The Ontological Argument

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. Its a nice thought,
but wouldnt it be better if the money really
existed?
7
So

• 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
Gods existence is necessary

• Ok, so Anselm has offered a proof for Gods
  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
  Gods 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 Anselms 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.
• Gods 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
The film follows the life of Helen. The film's
plot splits into two parallel universes which run
in tandem. In one universe, Helen manages to
catch a train home on time, in the other she
misses it. In the former, she gets home in time
to catch her boyfriend in bed with his
ex-girlfriend she promptly dumps him, and meets
a new man. In the latter, she carries on
oblivious in a miserable relationship after
arriving home after her boyfriend's lover has
left.
18
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).

19
The Ontological Argument Proof of the existence
of God by definition.