This paper outlines Lewis’s favoured foundational account of linguistic representation, and outlines and briefly evaluates variations and modifications. Section 1 gives an opinionated exegesis of Lewis’ work on the foundations of reference—his interpretationism. I look at the way that the metaphysical distinction between natural and non-natural properties came to play a central role in his thinking about language. Lewis’s own deployment of this notion has implausible commitments, so in section 2 I consider variations and alternatives. Section 3 briefly considers a (...) buck-passing strategy involving fine-grained linguistic conventions. (shrink)

*This work has turned into a bigger project, and some of it is published in "Lewis on reference".* Some things, argues Lewis, are just better candidates to be referents than others. Even at the cost of attributing false beliefs, we interpret people as referring to the most interesting kinds in their vicinity. How should this be accounted for? In section 1, I look at Lewis’s interpretationism, and the reference magnetism it builds in (not just for ‘perfectly natural’ properties, but for (...) certain kinds of auxiliary apparatus). In section 2, I draw on (Field, 1975) to argue that what properties are reference magnetic may be an ultimately conventional matter—though in the Lewisian setting, there may be an objectively best conventional choice to make. But Lewis’s own account has implausible commitments, so in section 3 I consider variations and alternatives, all of which have problems. In section 4, I look in more detail at eligibility-based interpretationism that do not appeal to naturalness, arguing that there are credible metasemantic theories of this form. (shrink)

Taking away grains from a heap of rice, at what point is there no longer a heap? It seems small changes – removing a single grain – can’t make a difference to whether or not something is a heap; but big changes obviously do. How can this be, since big changes are nothing but small changes chained together?

This article investigates the claim that some truths are fundamentally or really true — and that other truths are not. Such a distinction can help us reconcile radically minimal metaphysical views with the verities of common sense. I develop an understanding of the distinction whereby Fundamentality is not itself a metaphysical distinction, but rather a device that must be presupposed to express metaphysical distinctions. Drawing on recent work by Rayo on anti-Quinean theories of ontological commitments, I formulate a rigourous theory (...) of the notion. In the final sections, I show how this package dovetails with ' interpretationist' theories of meaning to give sober content to thought that some things — perhaps sets, or gerrymandered mereological sums — can be 'postulated into existence'. (shrink)

This article is an attempt to clarify a confusion in the brain death literature between logical sufficiency/necessity and natural sufficiency/necessity. We focus on arguments that draw conclusions regarding empirical matters of fact from conceptual or ontological definitions. Specifically, we critically analyze arguments by Tom Tomlinson and Michael B. Green and Daniel Wikler. which, respectively, confuse logical and natural sufficiency and logical and natural necessity. Our own conclusion is that it is especially important in discussing the brain death issue to observe (...) the distinction between logical and natural sufficiency/necessity in a strict fashion. (shrink)

This paper examines two puzzles of indeterminacy. The first puzzle concerns the hypothesis that there is a unified phenomenon of indeterminacy. How are we to reconcile this with the apparent diversity of reactions that indeterminacy prompts? The second puzzle focuses narrowly on borderline cases of vague predicates. How are we to account for the lack of theoretical consensus about what the proper reaction to borderline cases is? I suggest (building on work by Maudlin) that the characteristic feature of indeterminacy is (...) alethic normative silence, and use this to explain both plurality and lack of consensus. (shrink)

*This work is no longer under development* Two major themes in the literature on indicative conditionals are that the content of indicative conditionals typically depends on what is known;1 that conditionals are intimately related to conditional probabilities.2 In possible world semantics for counterfactual conditionals, a standard assumption is that conditionals whose antecedents are metaphysically impossible are vacuously true.3 This aspect has recently been brought to the fore, and defended by Tim Williamson, who uses it in to characterize alethic necessity by (...) exploiting such equivalences as: A⇔¬A A. One might wish to postulate an analogous connection for indicative conditionals, with indicatives whose antecedents are epistemically impossible being vacuously true: and indeed, the modal account of indicative conditionals of Brian Weatherson has exactly this feature.4 This allows one to characterize an epistemic modal by the equivalence A⇔¬A→A. For simplicity, in what follows we write A as KA and think of it as expressing that subject S knows that A.5 The connection to probability has received much attention. Stalnaker suggested, as a way of articulating the ‘Ramsey Test’, the following very general schema for indicative conditionals relative to some probability function P: P = P 1For example, Nolan ; Weatherson ; Gillies. 2For example Stalnaker ; McGee ; Adams. 3Lewis. See Nolan for criticism. 4‘epistemically possible’ here means incompatible with what is known. 5This idea was suggested to me in conversation by John Hawthorne. I do not know of it being explored in print. The plausibility of this characterization will depend on the exact sense of ‘epistemically possible’ in play—if it is compatibility with what a single subject knows, then can be read ‘the relevant subject knows that p’. If it is more delicately formulated, we might be able to read as the epistemic modal ‘must’. (shrink)

In the literature on supervaluationism, a central source of concern has been the acceptability, or otherwise, of its alleged logical revisionism. I attack the presupposition of this debate: arguing that when properly construed, there is no sense in which supervaluational consequence is revisionary. I provide new considerations supporting the claim that the supervaluational consequence should be characterized in a ‘global’ way. But pace Williamson (1994) and Keefe (2000), I argue that supervaluationism does not give rise to counterexamples to familiar inference-patterns (...) such as reductio and conditional proof. (shrink)

This volume provides the first complete edition of the third and final surviving draft of John Locke's Essay Concerning Human Understanding, dating from 1685, four years before the publication of the Essay itself (December 1689). There is a General Introduction that gives a detailed account of the content and circumstances of composition of this draft, and a Textual Introduction that provides a full description of the manuscript and its0history.

