Most commonly, the scientific realism debate is seen as dividing those who do and do not think that the striking empirical and practical successes of at least our best scientific theories indicate with high probability that those theories are ‘approximately true’. But I want to suggest that this characterization of the debate has far outlived its usefulness. Not only does it obscure the central differences between two profoundly different types of contemporary scientific realist, but even more importantly it serves to (...) disguise the most substantial points of actual disagreement between these two kinds of realists and those who instead think the historical record of scientific inquiry itself reveals that such realism is untenable in either form. (shrink)

We analyse the extent of possible computations following Hogarth ([2004]) conducted in Malament–Hogarth (MH) spacetimes, and Etesi and Németi ([2002]) in the special subclass containing rotating Kerr black holes. Hogarth ([1994]) had shown that any arithmetic statement could be resolved in a suitable MH spacetime. Etesi and Németi ([2002]) had shown that some relations on natural numbers that are neither universal nor co-universal, can be decided in Kerr spacetimes, and had asked specifically as to the extent of computational limits there. (...) The purpose of this note is to address this question, and further show that MH spacetimes can compute far beyond the arithmetic: effectively Borel statements (so hyperarithmetic in second-order number theory, or the structure of analysis) can likewise be resolved: Theorem A. If H is any hyperarithmetic predicate on integers, then there is an MH spacetime in which any query ? n H ? can be computed. In one sense this is best possible, as there is an upper bound to computational ability in any spacetime, which is thus a universal constant of that spacetime. Theorem C. Assuming the (modest and standard) requirement that spacetime manifolds be paracompact and Hausdorff, for any spacetime there will be a countable ordinal upper bound, , on the complexity of questions in the Borel hierarchy computable in it. Introduction 1.1 History and preliminaries Hyperarithmetic Computations in MH Spacetimes 2.1 Generalising SADn regions 2.2 The complexity of questions decidable in Kerr spacetimes An Upper Bound on Computational Complexity for Each Spacetime CiteULike Connotea Del.icio.us What's this? (shrink)

Child-to-parent violence has dramatically risen in the last decade, becoming a concerning issue in many countries, so research on this issue has also increased. However, most of the studies on this topic have been conducted with samples of adolescents, and very few with samples of parents. In addition, the variety of assessment instruments does not reflect the elements of this type of violence. Thus, the current study was aimed to examine the factor structure, reliability, and validity of the Child-to-parent Violence (...) Questionnaire, parents’ version, in a sample of Spanish parents of adolescents. Moreover, the prevalence rates of the different types of violence and the reasons for violence were also examined. A total of 1,012 Spanish parents of adolescents aged between 12 and 17 years old were assessed using the CPV-Q-P. Data indicated a matrix of four factors with 14 items, assessing psychological violence, physical violence, financial violence, and control/domain over parents, and two factors with 8 items capturing the reasons for child-to-parent violence, with adequate psychometric properties. The more frequent type of violence was control and domain over parents, followed by psychological, financial, and physical violence, with no significant differences between mothers and fathers. Otherwise, instrumental reasons were more frequent than reactive types, with no differences between mothers and fathers. The CPV-Q-P is a useful instrument to assess child-to-parent violence from the parents’ perspective in both professional and research settings. (shrink)

We show how in the hierarchies${F_\alpha }$of Fieldian truth sets, and Herzberger’s${H_\alpha }$revision sequence starting from any hypothesis for${F_0}$ that essentially each${H_\alpha }$ carries within it a history of the whole prior revision process.As applications we provide a precise representation for, and a calculation of the length of, possiblepath independent determinateness hierarchiesof Field’s construction with a binary conditional operator. We demonstrate the existence of generalized liar sentences, that can be considered as diagonalizing past the determinateness hierarchies definable in Field’s recent (...) models. The ‘defectiveness’ of such diagonal sentences necessarily cannot be classified by any of the determinateness predicates of the model. They are ‘ineffable liars’. We may consider them a response to the claim of Field that ‘the conditional can be used to show that the theory is not subject to “revenge problems”.’. (shrink)

We consider various concepts associated with the revision theory of truth of Gupta and Belnap. We categorize the notions definable using their theory of circular definitions as those notions universally definable over the next stable set. We give a simplified account of varied revision sequences-as a generalised algorithmic theory of truth. This enables something of a unification with the Kripkean theory of truth using supervaluation schemes.

