AQA Philosophy
Metaphysics of God

Summary notes for Ontological arguments

St Anselm’s ontological argument

A priori: the argument is not based on experience but a purely logical analysis of the concept of God.
Deductive: if the premises are true, the conclusion must be true.
In Proslogion 2, Anselm argues:
P1. God is by definition the greatest conceivable being
P2. It is greater to exist in the mind and reality than in the mind alone
P3. God exists in the mind
C1. God exists in reality
In Chapter 3 Anselm argues that a necessary being whose nonexistence is impossible is greater than a contingent being whose nonexistence is possible.
The greatest conceivable being would not have any dependence or limitation.
God doesn’t have any of the contingencies which could result in non-existence.
So, a being greater than which none may be conceived is one whose nonexistence is impossible.
Anselm concludes that if such a being is logically possible, then it must exist.

Descartes’ ontological argument

Descartes’ rejected the aristotelian logic of subject-predicate analysis. His argument does not try to deduce God’s existence through analysing predicates of the concept of God.
He claims that God’s existence can be known through rational intuition, which is our mind’s ability to grasp truths without a process of reasoning or inference.
This bases his argument on his rationalist epistemology.
Descartes illustrates with a triangle. When we conceive of a triangle, we are unable to clearly and distinctly perceive it while separating it from having three sides. So we can know through intuition that a triangle must have three sides.
Similarly, when we conceive of a supremely perfect being, we are unable to separate it from existence.
It is not possible to rationally conceive of the most supremely perfect being without existence.
So we can intuitively know that God necessarily exists.
Descartes does put his argument into standard deductive form however:
P1. God is a supremely perfect being, which contains all perfections.
P2. Existence is a perfection
C1. God exists

Malcolm’s ontological argument

A priori: the argument is not based on experience but a purely logical analysis of the concept of God.
Deductive: if the premises are true, the conclusion must be true.
Malcolm replaces Anselm’s term ‘greatest’ with ‘unlimited’.
As an unlimited being, God cannot be limited by contingency in any respect. So God cannot contingently exist or contingently not exist. This means that God is non-dependent, i.e., necessary.
So, if God is coherent, the conclusion follows that God is necessary.
P1. God is an unlimited being
P2. God either exists or does not exist.
P3. If God exists, God cannot go out of existence as that would require dependence on something else. So, if God exists, God’s existence is necessarily
P4. If God does not exist, God cannot come into existence as that would make God dependent on whatever brought God into existence. So, if God does not exist, God’s existence is impossible.
C1. So, God’s existence is either necessary or impossible
P5. The concept of God is not self-contradictory (like a four-sided triangle), therefore God’s existence is not impossible.
C2. Therefore, God exists necessarily.

Gaunilo’s ‘perfect island’ objection

Gaunilo argues there is a difference between existing in the mind and existing in reality. It’s possible to have an idea of something that is not real. This applies even in cases of greatest conceivable (Anselm), supremely perfect (Descartes) or unlimited (Malcolm) things.
Gaunilo attempts to show the ontological argument fails by applying it to another case which leads to an absurd result.
Imagine the greatest possible island. According to the ontological argument, it’s greater or perfect or less limited to exist, so this island must exist.
This would work for the greatest possible version of anything.
The ontological argument suggests reality would be overloaded with greatest possible things, which seems absurd.
Gaunilo is attempting to deny that the conclusion that God exists follows from the premises. So Gaunilo is denying that the ontological argument really is a valid deductive argument.

Empiricist objections to a priori arguments for existence

Hume’s fork claims:
A priori reasoning only tells us about relations between ideas (analytic truths).
A posteriori reasoning only tells us about matters of fact (synthetic truths).
Hume’s justification for the fork is that analytic truths are true regardless of what happens to be the factual state of reality.
Whatever we determine a priori using pure logic will be true independently of whatever is factually true. So, a priori reasoning cannot tell us factual truths, since factual truths depend on what happens to be the case, which can only be discoverable by experience.
The ontological argument is attempting to infer a conclusion about God’s existence, which is a matter of fact. But it uses purely a priori reasoning. It involves an analysis of the definition of God and its logical implications. That can only tell us conceptual analytic truths.
So, Hume’s fork objects to the ontological argument for ignoring the disconnect between the types of truth produced by the types of reasoning and trying to reach a factual conclusion a priori.

