Faith and understanding - Part I St Anselm's proof of God's existence

1.A proof of God’s existence

What, then, can be proved and what does all of the above have to do with God? Statements whose truth is entailed by the meanings of their terms can be proved. ‘A triangle has three sides’ and ‘a single man has no relationship’ are true in virtue of the terms ‘triangle’ and ‘single’ Mathematical theorems can also be proved. It can be demonstrated that  Pythagoras’ Theorem, a² + b² = c² the square of the hypothenuse is equal to the square of the sides, is true.

For our present purposes the former kind of proof is more relevant. The truth of a proposition can be shown to follow from the meaning of its constituent terms. Seeing the truth of this kind of proposition is the same as understanding the meaning of the terms that constitute it. To understand what a triangle is, is the same as understanding that it has three sides. To know that it is true that a single man or woman has no relationship is to understand the concept a single.

In this respect God is just like singles and triangles. To understand the concept God is to understand that he exists.

The eleventh century theologian and philosopher St Anselm of Canterbury showed this by what may be summarized as the following argument.

(1)Let us say that God is something such that nothing more perfect (“greater”) than it can be conceived.

(2)It is more perfect for something to exist than not to exist

(3)God is the most perfect being. (by 1)

Therefore God exists.

By definition God must exist. The concept of God semantically entails existence. That is to say that it follows from the idea of God’s perfection that He exists. For something to be perfect is for it to exist. One would not call a drink of wine perfect if the wine was imaginary rather than real.

         For a clear understanding it is of some interest to consider Anselm’s argument a little more precisely.

(1)Let us say that God is that more perfect than which cannot be conceived.

(2)We have a certain idea, a notion in our minds, of God, namely that than which nothing more perfect can be conceived.

(3)To have an idea of something is not the same as knowing that it exists.

After all I may very well have the idea of a pink flying elephant, but I do not on that count know that it exists. How, if at all, is God different in this respect?

(4) If something exists only in the mind, then something more perfect can be conceived of, for something that also exists outside the mind is more perfect than something that exists only inside the mind.

(5)God, however, is the most perfect being.

(6)For something that is perfect to exist only inside the mind, implies a contradiction: it would make God both perfect and imperfect.

(7) God exists outside the mind too.

(8) Therefore God exists.

All of the above argument can be found in chapter 2 of the Proslogion which can be found here: http://www.fordham.edu/halsall/basis/anselm-proslogium.asp

In chapter 3 Anselm adds an important remark. “That which can be conceived not to exist is not God”. There are many beings whose concept does not include existence. This is the case for all contingently existing beings. Both individuals and species of one kind or another may not have existed, that is to say, it is not part of their concept that they exist. One could perfectly well have the idea of a horse if there were no horses, just as once can have the idea of a flying pink elephant. To have the idea of God, however, is to have the idea that He exists. If one were to have the idea of a non-existing God, the idea of a still more perfect being would be conceivable. But it is by definition impossible for something to be more perfect than God.

         Many arguments have been devised against Anselm’s proof. I’ll consider some of these objections next. Then I’ll consider the very idea of the proof of God’s existence and another way of thinking about faith in God.