Online research in philosophy

In his great poem, Parmenides uses an argument by elimination to select the correct "way of inquiry" from a pool of two, the ways of is and of is not , joined later by a third, "mixed" way of is and is not . Parmenides' first two ways are soon given modal upgrades - is becomes cannot not be , and is not becomes necessarily is not (B2, 3-6) - and these are no longer contradictories of one another. And is the common view right, that Parmenides rejects the "mixed" way because it is a contradiction? I argue that the modal upgrades are the product of an illicit modal shift. This same shift, built into two Exclusion Arguments, gives Parmenides a novel argument to show that the "mixed" way fails. Given the independent failure of the way of is not , Parmenides' argument by elimination is complete.

This paper evaluates Richard Swinburne’s modal argument for the existence of souls. After a brief presentation of the argument, wedescribe the main known objection to it, which is called the substitution objection (SO for short), and explain Swinburne’s response to that objection. With this as background, we formalize Swinburne’s argument in a quantified propositional modal language, modifying it so that it is logically valid and contains no tacit assumptions, and we explain why we find Swinburne’s response to SO unsatisfactory. Next, we indicate that, even though SO is quite compelling, a weakening of one of the premises yields a valid argument for the same conclusion which is immune to SO. This version of the argument, however, is epistemically circular.

This note is a friendly amendment to Martis analysis of the failure of Føllesdals argument that modal distinctions collapse in Carnaps logic S2. Føllesdals argument turns on the treatment of descriptions. Marti considers how modal descriptions, which Carnap banned, might be handled; she adopts an approach which blocks Føllesdals argument, but requires a separate treatment of non-modal descriptions. I point out that a more general treatment of descriptions in S2 is possible, and indeed is implicit in Martis informal discussion, and that this treatment also blocks Føllesdals argument. Further, I show by a semantic argument that no revised version of Føllesdals argument could establish a collapse of modal distinctions.

Anselm is commonly credited with two a priori arguments for God's existence, the non-modal argument of Proslogion 2 and a modal argument some find in Proslogion 3. But his Reply to Gaunilo contains a third. The argument as Anselm gives it has flaws, but they are not fatal, and its main premise can serve as the basis of a simpler, stronger argument.

Can different material objects have the same parts at all times at which they exist? This paper defends the possibility of such coincidence against the main argument to the contrary, the ‘Indiscernibility Argument’. According to this argument, the modal supervenes on the nonmodal, since, after all, the non-modal is what grounds the modal; hence, it would be utterly mysterious if two objects sharing all parts had different essential properties. The weakness of the argument becomes apparent once we understand how the modal is grounded in the nonmodal. By extending the ideas of combinatorialism so that we recombine haecceities as well as fundamental properties, we see how modal properties can be grounded in non-modal properties in a way that allows coincidence and yet also explains why there are differences in the modal properties of coinciding objects. Despite this, some de re modal facts are not grounded in the non-modal but instead are brute. However, although we cannot explain why a particular object has the basic modal properties it has, we can explain a closely related, semantic fact and, comparing the facts we can’t explain to more familiar brute facts, we understand why there should be no better explanation. As a result, we can see how coincidence is, after all, possible.

I argue that an identity theorist can successfully resist a Kripkean modal argument by employing what I call a metaconceptual move. Furthermore, by showing how this move fails to apply straightforwardly to Chalmers' argument, I clarify the nature of the threat presented by Chalmers and how it differs from a Kripkean modal argument.

Most critics of Richard Swinburne’s modal argument for mind-body substance dualism have alleged that the argument is unsound, either because its premises are false or because it commits a modal fallacy. I show that the argument is epistemically circular, and thus provides no support for its conclusion even if it is sound.

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.

This paper investigates the view that digital hypercomputing is a good reason for rejection or re-interpretation of the Church-Turing thesis. After suggestion that such re-interpretation is historically problematic and often involves attack on a straw man (the ‘maximality thesis’), it discusses proposals for digital hypercomputing with Zeno-machines , i.e. computing machines that compute an infinite number of computing steps in finite time, thus performing supertasks. It argues that effective computing with Zeno-machines falls into a dilemma: either they are specified such that they do not have output states, or they are specified such that they do have output states, but involve contradiction. Repairs though non-effective methods or special rules for semi-decidable problems are sought, but not found. The paper concludes that hypercomputing supertasks are impossible in the actual world and thus no reason for rejection of the Church-Turing thesis in its traditional interpretation.

According to a basic dualistic conception that originated in Descartes, minds are immaterial, non-spatial and simple thinking particulars that are independent of anything material. Call this view the Cartesian conception, and minds thus conceived, Cartesian minds. In what follows I propose a new version of an argument against the Cartesian conception that can be traced back to Descartes" days (Garber and Ayers 1998, 232). The inspiration behind my version is an argument suggested by Strawson"s seminal discussion of the concept of a person (1959, Chaps. 3-4). However, in both form and substance my argument takes its own course.