Ontological argument
Encyclopedia
The ontological argument for the existence of God (or simply ontological argument) is an a priori argument for the existence of God
. The ontological argument was first proposed by the eleventh-century monk Anselm of Canterbury
, who defined God as the greatest possible being we can conceive. He suggested that the greatest possible being must exist in reality: A being that exists in reality is greater than one that exists only in the mind. Descartes developed the argument, suggesting that God is a "supremely perfect being" who holds all perfections. He argued that God must therefore hold the perfection of existence and, by definition, must exist. Gottfried Leibniz slightly augmented Descartes' ideas in an attempt to prove that a "supremely perfect" being is a coherent concept.
The ontological argument has been subject to numerous criticisms, initially from Anselm's contemporary, Gaunilo of Marmoutiers
. Gaunilo, using the analogy of a perfect island, suggests that the ontological argument was flawed and led to impossible or incoherent conclusions. Later, Thomas Aquinas
rejected the argument on the basis that humans cannot know God's nature, whilst David Hume
took empirical
objection to the argument, criticising its lack of evidential reasoning. He also rejected the idea that anything can exist necessarily. Immanuel Kant
put forward an objection to the argument, based on what he saw as the false premise that existence is a predicate. He proposed that, as it adds nothing to the essence of a being, existence is not a predicate (or perfection) and thus a "supremely perfect" being can be conceived to not exist. Douglas Gasking presented a parody to the ontological argument, recorded and published by William Grey. Gasking uses a form of ontological argument to prove God's existence in order to demonstrate the flaws with the argument. Finally, philosophers including C. D. Broad have dismissed the coherence of a maximally great being, proposing that some attributes of greatness are incompatible with others, making a maximally great being incoherent.
In light of criticism, some philosophers have attempted to revise the ontological argument to fix the problems presented. Mulla Sadra
, an Islamic philosopher, attempted to prove the existence of God through the reality of existence, concluding with God's pre-eternal necessity. Alvin Plantinga has used modal logic
to propose the necessary existence of God. Alexander R. Pruss has used Sankara's dictum that if something is impossible, we can have no perception of it. Thus, if we have a conception of something, then it is possible. Finally, Paul Oppenheimer and Edward Zalta have tried using an automated theorem prover to validate Anselm's proof.
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 position is doubted by a number of scholars.
The ontological argument was first proposed by Anselm of Canterbury
(1033–1109) in the second and third chapter of his Proslogion
. The argument Anselm puts forward is not, however, presented in order to prove God's existence. Rather, Proslogion is more a work of meditation, in which he documents how the idea of God had become self-evident.
In Chapter 2 of the Proslogion, Anselm defines what we understand as God to be a "being than which no greater can be conceived". Anselm suggests that we understand the concept of a "being than which no greater can be conceived" and what it brings causes to exist in the mind. The concept must exist either only in our mind or in our mind and in reality. If such a being exists only in our mind, then a greater being - that which exists in reality as well - can be conceived. Therefore, if we can conceive of a being that than which nothing greater can be conceived, then it must exist in reality. Therefore, a being that than which nothing greater could be conceived must exist in reality.
In Chapter 3 of the Proslogion, Anselm suggests the notion of a being that cannot be conceived not to exist (similar to the notion of a necessary being). He argues if something can be conceived not to exist, then it is not that than which nothing greater can be conceived. As a consequence, that than which nothing greater can be conceived 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 Malcolm argued superior) 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.
René Descartes
(1596–1650) composed a number of ontological arguments, which differed from Anselm's formulation. Generally speaking, it is less a formal argument than a natural intuition.
Descartes wrote in the Fifth Meditation
,
Descartes argues that God's existence can be deduced from his nature, just as geometric
ideas can be deduced from the nature of shapes - Descartes uses the deduction of the sizes of angles in a triangle as an example. Descartes suggests that the concept of God is that of a supremely perfect being, holding all perfections fully. He proposes that existence is a perfection: it would be better to exist than not to exist. Thus, if the notion of God did not include existence, it would not be supremely perfect, as it would be lacking a perfection. Consequently, the notion of a supremely perfect God who does not exist, Descartes argues, is unintelligible. Therefore, according to his nature, God must exist.
. He invites his reader to conceive an island "more excellent" than any other island. He suggests that, according to Anselm's proof, this island must necessarily exist, as an island that exists would be more excellent. Gaunilo's criticism does not explicitly demonstrate a flaw in Anselm's argument; rather, it argues that, if sound, so are many other argument of the same logical form
that cannot be accepted.
Gaunilo offered a further criticism of Anselm's ontological argument. He suggested that the notion of God cannot, as Anselm asserted, be conceived. He argued that many theists would accept that God, by nature, cannot be fully comprehended. Therefore, if humans cannot fully conceive of God, the ontological argument cannot work.
Anselm responded to Gaunilo's criticism by suggesting that argument applied only to concepts with necessary existence. He suggested that only a being with necessary existence can fulfill the remit of "that than which nothing greater can be conceived". Furthermore, a contingent object, such as an island, could always be improved and thus could never reach a state of complete perfection. For that reason, Anselm dismissed any argument which did not relate to a being with necessary existence.
