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History of the Ontological Argument for the Existence of God


"Philosophers who address the questions of what it is for an individual to exist, or what it is for an individual to be actual, often do so with reference to the fallacy they have uncovered in the classical Ontological Argument for God's existence. Indeed, the Ontological Argument is useful as a vehicle by which this and other issues in ontology and the philosophy of logic may be introduced and sharpened."

Nathan Salmon - Existence - in: Philosophical Perspectives, vol. 1 "Metaphysics" edited by James E. Tomberlin, 1987, p. 49.

"Higher-type classical logic is intensional logic with the intensional features removed, so this is a good place to start. Ontological arguments, Gödel's in particular, are natural examples of intensional logic at work, so this is a good place to finish." (page XI)

"There are many directions form which people have tried to prove the existence of God. There have been arguments based on design: a complex universe must have a designer. There have been attempts to show that the existence of an ethical sense implies the existence of God. There have been arguments based on causality: trace chain of effect and cause backward and one must reach a fist cause. Ontological arguments seek to establish the existence of God based on pure logic: the principles of reasoning require that God be part of ones ontology." (p. 133)

Melvin Fitting - Types, tableaus and Gödel's God - Dordrecht, Kluwer, 2002.

"Of all the arguments for the existence of God, the one which Anselm first formulated is the most refined and the least capable of a finally satisfactory statement. It draws its strength from an ambiguity, which appears to be an ambiguity in language, but is more deeply an ambiguity in human experience. If God exists, there must be a level of experience at which it is impossible to think of God as not existing. But at what level can this impossibility be made to appear? Must the demonstration await the experience of the Beatific Vision? Or can it, at the very opposite extreme, be made out at the level of linguistic-logical analysis? Whether valid or not, the first three chapters of the Proslogion were the first piece of writing in which this problem was raised and a solution proposed which will probably never be finally buried. It may be agreed that Descartes put it better, because more simply and with fewer philosophical presuppositions. He had the advantage, which Anselm lacked, of inheriting, if only to reject, a long philosophical tradition. The Augustinian and grammatical background of Anselm's thought, which made it possible for him to formulate the argument, also burdened it with limitations. But these pages of Anselm must be placed among the most deeply interesting pieces of reasoning ever written The early chapters of the Proslogion, in which the argument was first expressed, will never be read without excitement, nor thought about without appearing to be more cogent than they are. For the most extraordinary thing about the argument is that it loses nothing of its power, its freshness, or even in a curious way its persuasiveness, by being refuted. The Proslogion may not set forth a valid argument for belief in God, and even if it were valid it is doubtful whether it would ever persuade an unbeliever; but in its subtlety, and in a certain unsubstantial, ethereal quality which antagonizes men of robust common sense, it perfectly reflects the quality and mystery of Anselm's personality." (pp. 74-75).

Richard William Southern - Saint Anselm and His Biographer: A Study of Monastic Life and Thought 1059-c. 1130, Cambridge: Cambridge University Press, 1963.

"The ontological argument for the existence of Cod has fascinated philosophers ever since it was formulated by St. Anselm of Canterbury (1033-1109). It is doubtful, I think, that any person was ever brought to a belief in God by this argument, and unlikely that it has played the sort of role in strengthening and confirming religious belief that, for example, the teleological argument has played. To the unsophisticated, Anselm's argument is (at first sight at least) remarkably unconvincing, if not downright irritating, it smacks too much of word magic. And yet almost every major philosopher from the time of Anselm to the present has had his say about it; the last few years have seen a remarkable flurry of interest in it.

