1. The Ontological argument 2
This time it’s critical!

2. Meet the commentators Gaunilo of Marmoutier Immanuel Kant
Gottlob Frege
Bertrand Russell
Brian Davies

3. Gaunilo V Anselm
Round 1

4. Perfect! The Perfect Island ‘Inestimable wealth’ ‘Abundant delicacies’
‘all manner of riches’
‘uninhabited’
Perfect!

5. The Perfect Island The KEY issue:
“Anselm is trying to move from a definition of God to the suggestion of God’s existence. This is not a valid move.” Gaunilo
The KEY issue:
I do not deny that such an island could exist…
…I simply will not agree that it does, until I have been shown PROOF!
Gaunilo’s says: just because he can CONCEIVE of such a place, that does not actually mean such a place exists!

6. So this disproves the argument?
Well no, not really!
Anselm never compares things of a like kind.
‘that than which nothing greater can be conceived’
Whereas, Gaunilo is comparing islands
Islands have no intrinsic maximum
Gaunilo’s objections do not successfully refute Anselm

7. Kant V Descartes
Round 2

8. Kant successfully refutes Descartes’ idea of existence as a predicate.
Triangular logic?
Kant objected to Descartes’ claim that denying God’s existence was the same as trying to deny triangles have three sides, which is contradictory.
Kant states that if you dismiss both the three sides (predicate) and that of the triangle itself (subject) then you are left with no contradiction.
Kant successfully refutes Descartes’ idea of existence as a predicate.
In order to deal with Anselm he serves up another argument…
So: If you say God does not exist and then cease to imagine the concept of God, there is no contradiction. Therefore it can be logical to say ‘God does not exist.’

9. Kant V Anselm
Round 3

10. ‘existence is not a predicate’
Kant states that’s saying X exists tells us nothing about X
Whereas, ‘X is female, or tall’ does
A predicate must give info about X
Saying ‘X is’ does not
Existence does not add anything to the concept (idea of) X

11. Kant
If X exists tells us about a property that X has, then X does not exist denies that it has this property (or affirms that it lacks it).
Paradox!
Because ‘X exists’ does not tell us anything, Kant is saying it is meaningless and is the same as saying X does not exist

12. Frege V Anselm &Descartes
Round 4

13. Frege (1848-1925) 1st order predicates
Tell us about the nature of something
2nd order predicates Tell us about concepts
Frege argues that Anselm & Descartes only use 1st order predicates, when existence is a 2nd order predicate.

14. Bertrand Russell Claims Anselm uses the word ‘exist’ incorrectly.
Existence cannot be a predicate.
If it were, we could argue:
Men exist.
Santa Claus is a man.
Therefore, Santa Claus exists.
This is a syllogism.

15. Brian DaviesV the Ontological argument
Round 4

16. Brian Davies
Davies argues that is can be used to define the concept of God, as in 1), but not as in 2) which pre-supposes existence for no logical reason.
‘A pixie is a little man with pointed ears. Therefore there actually exists a pixie.’
‘is’ is used in two different ways
1) To define something: ‘a queen is a female monarch’
2) To explain there actually is something: ‘there is such a thing as a vampire’.

17. The argument against Plantinga’s ‘Possible worlds’ idea.
Round 5

18. Plantinga’s possible worlds
Is Plantinga’s claim coherent?
Even if we accept a being with ‘maximal greatness’ is possible, and therefore it is possible that such a being exists in our world…
…it does not follow that such a being actually exists!
It is possible, but not actual.

19. TASK:
In your groups you must prepare to present your case.
‘This house believes the Ontological argument cannot prove the existence of God.’
2 groups will speak for the motion, 2 groups against.
Everybody in your group must contribute.
Elect a scribe and 2 spokespeople.

20. Debate
‘This house believes the Ontological argument cannot prove the existence of God.’
Order of speaking:
For the argument
Against the argument
Reply for the argument
Reply against the argument

21. Russell’s idea To label & define something is to provide an intention
An animal with four legs & udders
Intention to describe a cow.
To say the cow exists is to provide an extension to my intention.
We see cows in field, so we accept they exist.

22. Russell cont.
‘that than which nothing greater can be conceived’ is simply the totality of everything the human mind can conceive. That is the intention of the phrase.
Extension? If any idea can be said to exist, then ‘that than which nothing greater can be conceived’ must exist as it is the totality of all ideas.