A logically impossible sentence is one which entails a contradiction, a logically necessary sentence is one whose negation entails a contradiction, and a logically possible sentence is one which does not entail a contradiction. Metaphysically impossible, necessary and possible sentences are ones which become logically impossible, necessary, or possible by substituting what I call informative rigid designators for uninformative ones. It does seem very strongly that a negative existential sentence cannot entail a contradiction, and so ”there is a God’ cannot (...) be a metaphysically necessary truth. If it were such a truth, innumerable other sentences which seem paradigm examples of logically possible sentences, such as ”no one knows everything’ would turn out to be logically impossible. The only way in which God could be a logically necessary being is if there were eternal necessary propositions independent of human language or God’s will, such that the proposition that there is no God would entail -- via propositions inaccessible to us -- a contradiction. But if there were such propositions, God would have less control over the universe than he would have otherwise. (shrink)

In “On Oppy’s Objections to the Modal Perfection Argument,” Philo 8, 2, 2005, 123–30, Robert Maydole argues that his modal perfection argument—set out in his “The Modal Perfection Argument for a Supreme Being,” Philo 6, 2, 2003, 299–313—“remains arguably sound” in the face of the criticisms that I made of this argument in my “Maydole’s 2QS5 Argument,” Philo 7, 2, 2004, 203–11. I reply that Maydole is wrong: his argument is fatally flawed, and his attempts to avoid the criticisms that (...) I have made of his argument are to no avail. (shrink)

Preface -- Introduction -- Preliminary matters -- Some big ideas -- Minimal theism and naturalism -- Standard theism and naturalism -- Conclusion.

This chapter contains sections titled: Introduction The PSR Nonlocal CPs Toward a First Cause The Gap Problem Conclusions and Further Research References.

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)

This paper is a reply to Robert Maydole’s “The Modal Perfection Argument for the Existence of a Supreme Being,” published in Philo 6, 2, 2003. I argue that Maydole’s Modal Perfection Argument fails, and that there is no evident way in which it can be repaired.

This book, one of the handful of truly pathbreaking works in twentieth-century philosophical theology, presents Hartshorne's persuasive rehabilitation of Anselm's Ontological Argument, recast in neoclassical form as "the Modal Proof.".

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.

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

I have always considered that the two questions respecting God and the Soul were the chief of those that ought to be demonstrated by philosophical rather than ...

The Principle of Sufficient Reason says that all contingent facts must have explanation. In this 2006 volume, which was the first on the topic in the English language in nearly half a century, Alexander Pruss examines the substantive philosophical issues raised by the Principle Reason. Discussing various forms of the PSR and selected historical episodes, from Parmenides, Leibnez, and Hume, Pruss defends the claim that every true contingent proposition must have an explanation against major objections, including Hume's imaginability argument and (...) Peter van Inwagen's argument that the PSR entails modal fatalism. Pruss also provides a number of positive arguments for the PSR, based on considerations as different as the metaphysics of existence, counterfactuals and modality, negative explanations, and the everyday applicability of the PSR. Moreover, Pruss shows how the PSR would advance the discussion in a number of disparate fields, including meta-ethics and the philosophy of mathematics. (shrink)

This paper is a reply to Graham Oppy’s “Maydole’s 2QS5 Argument,” published in Philo 7, 2 (2004). I argue that he fails to refute myModal Perfection Argument for the existence of a Supreme Being, and that it remains arguably sound in the face of his alleged counterexamples and parodies.

In this discussion note, I defend Gaunilo's famous parody of Anselm's Ontological Argument for God's existence against a well-known objection due to Alvin Plantinga.

How do we prove the existence of God? This book tackles head-on this fundamental question. It examines a cross-section of theistic proofs, explaining in clear terms what they are and what they try to accomplish.