Introduction to PhilosophyLecture 5

The Ontological Argument

By David Kelsey

Saint Anselm

• Saint Anselm of Canterbury lived from 1033-1109.• He was a monk and later Archbishop of Canterbury.• Wanted to see how far argument and reason could substantiate the central

doctrines of Christianity.• He invented the ontological argument for the existence of God.

A priori vs.A posteriori arguments

• A Posteriori Arguments:– An a posteriori argument has at least one premise which is contingent. It

has at least one premise that is a question of fact.

• A priori arguments:– Have absolutely no premises that are a question of fact.– Composed entirely of a priori claims.– An a priori claim: true or false in virtue of the meaning of it’s words alone.

• The cosmological and teleological arguments…

• The ontological argument…

Defining GOD

• According to the Judeao-Christian-Islamic tradition: God is the greatest or most perfect possible being.

– What can we infer about God from this?– If God is perfect, he has every perfection.

• Thus, God is:– Omnipotent: maximally powerful– Omniscient: maximally knowledgeable– Omnibenevolent: is perfectly good– Omnipresent: is everywhere

A Reductiofor God’s omnipotence

• An argument that God must be omnipotent:– Suppose God wasn’t omnipotent.– Then there could be a being more powerful than God.– That would be greater than God.– But God is the greatest of all possible beings.– So God must be omnipotent.

• This argument has the form of a reductio ad absurdum.– Reductio’s always assume the negation of the conclusion they are out

to prove.

– The argument then derives a contradiction

– The argument then concludes by asserting what it was to prove

Anselm’sOntological Argument

• Anselm’s concept of God:

– Anselm uses the notion of God seen in the Judeao-Christian-Islamic tradition.

– For Anselm: God is ‘something than which nothing greater can be conceived’.

• This is not the same concept as the greatest being we can conceive.

– Anselm is assuming the Great chain of being here.• If you run up and down the chain you find it easy to conceive of beings

both lesser and greater.• Your mind is carried to greater and greater things…

The Great Chain of Being

• The Great Chain of Being:– God created the world ex nihilo, out of nothing.

• The world is entirely dependent upon God.

– Reality is partitioned in graded steps, which are infinitely close to each other.

• Being and nothingness are mixed in all degrees in all things.• God has the most being, then the angels, then rational creatures, then

more primitive life forms such as dogs, insects, etc., then to inanimate matter, I.e. rocks…

– There is a direct correlation between being and goodness.• The more being something has, the more good it has. So God who has

the most being, is completely good.

Anselm’s Reductio

• Anselm’s argument is a Reductio Ad Absurdum. The basic form of the reductio:– Assume God doesn’t exist

– But then God isn’t the being than which nothing greater can be conceived.

– But God is the being than which nothing greater can be conceived.

– Thus, God exists.

The form of Anselm’s argument

• Anselm’s argument:– 1. Assume God exists in the understanding alone.

– 2. God is something than which nothing greater can be conceived.

– 3. Something than which nothing greater can be conceived can be conceived to exist in reality.

– 4. It is greater to exist in reality than in the understanding alone.

– 5. God is a being than which a greater can be conceived. (from 1 and 4)

– Thus, 6. God exists. (from 1, 2 and 5)

Evaluating Anselm’s argument

• Evaluating Anselm’s argument:– Is Anselm’s argument valid?– Is Anselm’s argument sound?

– Which premises might be false?• Premise 2…• Premise 3…• Premise 4…

Denying premise 2

• Denying premise 2:– Some argue that premise 2 is false.

– They say that such a definition of God is incorrect.

– Thoughts…

Denying premise 3

• Challenging the third premise:– Can you conceive of God as existing in reality?

Denying premise 4

• Can we deny premise 4:– We can do this by claiming that existence in reality is not a

perfection.

– Thus, a being that existed in both the understanding and in reality is not more prefect than a being that existed just in the understanding.

• Anselm’s reply would probably go like this: existence entails the ability to use all of one’s perfections

• Counter: Is existence the kind of thing that can even be a perfection at all?

Defining God into existence

• Hume criticizes the Ontological argument for trying to define God into existence.

– For Hume, it may be that thinking of God entails thinking that he exists but this concerns only relations of ideas not matters of fact.

• A relation of idea is:– Discoverable by the mere operations of thought, without

dependence on anything existent in the universe…• A matter of fact is:

– Discoverable by observation of the external world…– So even though thinking God entails thinking he exists, this has

nothing to do with whether God in fact exists.• A relation among ideas, even one that is necessary, gets no traction

and can have no causal power on how things are in the world.• Relations of ideas cannot prove matters of fact. About matters of fact,

we must consult experience.

Refutation bylogical analogy

• Refutation by Logical Analogy:– Many people think that Anselm’s argument just has to be wrong for it just

shows too much.

– Can’t we give an argument of the same form as Anselm’s, but for an obviously false conclusion.

• Since the new argument isn’t sound, neither is Anselm’s.• This move is called Refutation by logical analogy.

Gaunilo’s parody

• Here is the argument:– 1. Assume the greatest possible island exists in the understanding

alone.– 2. The greatest possible island is the island than which no greater

can be conceived.– 3. The island than which no greater can be conceived can be

conceived to exist in reality.– 4. It is greater to exist in reality than in the understanding alone.– 5. The greatest possible island is an island than which a greater

can be conceived. (from 1 & 4)– Thus, 6. The greatest possible island exists. (from 1, 2 and 5)

Anselm’s best reply

• Anselm’s reply:– Can the greatest possible island even exist in reality?

– Although the greatest possible being could have all the perfections to the greatest degree, could an island really have them?