The ontological argument was first formulated by St. Anselm in the 11th century. It argues the existence of God from a deductive and a priori stance. God is a being than which none greater can be conceived. This is the response given by St Anselm to the fool in the psalm who believed there was no God. St Anselm the Archbishop of Canterbury and of the Benedictine Order explained that for God to exist in the mind he would not be the greatest being. However were God to exist in the mind and reality this would make a being ‘than which none greater can be conceived’, this means God must exist.
This demonstration for the existence of God was immediately criticised by his contemporary Gaunilon. He argued that Anselm’s argument could easily be used to prove the existence of many different beings or even places. In Gaunilon’s ‘response on the behalf of the fool’, he argued that he could conceive of a perfect island ‘blessed with all manners of delight’, yet it did not mean it must exist. However, Anselm responded to this claim arguing that a perfect island contains contingency; it is dependent, whereas God possesses aseity, is self-sufficient. This means that God’s existence is therefore, necessary, independent.
Descartes famously wrote his version of the ontological argument in the ‘Meditations’ in which he argued that God is an infinite being, perfect. For God to remain perfect he must then retain existence. He used the illustration of a triangle with three angles which all add up to 180 degrees. This quality of the triangle allows the triangle to be perfect and to be defined as a triangle. If the angles were taken away from the triangle it would no longer be a triangle. This is similar as to God; he could not be God if he did not exist. This proves according to Descartes that God’s existence is necessary.
But, it can be argued that the ontological argument is using an