1. The Ontological Argument
An argument for the existence of God

2. Write down your response to:
What is your concept of ‘God’?
What do you think of when someone says the word ‘God’?

3. Is this a duck or a rabbit?
Epistemology is concerned with justifying what we perceive (or believe to know) this figure to be…
Ontology is concerned with the reality behind our perceptions.

4. The Classical form St Anselm of Canterbury (1033-1109)
God is defined as:
‘that than which nothing greater can be conceived’.

5. What does that mean? Anselm said this meant God must exist because:
That which exists in reality is greater than that which exists purely in the mind.

6. Imagine being given £1000. It’s a nice thought, but wouldn’t it be better if the money really existed?

7. So… So by definition, God must exist.
Since God is ‘that than which nothing greater can be conceived’ obviously it is greater to exist, than not to exist.
So by definition, God must exist.

8. Thinking point: What is the difference between:
That than which nothing greater can be conceived
And
Something greater than can be conceived?
Is the difference important?

9. The ontological argument is an a priori argument.
‘God exists’ becomes an existential analytic statement.

10. God’s existence is necessary
Ok, so Anselm has offered a proof for God’s existence, but for God to be God there must be more to Him than simply existing –after all we exist!
Anselm has a 2nd argument, in which he argues God’s existence is necessary.
What does he mean by ‘necessary’?

11. Necessary means…
Anselm is referring to the eternal and transcendent nature of God.
There is no possibility of God not existing

12. Anselm says we know:
It can be conceived that something exists that cannot be thought not to exist
God must be such a thing if He is ‘that than which nothing greater can be conceived’.
This is because something that can be though not to exist would be inferior to that which cannot.

13. Rene Descartes (1596-1650) Developed Anselm’s argument
God is ‘a supremely perfect being’.
We can conclude God exists, because existence is a predicate of a perfect being.
Therefore God must exist, to avoid being self-contradictory.

14. Try imaging a triangle without 3 sides.
Can you?

15. Modern versions Norman Malcolm (1911-1990)
A necessary God cannot be brought about nor threatened by anything.
God’s existence is either necessary or impossible
A necessary God cannot be impossible
Therefore God necessarily exists

16. Questions:
Why would God be a limited being if He had been caused to come into existence, or had ‘happened’ to come into existence?
Is it acceptable and coherent to conclude that God exists because He has the property of necessary existence? Why, or why is this not, the case?

17. Modern versions Alvin Plantinga 1974: notion of Possible Worlds
Also known as the modal form
There is a possible world in which there is a being who is maximally great and maximally excellent
In any possible world this being must exist if it had these attributes
This is a possible world
Therefore this being exists in our world (God).

18. The Ontological Argument
‘Proof’ of the existence of God by definition.