Proslogion (The Ontological Argument)
Anselm of Canterbury · 1078
Anselm's celebrated argument that God, understood as that than which nothing greater can be conceived, must exist in reality.
And so, Lord, do thou, who dost give understanding to faith, give me, so far as thou knowest it to be profitable, to understand that thou art as we believe; and that thou art that which we believe.#
And, indeed, we believe that thou art a being than which nothing greater can be conceived. Or is there no such nature, since the fool hath said in his heart, there is no God?#
“Hence, even the fool is convinced that something exists in the understanding, at least, than which nothing greater can be conceived.”#
And assuredly that, than which nothing greater can be conceived, cannot exist in the understanding alone. For, suppose it exists in the understanding alone: then it can be conceived to exist in reality; which is greater. Therefore, there is no doubt that there exists a being, than which nothing greater can be conceived, and it exists both in the understanding and in reality.#