1637–1641

Descartes: Method, the "Cogito" and Cartesianism in Theology

Descartes's method (Discourse on Method, 1637; Meditations, 1641) starts from universal doubt about sensory knowledge together with the absolute certainty of purely rational knowledge; doubt is not skepticism but a sieve. From "cogito, ergo sum" he passes to God, proving his existence from the idea of an infinite and perfect being, and then establishes the existence of the world and the body. Grenz and Olson write that the thinking subject, not revelation, became the starting point of philosophy. Descartes did not wish to deny the faith, but most Catholic theologians condemned his method. Some theologians adopted Cartesianism: Wittich (1659) and Malebranche, who taught that all ideas are known in God and that God is the only efficient cause.