The ontological argument

Anselm

He produced an ontological argument from the perspective of 'faith seeking understanding' in his book 'Proslogian'.

This means that its purpose was not to convince others of the existence of God, but, rather was trying to explore as a Christian what faith in God was all about.

What is the ontological argument?

• The ontological argument: a priori deductive proof for the existence of God.

How does Anselm argue that the existence of God is logical?

• It is not based on experience of the world, but, solely on logic and reasoning.
• Anselm attempts to argue from the definition of God, that it is not possible for God to not exist.

Anselm's two arguments for the ontological argument:

Form 1: highlights that because real things are better than imaginary things, God must be real:

• God is that which nothing greater can be conceived
• A real, existent being is greater than an imaginary being
• The concept of a real God is greater than an imaginary God
• Therefore, God must exist

Form 2: because necessary things are better than contingent things, God must exist necessarily:

• God is that which nothing greater can be conceived
• Contingent beings are inferior to necessary beings
• God is not inferior to anything
• Therefore, God exists necessarily

The fool of the Psalm

Referencing Psalm 14 "Fools in their hearts say there is no God"

To deny the existence of God you must first have an understanding of God, anyone who has an understanding of God would know that he is that which nothing greater can be conceived and therefore to reject his existence is a logical contradiction, thus, making you a fool.

Strengths of Anselm's ontological argument

• To accept on the one hand that God is 'that than which no greater can be conceived' and then to say that God doesn't exist is to make a logical error.
• Kant would respond: We can simply reject the definition
• The argument is intellectually stimulating and logically satisfying.
• It forces the believer to consider carefully what they mean by the term God.
• Logical arguments are much harder to disprove.

Weaknesses of Anselm's ontological argument

• Hume: Necessary existence is not a coherent concept as existence can only be contingent.
• Kant: Existence is not a predicate. If we add or take away existence from something, it does not change the definition. You cannot define God into existence
• Logical stimulation does not make something true.
• The argument is only valid for people who already believe in God, therefore the ontological argument is unsuccessful in convincing others of the existence of God
• Aquinas argued that the ontological argument doesn't work because it assumes we share an understanding of God.

Gaunilo's criticisms

Gaunilo: a fellow monk, writes to Anselm "on behalf of the fool" and argues that the ontological argument is unsuccessful in proving the existence of God.

He presents his reductio ad absurdum argument of the lost island.

Reductio ad absurdum: an argument that attempts to show that another argument is weak by reducing its conclusions to absurdity.

The analogy of the perfect lost island

Gaunilo argues that all we need to do to show the absurdity of Anselm's argument is replace the word 'God' with 'perfect lost island'

• The perfect lost Island is that which nothing greater can be conceived
• A real, existent Island is greater than an imaginary Island
• The concept of a real Island is greater than an imaginary Island
• Therefore, the perfect lost Island must exist Gaunilo dissects the claim that Anselm's argument is based entirely on logic, if there is no logic then the whole argument fails.

Anselm's response to Gaunilo:

Anselm responds to Gaunilo by highlighting that God is necessary whereas the Island is contingent so is not comparable.

Descartes ontological argument

• Descartes version of the ontological argument appears in his Meditations.
• He argues that God is supremely perfect and must therefore exist because if he did not exist he would not be supremely perfect.

What does Descartes argue?

He argues that "Existence can no more be separated from the essence of God than can having three angles equal to two right angles be separated from the essence of a triangle".

This means that it is necessary for a triangle to have an angle equalling 180 degrees otherwise it would not be a triangle; a perfect God must exist because if he didn't he would not be perfect.

Descartes is treating existence as a predicate of God.

Kant's criticisms

Kant argues that existence is not a predicate.

• A predicate is the part of a sentence that tells us what something/someone does or is.
• Existence cannot be a predicate because it does not give us any more information about the nature of the subject (in this case, God).
• Adding the predicate 'exists' adds nothing to the nature of God.
• First, the object must exist, then other predicates can be attached to it.

Kant also criticises the second form of the ontological argument: God can only exist necessarily if and only if it can be proven that God exists in the first place.

• This notion is supported by Hume who postulates that necessary existence is not a coherent concept in itself since all things that exist are contingent on something.

Kant's criticisms

A predicative statement: is one that adds to the description of something.

An existential statement: is one that shows that something actually exists. Russell highlights that it is possible to use predicative statements to describe something, but that something does not have to be an existential statement.

Russell argues that ontological arguments are "cases of bad grammar" because they make predictive statements like "God is the greatest conceivable thing" and assume from that that God must exist in reality.

Frege:

He states that statements of existence are statements of number.

• For example, saying "Mr. John exists" is the same as saying "there are more than zero Mr John's".
• This statement does not however communicate anything about Miss Scully such as "Mr John exists and is an RS teacher".
• When we apply this to the ontological argument we can see that Frege would support the idea that existence is not a predicate because statements of existence are statements of number rather than predicative.
• This means that at best, statements of God's existence can connote that there are more than zero Gods, but, this statement of existence cannot be used to attach predicates such as "supremely perfect" and "the greatest conceivable thing" to that God.

Strengths of a priori arguments

• If you accept the premise then the conclusion must be true as it is logically necessary and there is no need for empirical evidence to prove God's existence.
• A posteriori argument can only give us probable and provisional knowledge because it is always possible that additional experience could prove our conclusions wrong. E.g. "all swans are white" was considered to be a true statement until a black swan was seen. We do not face this problem with a priori reasoning which is always either valid or invalid.
• A priori arguments are immune to being disproved by science. There's no danger of a new scientific discovery or theory coming along to weaken the argument, the way Darwin's Theory of Evolution weakened the Design Argument.

Strengths of a posteriori arguments

• A posteriori arguments gain support from evidence.
• Scientific investigation reveals more and more puzzling features about the universe: its size, its physical laws, and its oddness. The more we learn about these things, the more persuasive the Design Argument becomes for example.
• The limitation of an a priori argument is that if one premise is shown to be inaccurate the whole argument falls to pieces.
• It is difficult to prove the existence of God using pure logic because God is beyond the constraints of logic, therefore these rules do not apply to him.