, objected to Anselm's argument. He suggested that people cannot know the nature of God and, therefore, cannot conceive of God in the way Anselm proposed. The ontological argument would be meaningful only to someone who understands the essence of God completely. Aquinas reasoned that, as only God can completely know his essence, only he can use the argument. Aquinas' rejection of the ontological argument caused some Catholic theologians to also reject the argument.
Scottish philosopher and empiricist, David Hume, argued that nothing can be proven to exist using only a priori reasoning. In his
Dialogues Concerning Natural Religion
, the character Cleanthes proposes this argument:
Hume also suggested that, as we have no abstract idea of existence (apart from as part of our ideas of other objects), we cannot claim that the idea of God implies his existence. He suggests that any conception of God we may have, we can conceive either of existing or of not existing. Existence is not a quality (or perfection), so the concept of a completely perfect being need not actually exist. Thus, he claims that it is not a contradiction to deny God's existence. Although this criticism is directed against a cosmological argument, similar to that of Samuel Clarke
in his first Boyle Lecture
, it can be applied to ontological arguments as well.
Immanuel Kant
put forward a key refutation of the ontological argument in his Critique of Pure Reason
(first edition, pp. 592–603; second edition, pp. 620–631). It was primarily and explicitly directed at René Descartes
, but also attacked the position of Gottfried Leibniz
. Kant's refutation consists of several separate but interrelated arguments, 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 concept of a necessary being. He considers examples of necessary proposition, such as "a triangle has three angles", and rejects the transfer of this logic to the existence of God. First, he argues that such necessary propositions are necessarily true only if such a being exists: If a triangle exists, it must have three angles. The necessary proposition, he argues, does not make the existence of a triangle necessary. Thus, he argued that, if the proposition "X exists" is posited, it would follow that, if X exists, it exists necessarily; this does not mean that X does exist in reality. Second, he argues that contradictions arise only when the subject and predicate are maintained and, therefore, a judgement of non-existence cannot be a contradiction, as it denies the predicate.
Kant then proposes that the statement "God exists" must be either analytic or synthetic - the predicate must be either inside or outside of the subject, respectively. If the proposition is analytic, as the ontological argument takes it to be, then the statement would be true only because of the meaning given to the words. Kants argues that this is merely a tautology and cannot say anything about reality. However, if the statement is synthetic, the ontological argument does not work, as the existence of God is not contained within the definition of God (and, as such, evidence for God would need to be found).
Kant goes on to argue that "'being' is obviously not a real predicate" and cannot be part of the concept of something. He proposes that existence is not a predicate, or quality. This is because existence does not add to the essence of a being, indicating merely its occurrence in reality. He suggests that, if he takes the subject of God with all its predicate and then asserts that God exists, "I add no new predicate to the conception of God". He argues that the ontological argument works only if existence is a predicate; if this is not so, then it is conceivable for a completely perfect being to not exist, thus defeating the ontological argument.
In addition, Kant argues that the concept of God is not of one a particular sense; rather, it is an "object of pure thought". He presents the view that God exists outside the realm of experience and nature. Because we cannot experience God through experience, Kant argues that it is impossible to know how we would verify God's existence. This is in contrast to material concepts, which can be verified by means of the senses.
Gasking's proposal of premise 4 is a response to Anselm's assumption that existence is a predicate and perfection. Gasking uses this logic to assume that non-existence must therefore be a disability. It is this use of Anselm's logic, which allows the conclusion that God must not exist.
Graham Oppy
, a philosopher of religion, has criticised the argument in the Stanford Encyclopedia of Philosophy
. He suggests that, though it may be accepted that it would be a greater achievement for a non-existent creator to create something than a creator who exists, there is no reason assume that a non-existent creator would be a greater being. He continues his criticism by arguing that there is no reason to view the creation of the world as "the most marvellous achievement imaginable". Finally, he suggests that it may be inconceivable for a non-existent being to create anything at all. Thus, Oppy views Gasking's criticism as a weak parody of the ontological argument.
: that God is omnipotent, omniscient, and morally perfect. There exist arguments that suggest that the combination of these characteristics is logically incoherent. For example, a morally perfect being must be perfectly merciful and perfectly just. Perfect justice requires punishing every person exactly according to what they deserve; perfect mercy requires punishing some people less than they deserve. This would make moral perfection inconsistent. Furthermore, the concepts of omniscience and omnipotence could be incompatible. The problem of divine foreknowledge is that, if omniscience includes the ability to know exactly what will happen at any given moment, and free will means the ability to make free choices at any given moment, then God cannot logically know what a being with free will shall choose to do. If he does, then the being does not have free will. However, if God is omnipotent (with the ability to do anything), then he should have the ability to create being with free will. This would suggest that omniscience and omnipotence are incompatible. If any properties of a supremely perfect being are incompatible, the idea of a supremely perfect being becomes incoherent. If this is true, the ontological argument does not work.
criticised the argument, asserting 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." During his early Hegelian
phase, Russell is also known to have said: "Great God in Boots! -- the ontological argument is sound!" Richard Dawkins
has also rejected the argument as "infantile" and “dialectical prestidigitation”.
