The first ontological argument in Western Christian tradition was proposed by Saint Anselm of Canterbury in his 1078 work, Proslogion (Latin: Proslogium, lit. 'Discourse [on the Existence of God]'), in which he defines God as "a being than which no greater can be conceived," and argues that such a being must exist in the mind, even in that of the person who denies the existence of God.

citation

Wikipedia contributors. (2024, February 21). Ontological argument. In Wikipedia, The Free Encyclopedia. Retrieved March 14, 2024, from https://en.wikipedia.org/w/index.php?title=Ontological_argument&oldid=1209431684

Ontological argument (Wikipedia) An ontological argument is a philosophical argument, made from an ontological basis, that is advanced in support of the existence of God. Such arguments tend to refer to the state of being or existing. More specifically, ontological arguments are commonly conceived a priori in regard to the organization of the universe, whereby, if such organizational structure is true, God must exist.