The Cartesian background: England and France

Abstract The 17th and 18th century opposition between Cartesian and Newtonian science is often depicted as a contest between a priorism and speculation on one hand, and observation and mathematical proof on the other, one of which won out. This is a simplification. In 17th century England Cartesian natural philosophy, including the vortex theory of the planetary orbits, was (intentionally) easy to understand. It was seen however as poorly disguised atheism and widely disparaged on that account by influential theologians. Amongst the 18th century French philosophes, this aspect of Cartesianism was hardly a problem. Newtonianism now denoted an appetite for exciting experimental demonstrations as against the dead letter of scientific books, including not only René Descartes’s Principles but also Isaac Newton’s (for most readers) largely impenetrable Principia .