(c. 1571–1640) was an Islamic philosopher
, influenced by Avicenna's
philosophy. Sadra discussed Avicenna's arguments for the existence of God, claiming that is was not an a priori argument
and rejecting the argument on the basis that existence precedes essence
.
Sadra put forward a new argument, known as Argument of the Righteous ( — Al-Burhan al-Siddiqin). The argument attempts to prove the existence of God through the reality of existence, and to conclude with God's pre-eternal necessity. In this argument, a thing is demonstrated through itself, and a path is identical with the goal. In other arguments, the truth
is attained from somewhere other than itself, for example from the possible to the necessary, from the originated to the eternal origin, or from motion to the unmoved mover. But in the argument of the righteous, there is no middle term other than the truth. His version of the ontological argument can be summarised as follows:
Mulla Sadra describes this argument in Asfar as follows:
has presented another version of the argument. The conclusion he provides logically follows from the premises, assuming axiom S5
of modal logic - if possibly p, then necessarily possible p and if possibly necessarily p, then necessarily p. A version of his argument is as follows:
This argument has two controversial premises: the axiom S5
and the "possibility premise" - that a maximally great being is possible. S5 is widely accepted, though not universally so. Paul Almond criticised the argument due to the "incoherence, incorrectness and triviality" of axiom S5.
The more controversial premise is the "possibility premise". Richard M. Gale, professor emeritus of philosophy at University of Pittsburgh
, argues that the "possibility premise" begs the question, because one has the epistemic right to accept it only 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 in essence the same as "necessarily".
. He starts with the 8th–9th century AD Indian philosopher Sankara
's dictum that if something is impossible, we cannot have a perception (even a non-veridical one) that it is the case. 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.
, Paul Oppenheimer and Edward Zalta describe how they used an automated theorem prover called Prover9
to validate Anselm's ontological thesis. The Prover9 reasoning engine subsequently discovered a simpler formally valid
(if not necessarily sound
) ontological argument from a single non-logical premise.
Existence of God
Arguments for and against the existence of God have been proposed by philosophers, theologians, scientists, and others. In philosophical terms, arguments for and against the existence of God involve primarily the sub-disciplines of epistemology and ontology , but also of the theory of value, since...
. The ontological argument was first proposed by the eleventh-century monk Anselm of Canterbury
Anselm of Canterbury
Anselm of Canterbury , also called of Aosta for his birthplace, and of Bec for his home monastery, was a Benedictine monk, a philosopher, and a prelate of the church who held the office of Archbishop of Canterbury from 1093 to 1109...
, who defined God as the greatest possible being we can conceive. He suggested that the greatest possible being must exist in reality: A being that exists in reality is greater than one that exists only in the mind. Descartes developed the argument, suggesting that God is a "supremely perfect being" who holds all perfections. He argued that God must therefore hold the perfection of existence and, by definition, must exist. Gottfried Leibniz slightly augmented Descartes' ideas in an attempt to prove that a "supremely perfect" being is a coherent concept.
The ontological argument has been subject to numerous criticisms, initially from Anselm's contemporary, Gaunilo of Marmoutiers
Gaunilo of Marmoutiers
Gaunilo of Marmoutiers was an 11th-century Benedictine monk, best known for his criticism of St Anselm's ontological argument for the existence of God. His thesis On Behalf of the Fool takes its name from the fools mentioned in Psalms 14:1 and Psalms 53:1, who say in their hearts that there is no...
. Gaunilo, using the analogy of a perfect island, suggests that the ontological argument was flawed and led to impossible or incoherent conclusions. Later, Thomas Aquinas
Thomas Aquinas
Thomas Aquinas, O.P. , also Thomas of Aquin or Aquino, was an Italian Dominican priest of the Catholic Church, and an immensely influential philosopher and theologian in the tradition of scholasticism, known as Doctor Angelicus, Doctor Communis, or Doctor Universalis...
rejected the argument on the basis that humans cannot know God's nature, whilst David Hume
David Hume
David Hume was a Scottish philosopher, historian, economist, and essayist, known especially for his philosophical empiricism and skepticism. He was one of the most important figures in the history of Western philosophy and the Scottish Enlightenment...
took empirical
Empiricism
Empiricism is a theory of knowledge that asserts that knowledge comes only or primarily via sensory experience. One of several views of epistemology, the study of human knowledge, along with rationalism, idealism and historicism, empiricism emphasizes the role of experience and evidence,...
objection to the argument, criticising its lack of evidential reasoning. He also rejected the idea that anything can exist necessarily. Immanuel Kant
Immanuel Kant
Immanuel Kant was a German philosopher from Königsberg , researching, lecturing and writing on philosophy and anthropology at the end of the 18th Century Enlightenment....
put forward an objection to the argument, based on what he saw as the false premise that existence is a predicate. He proposed that, as it adds nothing to the essence of a being, existence is not a predicate (or perfection) and thus a "supremely perfect" being can be conceived to not exist. Douglas Gasking presented a parody to the ontological argument, recorded and published by William Grey. Gasking uses a form of ontological argument to prove God's existence in order to demonstrate the flaws with the argument. Finally, philosophers including C. D. Broad have dismissed the coherence of a maximally great being, proposing that some attributes of greatness are incompatible with others, making a maximally great being incoherent.
