Ontological argument

An ontological argument for the existence of God attempts the method of a priori proof, which uses intuition and reason alone. The argument examines the concept of God, and states that if we can conceive of the greatest possible being, then it must exist.

In the context of the Abrahamic religions, ontological arguments were first proposed by the medieval philosopher Anselm of Canterbury (in his Proslogion). Important variations were developed by later philosophers like René Descartes, Gottfried Leibniz, Norman Malcolm, Charles Hartshorne, and Alvin Plantinga. A modal-logic version of the argument was devised by the mathematician Kurt Gödel.

The differences among the argument's principal versions arise mainly from using different concepts of God as the starting point. Anselm, for example, starts with the notion of God as a being of which no greater can be conceived, while Descartes starts with the notion of God as being totally perfect, and Leibniz with something having all "perfections".

The ontological argument has been a controversial topic in philosophy. Many philosophers, including Gaunilo of Marmoutiers, St. Thomas Aquinas, David Hume, Immanuel Kant, Gottlob Frege and Bertrand Russell, have openly criticized it.

History

The argument may have been implicit in the works of Greek philosophers such as Plato, and the Neoplatonists. The mainstream view is that the ontological argument was first clearly stated and developed by St Anselm. Some scholars have argued that the Islamic philosopher Avicenna (Ibn Sina) developed a special kind of ontological argument before Anselm; however this is doubted by most scholars on the subject.

Anselm's argument

Anselm of Canterbury was the first to attempt an ontological argument for God's existence.

The ontological argument was proposed by Anselm of Canterbury (1033–1109) in the second and third chapter of his Proslogion.

Anselm's basic argument in Chapter 2 of the Proslogion goes as follows. First, when we hear the words "than which nothing greater can be thought", we understand what the words convey. Secondly, we are able to understand that what exists does so in at least the form of a thought. At this point it must be conceded that what exists does so either only as a thought or as both a thought and reality. However, it must be conceded that such a concept cannot exist only in our thoughts simply because if it existed only in our thoughts, then we could think of something greater than it: that which exists not only in thought, but also in reality - a conclusion which is logically forbidden by the initial premise (since to do so implies the contradiction of thinking of something greater than that which nothing greater can be thought.) It is at this point that the existence of the very thing which nothing greater can be thought cannot be confined to simply an intellectual existence, but must be endowed with a greatness that supersedes mere intellectual existence so as to also enter into and permeate all of objective, ontological existence. In conclusion, that which nothing greater can be thought truly does exist, and in later chapters of the Proslogion Anselm argues that this being has the traditional attributes of God like being the omnipotent creator.

In Chapter 3 of the Proslogion, Anselm brings in the notion of a being that cannot be conceived not to exist, which is similar to the notion of a necessary being. He argues that if x is such that x can be conceived not to exist, then x is not that than which nothing greater can be thought. Consequently, that than which nothing greater can be thought cannot be conceived not to exist. This can be read either as a gloss on the argument in Chapter 2, or as a new (and superior according to Malcolm) version of the argument, or as the first of Anselm's derivations of divine attributes from the concept of the maximally great being, in this case the attribute of necessity.

Descartes' ontological arguments

French thinker René Descartes composed several arguments that could be termed ontological.

René Descartes (1596–1650) composed a number of ontological arguments, which 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,

But if the mere fact that I can produce from my thought the idea of something that entails 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 his argument 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 to 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)

In Meditations III-VI, Descartes offers a version of the ontological argument very similar to Anselm's, which employs the same reduction method. The perfection of God logically requires existence, Descartes says, in the way a mountain logically implies a valley. And while the logical relationship between a mountain and a valley (or a triangle and the sum of its sides) does not imply real existence of those things, on the other hand: "because I cannot conceive God unless as existing, it follows that existence is inseparable from him, and therefore that he really exists: not that this is brought about by my thought, or that it imposes any necessity on things, but, on the contrary, the necessity which lies in the thing itself, that is, the necessity of the existence of God, determines me to think in this way: for it is not in my power to conceive a God without existence, that is, a being supremely perfect, and yet devoid of an absolute perfection, as I am free to imagine a horse with or without wings." (Descartes, Meditation V)

Criticisms and objections

Bertrand Russell.

