Anselm of Canterbury

Anselm of Canterbury was the first medieval thinker to argue that faith could be reasoned about, not only confessed. His question was simple — faith says God exists, but can the why be put into words? His answer survives as the ontological argument of Proslogion chapter 2, which logicians still both attack and defend a thousand years later.

Born in 1033 in Aosta in northern Italy, then in the Burgundian kingdom of the Holy Roman Empire, Anselm grew up between a Lombard noble father and a devout Burgundian mother. From her he absorbed gentle piety and the conviction that became his motto: to love God so much that one must understand. At fifteen he wanted to enter a monastery; his father refused. After his mother's death he left home at twenty-three, wandered through France, heard of Lanfranc at the Norman abbey of Bec, and at twenty-seven took the habit there.

His fifteen years at Bec were his intellectual peak. Prior in 1063, abbot in 1078, he wrote the Monologion (1076) and the Proslogion (1077-78). The first attempted to prove God's existence by reason alone. The second offered the famous argument: from the definition "that than which nothing greater can be thought," God must exist not only in the mind but in reality. Gaunilo objected that one could equally prove a perfect island, but the argument keeps returning — Descartes, Leibniz, and Goedel each reformulated it for their own age.

In 1093, against his own wishes, he was made Archbishop of Canterbury. The Investiture Controversy was at its peak. A mild scholar found himself in the centre of a political storm. He clashed with William II and then Henry I over the king's right to appoint bishops, and was twice forced into exile. Through it all he held the same line: the church's independence was a matter of faith, not politics.

His late masterpiece, Cur Deus Homo, argued the necessity of Christ's Incarnation by reason — and shaped medieval theology for centuries. He died in 1109, was canonised in 1494, and.