Simon Blackburn puts forward a compelling original philosophy of human motivation and morality. He maintains that we cannot get clear about ethics until we get clear about human nature. So these are the sorts of questions he addresses: Why do we behave as we do? Can we improve? Is our ethics at war with our passions, or is it an upshot of those passions? Blackburn seeks the answers in an exploration of guilt, shame, disgust, and other moral emotions; (...) he draws also on game theory and cognitive science in his account of the structures of human motivation. Many philosophers have wanted a naturalistic ethics a theory that integrates our understanding of human morality with the rest of our understanding of the world we live in. What is special about Blackburn's naturalistic ethics is that it does not debunk the ethical by reducing it to the non-ethical. At the same time he banishes the spectres of scepticism and relativism that have haunted recent moral philosophy. Ruling Passions sets ethics in the context of human nature: it offers a solution to the puzzle of how ethics can maintain its authority even though it is rooted in the very emotions and motivations that it exists to control. (shrink)

Cambridge professor Simon Blackburn is best known to the general public as the author of several books of popular philosophy such as  ink, Being Good andTruth: a Guide for the Perplexed. Academic philosophers also know him as the author of one of the most important books of contemporary moral philosophy, Ruling Passions, and as a former editor of the leading journal Mind.

This volume collects some influential essays in which Simon Blackburn, one of our leading philosophers, explores one of the most profound and fertile of philosophical problems: the way in which our judgments relate to the world. This debate has centered on realism, or the view that what we say is validated by the way things stand in the world, and a variety of oppositions to it. Prominent among the latter are expressive and projective theories, but also a relaxed pluralism (...) that discourages the view that there are substantial issues at stake. The figure of the "quasi-realist" dramatizes the difficulty of conducting these debates. Typically philosophers thinking of themselves as realists will believe that they alone can give a proper or literal account of some of our attachments--to truth, to facts, to the independent world, to knowledge and certainty. The quasi-realist challenge, developed by Blackburn in this volume, is that we can have those attachments without any metaphysic that deserves to be called realism, so that the metaphysical picture that goes with our practices is quite idle. The cases treated here include the theories of value and knowledge, modality, probability, causation, intentionality and rule-following, and explanation. A substantial new introduction has been added, drawing together some of the central themes. The essays articulate a fresh alternative to a primitive realist/anti-realist opposition, and their cumulative effect is to yield a new appreciation of the delicacy of the debate in these central areas. (shrink)

This modern, advanced textbook reviews modal logic, a field which caught the attention of computer scientists in the late 1970's.

The twenty-sixth volume in the highly acclaimed Library of Living Philosophers series is devoted to the work of British philosopher of logic and metaphysician, P. F. Strawson. Following the Library of Living Philosophers series format, the volume contains an intellectual autobiography, twenty critical and descriptive essays by leading philosophers from around the world, Strawson's replies to the essays, and a bibliography of Strawson's works. Born in 1919, Strawson was a leading proponent of ordinary language philosophy. He is the author of (...) the early and extremely influential paper "On Referring" in which he criticized Russell's theory of definite descriptions. His most influential book, Individuals, helped to raise the status of metaphysics as a philosophical enterprise. Themes first addressed in this book continued to be of concern to him in his later work, including the possibility of objective knowledge, the subject-predicate distinction, the ontological status of persons, and the problem of individuation. Contributors to the book include: Ruth Garrett Millikan, Susan Haack, E. M. Adams, Panayot Butchvarov, Richard Behling, John McDowell, Simon Blackburn, Tadeusz Szubka, David Frederick Haight, Joseph S. Wu, Andrew G. Black, David Pears, Robert Boyd, Hilary Putnam, Paul F. Snowdon, Arindam Chakrabarti, Wenceslao J. Gonzalez, Ernest Sosa, Chung-M. Tse, John R. Searle, P. F. Strawson. (shrink)