The ontological argument received much criticism and was rejected by St Thomas Aquinas, and therefore by some Catholic theologians. It has also received its share of criticism from non-Christians: Bertrand Russell noted that "The argument does not, to a modern mind, seem very convincing, but it is easier to feel convinced that it must be fallacious than it is to find out precisely where the fallacy lies." Conversely, during his early Hegelian phase, Russell is also known to have said: "Great God in Boots! -- the ontological argument is sound!" 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. Others believe that existence is indeed a property and that, if the proof is fallacious, the fallacy must lie elsewhere.

Gaunilo's island

One of the earliest recorded objections to Anselm's argument was raised by one of Anselm's contemporaries, Gaunilo of Marmoutiers, who invited his readers to conceive of the greatest, or most perfect, island. As a matter of fact, it is likely that no such island actually exists. However, his argument would then say that we are not thinking of the greatest conceivable island, because the greatest conceivable island would exist, as well as having all those other desirable properties. Since we can conceive of this greatest or most perfect conceivable island, it must exist.

Such objections are known as "Overload Objections"; they do not claim to show where or how the ontological argument goes wrong; they simply argue that, if it is sound, so are many other arguments of the same logical form that we do not want to accept, arguments that would overload the world with an indefinitely large number of necessarily existing perfect islands, perfect lizards, perfect pencils and the like. The main problem with the ontological argument is that the final operation creates a contradiction between the two statements that are supposed to be equivalent. One assumes and the other implies. These are not equivalent and the operation is invalid.

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 of which nothing greater can be conceived. Therefore, the island analogy is not appropriate, as it has only limited application (islands). 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.

Scholastic Criticism

St. Thomas Aquinas, while proposing five proofs of God's existence, objected to Anselm's argument. He argued that, since the essence of God is his existence, the ontological argument would only be meaningful to someone who knew the essence of God completely. Since only God could completely know his own essence, only God can use the ontological argument to prove his own existence to himself.

Empiricist objection

David Hume did not believe an ontological argument was possible.

In David Hume's Dialogues Concerning Natural Religion, the character Cleanthes argues that no being could ever be proven to exist through an a priori demonstration:

[T]here is an evident absurdity in pretending to demonstrate a matter of fact, or to prove it by any arguments a priori. Nothing is demonstrable, unless the contrary implies a contradiction. Nothing, that is distinctly conceivable, implies a contradiction. Whatever we conceive as existent, we can also conceive as non-existent. There is no being, therefore, whose non-existence implies a contradiction. Consequently there is no being, whose existence is demonstrable.

Though this criticism is directed against a cosmological argument similar to that defended by Samuel Clarke in his first Boyle Lectures, the point applies to ontological arguments as well. However, Hume's criticism, when applied to the ontological argument, is generally seen as question begging, since his claim, that there is no being whose non-existence implies a contradiction, is precisely the claim in question; the ontological argument is an attempt to demonstrate that there is a being whose non-existence implies a contradiction. Hume's claim, as directed to the cosmological argument, cannot be used, therefore, to adequately respond to the ontological argument, since it affirms what is at question.

Kant: existence is not a predicate

Immanuel Kant

Immanuel Kant put forward a key refutation of the ontological argument in the Critique of Pure Reason (first edition, pp. 592–603; second edition, pp. 620–631). It is explicitly directed primarily against Descartes but also against Leibniz. His criticism was anticipated in Pierre Gassendi's Objections to Descartes' Meditations. Kant's refutation consists of several separate but interrelated arguments. They are shaped by his central distinction between analytic and synthetic judgments. In an analytic judgment, the predicate expresses something that is already contained within a concept and is therefore a tautology; in a synthetic judgment, the predicate, or claim, links the concept to something outside it that is not already logically implied by it. New knowledge consists of synthetic judgments.

