The Ontological Argument of St. Anselm is an a priori argument; it is formulated through reason alone, rather than experience. This argument does not rely on external evidence or sense experience. It is deductive (universal to particular) as it draws from its argument purely from a set of premises. In the 11th century, St. Anselm presented his argument for the existence of God in his published work, the Proslogion. His work was based on 4 premises which led to the conclusion that God must exist. His 1st premise was that he defined God as to mean “that than which nothing greater can be conceived.” For him God is the greatest conceivable entity. He also asked what is greater: God as an idea or God as in existing thing? St. Anselm stands for this: that “God as an existing thing” because existence means perfection, like it is better to exist than not to exist. Therefore, God exists. Since existence is a part of the definition of God, God doesn’t just exist, He exists necessarily. It means that it is impossible for God to stop existing or not to have always existed. The 2nd premise of St. Anselm was that both believers and non-believers accept this even “the fool” in Psalm 14. His 3rd premise was that it is possible to exist either just in the mind, or in both the mind and reality. In his 4th and last premise, he said that it is better to exist both in the mind and in reality. Therefore, St. Anselm came up with this conclusion that God must both exist in the mind and in the reality.
Gaunilo, the Benedictine monk, was not totally convinced in St. Anselm’s argument and propositions. Hence, he came up with this critique about the work of St. Anselm. For him, this argument will lead to absurd consequences. Gaunilo said that it allows us to define all sort of things into existence. This means that if we imagine the most perfect thing, then it exists. For him it was a faulty argument. Gaunilo used the analogy of a perfect island to