An original study of the philosophical problems associated with inductive reasoning. Like most of the main questions in epistemology, the classical problem of induction arises from doubts about a mode of inference used to justify some of our most familiar and pervasive beliefs. The experience of each individual is limited and fragmentary, yet the scope of our beliefs is much wider; and it is the relation between belief and experience, in particular the belief that the future will in some respects (...) resemble the past and the unobserved the observed, which forms the subject of this book. Dr Blackburn's first aim is to state the problem of induction properly, to show that there does exist a genuine problem immune to the solutions in vogue at present, yet no tin principle insoluble. He gives an extended and original account of the concept of a reason and goes on to discuss prediction. In the end Dr Blackburn produces a rationale for belief in certain short-term predictions based on his reinterpretation of the classical principle of indifference. He claims that a justification for induction can be found along the lines he has suggested and must indeed be found there if anywhere. (shrink)

From political scandals at the highest levels to inflated repair bills at the local garage, we are seemingly surrounded with unethical behavior, so why should we behave any differently? Why should we go through life anchored down by rules no one else seems to follow? Writing with wit and elegance, Simon Blackburn tackles such questions in this lively look at ethics, highlighting the complications and doubts and troubling issues that spring from the very simple question of how we ought (...) to live. Blackburn dissects many common reasons why we are skeptical about ethics. Drawing on all-too-familiar examples from history, politics, religion and everyday personal experience, he shows how cynicism and self-consciousness can paralyze us into considering ethics a hopeless pursuit. But ethics is neither futile nor irrelevant, he assures us, but an intimate part of the nitty gritty issues of living--of birth, death, happiness, desire, freedom, pleasure, justice. Indeed, from moral dilemmas about abortion and euthanasia, to our obsession with personal rights, to our longing for a sense of meaning in life, our everyday struggles are rife with ethical issues, whether we notice it or not. Blackburn distills the arguments of Hume, Kant and Aristotle down to their essences, to underscore the timeless relevance of our voice of conscience, the pitfalls of complacency, and our concerns about truth, knowledge and human progress. Blackburn's rare combination of depth, rigor and sparkling prose, and his distinguished ranking among contemporary philosophers, mark Being Good as an important statement on our current disenchantment with ethics. It challenges us to take a more thoughtful reading of our ethical climate and to ponder more carefully our own standards of behavior. (shrink)

The author of the highly popular book Think, which Time magazine hailed as "the one book every smart person should read to understand, and even enjoy, the key questions of philosophy," Simon Blackburn is that rara avis--an eminent thinker who is able to explain philosophy to the general reader. Now Blackburn offers a tour de force exploration of what he calls "the most exciting and engaging issue in the whole of philosophy"--the age-old war over truth. The front lines (...) of this war are well defined. On one side are those who believe in plain, unvarnished facts, rock-solid truths that can be found through reason and objectivity--that science leads to truth, for instance. Their opponents mock this idea. They see the dark forces of language, culture, power, gender, class, ideology and desire--all subverting our perceptions of the world, and clouding our judgement with false notions of absolute truth. Beginning with an early skirmish in the war--when Socrates confronted the sophists in ancient Athens--Blackburn offers a penetrating look at the longstanding battle these two groups have waged, examining the philosophical battles fought by Plato, Protagoras, William James, David Hume, Hans-Georg Gadamer, Jacques Derrida, Michel Foucault, Richard Rorty, and many others, with a particularly fascinating look at Nietzsche. Among the questions Blackburn considers are: is science mere opinion, can historians understand another historical period, and indeed can one culture ever truly understand another. Blackburn concludes that both sides have merit, and that neither has exclusive ownership of truth. What is important is that, whichever side we embrace, we should know where we stand and what is to be said for our opponents. (shrink)

