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.

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.

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 (some variant of) 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 (variants of) 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)

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)

Are interpersonal comparisons of desire possible? Can we give an account of how facts about desires are grounded that underpins such comparisons? This paper supposes the answer to the first question is yes, and provides an account of the nature of desire that explains how this is so. The account is a modification of the interpretationist metaphysics of representation that the author has recently been developing. The modification is to allow phenomenological affective valence into the “base facts” on which correct (...) interpretation is grounded. To use this extra resource within that theory to vindicate interpersonal comparisons, we will need to appeal rational connections between level of valence and level of desire, which this paper sets out and examines. (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)

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 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)

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 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)

*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)

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)

In this article we show that it is possible to completely classify the degrees of r.e. bases of r.e. vector spaces in terms of weak truth table degrees. The ideas extend to classify the degrees of complements and splittings. Several ramifications of the classification are discussed, together with an analysis of the structure of the degrees of pairs of r.e. summands of r.e. spaces.

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.

Ventricular Fibrillation is responsible for a majority of sudden cardiac death, but little is known about how ventricular tachycardia (VT) degenerates into ventricular fibrillation. Several clinical studies focused only on preventing VT with a class III antiarrhythmic drug resulted in many deaths. Our simulations investigate the interactions between an antiarrhythmic drug likely to suppress a VT and a Figure 8 reentry. A parameter AAR is introduced to increase the action potential duration and therefore simulate various Class III drugs. Simulations are (...) ran under several conditions (phases of the reentry, values of AAR, durations). They show that a VT can be suppressed whatever the phase of the reentry but it strongly depends on the duration of the effect. It confirms that a drug which can suppress a reentry can also worsen it. It also shows a great variety of activation patterns and thus the complexity of antiarrhythmic drugs effects. Simulations also demonstrate that suppressing VT is an increasing function of AAR. (shrink)

International array of contributors, bringing together both traditional and more recent approaches to provide valuable insights into the poets’ use of language.Covers authors from Lucilius to Juvenal.Of the peoples of ancient Italy, only the Romans committed newly composed poems to writing, and for 250 years Latin-speakers developed an impressive verse literature.The language had traditional resources of high style, e.g., alliteration, lexical and morphological archaism or grecism, and of course metaphor and word order; and there were also less obvious resources in (...) the technical vocabularies of law, philosophy and medicine.The essays in this volume show how the poets in the classical period combined these elements, and so created a poetic medium that could comprehend satire, invective, erotic elegy, drama, lyric, and the grandest heroic epos. (shrink)

Stronger collaboration between government organizations (GOs), NGOs, and rural people has long been advocated as a means of enhancing the responsiveness, efficiency, and accountability of GOs and NGOs. This paper reviews the arguments and evidence for specific types of collaboration for sustainable agricultural development, setting it into the context of Korten's (1980) concept of “learning process.” Taking recent examples from Udaipur District in India, it reviews the experiences and potential of collaboration, arguing that, while informal interaction increases and enriches the (...) fabric of pluralist development, certain strategic decisions often require a degree of formality. These include decisions on the development of human resources — here both the users and providers of services. Moreover, human resource development (HRD) must be viewed in the context of the mandates, aspirations, and systems of accountability and rewards of the institutions concerned. These determine whether institutions develop and expand their own human resources or draw upon those of others by collaborating with them. Individuals engaged in these organizations can be more effectively induced to collaborate with others by combinations of flexibility and appropriate reward systems than they can be forced to do so by instructions or commands. Several conclusions follow: decisions to act together are unlikely to progress unless translated into concrete actions; authority to take local-level decisions in GOs needs strengthening if they are to provide the necessary flexibility; and, although collaboration should in principle be built on the comparative advantage of different types of organization, in practice, each will have to incorporate the skills of the other, at least to some level, if they are to communicate effectively. NGOs and GOs must also enhance their understanding of farmers' ability to make demands on external organizations. Edging towards collaboration is a delicate and painstaking process. Only if many of the above conditions are given due priority will early examples have something to offer to the numerous NGOs, GOs and international agencies wishing to learn from them. (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)