As Anselm argues, there can be only two possibilities regarding the existence of God: either God exists in reality or there is no God at all. There can be no disputes on the fact that the idea of God is best perceived as a cognitive concept, which conceives the notion that God is the most perfect being possible and the greatest one ever conceived. Further, Anselm states that things that exist in reality are always greater than those that exist in the mind. At the same time, if we assume that God exists in reality, then we can also conceive of a God that exists in reality. The existence of God, in reality, is one thing and the understanding of this concept is another. Anselm clarifies this statement with a simple example,
“When a painter…thinks out …what he is going to paint, he has it in his understanding, but he does not yet understand that it exists…once he has painted it, he both has it in his understanding and understands that it exists.” (Cahn 381)
The same argument can be implied for the existence of God too. When we conceive in our mind that God exists, it is still a concept as we have not yet believed that God exists in reality. But once we believe in the existence of God in reality, we can both conceive of God as the greatest. .Aquinas’ third proof incorporates the nature of possibility. He argues that it is possible for things to exist or non-exist, however, it is impossible for all things to exist eternally. Further, if things exist, then it is also possible that there is a beginning point of everything – this is what is known as God. Nature includes things that are possible to exist or non-exist because they can be generated or destroyed.