René Descartes (1596–1650) inaugurated modern philosophy with a pair of questions that persist to this day: How are mind and matter different? and How is the mind connected to the body? He did not set out to invent these questions, but encountered them himself while on the way toward trying to do something else. He was trying to prove to the Catholic Church that rigorous philosophy was compatible with religion and that science could be both certain and compatible with religion.