Kant first questions the intelligibility of the very concept of an absolutely necessary being, considering "whether I am still thinking anything in the concept of the unconditionally necessary, or perhaps rather nothing at all". He examines one way of understanding the concept, which looks to examples of necessary propositions, e.g. "a triangle has three angles". But he rejects this account for two related reasons. First, no absolutely necessary judgments will ever yield an absolute necessity for things and their existence: e.g., "a triangle has three angles" yields only the conditioned necessity that, if a triangle exists, then necessarily three angles exist. Thus even if we defined a concept of a thing X so that "X exists" were a necessary judgment, all that would follow is the conditioned necessity that, if X exists, then necessarily X exists. Second, since contradictions arise only when we keep the subject and cancel the predicate (e.g., keeping God and canceling omnipotence), and since judgments of non-existence cancel both the subject and the predicate, therefore no judgment of non-existence can involve a contradiction. Kant concludes that there is a strong general case against the intelligibility of the concept of an absolutely necessary being.

Second, Kant argues that if we include existence in the definition of something, then asserting that it exists is a tautology. If we say that existence is part of the definition of God, in other words an analytic judgment, then we are simply repeating ourselves in asserting that God exists. We are not making a synthetic judgment that would add new information about the real existence of God to the purely conceptual definition of God.

Third, Kant argues that "'being' is obviously not a real predicate" and cannot be part of the concept of something. That is, to say that something is or exists is not to say something about a concept, but rather indicates that there is an object that corresponds to the concept, and "the object, as it actually exists, is not analytically contained in my concept, but is added to my concept". For objects of the senses, to say that something exists means not that it has an additional property that is part of its concept but rather that it is to be found outside of thought and that we have an empirical perception of it in space and time. A really existing thing does not have any properties that could be predicated of it that differentiate it from the concept of that thing. What differentiates it is that we actually experience it: for example, it has shape, a specifiable location, and duration. To give an example of Kant's point: the reason we say that horses exist and unicorns do not is not that the concept of horse has the property of existence and the concept of unicorn does not, or that the concept of horse has more of that property than the concept of unicorn. There is no difference between the two concepts in this regard. And there is no difference between the concept of a horse and the concept of a really existing horse: the concepts are identical. The reason we say that horses exist is simply that we have spatio-temporal experience of them: there are objects corresponding to the concept. So any demonstration of the existence of anything, including God, that relies on predicating a property (in this case existence) of that thing is fallacious.

Thus, in accordance with the second and third arguments, the statement "God is omnipotent" is an analytic judgment that articulates what is already contained in and implied by the concept of God, i.e. a particular property of God. The statement "God exists" is a synthetic judgment of existence that does not assert something contained in or implied by the concept of God and would require knowledge of God as an object of that concept. What the ontological argument does is attempt to import into the concept of God, as though it were a property, the synthetic assertion of the existence of God, thereby illegitimately and tautologically defining God as existing. In other words, it begs the question by assuming what it purports to prove.

But, fourth, Kant argues that the concept of God is in any case not the concept of one particular object of sense among others but rather an "object of pure thought", of something that by definition exists outside the field of experience and of nature. With regard to unicorns, we can specify how we could determine that unicorns exist, i.e., what spatio-temporal experience of them would look like. With regard to the concept of God, there is no way for us to know it as existing in the only legitimate and meaningful way we know other objects as existing. We cannot even determine "the possibility of any existence beyond that known in and through experience".

The typical response (e.g., Plantinga's ontological argument, below) to this objection to the ontological argument is this: "While 'existence' simpliciter 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. Some have objected that Plantinga's argument merely re-assumes that existence is a property and continues the argumentation by tautology.

Necessary nonexistence

Another rationale is attributed to Melbourne philosopher Douglas Gasking (1911–1994), 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.

Graham Oppy, a scholar on the ontological argument, isn't particularly impressed with this parody. 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 marvelous 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, it seems that one has no choice but to accept the fourth premise (although the validity of #3 is questionable). 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, [Gasking] is illicitly invoking the inverse principle that non-existence is a perfection."