In light of criticism, some philosophers have attempted to revise the ontological argument to fix the problems presented. Mulla Sadra
Mulla Sadra
Ṣadr ad-Dīn Muḥammad Shīrāzī also called Mulla Sadrā was a Persian Shia Islamic philosopher, theologian and ‘Ālim who led the Iranian cultural renaissance in the 17th century...
, an Islamic philosopher, attempted to prove the existence of God through the reality of existence, concluding with God's pre-eternal necessity. Alvin Plantinga has used modal logic
Modal logic
Modal logic is a type of formal logic that extends classical propositional and predicate logic to include operators expressing modality. Modals — words that express modalities — qualify a statement. For example, the statement "John is happy" might be qualified by saying that John is...
to propose the necessary existence of God. Alexander R. Pruss has used Sankara's dictum that if something is impossible, we can have no perception of it. Thus, if we have a conception of something, then it is possible. Finally, Paul Oppenheimer and Edward Zalta have tried using an automated theorem prover to validate Anselm's proof.
Development
Although the ontological argument may have been implicit in the works of Greek philosophers such as PlatoPlato
Plato , was a Classical Greek philosopher, mathematician, student of Socrates, writer of philosophical dialogues, and founder of the Academy in Athens, the first institution of higher learning in the Western world. Along with his mentor, Socrates, and his student, Aristotle, Plato helped to lay the...
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
Avicenna
Abū ʿAlī al-Ḥusayn ibn ʿAbd Allāh ibn Sīnā , commonly known as Ibn Sīnā or by his Latinized name Avicenna, was a Persian polymath, who wrote almost 450 treatises on a wide range of subjects, of which around 240 have survived...
(Ibn Sina) developed a special kind of ontological argument before Anselm; however, this position is doubted by a number of scholars.
Anselm
Anselm of Canterbury
Anselm of Canterbury , also called of Aosta for his birthplace, and of Bec for his home monastery, was a Benedictine monk, a philosopher, and a prelate of the church who held the office of Archbishop of Canterbury from 1093 to 1109...
(1033–1109) in the second and third chapter of his Proslogion
Proslogion
The Proslogion, , written in 1077-1078, was written as a prayer, or meditation, by the medieval cleric Anselm which serves to reflect on the attributes of God and endeavours to explain how God can have qualities which often seem contradictory...
. The argument Anselm puts forward is not, however, presented in order to prove God's existence. Rather, Proslogion is more a work of meditation, in which he documents how the idea of God had become self-evident.
In Chapter 2 of the Proslogion, Anselm defines what we understand as God to be a "being than which no greater can be conceived". Anselm suggests that we understand the concept of a "being than which no greater can be conceived" and what it brings causes to exist in the mind. The concept must exist either only in our mind or in our mind and in reality. If such a being exists only in our mind, then a greater being - that which exists in reality as well - can be conceived. Therefore, if we can conceive of a being that than which nothing greater can be conceived, then it must exist in reality. Therefore, a being that than which nothing greater could be conceived must exist in reality.
In Chapter 3 of the Proslogion, Anselm suggests the notion of a being that cannot be conceived not to exist (similar to the notion of a necessary being). He argues if something can be conceived not to exist, then it is not that than which nothing greater can be conceived. As a consequence, that than which nothing greater can be conceived 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 Malcolm argued superior) 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.
René Descartes
René Descartes
René Descartes ; was a French philosopher and writer who spent most of his adult life in the Dutch Republic. He has been dubbed the 'Father of Modern Philosophy', and much subsequent Western philosophy is a response to his writings, which are studied closely to this day...
(1596–1650) composed a number of ontological arguments, which differed from Anselm's formulation. Generally speaking, it is less a formal argument than a natural intuition.
Descartes wrote in the Fifth Meditation
Meditations on First Philosophy
Meditations on First Philosophy is a philosophical treatise written by René Descartes and first published in 1641 . The French translation was published in 1647 as Méditations Metaphysiques...
,
Descartes argues that God's existence can be deduced from his nature, just as geometric
Geometry
Geometry arose as the field of knowledge dealing with spatial relationships. Geometry was one of the two fields of pre-modern mathematics, the other being the study of numbers ....
ideas can be deduced from the nature of shapes - Descartes uses the deduction of the sizes of angles in a triangle as an example. Descartes suggests that the concept of God is that of a supremely perfect being, holding all perfections fully. He proposes that existence is a perfection: it would be better to exist than not to exist. Thus, if the notion of God did not include existence, it would not be supremely perfect, as it would be lacking a perfection. Consequently, the notion of a supremely perfect God who does not exist, Descartes argues, is unintelligible. Therefore, according to his nature, God must exist.
