The authors investigated the ontological argument computationally. The premises and conclusion of the argument are represented in the syntax understood by the automated reasoning engine PROVER9. Using the logic of definite descriptions, the authors developed a valid representation of the argument that required three non-logical premises. PROVER9, however, discovered a simpler valid argument for God's existence from a single non-logical premise. Reducing the argument to one non-logical premise brings the investigation of the soundness of the argument into better focus. Also, (...) the simpler representation of the argument brings out clearly how the ontological argument constitutes an early example of a ?diagonal argument? and, moreover, one used to establish a positive conclusion rather than a paradox. (shrink)

This paper is a defense of the view that existence is a property. Since the view is still a minority one, a fair amount of space is allotted to defending it against objections and counter-arguments. Positive arguments aren’t lacking, however, and emerge in the course of the discussion. Not all of the many positive or negative arguments which follow are wholly original—a fact to be expected in this context—but a fair number are, and both sorts of argument are seamlessly interwoven (...) in the warp and woof of what follows. (shrink)

Many scholars claimed that, according to Immanuel Kant, some judgements lack a truth-value: analytic judgements, judgements about items of which humans cannot have experience, judgements of perception, and non-assertoric judgements. However, no one has undertaken an extensive examination of the textual evidence for those claims. Based on an analysis of Kant's texts, I argue that: (1) according to Kant, only judgements of perception are not truth-apt. All other judgements are truth-apt, including analytic judgements and judgements about items of which humans (...) cannot have experience. (2) Kant sometimes states that truth-apt judgements are actual bearers of truth or falsity only when they are taken to state what is actually the case. Kant calls these judgements assertoric. Other texts ascribe truth and falsity to judgements, regardless of whether they are assertoric. Kant's views on truth-aptness raise challenges for correspondentist and coherentist interpretations of Kant's theory of truth; they rule out the identification of Kant's crucial notion of objective validity with truth-aptness; and they imply that Kant was not a verificationist about truth or meaning. (shrink)

Anselm of Canterbury’s so-called ontological proofs in the Proslogion have puzzled philosophers for centuries. The famous description “something / that than which nothing greater can be conceived” is part and parcel of his argument. Most commentators have interpreted this description as a definition of God. We argue that this view, which we refer to as “definitionism”, is a misrepresentation. In addition to textual evidence, the key point of our argument is that taking the putative definition as what Anselm intended it (...) to be – namely a description of a content of faith – allows getting a clear view of the discursive status and argumentative structure of Proslogion 2–4, as well as making sense of an often neglected part of the argument. (shrink)

This paper introduces the special issue on Logic and Philosophy of Religion of the journal Sophia: International Journal of Philosophy and Traditions (Springer). The issue contains the following articles: Logic and Philosophy of Religion, by Ricardo Sousa Silvestre and Jean-Yvez Béziau; The End of Eternity, by Jamie Carlin Watson; The Vagueness of the Muse—The Logic of Peirce’s Humble Argument for the Reality of God, by Cassiano Terra Rodrigues; Misunderstanding the Talk(s) of the Divine: Theodicy in the Wittgensteinian Tradition, by Ondřej (...) Beran; On the Concept of Theodicy, by Ricardo Sousa Silvestre; The Logical Problem of the Trinity and the Strong Theory of Relative Identity, by Daniel Molto; Thomas Aquinas on Logic, Being, and Power, and Contemporary Problems for Divine Omnipotence, by Errin D. Clark. -/- . (shrink)

According to many realist philosophers of fiction, one needs to posit an ontology of existing fictional characters in order to give a correct account of discourse about fiction. The realists' claim is opposed by pretense theorists for whom discourse about fiction involves, as discourse in fiction, pretense. On that basis, pretense theorists claim that one does not need to embrace an ontology of fictional characters to give an account of discourse about fiction. The ontolog-ical dispute between realists and pretense theorists (...) is mainly a dispute in the realm of the phi-losophy of language concerning the status relative to pretense of discourse about fiction. Realists are persuaded that there is a sharp line between discourse in fiction and discourse about fiction while pretense theorists deny there exists such a line. I suggest that realists may have a wrong picture of discourse in fiction since, in many cases, discourse in fiction already contains many occurrences of discourse about fiction. Consequently, discourse about fiction, instead of ending fiction, should be regarded, following pretense theorists, as adding extra lay-ers of fiction. (shrink)