Problem of coherence

Classical theism states that God is omnipotent, omniscient, and omnibenevolent. Ontological arguments proving the existence of such a God depend, explicitly or implicitly, upon these terms being meaningful in themselves and able to be jointly asserted coherently. Leibniz, who supported the ontological argument, especially as reformulated by Descartes, asserted that the argument "assumes something that must still be proved in order to render it mathematically evident; that is, it is tacitly assumed that this idea of the all-great or all-perfect being is possible, and implies no contradiction." This problem does not disprove the argument, but asserts that the possibility of God's existence, which is necessary to the argument, must be proven before the argument can be accepted.

Revisionists

God's essence is said to guarantee his existence—what this really means is that here what is at issue is not the existence of something.

Ludwig Wittgenstein

Obviously St. Anselm thought this argument was valid and persuasive, and it still has occasional defenders, but many contemporary philosophers believe that the ontological argument, as St. Anselm articulated it, does not stand up to strict logical scrutiny. Others, like John Duns Scotus, Gottfried Leibniz, Norman Malcolm, Charles Hartshorne, Kurt Gödel, and Alvin Plantinga, have reformulated the argument in an attempt to revive it. Another notable reformulation is offered by Iris Murdoch. She takes it that St. Anselm's argument, while not a proof of the existence of God, is a demonstration of the necessary existence of the Good.

Plantinga's modal form

Alvin Plantinga

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:

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 (by axiom S5) it is necessarily true that an omniscient, omnipotent and perfectly good being exists.
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. Paul Almond strongly disagrees with the argument based on the "incoherence, incorrectness and triviality" of axiom S5. One objection by Richard M. Gale, professor emeritus 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 within the system S5 (without which the argument fails) then one understands that "possibly necessarily" is basically the same as "necessarily".

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? No it would not. If it be a valid argument then it is not rooted in belief. Like anything it would be rooted in experience. Otherwise it is just a mental creation of which there are an infinite number, none of which need to be true or untrue. 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."

Both philosophers are technically correct. To deny premise (3) amounts to asserting that it is logically impossible that there is a being that exemplifies maximal greatness — thus the argument appears to demonstrate that either the existence of God is logically impossible or it is logically necessary. However, this is only the case if one conceives God as this 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 a probability of 50/50.

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.

Alexander R. Pruss and Samkara's dictum

Statue of Adi Shankara

A very different approach has recently been attempted by Alexander R. Pruss, currently of Baylor University. 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, therefore breaking the necessity of said maximally great being.

See also

• Gödel's ontological proof for the existence of God

References

• Hartshorne, 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.
• Leaman, Oliver (2007). Islamic Philosophy A-Z. Edinburgh University Press. ISBN 0748620893. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
• Logan, Ian (2009). Reading Anselm's Proslogion: The History of Anselm's Argument and its Significance Today. Ashgate. ISBN 9780754661238.
• Gracia, Jorge J. E. (2003). The Classics of Western Philosophy: A Reader's Guide. Blackwell Publishing. ISBN 0631236112. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
• 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
• Freddoso, Alfred J. "The Existence and Nature of God". The Ontological Argument. Univ of Notre Dame Pr, 1983.

External links

• Graham Oppy. "Ontological arguments". In Zalta, Edward N. (ed.). Stanford Encyclopedia of Philosophy.
• Lawrence Nolan. "Descartes' Ontological argument". In Zalta, Edward N. (ed.). Stanford Encyclopedia of Philosophy.
• Kenneth Einar Himma, The Ontological Argument — from the Internet Encyclopedia of Philosophy
• History of the ontological argument with an annotated bibliography
• 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
• Gregory S. Neal, "Anselm's Ontological Argument For the Existence of God" from Grace Incarnate (1990)
• Maciej Nowicki, "Anselm and Russell" Logic and Logical Philosophy (2006) 15:355-368.
• Mulla Sadra’s Argument of the Righteous and a Critical Study of Kant and Hume’s Views on the Proofs of God’s Existence by Hamid Reza Ayatullahi.
• Brown, Paterson. "Professor Malcolm on Anselm's Ontological Arguments", Analysis, 1961.