Ontological argument
Anselm:
If we accept God as the most perfect being in our minds, then he must exist, because if he did not exist in reality, he would not be perfect
His existence is also necessary
If he could leave existence, then he would not be perfect, as a more perfect being would never leave existence. Therefore, given he is perfect, he must be unable to leave existence
If he could come into existence, without having existed beforehand, he would not be perfect, as a more perfect being would be one that has always existed. Therefore, given he is perfect, he must have always existed
Gaunilo's response to anselm
You can use this argument for anything, if you argue that it is perfect, and then in order to be perfect it must exist
He uses the example of an island, making the case that, if you imagined an island that was perfect,it must exist, because it would be less perfect if it did not exist
Anselm's response to Gaunilo
The island's existence is contingent, it is probable that it can both exist and not exist, because it is reliant on other things e.g sea etc, whereas god is independent and his existence is not contingent, but necessary
The island does not possess maximal qualities e.g it could have more fruit, better scenery, it could always be technically improved. In contrast God possesses maximal qualities and therefore is the only truly perfect thing, meaning he must exist
Descartes support of Anselm through definitions
argues that the definition of God assumes existence, it is within God's own definition that he exists, in the same way that within the definition of a triangle it includes that it has 3 sides
Kant
First objection
second objection
Stating that ‘God does not exist’ is not a contradiction. Unless we assume that an object exists in the first place, we cannot make contradictory statements about it.
Brian Davies Reply to Kant
Anselm is not so much saying that a denial of God is a contradiction. Rather, he is suggesting that the greatest conceivable being cannot exist merely in the mind. There is a difference.
“Existence is not a predicate”. Saying that X exists does not add real information about X, because by talking about X in the first place we assume that X does indeed exist.
Brian Davies Reply to Kant
Existence is a meaningful predicate when applied to an object which can be conceived of as existing or not existing. Anselm’s argument is about the real existence of the God which exists in the intellect.