Online research in philosophy

Graham Oppy has argued that possible explanation entails explanation in order to object to Richard Gale and Alexander Pruss’s new cosmological argument that it does not improve upon familiar cosmological arguments. Gale and Pruss as well as Pruss individually have granted Oppy’s inference from possible explanation to explanation and argue that this inference provides a reason to believe that the strong principle of sufficient reason is true. In this article, I shall undermine Oppy’s objection to the new cosmological argument by arguing that it is logically possible that some truths are merely possibly explained.

Cosmological arguments have received more attention in the past ten years. One reason for this is that versions with restricted or even no reliance on the principle of sufficient reason (PSR) have been formulated. By not relying on PSR – what many consider to be a necessary falsehood – philosophers have been able to escape many of the old criticisms of cosmological arguments. In this essay I survey two recent attempts at presenting a sound version of a cosmological argument. I spend more time on Robert Koons' since his has not yet received the kind of quality attention that the other has.

Metaphysical rationalism, the doctrine which affirms the Principle of Sufficient Reason (the PSR), is out of favor today. The best argument against it is that it appears to lead to necessitarianism, the claim that all truths are necessarily true. Whatever the intuitive appeal of the PSR, the intuitive appeal of the claim that things could have been otherwise is greater. This problem did not go unnoticed by the great metaphysical rationalists Spinoza and Leibniz. Spinoza’s response was to embrace necessitarianism. Leibniz’s response was to argue that, despite appearances, rationalism does not lead to necessitarianism. This paper examines the debate between these two rationalists and concludes that Leibniz has persuasive grounds for his opinion. This has significant implications both for the plausibility of the PSR and for our understanding of modality.

The Clarke/Rowe version of the Cosmological Argument is sound only if the Principle of Sufficient Reason (PSR) is true, but many philosophers, including Rowe, think that there is not adequate evidence for the principle of sufficient reason. I argue that there may be indirect evidence for PSR on the grounds that if we do not accept it, we lose our best justification for an important principle of metaethics, namely, the Principle of Universalizability. To show this, I argue that all the other justifications of the Principle of Universalizability on offer, including Richard Hare's, are inadequate.

This essay examines arguments offered in support of the Principle of Sufficient Reason (PSR) by Leibniz and his followers as well as Hume's critique of the PSR. It is shown that Leibniz has a defensible argument for the PSR, whereas the arguments of his self-proclaimed followers are weak. Thus, Hume's challenge is met by Leibniz, by Wolff and Baumgarten not so much.

This paper presents an argument for the Principle of Sufficient Reason, the PSR, the principle according to which each thing that exists has an explanation. I begin with several widespread and extremely plausible arguments that I call explicability arguments in which a certain situation is rejected precisely because it would be arbitrary. Building on these plausible cases, I construct a series of explicability arguments that culminates in an explicability argument concerning existence itself. This argument amounts to the claim that the PSR is true. The plausibility of the initial cases in the series provides the basis of an argument for the PSR, an argument that can be rebutted only by drawing a line between the plausible early cases in the series and the apparently unacceptable later cases. I argue that no principled reason for drawing this line has been found and that one cannot draw an unprincipled or arbitrary line without begging the question. The paper concludes that, therefore, this defense of the PSR remains unrebutted and that we have a powerful, new reason to embrace the PSR.

The Principle of Sufficient Reason (PSR) says that all contingent facts must have explanation. In this volume, 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.

Outlines a conceptual argument against the Principle of Sufficient reason. The argument is presented in detail in earlier work, and is based on deductive inferences from PSR's own concept of explanation. The argument shows that not everything can have an explanation of the sort claimed by PSR. So far from being a presupposition of reason itself, as some think, PSR can be refuted by reason, arguing only from PSR's own concept of explanation. Hence PSR cannot be used to argue that there must be some explanation or reason for existence, invisible at least to science, or that because we do not or cannot know the explanation, there must be irreducible mystery about why there is anything at all rather than nothing, including why there was a Big Bang in the first place.

The Principle of Sufficient Reason (PSR) says that, necessarily, every contingently true proposition has an explanation. The PSR is the most controversial premise in the cosmological argument for the existence of God. It is likely that one reason why a number of philosophers reject the PSR is that they think there are conceptual counter-examples to it. For instance, they may think, with Peter van Inwagen, that the conjunction of all contingent propositions cannot have an explanation, or they may believe that quantum mechanical phenomena cannot be explained. It may, however, be that these philosophers would be open to accepting a restricted version of the PSR as long as it was not ad hoc. I present a natural restricted version of the PSR that avoids all conceptual counter-examples, and yet that is strong enough to ground a cosmological argument. The restricted PSR says that all explainable true propositions have explanations. (Published Online April 21 2004).

In a recent article in this journal, Richard Gale and Alexander Pruss offer a new cosmological proof for the existence of God relying only on the Weak Principle of Sufficient Reason, W-PSR. We argue that their proof relies on applications of W-PSR that cannot be justified, and that our modal intuitions simply do not support W-PSR in the way Gale and Pruss take them to.