Engagement with Voltaire and the Enlightenment

One of the defining moments of Du Châtelet’s intellectual career came in 1733, when she met the philosopher and writer Voltaire (François-Marie Arouet). The two became close collaborators and lovers, with Voltaire greatly appreciating Du Châtelet's intellect and sharp analytical mind. Their relationship spanned more than 15 years, and together, they discussed, debated, and wrote about a variety of topics, particularly science, mathematics, and philosophy.

Voltaire was instrumental in supporting Du Châtelet’s studies, particularly in her work on the ideas of Isaac Newton. Although Newton’s work was well-known in England, it was less familiar in France, and Du Châtelet’s translation and interpretation of Newton’s Principia Mathematica (Mathematical Principles of Natural Philosophy) helped make the English scientist’s groundbreaking work more accessible to a French-speaking audience. Her translation was not just a simple rendering of Newton’s words, but also a critical commentary that clarified and expanded on the concepts, making the work more understandable to those unfamiliar with Newtonian physics.

Major Contributions to Science and Philosophy

Du Châtelet’s contributions to science were profound, and her work in physics, particularly her interpretation of Newtonian mechanics, marked her as a leading intellectual of the Enlightenment. One of her key achievements was her work on energy and the law of conservation of motion. She demonstrated that the energy of a moving body depends on both its velocity and mass, an insight that prefigured the modern understanding of kinetic energy.

Her most important philosophical work, Institutions de Physique (Institutes of Physics), which was published posthumously, provided a comprehensive account of the physical world and the fundamental principles governing it. It combined empirical observations with mathematical reasoning, an approach that was uncommon at the time and placed Du Châtelet at the forefront of scientific thought.

In addition to her work on Newtonian mechanics, Du Châtelet also made significant contributions to the philosophy of science. She was deeply influenced by the ideas of René Descartes, but she also critiqued aspects of Cartesian physics. For instance, Du Châtelet rejected Descartes’ notion of "vortex theory" and instead supported a mechanistic view of nature that was more in line with Newton’s approach to explaining the forces of nature through universal laws. This marked a significant departure from the prevailing Cartesian tradition in French philosophy. shutdown123