This article is a brief overview of major ontological arguments. The most noteworthy feature of this article is the statement of a new parody of the Anselmian and Cartesian arguments that is obviously immune to objections adverting to intrinsic minima and maxima.

Latest version of my SEP entry on ontological arguments, which first appeared in 1996. General discussion of ontological arguments. Includes a brief historical overview, a taxonomy of different kinds of ontological arguments, a brief survey of objections to the different kinds of ontological arguments identified in the taxonomy, and more extended discussions of Anselm's ontological argument (Proslogion 2), Godel's ontological argument, and Plantinga's ontological argument.

Review of Graham Oppy *Ontological Arguments and Belief in God* (CUP).

This chapter contains sections titled: The Validity of Anselm's Ontological Argument The Truth of the Anselmian Premises On Whether Anselm's Ontological Argument Begs the Question On Parodies The Validity of the Ontological Argument of Descartes and Leibniz On the Truth of the Descartes–Leibniz Premises Critiques of the Descartes–Leibniz Ontological Argument Ontological Arguments of the Twentieth Century Gödel's Ontological Argument On Whether Gödel's Argument is Sound The Modal Perfection (...) class='Hi'>Argument The Temporal‐Contingency Argument Conclusion References Appendix 1. Logic Matters Appendix 2. Formal Proofs of Some Modal Arguments. (shrink)

This paper discusses: (1) Anselm’s ontological argument and its criticism by Gaunilo; (2) Plantinga’s ontological argument and its criticism by Mackie and Sobel; and (3) a simplified version of Gödel’s ontological argument. It also looks carefully at (4) Kant’s attempt to show that it is impossible for there to be a successful ontological argument.

This book is a unique contribution to the philosophy of religion. It offers a comprehensive discussion of one of the most famous arguments for the existence of God: the ontological argument. The author provides and analyses a critical taxonomy of those versions of the argument that have been advanced in recent philosophical literature, as well as of those historically important versions found in the work of St Anselm, Descartes, Leibniz, Hegel and others. A central thesis of the (...) book is that ontological arguments have no value in the debate between theists and atheists. There is a detailed review of the literature on the topic (separated from the main body of the text) and a very substantial bibliography, making this volume an indispensable resource for philosophers of religion and others interested in religious studies. (shrink)

Review of Graham Oppy *Ontological Arguments and Belief in God* (CUP).

Modal ontological arguments argue from the possible existence of a perfect being to the actual (necessary) existence of a perfect being. But modal ontological arguments have a problem of symmetry; they can be run in both directions. Reverse ontological arguments argue from the possible nonexistence of a perfect being to the actual (necessary) nonexistence of a perfect being. Some familiar points about the necessary a posteriori, however, show that the symmetry can be broken in favour of the (...) ontological argument. (shrink)

The ontological argument has run for a long time, regularly refuted, regularly re-appearing in a new form. Something can be learnt from its longevity. Its proponents must be on to something, or it would not have survived its many refutations. But equally, it must have been much misformulated, or it would not have seemed evidently fallacious to its many critics. Perhaps it does express a deep philosophical intimation. Certainly it has been taken to prove more than it really (...) can establish. Like many other philosophical arguments it has suffered by being made out to be more rigorous than in the nature of the case it can be. For some philosophers addressing some questions it may have been decisive in leading them to adopt one of the few options open to them: but it is quite inconclusive for others, with different presuppositions or different problems, and cannot be reduced into a valid proof cogent for all comers and compelling them to accept the conclusion it claims to demonstrate. (shrink)

The ontological argument from reason aims to show that deliberative reasoning cannot be located in a naturalistic ontology, because such reasoning requires a unified, enduring self with libertarian free will. The most popular way of avoiding this argument is to claim that some version of naturalistic compatibilism suffices for human reason, because even in a world of event causation, some creatures may be responsive to reason. In this paper, I argue that the best versions of this approach (...) either smuggle in nonnaturalistic commitments or else cannot distinguish between compulsive rationality merely occurring in someone’s brain from reasoning an agent does. (shrink)

Inspired by the third chapter of Anselm's Proslogion, twentieth century philosophers including Charles Hartshorne and Alvin Plantinga developed “modal” ontological arguments for the existence of God. Such arguments use modal logic to infer God's existence from the premises that (i) God's existence is possible and (ii) if God exists, He exists necessarily. Like other ontological arguments, modal arguments have won few converts to theism; many commentators consider them question‐begging or liable to parody. This article details how recent attempts (...) to defend these arguments have tried to overcome these difficulties by drawing on modern accounts of the epistemology and metaphysics of modality. (shrink)

