Anselm of Canterbury
1033 — 1109
A Benedictine monk and theologian who became Archbishop of Canterbury, Anselm is widely credited as a founder of Scholasticism for his method of applying philosophical reasoning to faith. He articulated the ontological argument for God's existence in the Proslogion and formulated the satisfaction theory of Atonement in Cur Deus Homo — all while defending the Church's independence against English kings.