Kant’s objection based on existence not being a predicate

Anselm, Descartes and Malcolm’s ontological arguments claim that denying God’s existence is an incoherent denial of what God is. God wouldn’t be the greatest/supremely perfect/unlimited being if God did not exist.
Kant objects that this misunderstands what existence is. Ontological arguments treat the concept of ‘existence’ like a predicate, a description of what a thing is, an attribute a thing possesses that defines it.
If I said ‘the cat exists’, the term ‘exists’ doesn’t describe a quality that the cat possesses. It describes that the cat exists, but not the cat itself.
Kant gave the example of 100 thalers (coins) existing in reality compared to their existing only in the mind.
If existence were a predicate, the existing coins would have existence added to their concept.
Then, the existing coins would then be conceptually different to the coins in the mind. But they are not. 100 coins is just 100 coins, defined by the predicates of 100, round, shiny, metal, etc.
So, existence is not a predicate.
This criticism attacks Anselm’s premise that existing is greater and Descartes’ premise that a supremely perfect being ‘contains’ the perfection of existence, and Malcolm’s claim that non-existence is a limitation for what a thing is.
So, existence is not an attribute that defines God. We can deny God’s existence without incoherently contradicting our definition of what God is.

Ontological argument model essay plan

Note that this model essay plan is merely one possible way to write an essay on this topic.

Points highlighted in light blue are integration points
Points highlighted in green are weighting points

The ontological argument

Anselm’s ontological argument

Anselm’s ontological argument is a priori, meaning it is not based on experience but a purely logical analysis of the concept of God.
Deductive, if the premises are true, the conclusion must be true.
In Proslogion 2, Anselm argues:
P1. God is by definition the greatest conceivable being
P2. It is greater to exist in the mind and reality than in the mind alone
P3. God exists in the mind
C1. God exists in reality
Descartes developed the argument, arguing God was the ‘supremely perfect’ being which contained the perfection of existence. He illustrated that God and existence is like a triangle and three sides. They are inseparable.
Malcolm and Hartshorne were responsible for renewing interest in the Ontological argument in the 20th century. They point to Proslogion chapter 3 as containing the strongest presentation of the argument.
There, Anselm adds that the greatest being would be necessary.
Malcolm interprets Anselm’s term ‘greater’ as referring to whether a being is limited due to depending on something else for its existence.
The greatest conceivable being would not have any dependence or limitation.
So, a being greater than which none may be conceived is one whose nonexistence is impossible.

Counter

Gaunilo attempts to show Anselm’s logic is absurd by applying it to another case which yields an absurd result.
Imagine the greatest possible island. If it’s greater to exist then this island must exist.
This would work for the greatest possible version of anything.
Anselm’s logic implies reality would be overloaded with greatest possible things, which seems absurd.
Gaunilo is attempting to deny that the ontological argument’s conclusion follows from the premises. So he is denying that it really is a valid deductive argument.

Evaluation:

However, Anselm successfully defends himself against Gaunilo by explaining why his argument only works for God.
An island by definition is contingent. It is land enclosed by water, so it depends on water for its existence. Everything in the world is contingent.
The reason for the existence of contingent things is whether what they depend on exists.
That cannot be determined by a priori analysis of its definition.
However the reason such logic won’t work for a contingent being doesn’t apply in the case of a necessary being.
So, there’s a relevant difference between God and contingent things like Islands which explains why the logic works exclusively for God.

Kant’s critique that existence is not a predicate

The ontological argument claims that denying God’s existence is an incoherent denial of what God is, i.e., the greatest or supremely perfect being.
Kant responds that this misunderstands what existence is. It treats ‘existence’ like a predicate, a description of what a thing is.
If I say ‘the cat exists’, the term ‘exists’ doesn’t describe a quality that the cat possesses.
It describes that the cat exists, but not the cat itself.
Kant gave the example of 100 thalers (coins) existing in reality compared to their existing only in the mind.
If existence were a predicate, it would be added to the concept of the existing coins.
The existing coins would then be conceptually different to the coins in the mind. But they are not. 100 coins is just 100 coins, defined by the predicates of 100, round, shiny, etc.
So, existence is not a predicate.
This criticism attacks Anselm’s premise that existing is greater and Descartes’ premise that a supremely perfect being ‘contains’ the perfection of existence.
So, existence is not part of what God is, which means we can deny God’s existence without contradicting what God is.