This paper and its predecessor () are about the question: 'Are the events in the entire universe encoded in and predictable from any of its parts?' To approach a positive answer in classical physics, the following result is proved and commented on: in Newton's theory of gravitation, the entire trajectory of a particle can be predicted given any segment of it, regardless of how the other particles are moving-provided that there is only a finite number of particles and that their (...) speeds remain bounded. (It is this condition, together with a set of parameters characterising the motion of the other particles, which enables us to estimate the effect of the other particles on the trajectory of the given particle.) The extension of this result to other theories, in particular to special relativity, is discussed. (shrink)

In his recent book Waar geest is, is vrijheid [Where there is mind, there is freedom], Guus Labooy sets forth an original and intriguing argument, inspired by the work of John Duns Scotus, for substance dualism in the philosophy of mind. In this paper we argue that his argument, although worthy of serious attention, is under-supported. In section 2 we question the significance of the particular scotistic notion of freedom he uses in his argument, even though we agree with his (...) premise that humans do possess freedom in the libertarian sense. In section 3 we argue that Labooy fails to make his key contention that significant freedom requires an irreducible immaterial soul sufficiently plausible. The key problem is that he does not consider the work of physicalists who also believe in libertarian freedom. In addition, it is not self-evident that an immaterial soul, as opposed to a physical body, can possess significant freedom. This requires argument. In section 4 we comment on Labooy’s specific conception of dualism and advise him to change it into a conception in which the soul — and not the composition of soul and body — is the human person, for the latter conception has absurd consequences. (shrink)

This study investigated the performance of boys with psychopathic tendencies and comparison boys, aged 9 to 17 years, on two tasks believed to be sensitive to amygdala and orbitofrontal cortex func- tioning. Fifty-one boys were divided into two groups according to the Psychopathy Screening Device (PSD, P. J. Frick & R. D. Hare, in press) and presented with two tasks. The tasks were the gambling task (A. Bechara, A. R. Damasio, H. Damasio, & S. W. Anderson, 1994) and the Intradimensional/ (...) Extradimensional (ID/ED) shift task (R. Dias, T. W. Robbins, & A. C. Roberts, 1996). The boys with psychopathic tendencies showed impaired performance on the gambling task. However, there were no group differences on the ID/ED task either for response reversal or extradimensional set shifting. The implications of these results for models of psychopathy are discussed. (shrink)

This study investigates the ability of individuals with psychopathy to perform passive avoidance learning and whether this ability is modulated by level of reinforcement/punishment. Nineteen psychopathic and 21 comparison individuals, as defined by the Hare Psychopathy Checklist Revised (Hare, 1991), were given a passive avoidance task with a graded reinforcement schedule. Response to each rewarding number gained a point reward specific to that number (i.e., 1, 700, 1400 or 2000 points). Response to each punishing number lost a point punishment specific (...) to that number (i.e., the loss of 1, 700, 1400 or 2000 points). In line with predictions, individuals with psychopathy made more passive avoidance errors than the comparison individuals. In addition, while the performance of both groups was modulated by level of reward, only the performance of the comparison population was modulated by level of punishment. The results are interpreted with reference to a computational account of the emotional learning impairment in individuals with psychopathy. (shrink)

Information can be public among a group. Whether or not information is public matters, for example, for accounts of interdependent rational choice, of communication, and of joint intention. A standard analysis of public information identifies it with common belief. The latter notion is stipulatively defined as an infinite conjunction: for p to be commonly believed is for it to believed by all members of a group, for all members to believe that all members believe it, and so forth. This analysis (...) is often presupposed without much argument in philosophy. Theoretical entrenchment or intuitions about cases might give some traction on the question, but give little insight about why the identification holds, if it does. The strategy of this paper is to characterize a practical-normative role for information being public, and show that the only things that play that role are common belief as stipulatively characterized. In more detail: a functional role for “taking a proposition for granted” in non-isolated decision making is characterized. I then present some minimal conditions under which such an attitude is correctly held. The key assumption links this attitude to beliefs about what is public. From minimal a priori principles, we can argue that a proposition being public among a group entails common commitment to believe among that group. Later sections explore partial converses to this result, the factivity of publicity and publicity from the perspective of outsiders to the group, and objections to the aprioricity of the result deriving from a posteriori existential presuppositions. (shrink)

A type of first-order analogues of ptykes, namely ‘ptykoids’, are introduced, and bounds are found for the ptykoids of level 1 and 2 which can be proved to be ptykoids in Peano arithmetic. This gives rise toΠ 3 0 andΠ 4 0 independence results.

The notion of a “ptyx” is formalised in second-order arithmetic, and, using proof-theoretic techniques based on sequent-calculus, bounds are obtained for the ptykes of type 1 and 2 which can be proved to be ptykes using arithmetic comprehension.

Based on the proceedings of a 1985 conference held in the U.K., this volume embraces most of the important concerns in AI today, emphasizing common techniques and methodologies rather than applications. Topics covered include building efficient computational logic, planning and design, the representation of uncertain knowledge, user modelling, and psychological and philosophical issues. Papers on perception, theorem proving, expert systems, robotics, and data bases are also included. Each section is preceded by an introduction which draws comparisons between various papers.

We discuss arguments against the thesis that the world itself can be vague. The first section of the paper distinguishes dialectically effective from ineffective arguments against metaphysical vagueness. The second section constructs an argument against metaphysical vagueness that promises to be of the dialectically effective sort: an argument against objects with vague parts. Firstly, cases of vague parthood commit one to cases of vague identity. But we argue that Evans' famous argument against will not on its own enable one to (...) complete the reductio in the present context. We provide a metaphysical premise that would complete the reductio, but note that it seems deniable. We conclude by drawing general morals from our case study. (shrink)