Gottfried Leibniz
Gottfried Leibniz saw a problem with Descartes' ontological argument: that Descartes had not asserted the coherence of a "supremely perfect" being. He proposed that, unless the coherence of a supremely perfect being could be demonstrated, the ontological argument fails. Leibniz saw perfection as impossible to analyse; therefore, it would be impossible to demonstrate that all perfections are incompatible. He reasoned that all perfections can exist together in a single entity, and that Descartes' argument is still valid.Gaunilo
One of the earliest recorded objections to Anselm's argument was raised by one of Anselm's contemporaries, Gaunilo of MarmoutiersGaunilo of Marmoutiers
Gaunilo of Marmoutiers was an 11th-century Benedictine monk, best known for his criticism of St Anselm's ontological argument for the existence of God. His thesis On Behalf of the Fool takes its name from the fools mentioned in Psalms 14:1 and Psalms 53:1, who say in their hearts that there is no...
. He invites his reader to conceive an island "more excellent" than any other island. He suggests that, according to Anselm's proof, this island must necessarily exist, as an island that exists would be more excellent. Gaunilo's criticism does not explicitly demonstrate a flaw in Anselm's argument; rather, it argues that, if sound, so are many other argument of the same logical form
Logical form
In logic, the logical form of a sentence or set of sentences is the form obtained by abstracting from the subject matter of its content terms or by regarding the content terms as mere placeholders or blanks on a form...
that cannot be accepted.
Gaunilo offered a further criticism of Anselm's ontological argument. He suggested that the notion of God cannot, as Anselm asserted, be conceived. He argued that many theists would accept that God, by nature, cannot be fully comprehended. Therefore, if humans cannot fully conceive of God, the ontological argument cannot work.
Anselm responded to Gaunilo's criticism by suggesting that argument applied only to concepts with necessary existence. He suggested that only a being with necessary existence can fulfill the remit of "that than which nothing greater can be conceived". Furthermore, a contingent object, such as an island, could always be improved and thus could never reach a state of complete perfection. For that reason, Anselm dismissed any argument which did not relate to a being with necessary existence.
Thomas Aquinas
St. Thomas Aquinas, while proposing five proofs of God's existence in his Summa TheologicaSumma Theologica
The Summa Theologiæ is the best-known work of Thomas Aquinas , and although unfinished, "one of the classics of the history of philosophy and one of the most influential works of Western literature." It is intended as a manual for beginners in theology and a compendium of all of the main...
, objected to Anselm's argument. He suggested that people cannot know the nature of God and, therefore, cannot conceive of God in the way Anselm proposed. The ontological argument would be meaningful only to someone who understands the essence of God completely. Aquinas reasoned that, as only God can completely know his essence, only he can use the argument. Aquinas' rejection of the ontological argument caused some Catholic theologians to also reject the argument.
David Hume
Dialogues Concerning Natural Religion
Dialogues Concerning Natural Religion
Dialogues Concerning Natural Religion is a philosophical work written by the Scottish philosopher David Hume. Through dialogue, three fictional characters named Demea, Philo, and Cleanthes debate the nature of God's existence...
, the character Cleanthes proposes this argument:
- ...there 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.
Hume also suggested that, as we have no abstract idea of existence (apart from as part of our ideas of other objects), we cannot claim that the idea of God implies his existence. He suggests that any conception of God we may have, we can conceive either of existing or of not existing. Existence is not a quality (or perfection), so the concept of a completely perfect being need not actually exist. Thus, he claims that it is not a contradiction to deny God's existence. Although this criticism is directed against a cosmological argument, similar to that of Samuel Clarke
Samuel Clarke
thumb|right|200px|Samuel ClarkeSamuel Clarke was an English philosopher and Anglican clergyman.-Early life and studies:...
in his first Boyle Lecture
Boyle Lectures
The Boyle Lectures were named after Robert Boyle, a prominent English/Irish natural philosopher of the 17th century. Boyle endowed a series of lectures in his will, which were designed as a forum where prominent academics could discuss the existence of God....
, it can be applied to ontological arguments as well.
Immanuel Kant
Immanuel Kant
Immanuel Kant was a German philosopher from Königsberg , researching, lecturing and writing on philosophy and anthropology at the end of the 18th Century Enlightenment....
put forward a key refutation of the ontological argument in his Critique of Pure Reason
Critique of Pure Reason
The Critique of Pure Reason by Immanuel Kant, first published in 1781, second edition 1787, is considered one of the most influential works in the history of philosophy. Also referred to as Kant's "first critique," it was followed by the Critique of Practical Reason and the Critique of Judgement...
(first edition, pp. 592–603; second edition, pp. 620–631). It was primarily and explicitly directed at René Descartes
René Descartes
René Descartes ; was a French philosopher and writer who spent most of his adult life in the Dutch Republic. He has been dubbed the 'Father of Modern Philosophy', and much subsequent Western philosophy is a response to his writings, which are studied closely to this day...
