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)
Simon Blackburn puts forward a compelling and original philosophy of human motivation and morality. 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 to such questions in an exploration of the nature of moral emotions and the structures of human motivation. He develops a naturalistic ethics, which integrates our understanding of ethics with the rest of our understanding (...) of the world we live in. His theory does not debunk the ethical by reducing it to the non-ethical, and it banishes the spectres of scepticism and relativism that have haunted recent moral philosophy. Ruling Passions reveals how ethics can maintain its authority even though it is rooted in the very emotions and motivations that it exists to control. (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)
In this clear introduction to ethics Simon Blackburn tackles the major moral questions surrounding birth, death, happiness, desire and freedom, showing us how ...
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)
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)
It is not only in our dark hours that scepticism, relativism, hypocrisy, and nihilism dog ethics. Whether it is a matter of giving to charity, or sticking to duty, or insisting on our rights, we can be confused, or be paralysed by the fear that our principles are groundless. Many are afraid that in a Godless world science has unmasked us as creatures fated by our genes to be selfish and tribalistic, or competitive and aggressive. Simon Blackburn, author of (...) the best-selling Think, structures this short introduction around these and other threats to ethics. Confronting seven different objections to our self-image as moral, well-behaved creatures, he charts a course through the philosophical quicksands that often engulf us. Then, turning to problems of life and death, he shows how we should think about the meaning of life, and how we should mistrust the sound-bite sized absolutes that often dominate moral debates. Finally he offers a critical tour of the ways the philosophical tradition has tried to provide foundations for ethics, from Plato and Aristotle through to contemporary debates. (shrink)
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 (Blackburn's favorite philosopher) 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)
Este artigo canta uma canção — uma canção criada ao unir o trabalho de quatro grandes nomes na história da lógica: Hans Reichenbach, Arthur Prior, Richard Montague, e Leon Henkin. Embora a obra dos primeiros três desses autores tenha sido previamente combinada, acrescentar as ideias de Leon Henkin é o acréscimo requerido para fazer com que essa combinação funcione no nível lógico. Mas o presente trabalho não se concentra nas tecnicalidades subjacentes (que podem ser encontradas em Areces, Blackburn, Huertas, (...) e Manzano [no prelo]), e sim nos instrumentos subjacentes e no modo como trabalham em conjunto. Esperamos que o leitor fique tentado a cantar junto. DOI:10.5007/1808-1711.2011v15n2p225. (shrink)
Plato is perhaps the most significant philosopher who has ever lived and The Republic , composed in Athens in about 375 BC, is widely regarded as his most famous dialogue. Its discussion of the perfect city — and the perfect mind — laid the foundations for Western culture and, for over two thousand years, has been the cornerstone of Western philosophy. As the distinguished Cambridge professor Simon Blackburn points out, it has probably sustained more commentary, and been subject to (...) more radical and impassioned disagreement, than almost any other of the great founding texts of the modern world. In Plato’s Republic , Blackburn explains the judicial, moral and political ideas in the Republic with dazzling insight and clarity. Blackburn also examines Republic’s remarkable influence and unquestioned staying power, and shows why, from St. Augustine to twentieth century philosophers such as Ludwig Wittgenstein and Henri Bergson, Western thought is still conditioned by this most important, and contemporary, of books. (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)
In this paper I contemplate two phenomena that have impressed theorists concerned with the domain of reasons and of normativity. One is the much-discussed ‘externality’ of reasons. 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, Gibbard or myself. Many contemporary philosophers compete to stress the external nature of reasons, their shining objectivity.1 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 shining beacon 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 meansend principle is both practical and the 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 corral knaves and villains in a compound reserved for those who trespass against reason and rationality may therefore represent definite progress. It is sad to have to spoil the party, but my claim is straightforward.. (shrink)
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)
I think it is a lapse of taste to spend a grown-up life on problems of which people in the office next door, let alone those outside the building, cannot see the point. I rather fear that the so-called semantic or logical problem of vagueness, Professor Williamson’s own showcase example of his compulsory methods, strikes me as like that.
