Anselm's proof of the existence of God is an excellent representation of the religious philosophy of his time:

Well, then, Lord, You who give understanding to faith, grant me that I may understand, as much as You see fit, that You exist as we believe You to exist, and that You are what we believe You to be. Now we believe that You are something than which nothing greater can be thought. Or can it be that a thing of such a nature does not exist, since "the Fool has said in his heart, there is no God"? [Psalm 14.1] But surely, whenthis same Fool hears what I am speaking about, namely, "something-than-which-nothing greater-can-be-thought," he understands what he hears, and what he understands is in his mind, even if he does not understand that it actually exists. For it is one thing for...