Ontological arguments like those of Gödel (1995) and Pruss (2009; 2012) rely on premises that initially seem plausible, but on closer scrutiny are not. The premises have modal import that is required for the arguments but is not immediately grasped on inspection, and which ultimately undermines the simpler logical intuitions that make the premises seem plausible. Furthermore, the notion of necessity that they involve goes unspecified, and yet must go beyond standard varieties of logical necessity. This leaves us little (...) reason to believe the premises, while their implausible existential import gives us good reason not to. (shrink)

The ontological argument in Anselm’s Proslogion II continues to generate a remarkable store of sophisticated commentary and criticism. However, in our opinion, much of this literature ignores or misrepresents the elegant simplicity of the original argument. The dialogue below seeks to restore that simplicity, with one important modification. Like the original, it retains the form of a reductio, which we think is essential to the argument’s great genius. However, it seeks to skirt the difficult question of (...) whether 'exists' is a genuine predicate by appealing instead to a distinction between having only mediated causal powers and having unmediated causal powers. Pegasus has no unmediated causal powers, but he has mediated causal powers through the thoughts, depictions, and literature in which he figures. This distinction allows us to argue about the existence of God without begging any questions. (shrink)

This was an attempt to show what is wrong with Anselm’s ‘Ontological Argument’ for the existence of God. My present view is that Peter Millican has given us a similar, but much better line of attack in his “The One Fatal Flaw….” Paper.

I argue that Descartes intended the so-called ontological "argument" as a self-validating intuition, rather than as a formal proof. The textual evidence for this view is highly compelling, but the strongest support comes from understanding Descartes's diagnosis for why God's existence is not 'immediately' self-evident to everyone and the method of analysis that he develops for making it self-evident. The larger aim of the paper is to use the ontological argument as a case study of Descartes's (...) nonformalist theory of deduction and his method of analysis, showing how he conceives the latter as a form of philosophical therapy. (shrink)

In this Introduction, we begin with two relatively uncontroversial matters: the broad contours of the history of discussion of ontological arguments, and the major topics that require discussion in connection with ontological arguments. We then move on to consideration of the much more difficult task of the characterisation of ontological arguments—i.e. the task of saying exactly what ontological arguments are and explaining how they differ from, say, cosmological, teleological, and moral arguments for the existence of God—and (...) then the equally contested question of the provision of general objections to ontological arguments, including, in particular, attempts to show that there could not possibly be a successful ontological argument. Finally, we consider some often-neglected questions about how to assess the merits of arguments, with a particular eye on the assessment of the merits of ontological arguments. (shrink)

This paper aims to show that Godel's ontological argument can be parodied in much the same kind of way in which Gaunilo parodied Anselm's Proslogion argument. The parody in this paper fails; there is a patch provided in "Reply to Gettings" (Analysis 60, 4, 2000, 363-7).

This article serves to explore the historical development of the ontological argument from Anselm to Present. Initially, the main goal is to introduce the lay reader to one of the most perplexing arguments for the theistic conception of God. Logically, this is an a priori argument, similar to one of a mathematical proof. Oddly, the argument has sort of fallen out of place in contemporary philosophy, apart from a reboot from Alvin Plantinga. The goal is to (...) illustrate that the initial argument as stated by Anselm seems to be an unsolved problem in philosophical inquiry. (shrink)

Anselm’s ontological argument is an argument for the existence of God. This paper presents Iris Murdoch’s ontological argument for the existence of the Good. It discusses her interpretation of Anselm’s argument, her distinctive appropriation of it, as well as some of the merits of her version of the argument. In doing so, it also shows how the argument integrates some key Murdochian ideas: morality’s wide scope, the basicness of vision to morality, moral (...) realism, and Platonism. (shrink)

Saint Anselm’s ontological argument is perhaps the most intriguing of all the traditional speculative proofs for the existence of God. Yet, his argument has been rejected outright by many philosophers. Most challenges stem from the basic conviction that no amount of logical analysis of a concept that is limited to the bounds of the "understanding" will ever be able to "reason" the existence in "reality" of any thing answering such a limited concept. However, it is not the (...) intent of this paper to prove or disprove Anselm’s argument. Rather, in this paper we concern ourselves with arriving at a sound interpretation of Anselm’s leading critic -- Immanuel Kant. Kant put forth perhaps the most vaunted criticism of Anselm’s argument. However, Kant has been perhaps the most misunderstood objector to Anselm’s argument. This paper confirms that charge, simultaneously offering what I believe to be a sound interpretation of Kant’s criticism. (shrink)

After so many centuries of debate, much of it even quite recent, as to the credibility of Anselm’s and others’ ontological arguments for the existence of God, it seems only fair to the opposition that some such argument be proposed for Satan’s existence. It must be noted, however, that in advocating the Devil’s existence, we may be no more than playing the Devil’s advocate.

