In the two arguments between Anselm and Gaunilo on the existence of god, I am more convinced by Anselm’s argument. Reasoning being is that Anselm defines god as something than in which nothing is greater conceived. For someone to understand the claim that god exist, it cannot go together with someone who does not believe god exists. If god only exist in the mind then you can imagine something greater than god. But if the concept of god not only exist in the mind, but also in reality, then god truly exists. Gaunilo’s counter argument of a parallel proof on the idea of the greatest lost island that he conceived must mean that it exist in the reality because it exist in his mind. However, Anselm argues that the greatest lost island only exist