Neil Tennant presents an original logical system with unusual philosophical, proof-theoretic, metalogical, computational, and revision-theoretic virtues. Core Logic is the first system that ensures both relevance and adequacy for the formalization of all mathematical and scientific reasoning.

I use the Corcoran–Smiley interpretation of Aristotle's syllogistic as my starting point for an examination of the syllogistic from the vantage point of modern proof theory. I aim to show that fresh logical insights are afforded by a proof-theoretically more systematic account of all four figures. First I regiment the syllogisms in the Gentzen–Prawitz system of natural deduction, using the universal and existential quantifiers of standard first-order logic, and the usual formalizations of Aristotle's sentence-forms. I explain how the syllogistic is (...) a fragment of my system of Core Logic. Then I introduce my main innovation: the use of binary quantifiers, governed by introduction and elimination rules. The syllogisms in all four figures are re-proved in the binary system, and are thereby revealed as all on a par with each other. I conclude with some comments and results about grammatical generativity, ecthesis, perfect validity, skeletal validity and Aristotle's chain principle. (shrink)

Anti-realism is a doctrine about logic, language, and meaning that is based on the work of Wittgenstein and Frege. In this book, Professor Tennant clarifies and develops Dummett's arguments for anti-realism and ultimately advocates a radical reform of our logical practices.

We compare Fregean theorizing about sets with the theorizing of an ontologically non-committal, natural-deduction based, inferentialist. The latter uses free Core logic, and confers meanings on logico-mathematical expressions by means of rules for introducing them in conclusions and eliminating them from major premises. Those expressions (such as the set-abstraction operator) that form singular terms have their rules framed so as to deal with canonical identity statements as their conclusions or major premises. We extend this treatment to pasigraphs as well, in (...) the case of set theory. These are defined expressions (such as ‘subset of’, or ‘power set of’) that are treated as basic in the lingua franca of informal set theory. Employing pasigraphs in accordance with their own natural-deduction rules enables one to ‘atomicize’ rigorous mathematical reasoning. (shrink)

This book develops Tennant's Natural Logicist account of the foundations of the natural, rational, and real numbers. Tennant uses this framework to distinguish the logical from the intuitive aspects of the basic elements of arithmetic.

Part philosophical meditation, part cultural critique, The Body in Pain is a profoundly original study that has already stirred excitement in a wide range of intellectual circles. The book is an analysis of physical suffering and its relation to the numerous vocabularies and cultural forces--literary, political, philosophical, medical, religious--that confront it.Elaine Scarry bases her study on a wide range of sources: literature and art, medical case histories, documents on torture compiled by Amnesty International, legal transcripts of personal injury trials, (...) and military and strategic writings by such figures as Clausewitz, Churchill, Liddell Hart, and Kissinger, She weaves these into her discussion with an eloquence, humanity, and insight that recall the writings of Hannah Arendt and Jean-Paul Sartre.Scarry begins with the fact of pain's inexpressibility. Not only is physical pain enormously difficult to describe in words--confronted with it, Virginia Woolf once noted, "language runs dry"--it also actively destroys language, reducing sufferers in the most extreme instances to an inarticulate state of cries and moans. Scarry analyzes the political ramifications of deliberately inflicted pain, specifically in the cases of torture and warfare, and shows how to be fictive. From these actions of "unmaking" Scarry turns finally to the actions of "making"--the examples of artistic and cultural creation that work against pain and the debased uses that are made of it. Challenging and inventive, The Body in Pain is landmark work that promises to spark widespread debate. (shrink)

The Taming of the True poses a broad challenge to realist views of meaning and truth that have been prominent in recent philosophy. Neil Tennant argues compellingly that every truth is knowable, and that an effective logical system can be based on this principle. He lays the foundations for global semantic anti-realism and extends its consequences from the philosophy of mathematics and logic to the theory of meaning, metaphysics, and epistemology.

An account of how a rational agent should revise beliefs in the light of new evidence.

N. Tennant; XI*—Entailment and Proofs, Proceedings of the Aristotelian Society, Volume 79, Issue 1, 1 June 1979, Pages 167–190, https://doi.org/10.1093/aristote.

Informally rigorous mathematical reasoning is relevant. So too should be the premises to the conclusions of formal proofs that regiment it. The rule Ex Falso Quodlibet induces spectacular irrelevance. We therefore drop it. The resulting systems of Core Logic $ \mathbb{C}$ and Classical Core Logic $ \mathbb{C}^{+}$ can formalize all the informally rigorous reasoning in constructive and classical mathematics respectively. We effect a revised match-up between deducibility in Classical Core Logic and a new notion of relevant logical consequence. It matches (...) better the deducibility relation of Classical Core Logic than does the Tarskian notion of consequence. It is implosive, not explosive. (shrink)

