Using labelled formulae, a cut-free sequent calculus for intuitionistic propositional logic is presented, together with an easy cut-admissibility proof; both extend to cover, in a uniform fashion, all intermediate logics characterised by frames satisfying conditions expressible by one or more geometric implications. Each of these logics is embedded by the Gödel–McKinsey–Tarski translation into an extension of S4. Faithfulness of the embedding is proved in a simple and general way by constructive proof-theoretic methods, without appeal to semantics other than in the (...) explanation of the rules. (shrink)

That every first-order theory has a coherent conservative extension is regarded by some as obvious, even trivial, and by others as not at all obvious, but instead remarkable and valuable; the result is in any case neither sufficiently well-known nor easily found in the literature. Various approaches to the result are presented and discussed in detail, including one inspired by a problem in the proof theory of intermediate logics that led us to the proof of the present paper. It can (...) be seen as a modification of Skolem’s argument from 1920 for his “Normal Form” theorem. “Geometric” being the infinitary version of “coherent”, it is further shown that every infinitary first-order theory, suitably restricted, has a geometric conservative extension, hence the title. The results are applied to simplify methods used in reasoning in and about modal and intermediate logics. We include also a new algorithm to generate special coherent implications from an axiom, designed to preserve the structure of formulae with relatively little use of normal forms. (shrink)

In the proof-theoretic semantics approach to meaning, harmony , requiring a balance between introduction-rules (I-rules) and elimination rules (E-rules) within a meaning conferring natural-deduction proof-system, is a central notion. In this paper, we consider two notions of harmony that were proposed in the literature: 1. GE-harmony , requiring a certain form of the E-rules, given the form of the I-rules. 2. Local intrinsic harmony : imposes the existence of certain transformations of derivations, known as reduction and expansion . We propose (...) a construction of the E-rules (in GE-form) from given I-rules, and prove that the constructed rules satisfy also local intrinsic harmony. The construction is based on a classification of I-rules, and constitute an implementation to Gentzen’s (and Pawitz’) remark, that E-rules can be “read off” I-rules. (shrink)

By considering the new notion of theinversesof syllogisms such asBarbaraandCelarent, we show how the rule ofIndirect Proof, in the form (no multiple or vacuous discharges) used by Aristotle, may be dispensed with, in a system comprising four basic rules of subalternation or conversion and six basic syllogisms.

The paper briefly surveys the sentential proof-theoretic semantics for fragment of English. Then, appealing to a version of Frege’s context-principle (specified to fit type-logical grammar), a method is presented for deriving proof-theoretic meanings for sub-sentential phrases, down to lexical units (words). The sentential meaning is decomposed according to the function-argument structure as determined by the type-logical grammar. In doing so, the paper presents a novel proof-theoretic interpretation of simple type, replacing Montague’s model-theoretic type interpretation (in arbitrary Henkin models). The domains (...) of derivations are collections of derivations in the associated “dedicated” natural-deduction proof-system, and functions therein (with no appeal to models, truth-values and elements of a domain). The compositionality of the semantics is analyzed. (shrink)

The paper presents a proof-theoretic semantics (PTS) for a fragment of natural language, providing an alternative to the traditional model-theoretic (Montagovian) semantics (MTS), whereby meanings are truth-condition (in arbitrary models). Instead, meanings are taken as derivability-conditions in a dedicated natural-deduction (ND) proof-system. This semantics is effective (algorithmically decidable), adhering to the meaning as use paradigm, not suffering from several of the criticisms formulated by philosophers of language against MTS as a theory of meaning. In particular, Dummett’s manifestation argument does not (...) obtain, and assertions are always warranted, having grounds of assertion. The proof system is shown to satisfy Dummett’s harmony property, justifying the ND rules as meaning conferring. The semantics is suitable for incorporation into computational linguistics grammars, formulated in type-logical grammar. (shrink)

We describe a sequent calculus, based on work of Herbelin, of which the cut-free derivations are in 1-1 correspondence with the normal natural deduction proofs of intuitionistic logic. We present a simple proof of Herbelin's strong cut-elimination theorem for the calculus, using the recursive path ordering theorem of Dershowitz.

This paper shows that, for the Hertz–Gentzen Systems of 1933, extended by a classical rule T1 and using certain axioms, all derivations are analytic: every cut formula occurs as a subformula in the cut’s conclusion. Since the Stoic cut rules are instances of Gentzen’s Cut rule of 1933, from this we infer the decidability of the propositional logic of the Stoics. We infer the correctness for this logic of a “relevance criterion” and of two “balance criteria”, and hence that a (...) particular derivable sequent has no derivation that is “normal” in the sense that the first premiss of each cut is cut-free. We also infer that Cut is not admissible in the Stoic system, based on the standard Stoic axioms, the T1 rule and the instances of Cut with just two antecedent formulae in the first premiss. OPEN ACCESS. (shrink)

We give a direct proof of admissibility of cut and contraction for the contraction-free sequent calculus G4ip for intuitionistic propositional logic and for a corresponding multi-succedent calculus: this proof extends easily in the presence of quantifiers, in contrast to other, indirect, proofs. i.e., those which use induction on sequent weight or appeal to admissibility of rules in other calculi.

