Anselm of Canterbury

Life

Anselm was born in 1033 in Aosta (in what is now northwestern Italy). After years of wandering, he entered the Benedictine monastery of Bec in Normandy around 1060, studying under Lanfranc (later Archbishop of Canterbury). Anselm succeeded Lanfranc as prior and then abbot of Bec, where he composed his most important philosophical works. In 1093, he reluctantly became Archbishop of Canterbury, a position that embroiled him in political conflicts with the English kings William II and Henry I over the investiture of bishops.

Anselm's philosophical writings are marked by extraordinary originality and a commitment to 'faith seeking understanding' (fides quaerens intellectum) — the attempt to use reason to understand what faith already believes, without depending on Scripture or authority as premises.

The Ontological Argument

In the Proslogion (1077–78), Anselm formulates his famous argument:

1. God is defined as 'that than which nothing greater can be conceived' (aliquid quo nihil maius cogitari possit).
2. Even 'the fool who says in his heart there is no God' understands this definition — the concept exists in the understanding (in intellectu).
3. But a being that exists both in the understanding and in reality (in re) is greater than one that exists only in the understanding.
4. Therefore, if 'that than which nothing greater can be conceived' exists only in the understanding, then a greater being could be conceived — one that also exists in reality.
5. But this contradicts the definition. Therefore, 'that than which nothing greater can be conceived' must exist in reality.

The monk Gaunilo immediately objected with the 'perfect island' parody: by the same logic, we could prove the existence of the greatest conceivable island. Anselm replied that the argument applies only to a being whose non-existence is inconceivable — i.e., a necessary being — and islands are not of that kind.

The argument has been criticized by Aquinas, Kant, Frege, and Russell, and defended by Descartes, Leibniz, Gödel, and Plantinga. It remains one of the most fertile arguments in philosophy of religion.

Other Works

Anselm's Monologion (1076) offers cosmological and design-style arguments for God's existence. Cur Deus Homo (1098) develops the 'satisfaction theory' of the atonement — the most influential medieval theory of why God became human. De Veritate explores the nature of truth and its relationship to justice.

Legacy

Anselm died in 1109 and was canonized in 1494. His combination of deep religious devotion with rigorous philosophical argumentation established the template for Scholastic philosophy. The ontological argument continues to generate philosophical literature — Plantinga's modal version (1974) and Gödel's ontological proof (published posthumously) are modern descendants.