What accounts for this fascination? Not, I think, the religious significance of the argument, although no doubt that can be underrated. The cause is perhaps twofold. First, the ontological argument offers an enormous return on a pretty slim investment - a definition, and a perplexing but not altogether implausible premise connecting existence and 'greatness,' yield the theistic conclusion. Second, although the argument certainly looks at first sight as if it ought to be unsound, it is profoundly difficult to say what exactly is wrong with it. Indeed, it is doubtful that any philosopher has given a really convincing and thorough refutation of the ontological argument. Too often philosophers merely remark that Kant refuted the argument by showing that existence is not a predicate and that 'one cannot build bridges from the conceptual realm to the real world.' But it is very doubtful that Kant specified a sense of 'is a predicate' such that, in that sense, it is clear both that existence is not a predicate and that Anselm's argument requires that it be one. Nor are the mere claims that no existential propositions are necessary or the above comment about bridge building impressive as refutations of Anselm - after all, he claims to have an argument for the necessity of at least one existential proposition. So one must either show just where his argument goes wrong, or else produce a solid argument for the claim that no existential (in the appropriate sense) propositions can be necessary-and this, I think, no one has succeeded in doing."

Alvin Plantinga - God and others minds. A study of the rational justification of belief in God. - Cornell University Press (1967) pp. 26-27.

"PROSLOGION 2-4 consists of four pages. Barth's book about them ["Fides Quaerens Intellectum" (1931)] has 165 pages. All the books and essays written about them in the last eight hundred years would fill libraries. It is a legitimate question to ask, What is it, in these four pages, that makes them so potent a challenge to the best minds of humanity? What is the spell they cast over the reader so that occupation with them becomes a passionate enterprise? These pages do not seem to have the completeness and remoteness of a classic; rather, they seem to call on the reader personally to do something about them. They arouse in him an intellectual passion -- either for or against them -- which makes him feel that the core of his own thinking is being touched. On the one hand, they seem so concise that nothing can be added, on the other, so loose that everything still has to be done. But what? The reader feels puzzled, teased, imposed upon. He feels called to take a personal part in a herculean intellectual struggle.

The reason for this spell -- which was already felt in Anselm's life time --cannot be solely Anselm's subject matter, for this has treated by many before and after with less than intriguing effects. It must be, to a large degree, his method. But what can there be so exciting about a logical demonstration?"

Robert S. Hartman - Prolegomena to a meta-Anselmian axiomatic - Review of Metaphysics, XIV, 4, June 1961 p. 637.

"No logician wishes to deny that in ordinary speech sentences such as 'tame tigers exist' can be used with perfect propriety. Some of them may be false, but it is not for the logician to determine which are and which are not. If, however, we assume that grammatical form is a sure guide to logical structure, we may be tempted to say that in these sentences the word 'existence' stands for a predicate, where 'predicate' has a logical sense distinct from its grammatical sense. That some philosophers have taken the word 'existence' to stand for a predicate in the logical sense, i.e., for an attribute, may be seen from their use of the ontological argument to prove the existence of God.

Descartes' exposition of the argument is clearer than most others. He starts from the position, supposed to be already established, that we can know some propositions, e.g., simple theorems of mathematics, to be necessarily true. It does not matter for our purposes whether he thinks that his necessary propositions are analytic or synthetic, although we may remark in passing that the language in which he refers to them suggests that they are analytic. He wishes to say that the proposition that God exists can be proved in the same way as that in which a necessary proposition of mathematics is proved.(...) [His] argument is based on the assumption that 'God exists' is a proposition of the same sort as a theorem of geometry. Descartes writes as though both propositions predicated something of a subject, the one being about 'God,' the other about 'the triangle.' If he did not assume this, he would not say that they can be proved in the same fashion. Gassendi was the first, I think, to criticize the argument on the ground that existence is not a property of God or of anything else. (...) No doubt Descartes and those who agree with him would say, if questioned, that they wished to make a distinction between existence and qualities such as redness. But refinements of the theory of existence as a predicate only introduce fresh difficulties. The theory is unacceptable."

William Calvert Kneale - Is Existence a Predicate? - Aristotelian Society, Supplementary volume 15, 1936 (reprinted in: Herbert Feigl and Wilfrid Sellars (eds.) - Readings in Philosophical Analysis - New York, Appleton-Century-Crofts, Inc. (1949) pp. 29-30.