We define theories of bounded arithmetic, whose definable functions and relations are exactly those in certain complexity classes. Based on a recursion-theoretic characterization of NC in Clote , the first-order theory TNC, whose principal axiom scheme is a form of short induction on notation for nondeterministic polynomial-time computable relations, has the property that those functions having nondeterministic polynomial-time graph Θ such that TNC x y Θ are exactly the functions in NC, computable on a parallel random-access machine in polylogarithmic parallel (...) time with a polynomial number of processors.0 We then define three theories of weak second-order arithmetic which respectively characterize relations in the classes of alternating logarithmic time, logspace and nondeterministic logspace. (shrink)

This paper examines Hume’s ‘Title Principle’ and its role in a response to one of the ‘manifest contradictions’ he identifies in the conclusion to Book I of A Treatise on Human Nature. This ‘contradiction’ is a tension between two ‘equally natural and necessary’ principles of the imagination, our causal inferences and our propensity to believe in the continued and distinct existence of objects. The problem is that the consistent application of causal reason undercuts any grounds with have for the belief (...) in continued and distinct existence, and yet that belief is as ‘natural and necessary’ as our propensity to infer effects from causes. The TP appears to offer a way to resolve this ‘contradiction’. It statesWhere reason is lively, and mixes itself with some propensity, it ought to be assented to. Where it does not, it never can have any title to operate upon us.’ In brief, if it can be shown that the causal inferences that undermine the belief in external world are not ‘lively’ nor mixed with some propensity’ then we have grounds for think that they have no normative authority. This is in part a response to another ‘manifest contradiction’, namely the apparently self-undermining nature of reason. In this paper I examine the nature and grounds of the TP and its relation to these ‘manifest contradictions’. (shrink)

We look at various notions of a class of definability operations that generalise inductive operations, and are characterised as “revision operations”. More particularly we: (i) characterise the revision theoretically definable subsets of a countable acceptable structure; (ii) show that the categorical truth set of Belnap and Gupta’s theory of truth over arithmetic using \emph{fully varied revision} sequences yields a complete \Pi13 set of integers; (iii) the set of \emph{stably categorical} sentences using their revision operator ψ is similarly \Pi13 and which (...) is complete in Gödel’s universe of constructible sets L; (iv) give an alternative account of a theory of truth—realistic variance that simplifies full variance, whilst at the same time arriving at Kripkean fixed points. (shrink)

Evolutionary fitness threats and rewards are associated with subjectively unpleasant and pleasant sensations, respectively. Initially, these correlations appear explainable via adaptation by natural selection. But here I analyse the major metaphysical perspectives on consciousness – physicalism, dualism, and panpsychism – and conclude that none help to understand the adaptive-seeming correlations via adaptation. I also argue that a recently proposed explanation, the phenomenal powers view, has major problems that mean it cannot explain the adaptive-seeming correlations via adaptation either. So the mystery (...) – call it the evolutionary paradox of consciousness – remains. Some have used this mystery to argue for non-naturalistic (e.g. theistic) explanations. But I propose a naturalistic, non-adaptive explanation of the adaptive-seeming correlations: namely, ‘sensational associative learning’ during development. In this perspective, pairing of particular sensations with unconditioned stimuli – fitness rewards or threats – cause the sensations themselves to come to be interpreted as good or bad, respectively. Sensations, like colours, that are not reliably paired with either fitness rewards or threats remain largely unvalenced. Sensational associative learning also provides explanations for adaptive-seeming structural aspects of sensations, such as the observation that sounds of different pitch are experienced as ordinal in correspondence to their wavelengths while the same is not true of colours of different hue. The sensational associative learning perspective appears compatible with physicalism, panpsychism, and dualism (though not epiphenomenalism). (shrink)

