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

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.

First, I suggest that it is possible to make some further improvements upon the Gödelian ontological arguments that Pruss develops. Then, I argue that it is possible to parody Pruss's Gödelian ontological arguments in a way that shows that they make no contribution towards 'lowering the probability of atheism and raising the probability of theism'. I conclude with some remarks about ways in which the arguments of this paper can be extended to apply to the whole family of Gödelian ontological (...) arguments. (shrink)

This book discusses and exemplifies the philosophy of religion, or philosophical reflection on central themes of religion.

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)

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)

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

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)

The Modal Perfection Argument (MPA) for the existence of a Supreme Being is a new ontological argument that is rooted in the insights of Anselm, Leibniz and Gödel. Something is supreme if and only if nothing is possibly greater, and a perfection is a property that it is better to have than not. The premises of MPA are that supremity is a perfection, perfections entail only perfections, and the negation of a perfection is not a perfection. I do three things (...) in this paper. First, I prove that MPA is valid by constructing a formal deduction of it in second order modal logic. Second, I argue that its premises are true. Third, I defend the argument and the logic used against some likely objections. (shrink)

According to leibniz, Descartes' ontological argument establishes that if God possibly exists then God exists. To complete the argument a proof that God possibly exists is required. Leibniz attempts a proof-Theoretic demonstration that 'god exists' is consistent and concludes from this that 'god possibly exists is true'. In this paper I formalize leibniz's argument in a system of modal logic. I show that a principle which leibniz implicitly uses, 'if a is consistent then a is possibly true' is either mistaken (...) or useless in completing the ontological argument. (shrink)

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.