Here at last is a coherent, unintimidating introduction to the challenging and fascinating landscape of Western philosophy. Written expressly for "anyone who believes there are big questions out there, but does not know how to approach them," Think provides a sound framework for exploring the most basic themes of philosophy, and for understanding how major philosophers have tackled the questions that have pressed themselves most forcefully on human consciousness. Simon Blackburn, author of the best-selling Oxford Dictionary of Philosophy, begins (...) by making a convincing case for the relevance of philosophy and goes on to give the reader a sense of how the great historical figures such as Plato, Hume, Kant, Descartes, and others have approached its central themes. In a lively and accessible style, Blackburn approaches the nature of human reflection and how we think, or can think, about knowledge, fate, ethics, identity, God, reason, and truth. Each chapter explains a major issue, and gives the reader a self-contained guide through the problems that the philosophers have studied. Because the text approaches these issues from the gound up, the untrained reader will emerge from its pages able to explore other philosophies with greater pleasure and understanding and be able to think--philosophically--for him or herself. Philosophy is often dismissed as a purely academic discipline with no relation to the "real" world non-philosophers are compelled to inhabit. Think dispels this myth and offers a springboard for all those who want to learn how the basic techniques of thinking shape virtually every aspect of our existence. (shrink)

The Handbook of Modal Logic contains 20 articles, which collectively introduce contemporary modal logic, survey current research, and indicate the way in which the field is developing. The articles survey the field from a wide variety of perspectives: the underling theory is explored in depth, modern computational approaches are treated, and six major applications areas of modal logic (in Mathematics, Computer Science, Artificial Intelligence, Linguistics, Game Theory, and Philosophy) are surveyed. The book contains both well-written expository articles, suitable for beginners (...) approaching the subject for the first time, and advanced articles, which will help those already familiar with the field to deepen their expertise. Please visit: http://people.uleth.ca/~woods/RedSeriesPromo_WP/PubSLPR.html - Compact modal logic reference - Computational approaches fully discussed - Contemporary applications of modal logic covered in depth. (shrink)

This volume is designed to set out some of the central issues in the theory of truth. It draws together, for the first time, the debates between philosophers who favor 'robust' or 'substantive' theories of truth, and those other, 'deflationist' or minimalists, who deny that such theories can be given. The editors provide a substantial introduction, in which they look at how the debates relate to further issues, such as the Liar paradox and formal truth theories.

Like all of Nagel's work, this is a book with a message: an apparently clear, simple message, forcefully presented and repeated. The message is that there is a limit to the extent to which we can "get outside" fundamental forms of thought, including logical, mathematical, scientific, and ethical thought. "Getting outside" means taking up a biological or psychological or sociological or economic or political view of ourselves as thinkers. It also inclines many people to talk of the contingency or subjectivity (...) or arbitrariness or "relativity" of our thoughts. Nagel believes that the standpoint is impossible, and the relativism it is apt to engender is self-refuting: "we cannot criticize some of our own claims of reason without employing reason at some point to formulate and support those criticisms". The general message is that first-order thoughts, the elementary certainties of mathematics, logic, science, and ethics, "dominate" any attempt to displace them. The book ends with the peroration: "Even if we distance ourselves from some of our thoughts and impulses, and regard them from outside, the process of trying to place ourselves in the world leads eventually to thoughts that we cannot think of as merely `ours'. If we think at all, we must think of ourselves, individually and collectively, as submitting to the order of reasons rather than creating it.". (shrink)

Expressivism is the view that the function of normative sentences is not to represent a kind of fact, but to avow attitudes, prescribe behavior, or the like. The idea can be found in David Hume. In the 20th century, G.E. Moore’s Open Question Argument provided important support for the view. Elizabeth Anscombe introduced the notion of “direction of fit,” which helped distinguish expressivism from a kind of naive subjectivism. The central advantage of expressivism is that it easily explains the motivational (...) force of moral conviction. Its chief problem is it has difficulty explaining the “realist surface” of moralizing. Quasi-realism is a strategy for explaining the realist surface without abandoning the underlying ideas of expressivism. It aims to explain moral error as well as deal with the so-called Frege-Geach problem. This chapter explains quasi-realism, and evaluates it by comparison with its chief rivals: Aristotelian approaches, Kantian approaches, realist moral naturalism, and fictionalism. (shrink)

Simon Blackburn. 1985. Garrett, Don. Cognition and Commitment in Hume's Philosophy. Oxford: Oxford University Press, 1997. Gaskin, J.C. A. Hume's Philosophy of Religion, 2nd ed. Basingstoke: Macmillan, 1988. Holden, T.The Architecture ...