This book is the 1906 second edition of the Hulsean Lectures delivered at the University of Cambridge between 1901 and 1902. In these four lectures, F. R. Tennant challenges conventional teachings on Original Sin and the story of the Fall, arguing that his contemporaries had misinterpreted the biblical presentation of sin and its manifestations. Tennant aims to redefine the sin of both the race and the individual, and in doing so engages with traducianism and the philosophies of Malebranche, (...) Kant and Hegel. He argues that action predates modern conceptions of right and wrong, and that transgression is only sin if the actor is aware of what is morally right. Of course, these theories were met with great opposition, an opposition which Tennant uses the preface of this second edition to confront. These fascinating lectures and their appendages will be of great interest to scholars of Christian theology and the fin de siècle alike. (shrink)

It is shown how Tarski’s 1929 axiomatization of mereology secures the reflexivity of the ‘part of’ relation. This is done with a fusion-abstraction principle that is constructively weaker than that of Tarski; and by means of constructive and relevant reasoning throughout. We place a premium on complete formal rigor of proof. Every step of reasoning is an application of a primitive rule; and the natural deductions themselves can be checked effectively for formal correctness.

In this paper I argue that category theory ought to be seen as providing the language for mathematical discourse. Against foundational approaches, I argue that there is no need to reduce either the content or structure of mathematical concepts and theories to the constituents of either the universe of sets or the category of categories. I assign category theory the role of organizing what we say about the content and structure of both mathematical concepts and theories. Insofar, then, as the (...) structuralist sees mathematics as talking about structures and their morphology, I contend that category theory furnishes a framework for mathematical structuralism. (shrink)

AGM-theory, named after its founders Carlos Alchourrón, Peter Gärdenfors and David Makinson, is the leading contemporary paradigm in the theory of belief-revision. The theory is reformulated here so as to deal with the central relational notions 'J is a contraction of K with respect to A' and 'J is a revision of K with respect to A'. The new theory is based on a principal-case analysis of the domains of definition of the three main kinds of theory-change (expansion, contraction and (...) revision). The new theory is stated by means of introduction and elimination rules for the relational notions. In this new setting one can re-examine the relationship between contraction and revision, using the appropriate versions of the so-called Levi and Harper identities. Among the positive results are the following. One can derive the extensionality of contraction and revision, rather than merely postulating it. Moreover, one can demonstrate the existence of revision-functions satisfying a principle of monotonicity. The full set of AGM-postulates for revision-functions allow for completely bizarre revisions. This motivates a Principle of Minimal Bloating, which needs to be stated as a separate postulate for revision. Moreover, contractions obtained in the usual way from the bizarre revisions, by using the Harper identity, satisfy Recovery. This provides a new reason (in addition to several others already adduced in the literature) for thinking that the contraction postulate of Recovery fails to capture the Principle of Minimal Mutilation. So the search is still on for a proper explication of the notion of minimal mutilation, to do service in both the theory of contraction and the theory of revision. The new relational formulation of AGM-theory, based on principal-case analysis, shares with the original, functional form of AGM-theory the idealizing assumption that the belief-sets of rational agents are to be modelled as consistent, logically closed sets of sentences. The upshot of the results presented here is that the new relational theory does a better job of making important matters clear than does the original functional theory. A new setting has been provided within which one can profitably address two pressing questions for A GM-theory: (1) how is the notion of minimal mutilation (by both contractions and revisions) best analyzed? and (2) how is one to rule out unnecessary bloating by revisions? (shrink)

I propose an anti-realist account of truth and paradox according to which the logico-semantic paradoxes are not genuine inconsistencies. The ‘global’ proofs of absurdity associated with these paradoxes cannot be brought into normal form. The account combines epistemicism about truth with a proof-theoretic diagnosis of paradoxicality. The aim is to combine a substantive philosophical account of truth with a more rigorous and technical diagnosis of the source of paradox for further consideration by logicians. Core Logic plays a central role in (...) the account on offer. It is shown that the account is not prey to the problem of revenge paradox. (shrink)

This is a reply to Timothy Williamson ’s paper ‘Tennant’s Troubles’. It defends against Williamson ’s objections the anti-realist’s knowability principle based on the author’s ‘local’ restriction strategy involving Cartesian propositions, set out in The Taming of the True. Williamson ’s purported Fitchian reductio, involving the unknown number of books on his table, is analyzed in detail and shown to be fallacious. Williamson ’s attempt to cause problems for the anti-realist by means of a supposed rigid designator generates a (...) contradiction with arithmetic right away, upon instantiating the obviously relevant theorem that every natural number is provably odd or provably even. The paper also explains and formulates a globally restricted knowability principle, which likewise blocks the attempted reductio. (shrink)