"It is much harder than one might first suspect to see what is wrong - if anything - with the ontological argument, in some of its variants at least. By way of criticism, it is often said that the argument fails because 'existence is not a predicate'. However, there are senses - and what is more, senses other than the purely grammatical one - in which existence clearly is a predicate. It is sometimes said that existence is not the kind of property that can be included in the essence of anything; but the reasons for saying so are far from clear, and the notion of essence is a notorious mess in the best of circumstances. One might suspect that something goes wrong with the logic of definite descriptions in the modal contexts involved in the argument; but I shall try to reconstruct some of the most important aspects of the ontological argument in terms having little to do with ordinary modalities and nothing whatsoever with definite descriptions. In fact, the independence of the essential features of the ontological argument from the theory of definite descriptions ought to be clear enough without much detailed argument. If what we are trying to do is to establish that there exists a unique being 'than which nothing greater can be conceived' - in short, a unique supremely perfect Being - surely the great difficulty is to show that there exists at least one such being, whereas we can face the problem of uniqueness with relative calm.

Furthermore, it has been complained that the notion 'being greater than anything else that can be conceived of' and the notion of supreme perfection are unclear. More than that, it is sometimes suggested that they are systematically ambiguous - that they make no sense until it has been specified in what respect greatness or perfection is to be measured. Certainly, greater evil or more perfect vice cannot be what is meant - but even if there be no such things as these, what precisely is meant? Yet a straightforward answer to this question is forthcoming. What is at stake is surely greatness or perfection with respect to existence. It does not take a neo-Platonist to agree that the greatest or most supreme being intended in the argument is certainly one whose powers of existing are maximal or whose mode of being is, as existence qua existence goes, supremely perfect."

Jaakko Hintikka - On the Logic of the Ontological Argument. Some elementary remarks - in: Models for Modalities - Dordrecht, D. Reidel Publishing Company (1969) pp. 45-46.

"Modal reasoning can be replaced by non-modal, ordinary reasoning about possible things. Given an obscure modal argument, we can translate it into a non-modal argument - or into several non-modal arguments, if the given argument was ambiguous. Once we have a nonmodal argument, we have clear standards of validity; and once we have non-modal translations of the premises, we can understand them well enough to judge whether they are credible. Foremost among our modal headaches is Anselm's ontological argument. How does if fare under the translation treatment I have prescribed? It turns out to have two principal non-modal translations. One is valid; the other has credible premises; the difference between the two is subtle. No wonder the argument has never been decisively refuted; no wonder it has never convinced the infidel. (pp. 10-11).

CONCLUSION. Of the alternative non-modal translations of our ontological argument, the best are the arguments from 3A and 3B. The premises of the argument from 3B enjoy some credibility, but the argument is invalid. The argument from 3A is valid, but 3A derives its credibility entirely from the illusion that because our world alone is actual, therefore our world is radically different from all other worlds - special in a way that makes it a fitting place of greatest greatness. But once we recognize the indexical nature of actuality, the illusion is broken and the credibility of 3A evaporates. It is true of any world, at that world but not elsewhere, that that world alone is actual. The world an ontological arguer calls actual is special only in that the ontological arguer resides there - and it is no great distinction for a world to harbor an ontological arguer. Think of an ontological arguer in some dismally mediocre world - there are such ontological arguers - arguing that his world alone is actual, hence special, hence a fitting place of greatest greatness, hence a world wherein something exists than which no greater can be conceived to exist. He is wrong to argue thus. So are we." (p. 20)

David Lewis - Anselm and Actuality - Noûs, 4 (1970) pp. 175-188 (reprinted with a Postscript (pp. 21-25) in: Philosophical Papers - vol. I Oxford, Oxford University Press 1983 p. 10-20.

"In the preface to his Proslogion Anselm audaciously claims discovery of 'a single formula which needs no other to prove itself but itself alone, and which by itself suffices to establish that God truly is, and that he is the greatest good needing no other, and that which everything needs if it is to be and be well, and whatever else we believe about divine being' (93.6-10). Anselm published his argument in 1077 or 1078. The dispute immediately kindled was bright but brief; and after Anselm's death his argument lay fallow for some hundred years. Then, in the thirteenth century, it was widely debated, and widely accepted, (...) until it received the authoritative disapproval of St Thomas Aquinas.