Hybrid languages have both modal and first-order characteristics: a Kripke semantics, and explicit variable binding apparatus. This paper motivates the development of hybrid languages, sketches their history, and examines the expressive power of three hybrid binders. We show that all three binders give rise to languages strictly weaker than the corresponding first-order language, that full first-order expressivity can be gained by adding the universal modality, and that all three binders can force the existence of infinite models and have undecidable satisfiability (...) problems. (shrink)

In this paper I am not so much concerned with movements of the mind, as movements of the will. But my question bears a similarity to that of the tortoise. I want to ask whether the will is under the control of fact and reason, combined. I shall try to show that there is always something else, something that is not under the control of fact and reason, which has to be given as a brute extra, if deliberation is ever (...) to end by determining the will. This is, of course, a Humean conclusion, and the only novelty comes in the way I wish to argue for it. I believe that many philosophers think, erroneously, that Hume relies on a naive and outdated conception of facts, or on an even more naive and outdated conception of reason, in order to put passion on their throne. My tortoise defends Hume: what we do with our premises is not itself construed as acceptance of a premise. As it stands the project is only described metaphorically. Presumably everything, including movement of the will, is under the control of facts in some sense, for even if they are only facts about our physiology or chemistry, still, they make us move. I am interested only in cognitive control, or control by the apprehension of fact and reason. (shrink)

Contemporary hybrid logic is based on the idea of using formulas as terms, an idea invented and explored by Arthur Prior in the mid-1960s. But Prior’s own work on hybrid logic remains largely undiscussed. This is unfortunate, since hybridisation played a role that was both central to and problematic for his philosophical views on tense. In this paper I introduce hybrid logic from a contemporary perspective, and then examine the role it played in Prior’s work.

This paper is about the good side of modal logic, the bad side of modal logic, and how hybrid logic takes the good and fixes the bad.In essence, modal logic is a simple formalism for working with relational structures . But modal logic has no mechanism for referring to or reasoning about the individual nodes in such structures, and this lessens its effectiveness as a representation formalism. In their simplest form, hybrid logics are upgraded modal logics in which reference to (...) individual nodes is possible.But hybrid logic is a rather unusual modal upgrade. It pushes one simple idea as far as it will go: represent all information as formulas. This turns out to be the key needed to draw together a surprisingly diverse range of work . Moreover, it displays a number of knowledge representation issues in a new light, notably the importance of sorting. (shrink)

In this journal Andy Egan argued that, contrary to what I have claimed, quasi-realism is committed to a damaging asymmetry between the way a subject regards himself and the way he regards others. In particular, a subject must believe it to be a priori that if something is one of his stable or fundamental beliefs, then it is true. Whereas he will not hold that this is a priori true of other people. In this paper I rebut Egan's argument, and (...) give further consideration to the correct way to think about our own fallibility. (shrink)

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This essay juxtaposes the position in metaethics defended, expressivism with quasirealistic trimmings, with the ancient problem of relativism. It argues that, perhaps surprisingly, there is less of a problem of normative truth on this approach than on others. Because ethics is not in the business of representing aspects of the world, there is no way to argue for a plurality of moral truths, simply from the existence of a plurality of moral opinions. The essay also argues that other approaches, which (...) superficially seem better adapted to defending robust and substantive conceptions of moral truth, in fact face more danger from the threat of relativism. This is particularly so in the case of 'secondary quality' or 'response-dependent' approaches, but also in the case of certain kinds of constructivism. (shrink)

This is a very short introduction to ethics. It divides into three parts: first, introducing and discussing reasons for skepticism about ethics; second introducing themes of birth, death, happiness, desire and freedom to show how deeply our lives are interwoven with ethics; third, introducing attempts to found ethics, due to Aristotle, Kant, and the contractarian tradition.