, but also attacked the position of Gottfried Leibniz
Gottfried Leibniz
Gottfried Wilhelm Leibniz was a German philosopher and mathematician. He wrote in different languages, primarily in Latin , French and German ....
. Kant's refutation consists of several separate but interrelated arguments, 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
Tautology (rhetoric)
Tautology is an unnecessary or unessential repetition of meaning, using different and dissimilar words that effectively say the same thing...
; 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 concept of a necessary being. He considers examples of necessary proposition, such as "a triangle has three angles", and rejects the transfer of this logic to the existence of God. First, he argues that such necessary propositions are necessarily true only if such a being exists: If a triangle exists, it must have three angles. The necessary proposition, he argues, does not make the existence of a triangle necessary. Thus, he argued that, if the proposition "X exists" is posited, it would follow that, if X exists, it exists necessarily; this does not mean that X does exist in reality. Second, he argues that contradictions arise only when the subject and predicate are maintained and, therefore, a judgement of non-existence cannot be a contradiction, as it denies the predicate.
Kant then proposes that the statement "God exists" must be either analytic or synthetic - the predicate must be either inside or outside of the subject, respectively. If the proposition is analytic, as the ontological argument takes it to be, then the statement would be true only because of the meaning given to the words. Kants argues that this is merely a tautology and cannot say anything about reality. However, if the statement is synthetic, the ontological argument does not work, as the existence of God is not contained within the definition of God (and, as such, evidence for God would need to be found).
Kant goes on to argue that "'being' is obviously not a real predicate" and cannot be part of the concept of something. He proposes that existence is not a predicate, or quality. This is because existence does not add to the essence of a being, indicating merely its occurrence in reality. He suggests that, if he takes the subject of God with all its predicate and then asserts that God exists, "I add no new predicate to the conception of God". He argues that the ontological argument works only if existence is a predicate; if this is not so, then it is conceivable for a completely perfect being to not exist, thus defeating the ontological argument.
In addition, Kant argues that the concept of God is not of one a particular sense; rather, it is an "object of pure thought". He presents the view that God exists outside the realm of experience and nature. Because we cannot experience God through experience, Kant argues that it is impossible to know how we would verify God's existence. This is in contrast to material concepts, which can be verified by means of the senses.
Douglas Gasking
As a criticism of the ontological argument, Melbourne philosopher Douglas Gasking (1911-1994) developed his own version of the ontological argument to prove God's non-existence. The argument is not intended to be a serious attempt to prove God's non-existence; its purpose is to illustrate the problems Gasking saw with the argument. The argument was published by William Grey at the University of Queensland.- The creation of the world is the most marvelous achievement imaginable.
- The merit of an achievement is the product of (a) its intrinsic quality, and (b) the ability of its creator.
- The greater the disability (or handicap) of the creator, the more impressive the achievement.
- The most formidable handicap for a creator would be non-existence.
- 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.
- An existing God therefore would not be a being greater than which a greater cannot be conceived because an even more formidable and incredible creator would be a God that did not exist.
- Therefore, God does not exist.
Gasking's proposal of premise 4 is a response to Anselm's assumption that existence is a predicate and perfection. Gasking uses this logic to assume that non-existence must therefore be a disability. It is this use of Anselm's logic, which allows the conclusion that God must not exist.
Graham Oppy
Graham Oppy
Graham Robert Oppy is an Australian philosopher whose main area of research is the philosophy of religion. He currently holds the posts of Professor of Philosophy and Associate Dean of Research at Monash University and serves as Associate Editor of the Australasian Journal of Philosophy, and...
, a philosopher of religion, has criticised the argument in the Stanford Encyclopedia of Philosophy
Stanford Encyclopedia of Philosophy
The Stanford Encyclopedia of Philosophy is a freely-accessible online encyclopedia of philosophy maintained by Stanford University. Each entry is written and maintained by an expert in the field, including professors from over 65 academic institutions worldwide...
. He suggests that, though it may be accepted that it would be a greater achievement for a non-existent creator to create something than a creator who exists, there is no reason assume that a non-existent creator would be a greater being. He continues his criticism by arguing that there is no reason to view the creation of the world as "the most marvellous achievement imaginable". Finally, he suggests that it may be inconceivable for a non-existent being to create anything at all. Thus, Oppy views Gasking's criticism as a weak parody of the ontological argument.
Coherence of a maximally great being
In his development of the ontological argument, Leibniz attempted to demonstrate the coherence of a supremely perfect being. This problem has, however, been criticised. C. D. Broad suggested that, if there are two characteristics necessary for God's perfection that are incompatible with a third, the notion of a supremely perfect being becomes incoherent. The ontological argument assumes the definition of God purported by classical theismClassical theism
Classical theism refers to the a form of Theism in distinction to modern ideas about God such as Theistic Personalism, Open Theism and Process Theism. Classical Theism began with the works of the Greek philosophers, especially Platonists and Neoplatonists and was developed into Christian Theology...
