Anselm's Subtle Proof of God's Existence

Dan Graves, MSL
Anselm's Subtle Proof of God's Existence

When St. Anselm died on this day, April 21, 1109, the church was poorer by a great mind and England by a zealous reformer. Anselm won a name for reform because he attempted to end abuses such as the slave trade. He urged the holding of regular synods and, while he was archbishop, enforced clerical celibacy within his see. Because of his powerful intellect, some scholars consider him one of the creators of scholasticism. But his most notable gift to history was what has become known as the ontological proof for the existence of God.

Can the existence of God be proven? Anselm thought so. Modern philosophers and theologians disagree. However, it is Anselm's argument, the ontological proof, which remains the most troublesome for them to disprove.

Anselm's argument went something like this: When we discuss the existence of God, we define him as a perfect being, greater than anything else which can be conceived. If God does not exist, then the name "God" refers to an imaginary being. This makes the definition of "God" contradictory, for to be real, to be living, to have power is greater than to be imaginary. It is clear I cannot even discuss the word "God" as defined if he does not exist, because I have to conceive of him as really existing in order for him to be greater than anything else, for a God who does not exist is not greater than anything else.

In short, no philosopher can legitimately argue that God does not exist if he defines God as a perfect being greater than any which can be imagined; for to be perfect, God must have real existence. Those who acknowledge He exists do not have a problem with self-contradiction when they affirm his existence. Since we can indeed raise the question of God's existence and argue the point, then God must exist. Bertrand Russell, one of the greatest logicians and mathematicians of the Twentieth Century, no friend of Christianity, grappled with Anselm's proof and at one time is said to have thought the proof worked.

As Archbishop of Canterbury, the zealous Anselm struggled with King William for church rights. He was exiled. Similar conflict would shortly afterward lead to the murder of Becket. As a theologian, the pious Anselm is remembered for his book, Why Did God Become Man? In it he argued that each of us has run up such a debt of sin that there is no way we can repay God. Christ, as infinite God, has merit enough and to spare to pay our debts. As a scholar, the learned Anselm argued that we must believe in order to understand. We could restate his insight in modern terms like this: truth only begins to come clear when one is committed to it. You cannot see around a bend in a trail unless you walk toward it.

Anselm died surrounded by friends who placed his body in ashes on the floor. He was probably canonized in 1494, although there is debate whether this occurred at all. His beatific status aside, Anselm will long be remembered as the author of the ontological proof.


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Last updated April, 2007.

Originally published April 28, 2010.