"We all have an idea of God. We understand what ‘God’ means,
whether or not we believe that God actually exists. No doubt
you are thinking about your idea of God now. That seems
very different from saying that God actually exists. Anselm
(c.1033–1109), an Italian priest who later became Archbishop of
Canterbury, was unusual in that with his Ontological Argument
he claimed to show that, as a matter of logic, the fact that we
have an idea of God proves that God actually exists."