Ontological argument

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An ontological argument for the existence of God is one that attempts the method of a priori proof, which utilizes intuition and reason alone.^[1] In the context of the Abrahamic religions, it was first proposed by the medieval philosophers Avicenna (in The Book of Healing)^[2] and Anselm of Canterbury (in his Proslogion), and important variations have been developed by later philosophers such as René Descartes, Gottfried Leibniz, Norman Malcolm, Charles Hartshorne, Alvin Plantinga, and Kurt Gödel. A modal logic version of the argument was devised by mathematician Kurt Gödel. The ontological argument has been a controversial topic in philosophy. Many philosophers, including David Hume, Immanuel Kant, Gottlob Frege, and Gaunilo of Marmoutiers, have openly criticized the argument.

The argument works by examining the concept of God, and arguing that it implies the actual existence of God; that is, if we can conceive of God, then God exists. However, this type of argument is often criticized as committing a bare assertion fallacy, meaning that it offers no outside premise to support its argument other than qualities inherent to the unproven statement.^{[citation needed]}

The argument's different versions arise mainly from using different concepts of God as the starting point. For example, Anselm starts with the notion of God as a being than which no greater can be conceived, while Descartes starts with the notion of God as being maximally perfect (as having all perfections).

Contents 1 Anselm's argument 1.1 A modern description of the argument 1.2 Anselm's second argument 2 Descartes' ontological arguments 3 Criticisms and objections 3.1 General objection 3.2 Gaunilo's island 3.3 Necessary nonexistence 3.4 Existence as a property 4 Revisionists 4.1 Plantinga's modal form and contemporary discussion 5 Notes 6 Bibliography 7 See also 8 External links

[edit] Anselm's argument

The ontological argument was first proposed by Anselm of Canterbury (1033–1109) in Chapter 2 of the Proslogion.^[3] While Anselm did not propose an ontological system, he was very much concerned with the nature of being. He stated that there are necessary beings — things that cannot not exist — and contingent beings — things that may exist but whose existence is not needed.

Anselm presents the ontological argument as part of a prayer directed to God. He starts with a definition of God, or a necessary assumption about the nature of God, or perhaps both.

"Now we believe that [the Lord] is something that than which nothing greater can be conceived."

Then Anselm asks: does God exist?

"Then is there no such nature, since the fool has said in his heart: God is not?"

To answer this, first he tries to show that God exists 'in the understanding':

"But certainly this same fool, when he hears this very thing that I am saying — something than which nothing greater can be imagined — understands what he hears; and what he understands is in his understanding, even if he does not understand that it is. For it is one thing for a thing to be in the understanding and another to understand that a thing is."

Anselm goes on to justify his assumption, using the analogy of a painter:

"For when a painter imagines beforehand what he is going to make, he has in his understanding what he has not yet made but he does not yet understand that it is. But when he has already painted it, he both has in his understanding what he has already painted and understands that it is.

"Therefore even the fool is bound to agree that there is at least in the understanding something than which nothing greater can be imagined, because when he hears this he understands it, and whatever is understood is in the understanding."

Now Anselm introduces another assumption (some authors have argued that this assumption introduces a new version of the argument):

"And certainly that than which a greater cannot be imagined cannot be in the understanding alone. For if it is at least in the understanding alone, it can be imagined to be in reality too, which is greater."

"Therefore if that than which a greater cannot be imagined is in the understanding alone, that very thing than which a greater cannot be imagined is something than which a greater can be imagined. But certainly this cannot be."

Anselm has thus found a contradiction, and from that contradiction, he draws his conclusion:

"There exists, therefore, beyond doubt something than which a greater cannot be imagined, both in the understanding and in reality."

[edit] A modern description of the argument

Anselm's Argument may be summarized thus:

1. God is, by definition, a being greater than anything that can be imagined.
2. Existence in both reality and imagination is greater than existence solely in one's imagination.
3. Therefore, God must exist in reality; if God did not, then God would not be a being greater than anything that can be imagined.

