1. THE ONTOLOGICAL ARGUMENT 1
This argument hinges on a concept of God, rather than on God himself.
It is to do with a definition of God.
Anselm’s argument was not an argument – it was a prayer from a believer who wanted to show his God was necessary.
It is useful for a believer but is not necessarily rational for a non-believer.

2. THE ONTOLOGICAL ARGUMENT 2
REDUCTIO AD ABSURDUM
All the arguments from the philosophers below begin from a proposition, and attempt to ‘prove’ (through logical reasoning) that it would be ‘absurd’ to reject the proposition.
Anselm & Descartes -The classical argument
And more recently: Malcolm & Plantinga.
The arguments are all ‘a priori’ – reasoned.

3. THE ONTOLOGICAL ARGUMENT 3
ST ANSELM OF CANTERBURY 1
“God is that than which nothing greater can be conceived” – Proslogion 2.
Even the unbeliever must have a definition of God in order to dismiss it as a concept.
If you accept the definition, God must exist in reality as that which exists in reality will always be greater than that which exists in intellectu.

4. THE ONTOLOGICAL ARGUMENT 4
ANSELM 2
It is possible to conceive of a being, the existence of which is necessary – Proslogion 3.
God must be such a being if he is ‘that than which nothing can be conceived’. This is because a being that possesses necessary existence will always be greater than a contingent being.

5. THE ONTOLOGICAL ARGUMENT 5
ANSELM 3
By necessary, Anselm is referring to the eternal & transcendent nature of God. This means that God exists outside our space & time, but is able to act within it. If he did not exist in this way, Anselm would say, we would not exist either.

6. THE ONTOLOGICAL ARGUMENT 6
RENE DESCARTES
His argument is based on God being a ‘supremely perfect being’.
From this, Descartes believes we can conclude that God exists, because existence is a predicate of a perfect being; therefore, God must exist to avoid being self-contradictory.
Descartes says that trying to imagine God without the predicate of existence is illogical, like imaging a triangle without 3 sides!

7. THE ONTOLOGICAL ARGUMENT 7
NORMAN MALCOLM 1
Taking Anselm’s argument, Malcolm thinks Proslogion 3 is more accurate than Proslogion 2.
Some versions of the argument are subject to the criticism that existence is treated as a predicate that things either have or lack.
According to Malcolm, P. 2 is subject to such criticism.
Malcolm believes that P. 3 doesn’t treat existence as a predicate. He thinks Anselm is saying that God must exist because the concept of God is the concept of a being whose existence is necessary.

8. THE ONTOLOGICAL ARGUMENT 8
NORMAN MALCOLM 2
If God is ‘that than which nothing greater can be conceived’, he cannot be brought into existence; nor can he simply happen to come into existence (as this would require the input of a greater being & would render God limited & finite).
Therefore, God’s existence is either necessary (if he does exist), or impossible (if he does not).
Unless God’s necessary existence presents us with a logical contradiction, we must accept it.

9. THE ONTOLOGICAL ARGUMENT 9
ALVIN PLANTINGA 1
He had the concept of possible world’s where things might be slightly different than here.
He said: “ there is a possible world, W, in which there exists a being with ‘maximal greatness’”.
“A being has maximal greatness only if it exists in every possible world”.
This means that in every possible world there is a being of maximal greatness – this however does not mean God!

10. THE ONTOLOGICAL ARGUMENT 10
ALVIN PLANTINGA 2
In response to the fact that there may be a greater individual being in each of these worlds he adds:
Maximal greatness entails maximal excellence.
Maximum excellence entails omnipotence, omniscience and moral perfection.

11. THE ONTOLOGICAL ARGUMENT 11
ALVIN PLANTINGA 3
Therefore:
There is a possible world in which there is a being that is maximally great
It has maximal excellence (entailed within maximal greatness).
If omnipotent, omniscient & morally perfect, & maximally great, it is existent in our world.
Therefore, there is a God whose existence follows from his essence.

