Ontological Argument

Ontology - The branch of metaphysics that studies the nature of existence or being as such. One of, if not, the first ontological arguments came from Anselm of Canterbury. He defined God as the greatest possible being we can conceive and argued that this being could exist in the mind. He suggested that, if the greatest possible being exists in the mind, it must also exist in reality. If it only exists in the mind, a greater being is possible - one which exists in the mind and in reality. In more layman terms, God is a perfect being. A perfect being must have all perfections. Existence is a perfection. Therefore, God must have existence. God must exist. To deny this is self-contradictory.

refutation :

<p class="reply">This was first refuted by Gaunilo of Marmoutiers using The Perfect Island argument. If we were to name this perfect island Serenity, and simply inject Serenity in place of God and replace being with island, we'd come to the conclusion that Serenity must exist, which it doesn't. It's a false conclusion and therefore Anselm's reasoning is flawed.
</p>

You are the 204th visitor