We give a direct proof of admissibility of cut and contraction for the contraction-free sequent calculus G4ip for intuitionistic propositional logic and for a corresponding multi-succedent calculus: this proof extends easily in the presence of quantifiers, in contrast to other, indirect, proofs. i.e., those which use induction on sequent weight or appeal to admissibility of rules in other calculi.

The decision problem for positively quantified formulae in the theory of linearly ordered Heyting algebras is known, as a special case of work of Kreisel, to be solvable; a simple solution is here presented, inspired by related ideas in Gödel-Dummett logic.

"The papers in this volume are extended versions of presentations at the fourth International Workshop on Extensions of Logic Programming, held at the University of St Andrews, March/April 1993. Among the topics covered in the volume are: defintional reflection and completion, modules in lambda-Prolog, representation of logics as partial inductive definitions, non-procedural logic programming, knowledge representation, contradiction avoidance, disjunctive databases, strong negation, linear logic programming, proof theory and regular search spaces, finite sets and constraint logic programming, search-space pruning and universal (...) algebra, and implementation on transputer networks."--PUBLISHER'S WEBSITE. (shrink)

A major strategy to reduce transport congestion and other social costs of transport is to ensure that travellers make the best decisions, based on real time information. A wide range of technological systems have been developed to provide this information, but little is known about how travellers actually respond to it. This book offers an overview of various transport telematics options and provides an appropriate methodological framework, followed by a presentation of results from actual applications of these telematics systems from (...) a range of European countries in various transport sectors. The empirical results are supplemented by analytical models and geographic information systems representations with a view on generalizing these findings and identifying the key parameters which determine user response. (shrink)

Logical pluralism is the view that there is more than one formal logic that correctly (or best, or legitimately) codifies the logical consequence relation in natural language. This essay provides a taxonomy of different variations on the logical pluralist theme based on a five-part structure, and then identifies an unoccupied position in this taxonomy: perspectival logical pluralism. Perspectival pluralism provides an attractive position from which to formulate a philosophy of logic from a feminist perspective (and from other, identity-based perspectives, such (...) as critical race theory). An example of how such an account might be developed is sketched. The essay concludes by defusing an obvious objection to the perspectival approach: the claim that the correct logic (or logics), in virtue of the formal nature of logic, should be independent of considerations regarding the identity of the reasoner. (shrink)

Can God create a stone too heavy for him to lift? Can time have a beginning? Which came first, the chicken or the egg? Riddles, paradoxes, conundrums--for millennia the human mind has found such knotty logical problems both perplexing and irresistible. Now Roy Sorensen offers the first narrative history of paradoxes, a fascinating and eye-opening account that extends from the ancient Greeks, through the Middle Ages, the Enlightenment, and into the twentieth century. When Augustine asked what God was doing before (...) He made the world, he was told: "Preparing hell for people who ask questions like that." A Brief History of the Paradox takes a close look at "questions like that" and the philosophers who have asked them, beginning with the folk riddles that inspired Anaximander to erect the first metaphysical system and ending with such thinkers as Lewis Carroll, Ludwig Wittgenstein, and W.V. Quine. Organized chronologically, the book is divided into twenty-four chapters, each of which pairs a philosopher with a major paradox, allowing for extended consideration and putting a human face on the strategies that have been taken toward these puzzles. Readers get to follow the minds of Zeno, Socrates, Aquinas, Ockham, Pascal, Kant, Hegel, and many other major philosophers deep inside the tangles of paradox, looking for, and sometimes finding, a way out. Filled with illuminating anecdotes and vividly written, A Brief History of the Paradox will appeal to anyone who finds trying to answer unanswerable questions a paradoxically pleasant endeavor. (shrink)

This book examines the intricate dynamics of when individuals adhere to laws, taking into account the context in which laws attempt to shape human behavior. While existing literature touches upon various reasons why people comply with laws, the book focuses on a critical question which has been missing from the discussion: when do people obey laws? By treating law as a form of social communication, it develops an integrated framework to answer this question. It explores how social, psychological, and institutional (...) conditions shape compliance decisions of individuals. What does a law signify? When does the compulsion to obey arise? When do individuals comply out of a fear for legal sanctions or social repercussions? Why do some laws have high symbolic values and others fail despite harsh punishments? The book unveils the contextual intricacies that underlie obedience to law. It challenges conventional wisdom and offers a fresh perspective on the power and limitations of law in shaping human behavior. For scholars and academics seeking a deeper understanding of legal compliance and role of law in shaping behaviors, this book will be an indispensable resource. (shrink)

The Vedanta of conciousness : transcendence, enlightenment and everyday life -- The alienated self and the Kabbala of transformation -- The Zen of creativity and the critique of the discursive intellect -- The Tao of love and unconditionality in commitment -- The yoga of action and effortless efficiency -- The nous of perception and the re-enchantment of the tree of life -- The gnosis of freedom and the Fana of fulfilment.

