We argue that Anselm’s ontological argument (or at least one reconstruction of it) is based on an empirical version of Berry’s paradox. It is invalid, but it takes some understanding of trivalence to see why this is so. Under our analysis, Anselm’s use of the notion of existence is not the heart of the matter; rather, trivalence is.

This article is a reply to Michael Gettings' criticisms of a previous paper of mine on Godel's ontological argument. (All relevant bibliographical details may be found in the article.) I provide a patch to my previous -- faulty -- attempt to provide a parody of Godel's ontological argument on the model of Gaunilo's parody of Anselm's Proslogion 2 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*.

In this paper, the authors show that there is a reading of St. Anselm's ontological argument in Proslogium II that is logically valid (the premises entail the conclusion). This reading takes Anselm's use of the definite description "that than which nothing greater can be conceived" seriously. Consider a first-order language and logic in which definite descriptions are genuine terms, and in which the quantified sentence "there is an x such that..." does not imply "x exists". Then, using an ordinary logic (...) of descriptions and a connected greater-than relation, God's existence logically follows from the claims: (a) there is a conceivable thing than which nothing greater is conceivable, and (b) if <em>x</em> doesn't exist, something greater than x can be conceived. To deny the conclusion, one must deny one of the premises. However, the argument involves no modal inferences and, interestingly, Descartes' ontological argument can be derived from it. (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).

Peter Millican (2004) provides a novel and elaborate objection to Anselm's ontological argument. Millican thinks that his objection is more powerful than any other because it does not dispute contentious 'deep philosophical theories' that underlie the argument. Instead, it tries to reveal the 'fatal flaw' of the argument by considering its 'shallow logical details'. Millican's objection is based on his interpretation of the argument, according to which Anselm relies on what I call the 'principle of the superiority of existence' (PSE). (...) I argue that (i) the textual evidence Millican cites does not provide a convincing case that Anselm relies on PSE and that, moreover, (ii) Anselm does not even need PSE for the ontological argument. I introduce a plausible interpretation of the ontological argument that is not vulnerable to Millican's objection and conclude that even if the ontological argument fails, it does not fail in the way Millican thinks it does. (shrink)

Anselm's Ontological Argument fails, but not for any of the various reasons commonly adduced. In particular, its failure has nothing to do with violating deep Kantian principles by treating ‘exists’ as a predicate or making reference to ‘Meinongian’ entities. Its one fatal flaw, so far from being metaphysically deep, is in fact logically shallow, deriving from a subtle scope ambiguity in Anselm's key phrase. If we avoid this ambiguity, and the indeterminacy of reference to which it gives rise, then his (...) argument is blocked even if his supposed Meinongian extravagances are permitted. Moreover it is blocked in a way which is straightforward and compelling (by contrast with the Kantian objections), and which generalizes easily to other versions of the Ontological Argument. A significant moral follows. Fear of Anselm's argument has been hugely influential in motivating ontological fastidiousness and widespread reluctance to countenance talk of potentially non-existing entities. But if this paper is correct, then the Ontological Argument cannot properly provide any such motivation. Some of the most influential contributions to ontology, from Kant to Russell and beyond, rest on a mistake. (shrink)

Yujin Nagasawa accuses me of attributing to Anselm a principle (the 'principle of the superiority of existence', or PSE) which is not present in his text and which weakens, rather than strengthens, his Ontological Argument. I am undogmatic about the interpretative issue, but insist on a philosophical point: that Nagasawa's rejection of PSE does not help the argument, and appears to do so only because he overlooks the same ambiguity that vitiates the original. My conclusion therefore remains: that the fatal (...) flaw in Anselm's argument—as in many other variants—is a relatively shallow ambiguity rather than a deep metaphysical mistake. (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.

Is it possible to prove or disprove God's existence? Arguments for the existence of God have taken many different forms over the centuries: in The Non-Existence of God, Nicholas Everitt considers all of the arguments and examines the role that reason and knowledge play in the debate over God's existence. He draws on recent scientific disputes over neo-Darwinism, the implication of 'big bang' cosmology, and the temporal and spatial size of the universe; and discusses some of the most recent work (...) on the subject, leading to a controversial conclusion. (shrink)

In this book, Graham Oppy examines arguments for and against the existence of God. He shows that none of these arguments is powerful enough to change the minds of reasonable participants in debates on the question of the existence of God. His conclusion is supported by detailed analyses of the arguments as well as by the development of a theory about the purpose of arguments and the criteria that should be used in judging whether or not arguments are successful. Oppy (...) discusses the work of a wide array of philosophers, including Anselm, Aquinas, Descartes, Locke, Leibniz, Kant, Hume and, more recently, Plantinga, Dembski, White, Dawkins, Bergman, Gale and Pruss. (shrink)

In recent years, the ontological argument and theistic metaphysics have been criticised by philosophers working in both the analytic and continental traditions. Responses to these criticisms have primarily come from philosophers who make use of the traditional, and problematic, concept of God. In this volume, Daniel A. Dombrowski defends the ontological argument against its contemporary critics, but he does so by using a neoclassical or process concept of God, thereby strengthening the case for a contemporary theistic metaphysics. Relying on the (...) thought of Charles Hartshorne, he builds on Hartshorne's crucial distinction between divine existence and divine actuality, which enables neoclassical defenders of the ontological argument to avoid the familiar criticism that the argument moves illegitimately from an abstract concept to concrete reality. His argument, thus, avoids the problems inherent in the traditional concept of God as static. (shrink)

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