Before you begin you need to know a bit about the man.
In addition to all the dates of birth and death etc, remember that the Anselm was essentially a monk and a priest. He lived his life within a believing monastic community. What we now call a “proof of the existence of God” was for Anselm part of a prayer. In our criticism of Anselm we may doubt and debate his main premise that God is “that, than which no greater can be thought to exist.” But for Anselm, living a thousand years ago, within a community who believed and never doubted the existence of God, this statement would not have seemed out of place or unusual.
Try this as a way in to the discussion. Click the picture to view a Powerpoint
Don’t forget this is an a priori argument, which relies totally on reasoning.
He starts with a Psalm. The fool has said in his heart, “there is no God”. But even the fool knows what the term “God” means. So, reasons Anselm, God exists in the mind of the fool.
Anselm begins with a premise. He tries a statement that sums up what might describe God. God is that, than which no greater can be conceived.
To look at two ideas, existence in the mind and existence in reality. “Which” asks Anselm is better, to exist in the realms of thought ie the mind or to exist in reality? The obvious conclusion is that it is greater to exist in reality than simply in the mind
If God is that than which no greater can be conceived, he must exist therefore in reality and not just in the mind. So God exists in reality
Gaunilo was also a monk who lived at the time of Anselm. Obviously he believed in God, but he was unhappy with Anselm’s argument for two reasons.
Gaunilo’s first objection – He disputes whether God exists in the mind of the fool. He may understand the meaning of the word “God,” but because he uses the word in a meaningful way, it does not imply that God exists in the man’s mind. He simply knows the meaning of the word and nothing else.
His second objection is about existence in reality being better than existence in the mind. Gaunilo talks about a perfect lost island. He imagines a perfect island and all the lovely things on it. But that does not mean that such an isalnd exists. Good point Gaunilo.
Anselm’s response to Gaunilo
Anselm maintains that one cannot compare an island with God. Gaunilo’s island is a contingent obect. It would be observable. God is not a contingent being he is a necessary being.
Gaunilo’s argument looks attractive and he does point out well that it is possible for something to exist purely in the mind. One does not alway have to have a reality in existence. For example everyone has an idea about unicorns. We know what the are supposed to look like and a child might well draw a picture of a unicorn, butof course in reality they do not exist. Gaunilo’s mistake is to place a contingent object alongside a necessary being and assume that the two can be treated in exactly the same way.
Anselm’s second argument
There are some things which exist and can be thought not to exist – that would include, you, me, all the objects in the room in which you are sitting etc.
So there must be things which exist which cannot be thought not to exist – that is quite a difficult one an not easy to say what Anselm had in mind. Some people talk about abstract ideas like love and beauty. Others go for basic elements of the universe. In fact Anselm probably didn’t have either of these two areas in mind. He might well have seen the second sentence as a logical opposite of the first.
Clearly God, who is that than which no greater can be conceived, must go in the second category.
Therefore God necessarily exists.