Pursuing the proof-theoretic program of Friedman and Simpson, we begin the study of the metamathematics of countable linear orderings by proving two main results. Over the weak base system consisting of arithmetic comprehension, II 1 1 -CA0 is equivalent to Hausdorff's theorem concerning the canonical decomposition of countable linear orderings into a sum over a dense or singleton set of scattered linear orderings. Over the same base system, ATR0 is equivalent to a version of the Continuum Hypothesis for linear orderings, (...) which states that every countable linear ordering either has countably many or continuum many Dedekind cuts. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Hume Studies Volume 29, Number 1, April 2003, pp. 125-141 Dr. George Cheyne, Chevalier Ramsay, and Hume's Letter to a Physician JOHN P. WRIGHT The publication of a new intellectual biography of George Cheyne1 provides a "propitious" occasion for "a thoroughly skeptical review"2 of the question which has long exercised Hume scholars, whether Cheyne was the intended recipient of David Hume's fascinating pie-Treatise Letter to a Physician,3 the letter (...) which describes his own hypochondriacal physical and mental symptoms and gives an account of his early philosophical development.4 Hume's nineteenth-century biographer, John Hill Burton, argued that Hume was probably writing to Cheyne,5 while Ernest Mossner claimed to definitively refute that hypothesis in an article entitled "Hume's Epistle to Dr. Arbuthnot," published in 1944.6 Anita Guerrini's intellectual biography does not discuss Cheyne as a possible recipient of Hume's letter, but she does present a well-rounded picture of this interesting eighteenth-century physician from which we can judge his appropriateness as its addressee. In the following discussion I will make use of the biographical material found in this new biography of Cheyne, as well as other sources, to show that Mossner's arguments are less than definitive, and that it would be wrong to dismiss the possibility that the letter was sent to George Cheyne.7 This is a possibility that, for reasons that I will make clear, makes good biographical and philosophical sense. At the same time, it is important to keep a proper suspense of judgment as Burton did, for the evidence that the letter was either intended for or actually sent to Cheyne is not definitive. John P. Wright is Professor of Philosophy, Central Michigan University, Mt. Pleasant, MI 48859, USA. e-mail: [email protected] 126 John P. Wright Burton, who first published the autobiographical letter of the 22-yearold Hume in 1846, narrowed down the possible addressees of Hume's letter to either Cheyne or John Arbuthnot. He also pointed out that it is possible that the letter was never sent, and that the ten and a half page manuscript is only a neatly written draft, rather than a fair copy of an actual letter. Nevertheless, Burton thought he could identify the unnamed addressee on the basis of the internal evidence of the manuscript and the records of Scottish physicians practicing in England at the time. In the letter, Hume refers to the intended recipient as his "Countryman, a Scotchman [,]... a skilful Physician, a man of Letters, of Wit, of Good Sense, & of great Humanity."8 Further he writes that he is consulting him because he is a person "of great Learning beyond [his]... own Profession" who is acquainted with the "Motions of the Mind" he has described in his letter, and that "Fame pointed [him]... out as the properest person to resolve my Doubts..." about the cure of his disorder.9 Burton tells us that "the first name that suggested itself... was Arbuthnot, whose fine genius was just then flickering in the socket."10 (John Arbuthnot had been ill for some time, and died a year later.) But he then added that "a more full consideration showed to my satisfaction that it must have been destined for Dr. George Cheyne." His main reason for settling on Cheyne was that Cheyne's immensely popular The English Malady (1733) had recently been published, and that "there is a certain unison of tone between Hume's letter and this book." Burton quotes a portion of Cheyne's own long autobiographical account of his own disease in The English Malady. Cheyne's autobiography begins with the claim that "I passed my Youth in close study, and almost constant Application to the abstracted Sciences, (wherein my chief pleasure consisted) and consequently in great Temperance and a Sedentary Life"; it is followed by the reflection that any overindulgence in food or drink led to physical and psychological problems.11 He goes on to describe these in great detail for 39 pages, along with a history of his life. Burton also quotes a section of the book in which Cheyne describes how a studious and sedentary life causes the symptoms... (shrink)