This is a shorter modern version of the argument. Anselm framed the argument as a reductio ad absurdum wherein he tried to show that the assumption that God does not exist leads to a logical contradiction. The following steps more closely follow Anselm's line of reasoning:

1. God is that entity than which nothing can be greater.
2. The concept of God exists in human understanding.
3. God exists in one's mind but not in reality.
4. The concept of God's existence is understood in one's mind.
5. If God existed in reality it would be a greater thing than God's existence in the mind.
6. The final step to God's existence is that God in reality must exist.

[edit] Anselm's second argument

Anselm in his Proslogion 3 made another a priori argument for God, this time based on the idea of necessary existence. He claimed that if God is that than which nothing greater can be conceived, it is better to be necessary than contingent. Therefore, God must be necessary. To sum it up:

1. God is the entity, which nothing greater can be conceived.
2. It is greater to be necessary than not.
3. God must be necessary.
4. God necessarily exists.

[edit] Descartes' ontological arguments

René Descartes (1596–1650) composed a number of ontological arguments that differed from Anselm's formulation in important ways. Generally speaking, it is less a formal argument than a natural intuition.

Descartes wrote in the Fifth Meditation:^[4]

But if the mere fact that I can produce from my thought the idea of something entails that everything which I clearly and distinctly perceive to belong to that thing really does belong to it, is not this a possible basis for another argument to prove the existence of God? Certainly, the idea of God, or a supremely perfect being, is one that I find within me just as surely as the idea of any shape or number. And my understanding that it belongs to his nature that he always exists is no less clear and distinct than is the case when I prove of any shape or number that some property belongs to its nature (AT 7:65; CSM 2:45).

The intuition above can be formally described as follows:

1. Whatever I clearly and distinctly perceive to be contained in the idea of something is true of that thing.
2. I clearly and distinctly perceive that necessary existence is contained in the idea of God.
3. Therefore, God exists.

In another, less formal statement of his argument, he draws an analogy between belief in the existence of God and the geometric demonstration:

Whatever method of proof I use, I am always brought back to the fact that it is only what I clearly and distinctly perceive that completely convinces me. Some of the things I clearly and distinctly perceive are obvious to everyone, while others are discovered only by those who look more closely and investigate more carefully; but once they have been discovered, the latter are judged to be just as certain as the former. In the case of a right-angled triangle, for example, the fact that the square on the hypotenuse is equal to the square on the other two sides is not so readily apparent as the fact that the hypotenuse subtends the largest angle; but once one has seen it, one believes it just as strongly. But as regards God, if I were not overwhelmed by philosophical prejudices, and if the images of things perceived by the senses did not besiege my thought on every side, I would certainly acknowledge him sooner and more easily than anything else. For what is more manifest than the fact that the supreme being exists, or that God, to whose essence alone existence belongs, exists? (AT 7:68–69; CSM 2:47)

[edit] Criticisms and objections

The ontological argument received much criticism at its time and was rejected by St. Thomas Aquinas,^[5] and therefore by some Catholic theologians.^[6] It has also received its share of criticism from non-Christians; Bertrand Russell noted of the argument: "it is easier to feel convinced that it must be fallacious than to find out precisely where the fallacy lies."^[7] The first objections were in the form of parodies, such as Gaunilo's island, but some believe Immanuel Kant to have finally settled the matter with his famous rejection of existence as a property.^[8] Others believe that existence is indeed a property, and that if the proof is fallacious, the fallacy must lie elsewhere.

[edit] General objection

David Hume claimed that nothing could ever be proven to exist through an a priori, rational argument by arguing as follows:^[9]

1. The only way to prove anything a priori is through an opposite contradiction. For example, I am a married bachelor.
2. The resulting contradiction makes something inconceivable. Obviously it is impossible to have a married bachelor.
3. It is impossible to comprehend anything not existing. Thus it is inconceivable to imagine anything not existing.
4. Nothing can be proven to exist a priori, including God.

