Philosophical Proofs for the Existence of God

St. Anselm believed that if one can think of a being "than which no greater can conceive", then one can conceive of such a being which exists in reality as well as in the mind. However, Kant believed that the assumed notion of an absolutely necessary and unconditioned being lacks intelligible content since merely holding the idea does not guarantee that non-existence of such a being is impossible.

In the Critique of Pure Reason, Kant dismisses the ontological proof for the existence of God which is based upon the premise of an absolutely necessary existence arising out of reason and the mere idea or possibility of objective reality of God. His objections are based on three premises: first, that existential propositions such as existence claims are not analytic but synthetic (arrived at conceptually); second, that existence is not a predicate (is and being are not quantifiers), and third, that negative existentials are never self-contradictory (atheists can conceive that there is no perfect being if they believe there is no God).

According to Kant, we cannot give meaning to the concept or arrive at the conclusion that God as a being necessarily exists, since neither the subject "God" nor predicate "exists" or "is almighty" can have necessity, but the concept can only be arrived at by judgments made which are ascribed to the predicates. Judgments are hypothetical and are merely assertions derived at when no denial is made of a being's possible existence. The ontological argument commits the fallacy of "begging the question" by assuming that such a being exists in fact when there might be alternative possible explanations or no existent being at all.