Born in the year 1033 A.D near Aosta, a small region in Italy, Anselm would spend his days teaching until becoming enthroned as the archbishop of Canterbury in 1093 and served until his death in 1109. Although his tenure would be unsmooth do to controversy with secular kings, Anselm is often renowned as the father of the scholastic tradition. His most popular contribution to theology and philosophy, the “Ontological Argument”  (his argument for the existence of God), is presented in his “Prosologion”, a complicated meditative prayer written for his fellow monks and intended for spiritual reflection and guided inquiry. 

Reason over Devotion

The argument is presented as Anselm anticipates the objection of a skeptic who does not believe that there is a God. From Anselm’s perspective, God has already revealed himself, and now he must construct an argument for the proof of God that relies on reason alone, given that non-believers will be unaided by faith and devotion when seeking God.   

Two Understandings

Before the argument is completely unfolded, a crucial distinction is asserted. It is one thing to know of the existence of an object in the understanding and a separate thing to understand an object’s existence. Anselm uses the analogy of a painter; the painter has the object of his future painting in his understanding before it is painted. After it is painted, he has both the understanding of the painting in his mind and the understanding of its physical existence (as the painting is now completed and in front of him). 

The Trick

Anselm and the non-believer both understand god to be this.

“A being than which nothing greater can be conceived,”

Anselm then argues that by virtue of our understanding of the definition of God, he must necessarily exist. By this point, you have already recognized the trick. He leverages our cooperation in accepting his definition of god as the greatest being, which means that in order for him to truly live up to said definition, he cannot merely exist in our understanding. God must exist in reality because he is greater than the existence he may possess in the understanding of somebody. 

Gaunilo’s Perfect Island

Despite its wit, Anselm’s argument is recognized as weak. Unsurprisingly, atheists do not convert on the spot when faced with such persuasion, and this is for multiple reasons. The main being that Anselm’s argument provides an illegitimate means for proving the existence of anything. This point was best articulated by a monk named Guanillo, who responded to Anselm with his “perfect island ” analogy. This argument poses the idea of a perfect island, described with attributes like the softest sand and the bluest water. However, in reality, it ceases to exist. Just because something is described as maximally great, does not mean that it exists even if our understanding of its nature forces us to conclude so in reason.