[edit] Gaunilo's island

One of the earliest recorded objections to Anselm's argument was raised by one of Anselm's contemporaries, Gaunilo of Marmoutiers. Gaunilo invited his readers to think of the greatest, or most perfect, conceivable island. As a matter of fact, it is likely that no such island actually exists. However, his argument would then say that we aren't thinking of the greatest conceivable island, because the greatest conceivable island would exist, as well as having all those other desirable properties. Note that this is merely a direct application of Anselm's own premise that existence is a perfection (point 5 in the previous section). Since we can conceive of this greatest or most perfect conceivable island, then it must exist. While this argument seems absurd, Gaunilo claims that it is no more so than Anselm's.

Such objections are known as "Overload Objections"; they don't claim to show where or how the ontological argument goes wrong, they simply argue that if it is sound, then so are many other arguments of the same logical form that we don't want to accept, arguments that would overload the world with an indefinitely large number of necessarily existing perfect islands, perfect lizards, perfect pencils, etc.^[10]

There is a possible answer to this objection, put forward by the Roman Catholic philosopher Paul J. Glenn (who himself disagreed with the proof on other grounds) in his 'An Introduction to Philosophy'. It is that Anselm's argument is only applicable to a Being than which nothing greater can be conceived. Therefore the island analogy is not appropriate, as it has only limited application (islands). The Supreme Being is not merely a Platonic Form, but a unique God Who necessarily exists because His greatness is limitless. Islands are by definition limited. They need not have every greatness. God, to be God, must have. And so this proof could only apply to the greatest Being possible.

[edit] Necessary nonexistence

Another rationale is attributed to Melbourne philosopher Douglas Gasking (1911–1994),^[11] one component of his proof of the nonexistence of God:

1. The creation of the world is the most marvelous achievement imaginable.
2. The merit of an achievement is the product of (a) its intrinsic quality, and (b) the ability of its creator.
3. The greater the disability (or handicap) of the creator, the more impressive the achievement.
4. The most formidable handicap for a creator would be non-existence.
5. Therefore if we suppose that the universe is the product of an existent creator we can conceive a greater being — namely, one who created everything while not existing.
6. Therefore, God does not exist.

The third premise might seem odd; the intuition is that we are generally more impressed by, for example, a four-year-old child composing a marvelous symphony than the same composition of a professional. In fact, Graham Oppy, an expert on the ontological argument, who isn't particularly impressed with this parody, does not object to (3). Writing in the Stanford Encyclopedia of Philosophy he is mainly concerned with the first premise, asking "what reason is there to believe that the creation of the world is 'the most marvellous achievement imaginable.' Gasking was apparently thinking of the "world" or "universe" as the same as "everything."

If one is willing to accept the first premise, one has no choice but to accept the fourth premise. Thus, the philosophical point of this parody is to highlight problems when existence is taken as property: "whereas Anselm illicitly supposed that existence is a perfection, [Fred] is illicitly invoking the inverse principle that non-existence is a perfection."^[11]

[edit] Existence as a property

Another traditional criticism of the argument (first found in Pierre Gassendi's Objections to Descartes' Meditations, and later modified by Kant) is that existence is not a perfection, because existence is not a property as such, and that referring to it as a property confuses the distinction between a concept of something and the thing itself. The argument is that anything that has the property of being non-existent could not possibly have any other properties, being non-existent, and thus not having color, location, or any other property. One cannot, the argument says, speak meaningfully of the non-existent apple that one is holding, saying that it is red, crisp, weighs a certain amount, is in one's right hand, and does not exist.^{[citation needed]}

It wasn't until Frege's development of first-order logic that a more formal treatment of existence could be given with the introduction of quantification.

