The ontological arguments

Question 1

Anselm (reductio ad absurdum)

Answer 1

1) we have an idea of god in our minds - a being which none greater can be conceived
2) existence in reality is better than existence solely in the mind
3) I can conceive a a being greater than god - one which holds all of his perfections but also exists
4) However, the existence of such a being would contradict premise one
5) therefore god must exist in reality

Question 2

Descartes (clear and distinct ideas)

Answer 2

1) I have an idea of a supremely perfect being - a being which holds all perfections
2) necessary existence is a perfection
3) Therefore a supremely perfect being must exist

Question 3

Malcolm

Answer 3

1) god as the greatest being conceivable cannot be a limited being
2) therefore if god doesn’t exist then he cannot merely come into existence or be caused to exist
3) if god does exists then he cannot simply come into existence or go out of existence
4) either god exists or he doesn’t exists
5) if god exists then his existence is necessary, if god doesn’t exist then his existence is impossible
6) god is either impossible or necessary
7) god is not impossible (there is no contradiction in the existence of God)
8) God must exist

Question 4

Existence is not a predicate - kant

Answer 4

existence cannot be treated as a property that some thing can have.
predicates tell us something new about the subject (eg blueness tell us the physical property.
existence adds not attribute to the given subject, saying something has existence tells us nothing about it (cake example)

Paradox: to say that princess Diana lacks existence is absurd because to lack a property presupposed the existence of the subject
this destroys the entire concept of existence.

Question 5

Gaunillos perfect island

Answer 5

Anselm’s line of reasoning is too powerful - it can be applied to all superlative things and prove their existence
apply his reasoning to a perfect island
the idea that such as island exists is absurd

Question 6

Empiricist objection to a priori arguments for existence

Answer 6

Humes fork split knowledge into matters of fact (synthetic a posteriori) and relation of ideas (analytic a priori)

1) if gods existence can be proven with a relation of ideas, then his nonexistence must be impossible (all analytic a priori truths are necessary)
2) however, whatever we can conceive of existing we can also conceive of not existing
3) we can conceive of the non-existence of God
4) Gods existence is possible
5) Gods existence cannot be known by a relation of ides
6) Gods existence cannot be known a priori