In the Seventeenth century Descartes discovered and vigorously defended an argument for the existence of God which was plainly similar to and allegedly identical with Anselm's argument. Controversy over the Cartesian argument culminated with Kant; in a section 'On the Impossibility of an Ontological Argument for the Existence of God' in the Critique of Pure Reason, Kant performed for Descartes the service Aquinas had rendered Anselm. Incidentally he gave the argument a title, imposing, universally adopted, and wholly opaque.

After Kant's assault the argument again languished - for the Hegelian claim to have revived it is specious (...). In recent years, however, philosophers and theologians have again looked with favour, or at least attention, on the Ontological Argument. In this renaissance of interest a new version of the argument has been brought to birth; Norman Malcolm and Charles Hartshorne, its independent obstetricians, both maintain that the new version, unlike the old, does provide a proof of the existence of God."

Jonathan Barnes - The Ontological Argument - London, Macmillan St. Martin's Press (1972) p. 1

"This argument has excited enormous controversy. Nearly every great philosopher from Anselm's time to ours had his say about it: Aquinas rejected it, John Duns Scotus 'coloured' (modified) it a bit and accepted it. René Descartes and Nicolas Malebranche accepted it; Leibniz accepted a version of it; Kant rejected it (and delivered what many have thought the final quietus to it); Arthur Schopenhauer thought it at best a charming joke; and many contemporary philosophers seem to think it as a joke all right, but at all a charming joke."

Alvin Plantinga - Ontological Arguments. I: Classical - in: Handbook of Metaphysics and Ontology, eds., B. Smith and H. Burkhardt, Philosophia Verlag, Munich, 1991pp. 622-623.

"Gödel showed his *1970 [Ontological Proof] to Dana Scott, and discussed it with him, in February 1970. Gödel was very concerned about his health at that time, feared that his death was near, and evidently wished to insure that this proof would not perish with him. Later in 1970, however, he apparently told Oskar Morgenstern that though he was 'satisfied' with the proof, he hesitated to publish it, for fear it would be thought "that he actually believes in God, whereas he is only engaged in a logical investigation (that is, in showing that such a proof with classical assumptions [completeness, etc.], correspondingly axiomatized, is possible)." Scott made notes on the proof and presented a version of the argument to his seminar on logical entailment at Princeton University in the fall of 1970. Through this presentation and the recollections and notes of those who attended the seminar, Gödel's ontological proof has become fairly widely known. Discussion of the proof, thus far, has been based largely on Scott's version of it (Dana Scott 'Gödel's ontological proof' in: Judith Jarvis Thomson (ed.) 'On being and saying: essays for Richard Cartwright' - Cambridge, Mass. MIT Press 1987), which differs somewhat in form from Gödel's own memorandum. The latter is published here - though not for the first time; like Scott's version, it was published as an appendix to John Howard Sobel 'Gödel's ontological proof' in: J. J. Thomson cit. pages 256-7.

Gödel had devised his ontological proof some time before 1970. Other, presumably earlier, versions of it have been found among his papers. A sheet of paper headed "Ontological Proof' (in German), and dated, in Gödel's own hand, 'ca. 1941', contains some but not all of the ideas of the proof. Extensive preparatory material is contained in the philosophical notebook 'Phil XIV'. The first page of this notebook bears a notation indicating that it was written during the period 'Ca. Ju1y 1946-May 1955". The last page of the notebook contains the note 'Asbury Park 1954 p. 100 ff.', which presumably applies to the pages (103-109) pertaining to the ontological proof. Other documents, including letters, indicate that Gödel intended to leave Princeton for the shore 9 August 1954, was vacationing in Asbury Park on 25 August 1954, and was probably back in Princeton by 3 October 1954. We may reasonably assume, then, that the notebook pages on the ontological proof were written in the late summer and early fall of 1954 and were completed at any rate by May 1955. Relevant excerpts from the notebook, and two of the (presumably earlier) loose sheets headed 'Ontological Proof', including the one dated 'ca. 1941', are published in Appendix B to this volume."

Robert Merrihew Adams - Introductory note to *1970 [Ontological proof] in: Kurt Gödel - Collected Works - vol. III Unpublished essays and lectures - Edited by Solomon Feferman and alii. - New York - Oxford University Press 1995 p. 388-389 (notes omitted).


