René Descartes's philosophical importance for the advent of the modern scientific age is matched only by the difficulty of fully evaluating what his doctrines imply for religion. Born in Poitou, France, in 1596, Descartes lived most of his adult life in Holland, incurring the opposition, but also gaining the support, of Catholics and Protestants alike. He died in 1650 in Stockholm, where Queen Christina of Sweden had invited him to reside and instruct her in philosophy.

In his lifetime, he published works in both French and Latin, aimed at two slightly different audiences: Discourse on the Method of Rightly Conducting Reason and Reaching the Truth in the Sciences (French, 1637), Meditations on First Philosophy (Latin, 1641), Principles of Philosophy (Latin, 1644), and Passions of the Soul (French, 1649). Descartes also left unfinished works, notably Rules for the Direction of the Mind (Latin),...