This best-selling dictionary is written by one of the most famous philosophers of our time, and it is widely recognized as the best dictionary of its kind. Comprehensive and authoritative, it covers every aspect of philosophy from Aristotle to Zen. With clear and concise definitions, it provides lively and accessible coverage of not only Western philosophical traditions, but also themes from Chinese, Indian, Islamic, and Jewish philosophy. Entries include over 500 biographies of famous and influential philosophers, in-depth analysis of philosophical (...) terms and concepts, and a chronology of philosophical events stretching from 10,000 BC to the present day. The first edition of this dictionary became a market-leader and a standard work of reference, selling over 100,000 copies. Now the author, Professor Simon Blackburn, has revised it to include web links which provide up-to-date and valuable extra information via the Dictionary of Philosophy companion website. Fully cross-referenced and containing over 3,000 alphabetical entries, it is the ideal introduction to philosophy for anyone with an interest in the subject, and it is an indispensable work of reference for students and teachers. (shrink)

In this clear introduction to ethics Simon Blackburn tackles the major moral questions surrounding birth, death, happiness, desire and freedom, showing us how ...

This modern, advanced textbook reviews modal logic, a field which caught the attention of computer scientists in the late 1970's.

Lust, says Simon Blackburn, is furtive, headlong, always sizing up opportunities. It is a trail of clothing in the hallway, the trashy cousin of love. But be that as it may, the aim of this delightful book is to rescue lust "from the denunciations of old men of the deserts, to deliver it from the pallid and envious confessor and the stocks and pillories of the Puritans, to drag it from the category of sin to that of virtue." (...) class='Hi'>Blackburn, author of such popular philosophy books as Think and Being Good, here offers a sharp-edged probe into the heart of lust, blending together insight from some of the world's greatest thinkers on sex, human nature, and our common cultural foibles. Blackburn takes a wide ranging, historical approach, discussing lust as viewed by Aristophanes and Plato, lust in the light of the Stoic mistrust of emotion, and the Christian fear of the flesh that catapulted lust to the level of deadly sin. He describes how philosophical pessimists like Schopenhauer and Sartre contributed to our thinking about lust and explores the false starts in understanding lust represented by Freud, Kinsey, and modern "evolutionary psychology." But most important, Blackburn reminds us that lust is also life-affirming, invigorating, fun. He points to the work of David Hume who saw lust not only as a sensual delight but also "a joy of the mind." Written by one of the most eminent living philosophers, attractively illustrated and colourfully packaged, Lust is a book that anyone would lust over. (shrink)

How can computers distinguish the coherent from the unintelligible, recognize new information in a sentence, or draw inferences from a natural language passage? Computational semantics is an exciting new field that seeks answers to these questions, and this volume is the first textbook wholly devoted to this growing subdiscipline. The book explains the underlying theoretical issues and fundamental techniques for computing semantic representations for fragments of natural language. This volume will be an essential text for computer scientists, linguists, and anyone (...) interested in the development of computational semantics. (shrink)

Hybridization is a method invented by Arthur Prior for extending the expressive power of modal languages. Although developed in interesting ways by Robert Bull, and by the Sofia school , the method remains little known. In our view this has deprived temporal logic of a valuable tool.The aim of the paper is to explain why hybridization is useful in temporal logic. We make two major points, the first technical, the second conceptual. First, we show that hybridization gives rise to well-behaved (...) logics that exhibit an interesting synergy between modal and classical ideas. This synergy, obvious for hybrid languages with full first-order expressive strength, is demonstrated for a weaker local language capable of defining the Until operator; we provide a minimal axiomatization, and show that in a wide range of temporally interesting cases extended completeness results can be obtained automatically. Second, we argue that the idea of sorted atomic symbols which underpins the hybrid enterprise can be developed further. To illustrate this, we discuss the advantages and disadvantages of a simple hybrid language which can quantify over paths. (shrink)

In this paper we argue that hybrid logic is the deductive setting most natural for Kripke semantics. We do so by investigating hybrid axiomatics for a variety of systems, ranging from the basic hybrid language (a decidable system with the same complexity as orthodox propositional modal logic) to the strong Priorean language (which offers full first-order expressivity).We show that hybrid logic offers a genuinely first-order perspective on Kripke semantics: it is possible to define base logics which extend automatically to a (...) wide variety of frame classes and to prove completeness using the Henkin method. In the weaker languages, this requires the use of non-orthodox rules. We discuss these rules in detail and prove non-eliminability and eliminability results. We also show how another type of rule, which reflects the structure of the strong Priorean language, can be employed to give an even wider coverage of frame classes. We show that this deductive apparatus gets progressively simpler as we work our way up the expressivity hierarchy, and conclude the paper by showing that the approach transfers to first-order hybrid logic. (shrink)

