%0 Journal Article %T Gaunilo's Cogito Argument %A Miroslav Imbrisevic %J The Saint Anselm Journal %D 2007 %I Institute for Saint Anselm Studies %X Gaunilo presents Anselm with a dilemma in section 7 of his Responsio: I know most certainly that I exist. But If I cannot think my non-existence at the same time, then Anselm's claim in Proslogion 3 (that my inability to think God's non-existence, while knowing most certainly that He exists, is a unique property of God) would be false. If I can do so, however, then I should also be able to know most certainly that God exists and, at the same time, think his non-existence. I will show that Anselm's response to Gaunilo's attack is not adequate because it does not address the issue of certainty, which is at the heart of Gaunilo's objection. %K Gaunilo %K Cogito %K Certainty %K Ontological Argument %K Anselm %U http://www.anselm.edu/Documents/Institute%20for%20Saint%20Anselm%20Studies/Abstracts/4.5.3.2c_51Imbrisevic.pdf