Anselms Ontological Argument

As a theologian and philosopher, Saint Anselm strove to prove the existence of God in reality. The bulk of his argument is found in Chapter II of Proslogium.

Anselm begins by defining God as “a being than which nothing greater can be conceived';. He continues by stating that “even a fool'; has the capacity to understand this definition of God and that whatever is understood exists in the understanding. Anselm now draws his first intermediate inference based on these initial premises; God must exist in the understanding, and is therefore a possible being. Aneselm next draws on the premise that if something exists in reality, it is greater than if it exists in the understanding alone. At this point in his argument Anselm switches tactics and supposes that God exists only in the understanding. Based on the former premise this would mean that is possible that God (had He existed in reality) might have been greater than He is (existing only in the understanding). Based on that supposition, God is not the being than which none greater is possible. If Anselm’s initial definition of God is substituted into the previous inference, it becomes a contradictory statement: the being than which none greater is possible is not the being than which none greater is possible. Therefore Anselm supposition that God exists only in the understanding is false. By proving this to be invalid Anselm has, in effect, proven that God must exist in the understanding and real...