General discussion of ontological arguments. (Extended the discussion of ontological arguments in the then current version of my SEP entry on ontological arguments.).

Dombrowski and Murdoch offer versions of the ontological argument which aim to avoid two types of objection – those concerned with the nature of the divine, and those concerned with the move from an abstract concept to a mind-independent reality. For both, the nature of the concept of God/Good entails its instantiation, and both supply a supporting argument from experience. It is only Murdoch who successfully negotiates the transition from an abstract concept to the instantiation of that (...) concept, however, and this is achieved by means of an ontological argument from moral experience which, in a reversal of the Kantian doctrine, depends ultimately on a form of the cosmological argument. (shrink)

The ontological argument--first proposed by St. Anselm and subsequently deveIoped by Descartes, Leibniz, Kant, Hegel and Marx--furnishes a key to understanding the relationship between thought and reality. In this article we shall focus on Hegel’s attitude towards the ontological argument as set out in his Science of Logic, where it appears as a paradigm of the relationship between thought and reality. It should be remarked, moreover, that our choice of the subject was not random and that (...) it was seIected for the reason that belief in God is a preeminent social reality, inasmuch as faith in God creates His existence. Therefore, an investigation of the concept of God is an inquiry into the most profound recesses of human consciousness.The great opponents of the ontological argument, from Hume down to our day--and even Kant--have based their arguments upon the fundamental empiricist assertion that existential judgments are not analytical. In this paper we attempt to defend the ontological argument against its opponents. (shrink)

This is a short introduction to ontological arguments. It begins with a brief characterization of ontological arguments that proceeds mainly by way of example. The rest of the discussion is given over to consideration of what looks like a very simple ontological argument. This consideration turns up many of the issues that arise when more complex ontological arguments are examined.

The intention of this article is to show that the Tractatus deals with the problem of the relation between reality, possibility, and necessity as traditionally considered in the ontological argument, that is, in relation to the idea of limit, and that in Section 5.5521, we find an especially clarifying formulation of this question; the formulation itself, however, is not at all clear, so that a lengthy commentary of it is justified.

Any argument which attempts to prove God's existence a priori based only on His nature can be termed an "Ontological Argument". Historically, however, the term is inextricably associated with the famous argument presented in Anselm's Proslogion chapter II, and with the later variant advanced by Descartes in his fifth Meditation and subsequently developed by Leibniz. Some have claimed that Anselm's argument was anticipated in the thought either of various classical philosophers (notably Aristotle, Parmenides, Plato, and (...) Zeno of Cition) or of Augustine, but although there are indeed suggestive passages in their writings, Anselm's explicit "proof" of God's existence based on his Nature does appear to be a genuinely original discovery. (shrink)

One of the more famous criticisms of ontological arguments is that provided by Kant in his Critique of Pure Reason, and two of the more frequent comments on it are essentially these: Kant points out that existence is no predicate; his criticism contains several puzzling elements which can just as well be neglected, since the first point is enough. It is the intent of this paper to substantiate a protest against such analyses of Kant’s anti–ontological–arguments argument and (...) to develop certain consequences from this for current attempts to rehabilitate ontological arguments. The protest is not that such analyses are simply wrong, but that they are dangerously misleading and represent Kant’s argument as weaker than it in fact is. The substantiation is provided by the examination of the three main elements of Kant’s criticism of ontological arguments: the distinction of real and logical predicates, the analysis of uses of ‘to be’, and the discussion of concepts of possible and of actual things. The consequences for current attempted rehabilitations of ontological arguments center upon the alleged distinction of ‘existence’ and ‘necessary existence’. On the basis of the foregoing substantiation it is shown that this distinction, despite its proponents’ claims, does not make Kant’s criticism inapplicable, that the sense of ‘necessity’ remains a problem, that Kant knew quite well what he was doing in criticizing ontological arguments, and that the necessary existence allegedly proved by ontological arguments is not that which is also alleged to be religiously required. (shrink)