An argument for the existence of gods given by the Stoic Diogenes of Babylon and reported by Sextus Empiricus appears to be an ancient version of the ontological argument. In this paper I present a new reconstruction of Diogenes' argument that differs in certain important respects from the reconstruction presented by Jacques Brunschwig. I argue that my reconstruction makes better sense of how Diogenes' argument emerged as a response to an attack on an earlier Stoic argument presented by Zeno of (...) Citium. Diogenes' argument as reconstructed here is an example of a modal ontological argument that makes use of the concept of being of such a nature as to exist. I argue that this concept is a modal concept that is based on the Philonian definition of possibility, and thus that Diogenes' argument is a source of important evidence about the use of non-Stoic modalities in the post-Chrysippean Stoa. I conclude by arguing that the objections made against considering Diogenes' argument as ontological are unfounded and that Diogenes' argument clearly resembles modern versions of modal ontological arguments. (shrink)

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)

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)

The most famous objection to the ontological argument is given in Kant's dictum that existence is not a real predicate. But it is not obvious how this slogan is supposed to relate to the ontological argument. Some, most notably Alvin Plantinga, have even judged Kant's dictum to be totally irrelevant to Anselm's version of the ontological argument. In this paper I argue, against Plantinga and others, that Kant's claim is indeed relevant to Anselm's argument, in the straightforward sense that if (...) the claim is true, then Anselm's argument is unsound. (shrink)

It is often said that the ontological argument fails because it wrongly treats existence as a first-level property or predicate. This has proved a controversial claim, and efforts to evaluate it are complicated by the fact that the words ‘existence is not a property/predicate’ have been used by philosophers to make at least three different negative claims: (a) one about a first-level phenomenon possessed by objects like horses, stones, you and me; (b) another about the logical form of assertions of (...) existence; and (c) still another about a second-level phenomenon possessed by concepts when they are instantiated. I argue that only the last of these claims, originally voiced by Kant, is both plausible and relevant to the ontological argument. And I try to show that the relevance of the Kantian version comes from its providing the underlying justification for a different, and far less controversial, criticism of the ontological argument. (shrink)

It is often said that the ontological argument fails because it wrongly treats existence as a first-level property or predicate. This has proved a controversial claim, and efforts to evaluate it are complicated by the fact that the words ‘existence is not a property/predicate’ have been used by philosophers to make at least three different negative claims: (a) one about a first-level phenomenon possessed by objects like horses, stones, you and me; (b) another about the logical form of assertions of (...) existence; and (c) still another about a second-level phenomenon possessed by concepts when they are instantiated. I argue that only the last of these claims, originally voiced by Kant, is both plausible and relevant to the ontological argument. And I try to show that the relevance of the Kantian version comes from its providing the underlying justification for a different, and far less controversial, criticism of the ontological argument. (shrink)

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.

I argue that Kant's and Frege's refutations of the ontological argument are more similar than has generally been acknowledged. As I clarify, for both Kant and Frege, to say that something exists is to assert of a concept that it is instantiated. With such an assertion one expresses that there is a particular relation between the instantiating object and a rational subject - a particular mode of presentation for the object in question. By its very nature such a relation cannot (...) be the property of an object and thus cannot be included in the concept of that object. Thus the ontological argument, which takes existence to be a part of the concept of the supreme being, cannot, according to Kant and Frege, succeed. A secondary goal of the paper is to illuminate what I take to be an important affinity between Kant's and Frege's views more generally: that Frege's fundamental distinction between the sense and the referent of a proposition echoes, in an important way, Kant's distinction between concepts and the formal principles for their application to experience. (shrink)

I argue that if one accepts the existence of a multiverse model that posits the existence of all possible realities, and also wants to maintain the existence of a God who exemplifies omnipotence, omnibenevolence and omniscience then the brand of God that he should ascribe to is one of deism rather than the God of classical theism. Given the nature and construct of such a multiverse, as well as some specific interpretations of the divine attributes, this points us to a (...) God who is inactive in the natural world, not one who is. This deistic conception of God not only sits better with the idea of a multiverse and is also compatible with many arguments for theism, but it also responds to certain arguments for atheism better than the classical conception of God. I ultimately argue that deism ought to be given consideration as a plausible alternative conception to the classical conception of God, given the acceptance of a multiverse. (shrink)