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).

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

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)

Proof and perception : the context of the argumentum cartesianum -- Refutations of atheism : ontological arguments in English philosophy, 1652-1705 -- Being and intuition : Malebranche's appropriation of the argument -- An adequate conception : the argument in Spinoza's philosophy -- Ontological arguments in Leibniz and the German enlightenment -- Kant's systematic critique of the ontological argument -- Hegel's reconstruction of the argument.

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.

Gödel's ontological argument is a formal argument for a being defined in terms of the concept of a positive property. I shall defend several versions of Gödel's argument, using weaker premises than Anderson's (1990) version, and avoiding Oppy's (1996 and 2000) parody refutations.

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.

In arithmetic, if only because many of its methods and concepts originated in India, it has been the tradition to reason less strictly than in geometry, ...

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 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.

The book Ontological Proofs Today, apart from the introduction, consists of six parts. Part II comprises papers each of which pertains either to historical ontological arguments, or to some other, rather new, ontological arguments, but what makes them stand out from the other papers in this volume, is the fact that they all treat of the omniscience or the omnipotence of God. Part III includes papers which introduce new ontological arguments for the existence of God, without referring to omniscience and (...) omnipotence as the transparent attributes of God. The issue of the type of necessity with which ontological proofs work or may work is raised in the articles of Part IV. In Part V the semantics for some ontological proofs are defined. Part VI consists of papers which, although quite different from each other in terms of content, all explore some ontological issues, and formal ontology may be considered the link between them. Part VII comprises two articles, by R. E. Maydole and G. Oppy, mutually controversial and different in their assessment of some ontological proofs. (shrink)

The main objective is an interpretation of the island parody, in particular a logical reconstruction of the parodying argument that stays close to the text. The parodied reasoning is identified as the proof in the second chapter of the Proslogion, more specifically, this proof as it is represented by Gaunilo in the first chapter of his Liber pro insipiente. The second task is a detailed comparison between parodied and parodying argument as well as an account of their common structure. The (...) third objective is a tentative characterization of the nature and function of parodies of arguments. It seems that parodying does not add new pertinent points of view to the usual criticism of an argument. (shrink)

"I began to ask myself whether there might be found a single argument which would require no other for its proof than itself alone, and would suffice to demonstrate that God truly exists." - St. Anselm.

This book, one of the first full-length studies of the modalities to emerge from the debate to which Saul Kripke, David Lewis, Ruth Marcus, and others are contributing, is an exploration and defense of the notion of modality de re, the idea that objects have both essential and accidental properties. Plantinga develops his argument by means of the notion of possible worlds and ranges over such key problems as the nature of essence, transworld identity, negative existential propositions, and the existence (...) of unactual objects in other possible worlds. He also applies his logical theories to the elucidation of two problems in the philosophy of religion: the problem of evil and the ontological argument. (shrink)

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.

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 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 Argument The Temporal‐Contingency Argument Conclusion References Appendix 1. Logic Matters Appendix 2. Formal (...) Proofs of Some Modal Arguments. (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 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.

We describe a KB Gödelian ontological system, and some other weak systems, in a fully formal way using theory of types and natural deduction, and present a completeness proof in its main and specific parts. We technically and philosophically analyze and comment on the systems (mainly with respect to the relativism of values) and include a sketch of some connected aspects of Gödel's relation to Kant.

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.

Adams presents an in-depth interpretation of three important parts of Leibniz's metaphysics, thoroughly grounded in the texts as well as in philosophical analysis and critique. The three areas discussed are the metaphysical part of Leibniz's philosophy of logic, his essentially theological treatment of the central issues of ontology, and his theory of substance. Adams' work helps make sense of one of the great classic systems of modern philosophy.

Of all the thinkers of the century of genius that inaugurated modern philosophy, none lived an intellectual life more rich and varied than Gottfried Wilhelm Leibniz. Maria Rosa Antognazza's pioneering biography provides a unified portrait of this unique thinker and the world from which he came. At the centre of the huge range of Leibniz's apparently miscellaneous endeavours, Antognazza reveals a single master project lending unity to his extraordinarily multifaceted life's work. Throughout the vicissitudes of his long life, Leibniz tenaciously (...) pursued the dream of a systematic reform and advancement of all the sciences. As well as tracing the threads of continuity that bound these theoretical and practical activities to this all-embracing plan, this illuminating study also traces these threads back into the intellectual traditions of the Holy Roman Empire in which Leibniz lived and throughout the broader intellectual networks that linked him to patrons in countries as distant as Russia and to correspondents as far afield as China. (shrink)

This is a wide-ranging 2004 book about arguments for and against beliefs in God. The arguments for the belief are analysed in the first six chapters and include ontological arguments from Anselm to Gödel, the cosmological arguments of Aquinas and Leibniz, and arguments from evidence for design and miracles. The next two chapters consider arguments against belief. The last chapter examines Pascalian arguments for and against belief in God. There are discussions of Cantorian problems for omniscience, of challenges to divine (...) omnipotence, and of the compatibility of everlasting complete knowledge of the world with free-will. There are appendices that present formal proofs in a system for quantified modal logic, a theory of possible worlds, notes on Cantorian set theory, and remarks concerning non-standard hyperreal numbers. This book will be a valuable resource for philosophers of religion and theologians and will interest logicians and mathematicians as well. (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)

Here is the crucial passage from Proslogion II.

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.