This objection centers around the belief that existence is not a predicate. Since a predicate is a quality, it would be right to conclude 'God is great' (since greatness is a predicate) but not right to conclude 'God is'. This has come about because of the use of 'is' by Anselm. Anselm uses 'is' in the same way both for the predicate (God is great) as for the existential (God is), i.e. you can't define God into existence.^{[citation needed]}

For example, in the simple equation 3x = 9 the answer is x = 3; however, x does not exist. x has the quality (the predicate) of 3 but this does not mean that there is an actual "x."^{[citation needed]}

Another way to make this objection, first put forward by Descartes' critic Pierre Gassendi and later developed by Immanuel Kant, was to argue that existence is not a quality of things at the same level of other qualities, such as the shape or the size of an object. If you think of a certain object conceptually, and if you think of the object existing, the two thoughts are essentially the same. The idea behind the two remains unaltered because no other essential qualities are imposed on said object.

In short, to think of a thing that exists and to think of that thing if it did not exist, is to in effect think of the same idea; existence does not do anything to change the idea in question.

The typical response to this objection to the ontological argument is this: "While 'existence' per se cannot be a predicate, 'necessary existence' (like 'contingent existence') can be a predicate." Some things are contingently so, and some things are necessarily so. God, it is said, is a necessary being de re. See Plantiga's ontological argument below for a discussion of "necessary existence."

[edit] Revisionists

Obviously Anselm thought this argument was valid and persuasive, and it still has occasional defenders, but many contemporary philosophers believe that the ontological argument, as Anselm articulated it, does not stand up to strict logical scrutiny.^[1] Others, like Gottfried Leibniz, Norman Malcolm, Charles Hartshorne, Kurt Gödel and Alvin Plantinga, have reformulated the argument in an attempt to revive it.

[edit] Plantinga's modal form and contemporary discussion

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Alvin Plantinga has given another descriptive, initial version of the argument, one where the conclusion follows from the premises, assuming axiom S5 of modal logic. A version of his argument is as follows^[12]:

1. It is proposed that a being has maximal excellence in a given possible world W if and only if it is omnipotent, omniscient and wholly good in W; and
2. It is proposed that a being has maximal greatness if it has maximal excellence in every possible world.
3. Maximal greatness is possibly exemplified. That is, it is possible that there be a being that has maximal greatness. (Premise)
4. Therefore, possibly it is necessarily true that an omniscient, omnipotent and perfectly good being exists
5. Therefore, it is necessarily true that an omniscient, omnipotent and perfectly good being exists. (By S5)
6. Therefore, an omniscient, omnipotent and perfectly good being exists.

This argument has two controversial premises: The axiom S5 and the "possibility premise" that a maximally great being is possible. The more controversial of these two is the "possibility premise" since S5 is widely (though not universally) accepted. One objection by Richard M. Gale, professor of philosophy at University of Pittsburgh, is that the "possibility premise" begs the question, because one only has the epistemic right to accept it if one understands the nested modal operators, and if one understands them then one understands that "possibly necessarily" is basically the same as "necessarily".^[13] Plantinga replies to this objection as follows: "Once you see how the argument works, you may think that asserting or believing the premise is tantamount to asserting or believing the conclusion; the canny atheist will say that he does not believe it is possible that there be a maximally great being. But would not a similar criticism hold of any valid argument? Take any valid argument: once you see how it works, you may think that asserting or believing the premise is tantamount to asserting or believing the conclusion." To deny premise (3) amounts to asserting that it is logically impossible that there is a being the exemplifies maximal greatness — thus the argument appears to demonstrate that either the existence of God is logically impossible or it is logically necessary.^[14]

There are, nonetheless, other approaches to the possibility premise. Leibniz thought that the possibility premise followed from the claim that "positive qualities" could not logically conflict with one another, and hence the notion of a being that had all the positive qualities had to be coherent. Gödel's ontological proof uses similar ideas.