Is philosophy worth it? -- Explanation and the laws of nature -- Reference, truth, and meaning -- Causality, change, and emergence -- Making it happen (social agency) -- Dialectic -- Living well -- Dialectic critical realism -- Socrates and so on? -- Philosophy and the dialectic of emancipation -- Appendix: explaining philosophies.

Paradoxes are arguments that lead from apparently true premises, via apparently uncontroversial reasoning, to a false or even contradictory conclusion. Paradoxes threaten our basic understanding of central concepts such as space, time, motion, infinity, truth, knowledge, and belief. In this volume Roy T Cook provides a sophisticated, yet accessible and entertaining, introduction to the study of paradoxes, one that includes a detailed examination of a wide variety of paradoxes. The book is organized around four important types of paradox: the semantic (...) paradoxes involving truth, the set-theoretic paradoxes involving arbitrary collections of objects, the Soritical paradoxes involving vague concepts, and the epistemic paradoxes involving knowledge and belief. In each of these cases, Cook frames the discussion in terms of four different approaches one might take towards solving such paradoxes. Each chapter concludes with a number of exercises that illustrate the philosophical arguments and logical concepts involved in the paradoxes. _Paradoxes_ is the ideal introduction to the topic and will be a valuable resource for scholars and students in a wide variety of disciplines who wish to understand the important role that paradoxes have played, and continue to play, in contemporary philosophy. (shrink)

This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work. This work is in the public domain (...) in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant. (shrink)

An entertaining history of the idea of nothing - including absences, omissions, and shadows - from the Ancient Greeks through the 20th century How can nothing cause something? The absence of something might seem to indicate a null or a void, an emptiness as ineffectual as a shadow. In fact, 'nothing' is one of the most powerful ideas the human mind has ever conceived. This short and entertaining book by Roy Sorensen is a lively tour of the history and philosophy (...) of nothing, explaining how various thinkers throughout history have conceived and grappled with the mysterious power of absence -- and how these ideas about shadows, gaps, and holes have in turned played a very positive role in the development of some of humankind's most important ideas. Filled with Sorensen's characteristically entertaining mix of anecdotes, puzzles, curiosities, and philosophical speculation, the book is ordered chronologically, starting with the Taoists, the Buddhists, and the ancient Greeks, moving forward to the middle ages and the early modern period, then up to the existentialists and present day philosophy. The result is a diverting tour through the history of human thought as seen from a novel and unusual perspective. (shrink)

In this book, Roy Bhaskar sets out to revindicate ontology, critiquing the reduction of being in favor of knowledge, which he calls the "epistemic fallacy".

This introduction reflects on the themes of viscosity, death and the Other in three essays, written by John Milbank, Julia Hell, and Martin Jay, which provide a response — respectively — to three of Professor Zygmunt Bauman’s key works: Legislators and Interpreters, Modernity and the Holocaust, and Liquid Modernity.

The No-No Paradox consists of a pair of statements, each of which ?says? the other is false. Roy Sorensen claims that the No-No Paradox provides an example of a true statement that has no truthmaker: Given the relevant instances of the T-schema, one of the two statements comprising the ?paradox? must be true (and the other false), but symmetry constraints prevent us from determining which, and thus prevent there being a truthmaker grounding the relevant assignment of truth values. Sorensen's view (...) is mistaken: situated within an appropriate background theory of truth, the statements comprising the No-No Paradox are genuinely paradoxical in the same sense as is the Liar (and thus, on Sorensen's view, must fail to have truth values). This result has consequences beyond Sorensen's semantic framework. In particular, the No-No Paradox, properly understood, is not only a new paradox, but also provides us with a new type of paradox, one which depends upon a general background theory of the truth predicate in a way that the Liar Paradox and similar constructions do not. (shrink)

Since its original publication in 1979, The Possibility of Naturalism has been one of the most influential works in contemporary philosophy of science and social science. It is a cornerstone of the critical realist position, which is now widely seen as offering a viable alternative to move positivism and postmodernism. This revised edition includes a new foreword.