Graham Oppy wrote (Ontological Arguments and Belief in God - Cambridge University Press, 1995, pp. 202-203):


As far as I know, there has been no exhaustive historical study of ontological arguments, even for relatively narrow historical periods. In particular, I found the pre-Cartesian discussion of ontological arguments very hard to investigate. An accessible book of translations, commentary, and analysis would be very useful.


Gilson (1955) [History of Christian Philosophy in the Middle Ages] contains much information about the status of ontological arguments - versions of the arguments of St. Anselm - in the Middle Ages. Unfortunately, there is no subject index to this book, so the information is not easily accessed. As we have seen, Thomists rejected ontological arguments; but other philosophers of a more rationalistic bent - for example, Scotists - accepted them. Consequently, there were lively debates about ontological arguments during the golden age of Scholasticism. However, the victory of Occamist nominalism seems to have led to a widespread rejection of those arguments by the end of the fourteenth century. Among those who discussed St. Anselm's argument, there are the following: William of Auxerre, Richard Fishacre, Alexander of Hales, Matthew of Aquasparta, Johannes Peckham, Nicolaus of Cusa, [this is the same error of Hartshorne (1965) p. 154: Daniels (1909) speaks of Nicolaus Occam] Aegidius of Rome, William of Ware, Albertus Magnus, Peter of Tarentaise, Henry of Ghent, Gregory of Rimini, Robert Holcot, John of Beverley, John Wyclif, Richard Rufus of Cornwall, Pierre Oriole, and Richard Middleton."

That no historical study of ontological arguments exists, is not exact (see the bibliography at the bottom of this page).


In English: The Part Two of Hartshorne (1965) titled "A critical survey of responses to Anselm's proof" pp. 137-303, Harrelson (2009) and Logan (2009) Chapter 6, 7, 8.

In German: Grunwald (1907), Daniels (1909), Dyroff (1928), Henrich (1960), Rohls (1987), Röd (1992).

In French: Chatillon (1959).

In Italian: Scribano (1994), Tomatis (1997), Piazza (2000).

In Spanish: Ceñal (1970).

Daniels (1909) contains "an invaluable collection of medieval Latin texts referring to the Argument, with a penetrating analysis of them as indications that the author accepted or rejected Anselm's Proof, and a careful discussion of the philosophical beliefs which determined this acceptance or rejection" Hartshorne (1965) p. 306.

"The reception of the Argument in the Twelfth and thirteenth centuries was almost as odd as what happened in its inventor's own lifetime or in the modern period. (In this section I am heavily indebted - and deeply grateful -to P. A. Daniels 1909). In the twelfth century the Proof was simply ignored, so far as our records go. Three conclusions have been drawn from this: all accepted the Proof, all rejected it, they were unacquainted with it. Daniels shows that the last is the most reasonable. In the next three centuries things were dramatically different. Fifteen authors refer to the Proof, of whom the following ten accept it: William of Auxerre, Richard Fishacre, Alexander of Hales, Bonaventura, Matthew of Aquasparta, Johannes Peck ham, Nicolaus of Cusa, [this is a lapsus: Daniels (1909) speaks of Nicolaus Occam] Aegidius of Rome, William of Ware, and Duns Scotus. Of these at least four, Alexander, Bonaventura, Nicolaus, and Scotus seem to have some appreciation of Proslogion III and of the true Anselmian Principle; the rest seem to be thinking largely or exclusively of Proslogion II. Albertus Magnus, Peter of Tarentaise, and Henry of Ghent take no position on the Proof; of these, only the first seems to have read past Proslogion II. St. Thomas and his disciple Richard of Middleton reject the Proof; Richard cites only Proslogion II, while Thomas refers (in five different writings) sometimes to this and sometimes to the following chapter; however, where he is explicitly rejecting the Proof (in the two Summas) he mentions only Proslogion II; and where he does mention the other chapter he, in my opinion, misconceives the relationship of the two.