Response:

However, Kant’s criticism fails for two reasons.
Firstly, Kant’s criticism fails to attack Descartes’ ontological argument, which therefore seems to be in a stronger position than Anselm’s.
Descartes did put his argument into a deductive form, which Kant seems to be attacking. However today Descartes is typically interpreted as having intended his argument to be ultimately based on intuition.
This reading of his argument gets around Kant’s critique, so seems the stronger form.
Descartes’ rejected the aristotelian logic of subject-predicate analysis. He does not try to deduce God’s existence through assigning predicates to the concept of God.
He claims that God’s existence can be known through rational intuition, our mind’s ability to grasp truths without a process of reasoning or inference.
He illustrates with a triangle. We are unable to clearly and distinctly conceive of a triangle while separating it from having three sides. So we can know through intuition that a triangle must have three sides.
Similarly, when we conceive of a supremely perfect being, we are unable to separate it from existence.
Descartes concludes we can intuitively know that God necessarily exists.
Malcolm also defends Anselm’s scholastic version.
Kant is correct, but only about contingent existence.
The reason for the existence of a contingent thing is dependence on something else, so is external and not a defining part of it.
However a necessary being contains the reason for its existence within itself.
So, necessary existence is a defining quality of a thing, in a way contingent existence is not.
So necessary existence is a predicate.

Evaluation:

So, both Anselm and Descartes’ versions of the ontological argument succeed against Kant’s criticism.
Kant makes the same mistake Gaunilo did, comparing God to contingent beings and thinking the ontological argument fails because it doesn’t work in the case of contingent beings (like cats and coins).

Kant’s critique that existence being a predicate doesn’t establish actual existence

Gaunilo distinguished necessity in mental judgement from necessity in reality.
E.g., the existence of the greatest island seems necessary in our minds, but isn’t in reality.
Kant developed Gaunilo’s underlying point in a stronger direction.
He focuses on Descartes’ illustration of a triangle having three sides, which is an example of necessity.
This avoids the mistake of testing Anselm’s logic with a contingent thing like an island or Thalers/coins.
It is necessary that a triangle has three sides.
This shows that if a triangle exists, then it necessarily has three sides.
Similarly, the ontological argument shows that the concept of God is necessarily connected to the concept of existence.
However, this only shows that if God exists, then God exists necessarily.
It cannot show that God actually does exist necessarily.
A necessary connection between an idea of something and the idea of existence, only tells us about ideas, not reality.
If God exists, it’s contradictory to deny God’s necessity. But if God does not exist, then neither does God’s necessity.

Response:

Malcolm responds that Kant’s criticism is incoherent because a necessary being must exist.
We cannot accept that God is a necessary being yet deny that God exists.

Evaluation

Hick successfully defends Kant’s style of objection.
Anselm & Malcolm claim that as the greatest or unlimited being, God cannot have the dependencies of ordinary beings, i.e., contingent existence or contingent non-existence.
God is defined by the impossibility of non-existence.
Hick objects that:
Non-contingency does not entail that non-existence is logically contradictory.
It only implies something metaphysical, that God is an eternal, non-dependent and self-explaining being (aseity). Hick calls this ‘ontological’ necessity.
Such a being could not exist. Not because it’s contingent, but because its existence or non-existence is what Hick calls a ‘sheer fact’.
God’s impossibility of non-existence just means absolute non-contingency. A non-dependent being could not exist, without contradiction.
So, the ontological argument cannot establish the logical necessity of God’s existence.
It at most proves that if God exists, then God exists in a metaphysically special way, with ontological necessity.
Gaunilo’s underlying point was right, but needed to be improved with this concept of ontologically necessity.

Conclusion

Gaunilo’s illustration of the island fails. However Gaunilo’s underlying claim was that there is a distinction between mental judgement and reality. Kant developed this criticism more convincingly:
“The unconditioned necessity of judgements is not the same as an absolute necessity of things” – Kant.
Hick adds the terminology to then capture this difference:
The ontological argument can only show that if God exists, God exists with ontological necessity.