Does the Ontological Argument prove the existence of God

The ontological argument is a deductive argument for the existence of God first formulated by Anselm in 1078. It has subsequently been called upon by famous Philosophers such as Descartes and Malcolm. The argument is as follows: Premise 1 - God is the greatest possible being which can be conceived. Premise 2 - God may exist in the mind or in reality. Premise 3 - Something existing in reality is better than in the mind. Conclusion - God must exist in reality in order to be perfectOne rebuttal of this argument comes from the Eleventh century monk Gaunilo. He gives the idea of the perfect island, this being an Island of which there can be none better. Following the Logic of ontological argument this Island must exist, as to not exist would be to portray the premise that perfection relates not only to the concept but to the concept's existence. This leads to the conclusion that the ontological argument is debunked from the shear fact that such an Island obviously doesn't necessarily exist. Furthermore this opens the possibility for the perfect concept of anything to exist, this goes on Ad Infinitum, rendering the argument false.This criticism from absurdity highlights Kant's objection, which is that "Existence is not a predicate", this being that existence is not a part of the concept of God. Existence adds nothing to the concept of God. The ontological argument adding existence to the concept of God is defining God into existence. The Ontological Argument therefore does not prove the existence of God.