12. THE ONTOLOGICAL ARGUMENT 12
GAUNILO OF MARMOUTIER 1
He criticised Anselm’s Proslogion 2 by using ‘The perfect Island’ analogy.
He said, if someone describes this perfect island & then state that it must exist because of its perfection, then you would be a fool to believe him.
He was saying you cannot define something into existence.

13. THE ONTOLOGICAL ARGUMENT 13
GAUNILO OF MARMOUTIER 2
Gaunilo’s criticism was invalid because Anselm never compares things of a like kind.
Anselm states that God is, ‘that than which nothing greater can be conceived.
But Gaunilo was comparing an island with another island.
Also an object like an island can always be bettered by adding a few more palm trees etc
As Plantinga would say, islands have no intrinsic maximum.

14. THE ONTOLOGICAL ARGUMENT 14
IMMAUNUEL KANT 1
Kant objects to Descartes’ claim that denying God’s existence is tantamount to denying that a triangle has 3 sides (predicate).
He states that if one dismisses both the idea of the 3 sides (predicate) and that of the triangle itself (subject), one is left with no contradiction.
One can define a thing as one sees fit, but whether or not anything matches that definition in reality is another question altogether.
Kant thus dismisses Descartes notion of existence as a predicate.

15. THE ONTOLOGICAL ARGUMENT 15
IMMAUNUEL KANT 2
In his criticism of Anselm, Kant raises a 2nd objection.
He states that existence is not a predicate.
This means that saying that X exists tells us nothing about X.
A predicate, says Kant, must give us information about X; the statement X is does not. In fact the opposite statement presents us with a paradox.
If X exists tells us about a property that X has, then X does not exist denies that it has this property. But how can that which does not exist lack anything?

16. THE ONTOLOGICAL ARGUMENT 16
GOTTLOB FREGE
He distinguishes between 1st and 2nd order predicates.
1st order ones tell us about the nature of something – EG the horses are brown.
2nd order ones tell us about concepts – EG the horses are numerous.
Frege’s objection to Anselm & Descartes is that they seem to use existence as a 1st order predicate, whereas it is actually a 2nd order one.

17. THE ONTOLOGICAL ARGUMENT 17
BERTRAND RUSSELL 1
He says that existence cannot be a predicate. If it were, we could construct a syllogism:
Men exist (Fact)
Santa Claus is a man (Concept)
Therefore, Santa Claus exists. (Not fact)

18. THE ONTOLOGICAL ARGUMENT 18
BERTRAND RUSSELL 2
He is saying that existence is not a property of things but of the idea of those things.
So, to say that dragons do not exist is to say that of all the things that do exist, none of them are referred to by the word, dragon.
He says to label & define something is to provide an intention concerning the thing.
EG if I say a cow is a quadruped with udders etc., my intention would be to describe a cow.
The fact that a cow exists provides an extension to my intention.
So, existence is an extension of an intention.

19. THE ONTOLOGICAL ARGUMENT 19
BERTRAND RUSSELL 3
Russell concludes that ‘that than which nothing greater can be conceived’ is simply the totality of everything that can be conceived by the human mind. That is the intention; but does it have extension?
Yes! If any idea can be said to exist then ttwngcbc must exist, as it is the totality of all ideas. It does not have to have physical existence or even be conceived, as long as it is conceivable.
Therefore, Russell would support Anselm’s claim but not Anselm’s belief that this proves God’s existence in reality.

20. THE ONTOLOGICAL ARGUMENT 20
BRIAN DAVIS 1
Davies states that the word IS can be used in 2 different ways:
1/ It can be used to define something – EG a queen is a female monarch.
2/ It can be used to explain that there actually IS something – EG there is such a thing as a vampire.
The 1st says nothing about existence.
The 2nd does neither, but implies existence.
Davies is saying that Malcolm is moving from 1/ to 2/ and supposing existence from a definition.

21. THE ONTOLOGICAL ARGUMENT 21
BRIAN DAVIES 2
Davies criticises Plantinga’s argument by saying: If we accept that a being with maximal excellence 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.
All we can coherently conclude from Plantinga’s evidence, is that maximal excellence is possible, and therefore, God is possible, not actual.