A very different approach has recently been attempted by Alexander R. Pruss of Georgetown University.^[15] He starts with the 8th–9th century AD Indian philosopher Samkara's dictum that if something is impossible, then we cannot have a perception (even a non-veridical one) that it is the case. Contraposing, it follows that if we have a perception that p, then even though it might not be the case that p, it is at least the case that possibly p. If mystics in fact perceive the existence of a maximally great being, it follows that the existence of a maximally great being is at least possible. And that is all that is needed to get the modal ontological argument off the ground. One difficulty in this argument is that one might misinterpret the content of one's experience, and hence the mystic might be incorrect even in a cautious description of an experience as an experience "as of a maximally great being." Another problem would be if one could have an experience as of a universe that is uncreated, eternal and godless (i.e., devoid of a maximally great being), which, if experienced, must be possible, ergo breaking the necessity of said maximally great being.

Interestingly, Plantinga himself does not think the modal ontological argument is always a good proof of the existence of God. It depends on what his interlocutor thinks of the possibility premise. Nonetheless, Plantinga has suggested that because we do not have any evidence against the possibility premise, it might be reasonable to suppose it has probability 1/2. It follows from this that the existence of God can at the outset be held to have probability 1/2, though further evidence may increase or decrease this. Even though the possibility God does not exist is just as likely by this reasoning, Plantinga's point is to establish that even if one can't prove the existence of God, the argument is still victorious in the sense of justifying that belief in God is at least rational.

[edit] Notes

[edit] Bibliography

• Hartshore, Charles, The Logic of Perfection (LaSalle, IL: Open Court, 1962)
• Jori, Alberto, 'Die Paradoxien des menschlichen Selbstbewusstseins und die notwendige Existenz Gottes — Zu 'Cogitatio' und 'Intellectus' im Streit zwischen Anselm und Gaunilo', in: C. Viola and J. Kormos (ed.), Rationality from Saint Augustine to Saint Anselm. Proceedings of the International Anselm Conference — Piliscsaba (Hungary) 20–23 June 2002 (Piliscsaba 2005), pp. 197–210.
• Malcolm, Norman, "Anselm's Ontological Arguments" Philosophical Review, vol. 69, no. 1 (1960), 41–62

{reprinted in: "The Existence of God (Problems of Philosophy)" edited John Hick published Macmillan 1964 ISBN 0020854501 and also in : Knowledge and Certainty: Essays and Lectures by Norman Malcolm published Cornell University Press (Dec 1975) ISBN 0801491541.}

• Plantinga, Alvin, The Ontological Argument from St. Anselm to Contemporary Philosophers (Garden City, NY: Doubleday, 1965)
• Plantinga, Alvin. God, Freedom and Evil. (Grand Rapids, Michigan: Eerdmans, 1977) pp.85–112

[edit] See also

• Overviews: Arguments for the existence of God, Arguments against the existence of God
• Other major attempted proofs: Cosmological argument, Teleological argument, Argument from morality
• Gödel's ontological proof for the existence of God
• Pascal's Wager

[edit] External links

• Ontological Arguments — from the Stanford Encyclopedia of Philosophy
• Descartes' Ontological Argument — from the Stanford Encyclopedia of Philosophy
• Kenneth Einar Himma, The Ontological Argument — from the Internet Encyclopedia of Philosophy
• Medieval Sourcebook: Gaunilo: In Behalf of the Fool, and Anselm's Reply
• Medieval Sourcebook: Philosophers' Criticisms of Anselm's Ontological Argument for the Being of God
• Paul E. Oppenheimer & Edward N. Zalta, "On the Logic of the Ontological Argument" from James Tomberlin ed., Philosophical Perspectives 5: The Philosophy of Religion (Atascadero: Ridgeview, 1991) pp. 509–529
• Peter Millican, "The one fatal flaw in Anselm's argument" from Mind Vol.113, pp451ff (2004)
• Gregory S. Neal, "Anselm's Ontological Argument For the Existence of God" from Grace Incarnate (1990)
• Cartoon example of the ontologial argument, from Mac Hall
• Brief Synopsis of the Ontological Argument

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