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)
The idea behind expressivism as a philosophy of ethics faces a number of different challenges, and has a number of different choices to make as it tries to meet them. Perhaps the first is to specify what is the primitive of the theory, which will be something that is expressed, and is usually identified as a state of mind. Later in this paper, I shall suggest caution about this, but for the moment we can go along with it. Emotion was (...) one suggestion, prescriptions are another, desires of various orders are candidates, but I prefer the less specific term ‘attitude’. One might ask why we should not go with the equally general term ‘belief’. The answer derives from the second challenge, which queries whether we have actually managed to locate a primitive suited to play its role in a substantive theory. This in turn depends on what exactly the substantive theory is trying to do, so we need to sketch an answer to that first. The need is more pressing since for some time now there have been theorists who have more or less explicitly turned their backs on the whole idea of ‘metaethics’ or theory of ethics, supposing that the only questions that should bother the philosopher come from within first-order practice, as we try to articulate our standards, to rank obligations and duties, or to relate those to utility and virtue. (shrink)
How come we are so successful, unless we are hooked up right to the world? A good question, and one that suggests a way of thinking of our hook-up to the world. Success semantics is the result of that suggestion. It is the view that a theory of success in action is a possible basis for a theory of representation, or a theory of content or intentionality (throughout this paper I shall use these interchangeably). At its most simple we can (...) think of representation in terms of disquotation, as in the famous “Fido” – Fido relationship. Then the idea is that the disquotation of representation is explained or illuminated or even analyzed by the disquotation of explanation, where whatever is represented explains something about the person representing it. And what it explains is primarily the success of the actions that the person bases upon the representing. The view is an heir to the pragmatist tradition. At the most general level, the idea is that we get our way, or flourish, or fulfill our desires or our needs because we get things right about the world. The contents of our sentences are then whatever it is that we get right. The ancestor of success semantics, as of so much else, is Frank Ramsey, who wrote that it is right to talk of a chicken’s belief that a certain sort of caterpillar is poisonous if the chicken’s actions were such as to be useful if, and only if, the caterpillars were actually poisonous. “Thus any set of actions for whose utility p is a necessary and sufficient condition might be called a belief that p, and so would be true if p, i.e. if they are useful”.1 Ramsey did not develop the idea, and it may even be doubted whether his chicken was thought of in representative terms at all. Perhaps it was a primitive precursor.. (shrink)
Some years ago, without realizing what it might mean, I accepted a dinner invitation from a Jewish colleague for dinner on Friday night. I should say that my colleague had never appeared particularly orthodox, and he would have known that I am an atheist. However, in the course of the meal, some kind of observance was put in train, and it turned out I was expected to play along—put on a hat, or some such. I demurred, saying that I felt (...) uncomfortable doing something that might be the expression of some belief that I do not hold, or of joining a “fellowship” with which I felt no special community, and with which I would not have any particular fellow-feeling beyond whatever I feel for human beings in general. I was assured that what it would signify, if I went through with the observance, was not that I shared the world views or beliefs of my host, or wished myself to identify uniquely with some particular small subset of humanity, but only that I respected his beliefs, or perhaps his stance. I replied that in that case, equally, I could not in conscience do what was required. (shrink)
This paper sets out to raise questions about the metaphor of the spaceof reasons. It argues that a proper appreciation of Wittgensteinundermines the metaphysical or dualistic way of taking the metaphor thatis supposed to prevent the naturalization of reason.
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.
1. Some twenty years ago I voiced reservations about John McDowell’s embrace of a spatial metaphor, whereby we should expand our idea of the ‘space’ occupied by the mind, locating its boundaries far outside the skin, way into the world.1 I thought at the time that the spatial metaphor was a flourish McDowell had been betrayed into, particularly by some of the terminology of his dispute with Dummett over ‘manifestation’. But over the years it began to be clear that it (...) was more than that, being one of several metaphors that figure centrally in his extensive and influential meditations on the relationship between ourselves and our world. Indeed, the best thumbnail description of his aim would be to show that the world is not ‘blankly external’ to the mind, and this description uses the metaphor. So the reservation went unheeded, and years later the metaphor and its cousins occupied large parts of Mind and World, which is the principal text which I shall consider, although they liberally sprinkle other writings as well. I shall use this opportunity to try to sensitize others to my reasons for discomfort. (shrink)
In this paper I consider recent developments in neo-pragmatism, and in particular the degree of convergence between such approaches and those placing greater emphasis on truth and truth-makers. I urge that although a global pragmatism has its merits, it by no means closes the space for a more Wittgensteinian, finer-grained, approach to the diversity of functions served by modal, causal, moral, or other modes of thought.