: that God is omnipotent, omniscient, and morally perfect. There exist arguments that suggest that the combination of these characteristics is logically incoherent. For example, a morally perfect being must be perfectly merciful and perfectly just. Perfect justice requires punishing every person exactly according to what they deserve; perfect mercy requires punishing some people less than they deserve. This would make moral perfection inconsistent. Furthermore, the concepts of omniscience and omnipotence could be incompatible. The problem of divine foreknowledge is that, if omniscience includes the ability to know exactly what will happen at any given moment, and free will means the ability to make free choices at any given moment, then God cannot logically know what a being with free will shall choose to do. If he does, then the being does not have free will. However, if God is omnipotent (with the ability to do anything), then he should have the ability to create being with free will. This would suggest that omniscience and omnipotence are incompatible. If any properties of a supremely perfect being are incompatible, the idea of a supremely perfect being becomes incoherent. If this is true, the ontological argument does not work.
Other criticisms
Bertrand RussellBertrand Russell
Bertrand Arthur William Russell, 3rd Earl Russell, OM, FRS was a British philosopher, logician, mathematician, historian, and social critic. At various points in his life he considered himself a liberal, a socialist, and a pacifist, but he also admitted that he had never been any of these things...
criticised the argument, asserting 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." During his early Hegelian
Hegelianism
Hegelianism is a collective term for schools of thought following or referring to G. W. F. Hegel's philosophy which can be summed up by the dictum that "the rational alone is real", which means that all reality is capable of being expressed in rational categories...
phase, Russell is also known to have said: "Great God in Boots! -- the ontological argument is sound!" Richard Dawkins
Richard Dawkins
Clinton Richard Dawkins, FRS, FRSL , known as Richard Dawkins, is a British ethologist, evolutionary biologist and author...
has also rejected the argument as "infantile" and “dialectical prestidigitation”.
Mulla Sadra
Mulla SadraMulla Sadra
Ṣadr ad-Dīn Muḥammad Shīrāzī also called Mulla Sadrā was a Persian Shia Islamic philosopher, theologian and ‘Ālim who led the Iranian cultural renaissance in the 17th century...
(c. 1571–1640) was an Islamic philosopher
Islamic philosophy
Islamic philosophy is a branch of Islamic studies. It is the continuous search for Hekma in the light of Islamic view of life, universe, ethics, society, and so on...
, influenced by Avicenna's
Avicenna
Abū ʿAlī al-Ḥusayn ibn ʿAbd Allāh ibn Sīnā , commonly known as Ibn Sīnā or by his Latinized name Avicenna, was a Persian polymath, who wrote almost 450 treatises on a wide range of subjects, of which around 240 have survived...
philosophy. Sadra discussed Avicenna's arguments for the existence of God, claiming that is was not an a priori argument
A priori and a posteriori (philosophy)
The terms a priori and a posteriori are used in philosophy to distinguish two types of knowledge, justifications or arguments...
and rejecting the argument on the basis that existence precedes essence
Existence precedes essence
The proposition that existence precedes essence is a central claim of existentialism, which reverses the traditional philosophical view that the essence or nature of a thing is more fundamental and immutable than its existence...
.
Sadra put forward a new argument, known as Argument of the Righteous ( — Al-Burhan al-Siddiqin). The argument attempts to prove the existence of God through the reality of existence, and to conclude with God's pre-eternal necessity. In this argument, a thing is demonstrated through itself, and a path is identical with the goal. In other arguments, the truth
Truth
Truth has a variety of meanings, such as the state of being in accord with fact or reality. It can also mean having fidelity to an original or to a standard or ideal. In a common usage, it also means constancy or sincerity in action or character...
is attained from somewhere other than itself, for example from the possible to the necessary, from the originated to the eternal origin, or from motion to the unmoved mover. But in the argument of the righteous, there is no middle term other than the truth. His version of the ontological argument can be summarised as follows:
- There is existence
- Existence is a perfection above which no perfection may be conceived
- God is perfection and perfection in existence
- Existence is a singular and simple reality; there is no metaphysical pluralism
- That singular reality is graded in intensity in a scale of perfection (that is, a denial of a pure monism).
- That scale must have a limit point, a point of greatest intensity and of greatest existence.
- Hence God exists.
Mulla Sadra describes this argument in Asfar as follows:
Existence is a single, objective and simple reality, and there is no difference between its parts, unless in terms of perfection and imperfection, strength, and weakness… And the culmination of its perfection, where there is nothing more perfect, is its independence from any other thing. Nothing more perfect should be conceivable, as every imperfect thing belongs to another thing and needs to become perfect. And, as it has already been explicated, perfection is prior to imperfection, actuality to potency, and existence to non-existence. Also, it has been explained that the perfection of a thing is the thing itself, and not a thing in addition to it. Thus, either existence is independent of others or it is in need of others. The former is the Necessary, which is pure existence. Nothing is more perfect than Him. And in Him there is no room for non-existence or imperfection. The latter is other than Him, and is regarded as His acts and effects, and for other than Him there is no subsistence, unless through Him. For there is no imperfection in the reality of existence, and imperfection is added to existence only because of the quality of being caused, as it is impossible for an effect to be identical with its cause in terms of existence.
