The Intersections of Knowledge: Hobbes, Mersenne, Descartes

Abstract Gregorio Baldin’s book, La croisée des savoirs , concerns the intellectual relations among Hobbes, Mersenne, and Descartes. The study is limited to the time between 1634 and 1648, starting when Hobbes first met Mersenne in Paris and ending when Mersenne died. It covers three main topics. Part i is devoted to the relations maintained by Hobbes with the circle of Mersenne during 1634–1636, which Baldin thinks are essential for the development of Hobbes’ scientific thought. Part ii develops the theme of the “hidden” influence of Mersenne on Hobbes’ thought, highlighting points of contact between the two authors, such as mechanism, research in optics, and their approach to epistemology. Part iii concerns Hobbes’ influence on Mersenne’s thought. It addresses several themes, starting with Mersenne’s interest in Hobbes’ system, the attitudes of Mersenne, Gassendi, and Hobbes toward Cartesian metaphysics, and ending with scientific themes debated in Mersenne’s circle during the 1640s.