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)
Practical philosophy and ethics -- Practical tortise raising -- Truth, beauty, and goodness -- Dilemmas: dithering, plumping, and grief -- Group minds and expressive harm -- Trust, cooperation, and human psychology -- Must we weep for sentimentalism? -- Through thick and thin -- Perspectives, fictions, errors, play -- The steps from doing to saying -- Success semantics -- Wittgenstein's irrealism -- Circles, finks, smells, and biconditionals -- The absolute conception: Putnam vs. Williams -- Julius Caesar and George Berkeley play leapfrog (...) -- The majesty of reason -- Fiction and conviction. (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)
Peter Lamarque's splendid and informative book, The Philosphy of Literature , deserves a much fuller response than I can give in this brief note. It is brimful with insights into the nature of literature, and into the debates between philosophers interested in literature, and I cannot imagine anyone failing to learn from it. The question I propose to take up is by no means the most important that Lamarque raises, nor am I even certain that I can add anything useful (...) to his own discussion of it. Yet I find myself puzzled by it, and hope that it may repay further thought. (shrink)
In my article I summarize a 'Humean' view of deliberation, and in particular deliberation with an ethical aspect. I regard Hume as having paved the way for a 'naturalistic' account of these things, avoiding Kantian fantasies of agency that dominate much current work. Contrary to what is often supposed, the Humean story gives a satisfactory account of dutiful or principled motivations, and a rich account of the ways in which different aspects of character are selected as 'useful or agreeable to (...) ourselves or others'. (shrink)
In this paper I consider the 'disappearing we' account of Wittgenstein's attitude to other ways of thought or other 'conceptual schemes'. I argue that there is no evidence that Wittgenstein expected the 'we' to disappear, in the manner of Davidson, and that his affinities with relativistic trains of thought in fact go much deeper.
The title reflects my conviction that, viewed semantically,modal logic is fundamentally dialogical; this conviction is based on the key role played by the notion of bisimulation in modal model theory. But this dialogical conception of modal logic does not seem to apply to modal proof theory, which is notoriously messy. Nonetheless, by making use of ideas which trace back to Arthur Prior (notably the use of nominals, special proposition symbols which name worlds) I will show how to lift the dialogical (...) conception to modal proof theory. I argue that this shift to hybrid logic has consequences for both modal and dialogical logic, and I discuss these in detail. (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.
One important difference between adaptive and nonadaptive explanations can be found in the evolutionary sequence of structural and functional modifications. Phylogenetic analysis (cladistics) provides a powerful methodology for distinguishing exaptation from adaptation, by indicating whether character traits have predated, accompanied, or followed evolution of particular functions. Such analysis yields falsifiable hypotheses that can help to distinguish causal relationships from mere correlation.
It is inherent in the concept of a terrorist act that it aims at an effect very much larger than the direct physical destruction it causes. Proponents of what used to be called the 'propaganda of the deed' also believed that in the illuminating glare of terror the vulnerability of a corrupt ...
Abstract In this piece I take issue with Bernard Williams's interpretation of Herodotus as lacking something of our conception of time. I claim that there is nothing so unusual in the interleaving of myth or fiction and history that Williams finds in Herodotus. I also reflect on the difficulty of separating acceptance of truth from acceptance of myth, metaphor, and model, not only in history but also in science.
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)
Craig's interpolation lemma (if φ → ψ is valid, then φ → θ and θ → ψ are valid, for θ a formula constructed using only primitive symbols which occur both in φ and ψ) fails for many propositional and first order modal logics. The interpolation property is often regarded as a sign of well-matched syntax and semantics. Hybrid logicians claim that modal logic is missing important syntactic machinery, namely tools for referring to worlds, and that adding such machinery solves (...) many technical problems. The paper presents strong evidence for this claim by defining interpolation algorithms for both propositional and first order hybrid logic. These algorithms produce interpolants for the hybrid logic of every elementary class of frames satisfying the property that a frame is in the class if and only if all its point-generated subframes are in the class. In addition, on the class of all frames, the basic algorithm is conservative: on purely modal input it computes interpolants in which the hybrid syntactic machinery does not occur. (shrink)
