions of “space” and “hypothesis” were extensively copied, for example, in the Encyclopedia of Diderot and D’Alembert. Du Châtelet was an influential figure in the Leibniz-Newton debates about nature, and she was an inspiring philosopher to her contemporaries.