I critically examine an argument, due to howard wettstein, purporting to show that sentences containing definite descriptions are semantically ambiguous between referential and attributive readings. Wettstein argues that many sentences containing nonidentifying descriptions--descriptions that apply to more than one object--cannot be given a Russellian analysis, and that the descriptions in these sentences should be understood as directly referential terms. But because Wettstein does not justify treating referential uses of nonidentifying descriptions differently than attributive uses of nonidentifying descriptions, his argument fails.

A modal logic is developed to deal with finite ordered binary trees a they are used in linguistics. A modal language is introduced with operators for the ‘mother of’, ‘first daughter of’ and ‘second daughter of’ relations together with their transitive reflexive closures. The relevant class of tree models is defined and three linguistic applications of this language are discussed: context free grammars, command relations, and trees decorated with feature structures. An axiomatic proof system is given for which completeness is (...) shown with respect to the class of finite ordered binary trees. A number of decidability results follow. (shrink)

We maximally extend the quantum‐mechanical results of Muller and Saunders ( 2008 ) establishing the ‘weak discernibility’ of an arbitrary number of similar fermions in finite‐dimensional Hilbert spaces. This confutes the currently dominant view that ( A ) the quantum‐mechanical description of similar particles conflicts with Leibniz’s Principle of the Identity of Indiscernibles (PII); and that ( B ) the only way to save PII is by adopting some heavy metaphysical notion such as Scotusian haecceitas or Adamsian primitive thisness. We (...) take sides with Muller and Saunders ( 2008 ) against this currently dominant view, which has been expounded and defended by many. *Received July 2008; revised May 2009. †To contact the authors, please write to: F. A. Muller, Faculty of Philosophy, Erasmus University Rotterdam, Burg. Oudlaan 50, H5–16, 3062 PA Rotterdam, The Netherlands; e‐mail: [email protected] , and Institute for the History and Foundations of Science, Utrecht University, Budapestlaan 6, IGG–3.08, 3584 CD Utrecht, The Netherlands; e‐mail: [email protected] . M. P. Seevinck, Institute for the History and Foundations of Science, Utrecht University, Budapestlaan 6, IGG–3.08, 3584 CD Utrecht, The Netherlands; e‐mail: [email protected]. (shrink)

In this paper I contemplate two phenomena that have impressed theorists concerned with the domain of reasons and of what is now called ‘normativity’. One is the much-discussed ‘externality’ of reasons. According to this, reasons are just there, anyway. They exist whether or not agents take any notice of them. They do not only exist in the light of contingent desires or mere inclinations. They are ‘external’ not ‘internal’. They bear on us, even when through ignorance or wickedness we take (...) no notice of them. They thus very conspicuously shine the lights of objectivity, and independence, and even necessity. By basking in this light, ethics is rescued from the slough of sentiment and preference, and regains the dignity denied to it by theorists such as Hobbes or Hume, Williams, Gibbard or myself. Hence, many contemporary philosophers compete to stress and to extol the external nature of reasons, their shining objectivity. The other phenomenon is that of the inescapable ‘normativity’ of means-ends reasoning. Here the irrationality of intending an end but failing to intend the means is a different shining beacon. It is that of pure practical reason in operation: an indisputable norm, again showing a sublime indifference to whatever weaknesses people actually have, and ideally fitted to provide a Trojan horse for inserting rationality into practical life. If the means-end principle is both unmistakably practical and yet the darling child of rationality itself, then other principles of consistency or of humanity, or of universalizing the maxims of our action, can perhaps follow through the breach in the Humean citadel that it has spearheaded. And so we get the dazzling prospect that if people who choose badly are choosing against reason, then this can be seen to be a special and grave defect. It would locate the kind of fault they are indulging. It would give us, the people of reason, a special lever with which to dislodge their vices. Being able to herd knaves and villains in a compound reserved for those who trespass against reason and rationality therefore represents definite progress. (shrink)