We have then fifteen medieval judges, of whom at most five show that they have the Principle clearly and centrally in mind; one or two others exhibit some conception of it, and the rest, little or none. Of the five having the Principle (as Anselm did) clearly and centrally in mind, four accept the Proof, and the fifth takes no stand. Of the other ten, those who seem not to grasp the centrality of Proslogion III, six accept, two reject, and two give no verdict. Thus even where the Proof was taken at its weakest, still six found it convincing and but two rejected it; and where it was taken at its strongest, four out of five accepted and none rejected i t. This seems to show the power of the Proof even when incompletely grasped, and its much greater power when fully grasped. It also shows the blighting influence of Gaunilo's inability to read beyond Chapter II.

Unfortunately, the example of Thomas has in the end outweighed in prestige all the others put together. Bonaventura's cogent rebuttal of Gaunilo's 'island' analogy has been passed over as though it had never happened, while the objections of Thomas have been treasured."

Charles Harstshorne - Anselm's Discovery: A re-examination of the Ontological Proof for God's Existence - Lasalle - Open Court 1965 pp. 154-155.


Legenda: P = Pro (accept the proof); C = Contra (rejected the proof); I = indifferent (take no position on the proof); ca. = circa; fl = flourished; d. died.

References are to the most important works where ontological argument is discussed.

The Medieval Period from Anselm to Scotus

P Anselm of Canterbury [Anselmus Cantuariensis, Doctor Angelicus]

C Gaunilo of Marmoutiers [Gaunilo, monachus]

P William of Auxerre [Guillelmi Altissiodorensis]

P Alexander of Hales [Alexander Halensis, Doctor Irrefragabilis]

P Richard Fishacre [Richardus Flamesburensis]

C Richard Rufus of Cornwall [Richaruds Rufus Cornubiensis]

P Bonaventure of Bagnorea [Bonaventurae, Johannes Fidanza, Doctor Seraphicus]

I Albert the Great [Albertus Magnus, Doctor Universalis ]

C Thomas Aquinas [Thomae Aquinatis, Doctor Angelicus]

I Peter of Tarentaise [Petrus a Tarentasia, Pope Innocent V]

P John Peckham [Johannis Packham, Doctor Ingeniosus]

I Henry of Ghent [Henrici de Gandavo, Doctor Solemnis]

P Nicolaus of Ockham [Nicolaus de Ockham]

P Matthew of Aquasparta [Matthaei ab Aquasparta]

P Giles of Rome [Aegidius Romanus, Egidio Colonna]

C Richard of Middletown [Richardus of Mediavilla]

P William of Ware [Gulielmi Guarae]

P John Duns Scotus [Johannes Duns Scotus, Doctor Subtilis]

The Modern Era from Suárez to Frege

P Francisco Suárez

P René Descartes

C Pierre Gassendi

P Henry More

P Ralph Cudworth

P Baruch Spinoza

P Nicolas Malebranche

P Gottfried Wilhelm Leibniz

P François Fénelon

P Samuel Clarke

P Christian Wolff

C David Hume

P Alexander Baumgarten

C Immanuel Kant

P Moses Mendelssohn

P Georg Wilhelm Friedrich Hegel

P Friedrich Wilhelm Joseph Schelling

C Ludwig Feuerbach

P Robert Flint

P Franz Brentano

C Gottlob Frege

The Contemporary Debate

P Heinrich Scholz

P Karl Barth

P Robin George Collingwood

P Charles Hartshorne

C John Niemeyer Findlay

P Kurt Gödel

P Norman Malcolm

P Jan Berg

C John Howard Sobel

P Alvin Plantinga

C David Kellogg Lewis

P Robert Maydole

C Graham Oppy

P Alexander Pruss


Pages about the History of the Ontological Proof:

History of the Ontological Argument. Introductory Remarks

Bibliography of General and Introductory Studies

The Medieval Period from Anselm of Canterbury to Duns Scotus

Bibliography on Medieval Authors

The Modern Period from Suárez to Frege

Bibliography on Modern Authors

The Contemporary Period from Barth to the Present Time

Bibliography on Contemporary Authors

A Selection of Text of Primary Authors

Index of the Section "Ontological Topics in the History of Philosophy"