Following on from Roy Bhaskarâe(tm)s first two books, A Realist Theory of Science and The Possibility of Naturalism, Scientific Realism and Human Emancipation, establishes the conception of social science as explanatoryâe"and thence emancipatoryâe"critique. Scientific Realism and Human Emancipation starts from an assessment of the impasse of contemporary accounts of science as stemming from an incomplete critique of positivism. It then proceeds to a systematic exposition of scientific realism in the form of transcendental realism, highlighting a conception of science as explanatory (...) of a structured, differentiated and changing world. Turning to the social domain, the book argues for a view of the social order as conditioned by, and emergent from, nature. Advocating a critical naturalism, the author shows how the transformational model of social activity together with the conception of social science as explanatory critique which it entails, resolves the divisions and dualisms besetting orthodox social and normative theory: between society and the individual, structure and agency, meaning and behavior, mind and body, reason and cause, fact and value, and theory and practice. The book then goes on to discuss the emancipatory implications of social science and sketches the nature of the depth investigation characteristically entailed. In the highly innovative third part of the book Roy Bhaskar completes his critique of positivism by developing a theory of philosophical discourse and ideology, on the basis of the transcendental realism and critical naturalism already developed, showing how positivism functions as a restrictive ideology of and for science and other social practices. (shrink)

Since its inception in the 1970's, critical realism has grown to address a broad range of subjects, including economics, philosophy, science, and religion. It has also gone through a number of key evolutions that have changed its direction, and seen it develop into a complex and mature branch of philosophy. Critical Realism: A Brief Introduction, is the first book to look back over the entire field of critical realism in one concise and accessible volume. As the originator and chief exponent (...) of CR, Roy Bhaskar draws from his experience of countless introductory lectures, seminars, workshops and courses to give a definitive and compelling account of this increasingly influential, international and multi-disciplinary approach. Its eight chapters examine the following topics: Transcendental Realism and the Philosophy of Science Critical Naturalism and the Philosophy of Social Science Explanatory Critique and Ethics Language and Critical Discourse Analysis The Development of Critical Realism Interdisciplinarity and Applied Critical Realism Modernity, Theories of Science and Metacritique The Advantages of Critical Realism Everything from the definition of CR and its applicability to the social sciences, to explanations of dialectical critical realism and the philosophy of meta-reality are addressed in detail, making this the essential introduction for students of CR at all levels. (shrink)

The purpose of this article is to analyse the mathematical practices leading to Rafael Bombelli’s L’algebra (1572). The context for the analysis is the Italian algebra practiced by abbacus masters and Renaissance mathematicians of the fourteenth to sixteenth centuries. We will focus here on the semiotic aspects of algebraic practices and on the organisation of knowledge. Our purpose is to show how symbols that stand for underdetermined meanings combine with shifting principles of organisation to change the character of algebra.

Offering a Canadian perspective on the emotional health of servicemen and women, Military Operations and the Mind brings together researchers and practitioners from across the country to consider the impact that ethical issues have on the well-being of those who serve. Stemming from an initiative to enhance the lives of serving members by providing them with the best education and training in military ethics before and after deployments, this volume will better inform politics and public policies and enhance the welfare (...) of the soldiers, sailors, and airmen and women who serve in singular, often harsh, and sometimes dangerous conditions. By integrating into the analysis the critical issue of well-being, this emerging field demonstrates a more holistic approach and is distinct from other fields in military, historical, philosophical, and behavioural studies. The first study of its kind, Military Operations and the Mind presents a new and helpful way to focus on the life of soldiers not only in operations overseas, but also once they return home. (shrink)

Ethics in the West too often equates morality with universal moral principles, thus imposing lifestyles and moral criteria that do not respect differences and local histories. Even Christianity proposes ethics that is based on eternal, absolute and universal truths or principles, independent of sociocultural and historical contexts. The problem is that these universal moral laws become a means of social control to exclude those who are different: non-Christian religions, nonwhite races, non-Western cultures, and poor and marginalized social classes everywhere. To (...) these can be added minorities marginalized because of sexual orientation, physical handicaps, and women of all sectors and cultures. Another kind of ethics is urgent. For these reasons, Christians in Latin America and other parts are seeking innovative ways of envisioning ethics from their marginalized and discriminated social locations in order to find another possible ethics, an ethics that is not universal and not based on eternal truths or principles, but rather is contextual and historical and that takes into account real-life realities. Only an ethics that does this will be liberative. Important steps toward this other possible ethics have been taken by the theology of liberation by developing a contextual and intercultural morality. (shrink)

A Cabinet of Philosophical Curiosities is a collection of puzzles, paradoxes, riddles, and miscellaneous logic problems. Depending on taste, one can partake of a puzzle, a poem, a proof, or a pun.

This appendix is intended to assist the reader in becoming comfortable with the notations, rules, and definitions of Frege's Grundgesetze.