Nicolas Malebranche is one of the most important philosophers of the 17th Century after Descartes. A pioneer of Rationalism, he was one of the first to champion and to further Cartesian ideas. Andrew Pyle places Malebranche's work in the context of Descartes and other philosophers, and also in its relation to ideas about faith and reason. He examines the entirety of Malebranche's writings, including the famous "The Search After Truth," which was admired and criticized by both Leibniz and Locke. Pyle presents an integrated account of Malebranche's central theses, occasionalism and 'vision in God', before exploring and assessing Malebranche's contribution to debates on physics and biology, and his views on the soul, self-knowledge, grace, and the freedom of the will. This penetrating and wide-ranging study will be of interest to not only philosophers, but also to historians of science and philosophy, theologians, and students of the Enlightenment or 17th Century thought.