What are Anselm’s aims in the ontological argument?
What definition of God does Anselm’s argument depend on?
Answer by Tony Fahey
Anselm’s argument for the existence of god is called the ontological argument, and can be found in chapters two and three of his Proslogion. Very roughly, his argument, or definition, goes like this: god is the most perfect being; it is more perfect to exist than not to exist; therefore god exists. It should be said that Anselm was a monk and bishop of Canterbury who held that faith is prior to and provides the context for understanding. Thus, for Anselm, it is not the case that we understand first in order to believe, rather it is that we believe in order to understand. According to Anselm, if God is defined as a being than which nothing greater can be conceived or thought, then God must exist, since it is greater to exist in reality than just in the mind as notional or conceptual
One of the earliest critics of Anselm’s ontological proof was his contemporary Gaunilo (also a monk), who, in his Liber pro Insipiente, opposed it on the grounds that humans cannot pass from intellect to reality. According to Gaunilo, Anselm’s argument would imply that anything, no matter how fictitious or chimerical, which was thought in the mind, would have to exist in reality. To prove his point Gaunilo uses the example of an ‘island more blessed than any other, a perfect island… greater than which nothing greater can be conceived’. Given Anselm’s ‘proof’, he argues, if one can conceive of such an island in this way, then it follows that such an island must exist in reality as well as in the mind – this, of course is absurd. In his defence, Anselm claimed that his argument applied exclusively to God.