The ontological argument is based entirely upon logic and reason and doesn’t really try to give a posteriori evidence to back it up. Anselm would claim the statement ‘God exists’ makes perfect sense in the same way that saying a triangle has three sides also makes perfect sense.

Which of these six statements is a priori?

2+2=4

2+2=4

Humes’ Fork

According to Hume which of these is necessarily true?

2+2=4

Humes’ Fork

According to Hume which of these is contingently true?

2+2=4

Humes’ Fork

According to Hume which of these is analytic?

2+2=4

Humes’ Fork

According to Hume which of these is synthetic?

Empiricist or Rationalist?????

Remember, Empiricism is based upon knowledge we get through the senses and rationalism is based on logic and reason using the brain.

Ontological

Cosmological

Cosmological

Teleological

Ontological

Is the Cosmological Argument Empiricist or Rationalist?????

Teleological is a posteriori as it is based on the complexity of life. We know there is complexity because we can observe this! Where does this complexity come from – well a designer must exist and this designer is God.

Cosmological is a posteriori as it is based on causation and the beginning of the Universe. We know that all contingent things need a beginning as we can observe this! There must be something that is not contingent – a necessary being and this must be God.

Teleological Argument – complexity of a forest?

2 + 2 = 4Triangle has 3 sidesThe shortest distance

between 2 points is a straight line

All bachelors are unmarried males

Logic and reason tell us these things are true!

Anselm begins by saying that God can be defined as a perfect being and so must exist but how does he justify this claim?

It would seem that he has a point as it is difficult to imagine a being greater than an all-powerful God?

GodOntological – we can all imagine a greatest being

GodGod

God

God

Is it better to exist or not to exist?

So, existence in reality is greater than existence in the imagination.

If God exists in the imagination, then to exist in the imagination and in reality would be greater .

Well, quite a few actually!

Gaunilo's reductio ad absurdum

Gaunilo's reductio ad absurdum

Defining things into existence

Uses reductio ad absurdum

Not rational

We can all imagine

God

Aquinas’ criticism of Anselm – we all have different ideas of what God is like so God cannot be a universal concept?

The term ‘black cat’ tells us something about the cat i.e. that it is black! The predicate ‘black’ is a defining term of the cat. ‘God exists’ contains no such predicate and so cannot tell us about God!