The Scientific Revolution Devours Its Children: The Legacy of Descartes in the 18th Century

Anton Matytsin

Stanford University

René Descartes’s first supporters were extremely effective in promoting his metaphysics and natural philosophy despite the opposition from traditional intellectual authorities. They managed to penetrate both university curricula and new scientific societies in the second half of the 17th century. His distant disciples in the 18th century, however, were far less successful in continuing the initial triumph of the Cartesian philosophy in the French-speaking world. By finding themselves on the losing side of debates about the origin of human ideas, about the theory of animal cognition, and about the structure of the cosmos, Descartes’s distant disciples largely failed to defend his theories against the growing popularity of John Locke’s empiricism and Newtonian physics. The issue, however, was not just with the content of the philosophical ideas, but with how and by whom these ideas were articulated. Descartes’s metaphysical account of an immaterial soul became particularly popular among Catholic and Protestant theologians who struggled to uphold the rational demonstrability of the immortality of the human soul against materialist and fideist critiques. Similarly, his deductive method and the cogito argument were appropriated by thinkers who sought to refute the growing number of Pyrrhonian skeptics. Through the association with these apologetic thinkers, Descartes became a proxy target for philosophes such as Voltaire and d’Alembert, who openly championed his opponents Locke and Newton. They constructed narratives of the history of philosophy in order to legitimize their own intellectual projects. The philosophes depicted themselves as the rightful heirs of the so-called “heroes” of the Scientific Revolution, and they established a hierarchy of those to whom they owed their greatest allegiances. Consequently, their accounts tended to marginalize Descartes’s contributions to the alleged progress of philosophy and to the Scientific Revolution with respect to those of his English competitors. This paper will discuss these triumphalist narratives composed early in the 18th century by thinkers such as Voltaire, d’Alembert, La Mettrie, and Formey, among others. It will describe the particular strategies that the philosophes employed for appropriating specific arguments and thinkers of the Scientific Revolution in order to justify their own claims. It will compare the treatment of Descartes, on the one hand, and of his empiricist opponents, on the other. It will consider how contingent and unpredictable factors (particularly the intensification of theological debates that had little to do with natural philosophy) may have influenced the philosophical success and failure of Descartes’s theories. I will thus attempt to explain the apparent decline of Cartesianism in the 18th century.