Pragmatists have traditionally been enemies of representationalism but friends of naturalism, when naturalism is understood to pertain to human subjects, in the sense of Hume and Nietzsche. In this volume Huw Price presents his distinctive version of this traditional combination, as delivered in his René Descartes Lectures at Tilburg University in 2008. Price contrasts his view with other contemporary forms of philosophical naturalism, comparing it with other pragmatist and neo-pragmatist views such as those of Robert Brandom and Simon Blackburn. (...) Linking their different 'expressivist' programmes, Price argues for a radical global expressivism that combines key elements from both. With Paul Horwich and Michael Williams, Brandom and Blackburn respond to Price in new essays. Price replies in the closing essay, emphasising links between his views and those of Wilfrid Sellars. The volume will be of great interest to advanced students of philosophy of language and metaphysics. (shrink)

Dreier’s sympathy with expressivism is welcome, and yet he comes upon an ‘uncomfortable surprise’, in a circularity or regress that he detects in my attempt to place ethical commitments in a natural world. The circularity is that the expressivist analysis of what is going on, when we invoke norms, identifies particular states of mind: valuings, or acceptance of norms, or complexes of attitude. But states of mind are themselves normatively tainted. Hence: ‘the kernel of expressivist analysis invokes normative concepts’.

In this note we show that the classical modal technology of Sahlqvist formulas gives quick proofs of the completeness theorems in [8] (D. Gregory, Completeness and decidability results for some propositional modal logics containing "actually" operators, Journal of Philosophical Logic 30(1): 57-78, 2001) and vastly generalizes them. Moreover, as a corollary, interpolation theorems for the logics considered in [8] are obtained. We then compare Gregory's modal language enriched with an "actually" operator with the work of Arthur Prior now known under (...) the name of hybrid logic. This analysis relates the "actually" axioms to standard hybrid axioms, yields the decidability results in [8], and provides a number of complexity results. Finally, we use a bisimulation argument to show that the hybrid language is strictly more expressive than Gregory's language. (shrink)

Many of the formalisms used in Attribute Value grammar are notational variants of languages of propositional modal logic, and testing whether two Attribute Value Structures unify amounts to testing for modal satisfiability. In this paper we put this observation to work. We study the complexity of the satisfiability problem for nine modal languages which mirror different aspects of AVS description formalisms, including the ability to express re-entrancy, the ability to express generalisations, and the ability to express recursive constraints. Two main (...) techniques are used: either Kripke models with desirable properties are constructed, or modalities are used to simulate fragments of Propositional Dynamic Logic. Further possibilities for the application of modal logic in computational linguistics are noted. (shrink)

On the 4th of December 1967, Hans Kamp sent his UCLA seminar notes on the logic of ‘now’ to Arthur N. Prior. Kamp’s two-dimensional analysis stimulated Prior to an intense burst of creativity in which he sought to integrate Kamp’s work into tense logic using a one-dimensional approach. Prior’s search led him through the work of Castañeda, and back to his own work on hybrid logic: the first made temporal reference philosophically respectable, the second made it technically feasible in a (...) modal framework. With the aid of hybrid logic, Prior built a bridge from a two-dimensional UT calculus to a one-dimensional tense logic containing the ‘now’ operator J. Drawing on material from the Prior archive, and the paper “‘Now”’ that detailed Prior’s findings, we retell this story. We focus on Prior’s completeness conjecture for the hybrid system and the role played by temporal reference. (shrink)

In this paper we argue that Prior and Reichenbach are best viewed as allies, not antagonists. We do so by combining the central insights of Prior and Reichenbach in the framework of hybrid tense logic. This overcomes a well-known defect of Reichenbach’s tense schema, namely that it gives multiple representations to sentences in the future perfect and the future-in-the-past. It also makes it easy to define an iterative schema for tense that allows for multiple points of reference, a possibility noted (...) by Prior and demanded by Comrie, and we sketch how this schema can be generalized to a shift-and-restrict pattern in which special propositional symbols act as restrictors on the range of tense operators. (shrink)