Plantinga's modal form
Alvin PlantingaAlvin Plantinga
Alvin Carl Plantinga is an American analytic philosopher and the emeritus John A. O'Brien Professor of Philosophy at the University of Notre Dame. He is known for his work in philosophy of religion, epistemology, metaphysics, and Christian apologetics...
has presented another version of the argument. The conclusion he provides logically follows from the premises, assuming axiom S5
Axiom S5
Axiom S5 is the distinctive axiom of the S5 modal logic and states that if possibly p, then necessarily possibly p. It also states, perhaps less intuitively and more controversially, that if possibly necessarily p, then necessarily p...
of modal logic - if possibly p, then necessarily possible p and if possibly necessarily p, then necessarily p. A version of his argument is as follows:
- 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
- A being has maximal greatness if it has maximal excellence in every possible world.
- It is possible that there is a being that has maximal greatness. (Premise)
- Therefore, possibly, it is necessarily true that an omniscient, omnipotent, and perfectly good being exists.
- Therefore, (by axiom S5Axiom S5Axiom S5 is the distinctive axiom of the S5 modal logic and states that if possibly p, then necessarily possibly p. It also states, perhaps less intuitively and more controversially, that if possibly necessarily p, then necessarily p...
) it is necessarily true that an omniscient, omnipotent and perfectly good being exists. - Therefore, an omniscient, omnipotent and perfectly good being exists.
This argument has two controversial premises: the axiom S5
Axiom S5
Axiom S5 is the distinctive axiom of the S5 modal logic and states that if possibly p, then necessarily possibly p. It also states, perhaps less intuitively and more controversially, that if possibly necessarily p, then necessarily p...
and the "possibility premise" - that a maximally great being is possible. S5 is widely accepted, though not universally so. Paul Almond criticised the argument due to the "incoherence, incorrectness and triviality" of axiom S5.
The more controversial premise is the "possibility premise". Richard M. Gale, professor emeritus of philosophy at University of Pittsburgh
University of Pittsburgh
The University of Pittsburgh, commonly referred to as Pitt, is a state-related research university located in Pittsburgh, Pennsylvania, United States. Founded as Pittsburgh Academy in 1787 on what was then the American frontier, Pitt is one of the oldest continuously chartered institutions of...
, argues that the "possibility premise" begs the question, because one has the epistemic right to accept it only 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 in essence the same as "necessarily".
Sankara's dictum
An approach to supporting the possibility premise in Plantinga's version of the arfument has been attempted by Alexander R. Pruss, currently of Baylor UniversityBaylor University
Baylor University is a private, Christian university located in Waco, Texas. Founded in 1845, Baylor is accredited by the Southern Association of Colleges and Schools.-History:...
. He starts with the 8th–9th century AD Indian philosopher Sankara
Adi Shankara
Adi Shankara Adi Shankara Adi Shankara (IAST: pronounced , (Sanskrit: , ) (788 CE - 820 CE), also known as ' and ' was an Indian philosopher from Kalady of present day Kerala who consolidated the doctrine of advaita vedānta...
's dictum that if something is impossible, we cannot have a perception (even a non-veridical one) that it is the case. 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.
Automated reasoning and the Ontological Argument
In a paper published in the Australasian Journal of PhilosophyAustralasian Journal of Philosophy
The Australasian Journal of Philosophy , founded in Sydney in 1923 as The Australasian Journal of Psychology and Philosophy, is Australasia's oldest and most respected philosophy journal. Sponsored by the Australasian Association of Philosophy, it aims to publish the best work in the analytic...
, Paul Oppenheimer and Edward Zalta describe how they used an automated theorem prover called Prover9
Prover9
Prover9 is an automated theorem prover for First-order and equational logic developed by William McCune. Prover9 is the successor of the Otter theorem prover.Prover9 is intentionally paired with Mace4, which searches for finite models and counterexamples...
to validate Anselm's ontological thesis. The Prover9 reasoning engine subsequently discovered a simpler formally valid
Validity
In logic, argument is valid if and only if its conclusion is entailed by its premises, a formula is valid if and only if it is true under every interpretation, and an argument form is valid if and only if every argument of that logical form is valid....
(if not necessarily sound
Soundness
In mathematical logic, a logical system has the soundness property if and only if its inference rules prove only formulas that are valid with respect to its semantics. In most cases, this comes down to its rules having the property of preserving truth, but this is not the case in general. The word...
) ontological argument from a single non-logical premise.
External links
- 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. ZaltaEdward N. ZaltaEdward N. Zalta is a Senior research scholar at the Center for the Study of Language and Information. He received his Ph.D. in philosophy from the University of Massachusetts - Amherst in 1980. Zalta has taught courses at Stanford University, Rice University, the University of Salzburg, and the...
, "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.