The first aim of this paper is to try and determine what St. Anselm meant in his original argument in the Proslogion. This needs to be done because not only are the writers who expound his demonstration divided in their interpretations of it, and these interpretations quite different, but, very strangely, one does not find that they mention that there is any ambiguity and that other writers construe Anselm's words differently from themselves. Since there are in fact two arguments (...) in the classical formulation of his proof, I want to try and disentangle them, decide which of them Anselm intendedand what is its connection with the demonstration in the third chapter of the Proslogion, and thus to offer an opinion on what exactly the ontological argument of St. Anselm is. Then on the basis of the clarification, I hope to show what it was that Gaunilo and St. Thomas attacked, to touch briefly on the relation of the 17th century ontological argument to Anselm's, and in general to indicate the curious round-aboutness of the historical criticism of Anselm. Anselm argued and Gaunilo and Thomas refuted something, though not, I think, precisely what Anselm meant, or, at any rate, not all that he meant. Actually it was Descartes that Thomas refuted by refuting half of Anselm. Kant refuted the other half of Anselm in an irrelevant criticism of Descartes. So that it could properly be said that Anselm's proof has been broken by philosophers who were either only partly aware of what he was maintaining, or who never had him in mind at all. Finally, because the important thing about the ontological argument, in my opinion, is not whether it is a demonstration of God's existence, but whether its refutation is a demonstration of the impossibility of God's existence, and because this question seems to arise most sharply in connexion with Anselm's position, I want to say something about that. (shrink)

This chapter contains sections titled: The History of the Argument The Modal Ontological Argument The Possibility of a Perfect Being: Leibniz The Possibility of a Perfect Being: Gödel The Rationality of Belief in a Perfect Being: Plantinga Summary Works cited.

Leibniz's version of the ontological argument, a modal argument for theism on which he worked most intensively in the 1670s, has two stages. The first, an “incomplete” proof, concludes that God can only be a necessary being, and therefore if God's existence is possible, then God exists. The second stage is an a priori argument that the existence of such a necessary God is indeed possible. Leibniz's fullest attempts at a possibility proof turn on his conception (...) of a most perfect being, and the chapter concludes that they are not likely to succeed, in part because of difficulties in connecting the concepts of perfection and necessary existence. (shrink)

Anselm's argument has two distinct conclusions: (a) we cannot intelligibly doubt that god exists, and (b) this god, whose existence we cannot doubt, exists necessarily. if we replace anselm's vague conception of god by the spinozistic conception of substance, a defensible version of the ontological argument, understood as having these two conclusions, can be constructed. two important consequences of this analysis are: (1) the ontological argument, properly understood, deals simply with the concept of substance. it (...) is a further question whether substance ought to be understood as god. (2) the ontological argument does not actually demonstrate the existence of anything. it simply makes clear the consequences of adopting a metaphysical view which employs the spinozistic conception of substance. (shrink)

After so many centuries of debate, much of it even quite recent, as to the credibility of Anselm’s and others’ ontological arguments for the existence of God, it seems only fair to the opposition that some such argument be proposed for Satan’s existence. It must be noted, however, that in advocating the Devil’s existence, we may be no more than playing the Devil’s advocate.

This essay examines how, in the early twentieth century, ontological arguments were employed in the defense of metaphysical idealism. The idealists of the period tended to grant that ontological arguments defy our usual expectations in logic, and so they were less concerned with the formal properties of Anselmian arguments. They insisted, however, that ontological arguments are indispensable, and they argued that we can trust argumentation as such only if we presume that there is a valid ontological (...) argument. In the first section I outline the history of this metalogical interpretation of the ontological argument. In the subsequent sections I explain how Royce and Collingwood each developed the argument, and how this impacted their respective conceptions of both logic and metaphysics. (shrink)

Review of Graham Oppy *Ontological Arguments and Belief in God*.

Within the past two decades or so there has been a gradual renewal of interest in metaphysics in general and in the theistic arguments in particular. "the ontological argument: a research bibliography," is the most comprehensive bibliography ever done on this argument for god's existence, with over 330 items listed. the article is divided into the following categories: general histories of the argument; the argument in anselm; in the middle ages after anselm; from descartes to (...) kant; in continental philosophy; in british and american philosophy; the logic of "exists"; the concept of necessary being, etc. (shrink)

There are good reasons for being dissatisfied with standard criticisms of the various arguments, all of which are referred to as being “The Ontological Argument”. While refutation by logical analogy is compelling, it merely teaches us that something is amiss. It does not specify the exact nature of the flaw. The first part of this paper examines and rejects several well-known attempts at refuting and clarifying the argument(s). The second part attempts to provide a principled uniform account (...) of what is wrong by treating the arguments as resting on definitions. Then, by bringing to bear Ajdukiewicz’s exhaustive classification of definitions, we arrive at a unified account of the flaw common to such arguments. In effect we have an explication of the dictum that one cannot define into existence. (shrink)

Assuming S5, the main controversial premise in modal ontological arguments is the possibility premise, such as that possibly a maximally great being exists. I shall offer a new way of arguing that the possibility premise is probably true.

Saint Anselm’s ontological argument is usually interpreted either (1) as an attempt to deductively prove God’s existence or (2) as a form of prayer, which is not intended to “prove” God’s existence, but rather to deepen the devotion of those who already believe. In this paper I attempt to find a mean between these two interpretations, showing that while Anselm’s argument is not a deductive proof, it is nevertheless a proof of God’s existence. I argue that Anselm’s (...) ontological argument is analogous to Aristotle’s to elegktikōs apodeixai (retorsive argument) for the truth of the principle of non-contradiction in Metaphysics IV: an argument that does not move from premises to conclusion, but rather demonstrates the truth of its conclusion by showing that its conclusion is always presupposed. I argue that interpreting Anselm’s ontological argument in this way exempts it from the most common objections against it. (shrink)

This article shows that Descartes’ ontological argument in Meditation V is needed to ground essential distinctions, particularly the mind/body distinction. It does this by tracing out Descartes’ di...

Proving the existence of God is a perennial philosophical ambition. An armchair proof would be the jackpot. Ontological arguments promise as much. This Element studies the most famous ontological arguments from Anselm, Descartes, Plantinga, and others besides. While the verdict is that ontological arguments don't work, they get us entangled in fun philosophical puzzles, from philosophy of religion to philosophy of language, from metaphysics to ethics, and beyond.

Among the rational arguments for God’s existence there is the ontological argument, originally put forth – in its classical form – by the scholastic theologian and philosopher Anselm of Canterbury and subsequently reiterated, in slightly altered versions, by some of the modern thinkers. The present paper aims to outline a comparative presentation of the ontological argument as formulated by Anselm and Descartes, respectively, and to investigate the ways in which the two Christian philosophers perceived the relationship (...) between faith and reason, between unconditional acceptance of divine Revelation and its expression in the terms of discursive thinking. (shrink)

This chapter presents and critically discusses the main historical variants of the “ontological argument,” a form of a priori argument for the existence of God pioneered by Anselm of Canterbury. I assess the contributions of Anselm, Descartes, Leibniz, and Gödel, and criticisms by Gaunilo, Kant, and Oppy among others.

Daniel Dombrowski contends that: a number of versions of the ontological argument [OA] are sound; the deity whose existence is most well established by the OA is the deity picked out by Hartshorne’s neoclassical concept of God; skeptics who insist that the OA only shows that “if God exists, then God exists necessarily” are contradicting themselves, and the OA is worth a great deal since it effectively demonstrates the rationality of theism. I argue that theses and are clearly (...) false and offer a presumptive case for thinking that is false, since, absent an independent proof of God’s existence, the theist appears to be in no position to rationally assert. I also show that the Anselmian OA harmonizes rather poorly with a Hartshornean neoclassical conception of God. I conclude by assessing the philosophical and dialectical worth of ontological arguments vis-à-vis establishing the rationality of theism. (shrink)

There are several styles of ontological argument. Here are examples of the first style. God has all perfections. Existence is a perfection. ∴God exists. All perfect beings exist. God is a perfect being. ∴God exists. God couldn't be improved. A being that doesn't exist could be improved . ∴God exists.

I argue that spinoza's ontological argument is successful when it is understood to have two premises: (i) it is possible for god to exist, (ii) it is necessary that, if god exists, he necessarily does. the argument is valid in s5. spinoza is in a position to establish the second premise of the argument on the basis of his definitions and axioms. the first premise was assumed to be true, but, as leibniz noted, it must be (...) established for the conclusion of the argument to be forthcoming. this is one of the main problems with the argument, and it requires a solution to the problem of the attributes. certain alternate interpretations of spinoza are then argued to be deficient on textual and logical grounds. (shrink)