Written for any readers interested in better harnessing philosophy’s real value, this book covers a broad range of fundamental philosophical problems and certain intellectual techniques for addressing those problems. In Introducing Philosophy: God, Mind, World, and Logic , Neil Tennant helps any student in pursuit of a ‘big picture’ to think independently, question received dogma, and analyse problems incisively. It also connects philosophy to other areas of study at the university, enabling all students to employ the concepts and techniques (...) of this millennia-old discipline throughout their college careers – and beyond. KEY FEATURES AND BENEFITS: -- Investigates the philosophy of various subjects , helping students contextualize philosophy and view it as an interdisciplinary pursuit; also helps students with majors outside of philosophy to see the relationship between philosophy and their own focused academic pursuits -- Author comes from a distinguished background in Logic and Philosophy of Language, which gives the book a level of rigor, balance, and analytic focus sometimes missing from primers to philosophy -- Introduces students to various important philosophical distinctions providing skills that are important for undergraduates to develop in order to inform their study at higher levels. They are essential for further work in philosophy but they are also very beneficial for students pursuing most other disciplines -- Is much more methodologically comprehensive than competing introductions, giving the student the ability to address a wide range of philosophical problems – and not just the ones reviewed in the book -- Offers a companion website with links to apt primary sources, organized chapter-by-chapter, making unnecessary a separate Reader/Anthology of primary sources – thus providing students with all reading material necessary for the course -- Provides five to ten discussion questions for each chapter, helping instructors and students better interact with the ideas and concepts in the text. (shrink)

Este artigo reformula a Apologia de Sócrates de Platão como uma peça de oratória forense. Examinando os topoi retóricos utilizados por Platão, demonstro como Platão impele os limites do gênero forense da oratória em direção à criação de uma nova prática discursiva: a filosofia. Inicialmente, o artigo examina o conceito de “gênero” em conexão com a oratória forense. Esboçado a partir do trabalho de Mikhail Bakhtin, Tzvetan Todorov e Andrea Nightingale, o artigo estabelece uma consonância entre as concepções de gênero (...) destes eruditos e aquilo que outros eruditos definiram como “gênero” oratório forense. Assim, o artigo levanta a questão do porquê a Apologia de Platão tradicionalmente ter sido excluída deste gênero. Argumento que certas visões concernentes à presumida historicidade das falas rotuladas como “oratória forense” precisam ser reexaminadas, já que não há evidência clara de que os atenienses requeressem acurácia histórica de discursos que agora classificamos como oratória forense. Ao remover a exigência de historicidade, obtemos um quadro mais preciso do que constitui a oratória forense e porque a Apologia de Platão merece pertença neste gênero. O artigo, então, examina detalhadamente vários topoi retóricos na Apologia. Argumento que, pela manipulação e remodelação de tais topoi, Platão expande e redefine o gênero da oratória forense para incluir a nova prática discursiva da filosofia. O artigo revela como a redefinição platônica dos limites da oratória forense transformaram uma fala jurídica de defesa em um tribunal na condição sine qua non do filósofo e da vida filosófica. (shrink)

We examine the sense in which logic is a priori, and explain how mathematical theories can be dichotomized non-trivially into analytic and synthetic portions. We argue that Core Logic contains exactly the a-priori-because-analytically-valid deductive principles. We introduce the reader to Core Logic by explaining its relationship to other logical systems, and stating its rules of inference. Important metatheorems about Core Logic are reported, and its important features noted. Core Logic can serve as the basis for a foundational program that could (...) be called Natural Logicism, an exposition of which will build on the (meta)logical ideas explained here. (shrink)

Shows how to program on a computer (in Prolog) the effective skills taught in introductory and intermediate logic courses. The topics include the relevance of relevance, representing formulae and proofs, avoiding loops and blind alleys, and other aspects. Of interest to computational logicians, proof-theorists, cognitive scientists, and workers in artificial intelligence. Distributed by Columbia U. Press. Annotation copyright by Book News, Inc., Portland, OR.

Just Business provides the first comprehensive, reasoned framework for resolving questions of business ethics and corporate governance. Innovative, accessible, and global in scope, its powerful Ethical Decision Model can be used to manage the ethical problems of business as they arise in all their complexity and variety. Just Business combines business realism with philosophical rigor, and demonstrates that it is not necessary to emasculate or to adulterate business for business to be ethical. The book benefits from Elaine Sternberg's extensive (...) experience as an academic philosopher, an international investment banker, and head of successful businesses. She is now Principal of a London-headquartered consultancy firm, and Research Fellow in Philosophy at the University of Leeds. (shrink)

The aim of this paper is to put into context the historical, foundational and philosophical significance of category theory. We use our historical investigation to inform the various category-theoretic foundational debates and to point to some common elements found among those who advocate adopting a foundational stance. We then use these elements to argue for the philosophical position that category theory provides a framework for an algebraic in re interpretation of mathematical structuralism. In each context, what we aim to show (...) is that, whatever the significance of category theory, it need not rely upon any set-theoretic underpinning. (shrink)

This chapter explains an approach to relevantization of logical reasoning that seeks to maximize epistemic gain. It does so by retaining Disjunctive Syllogism and making admissible only a restricted rule of Cut. The virtue of this approach is that one can show that the resulting relevant logic is adequate for mathematics and science. In the course of explaining this kind of relevant logic, we compare and contrast our approach with the Anderson-Belnap tradition.

The motivation for Core Logic is explained. Its system of proof is set out. It is then shown that, although the system has no Cut rule, its relation of deducibility obeys Cut with epistemic gain.

Kant writes: If … the only aim of Nature regarding some creature possessed of reason and a will were its preservation, its well-being, in a word its happiness, then she would have come to a very bad arrangement in choosing its reason as executor of that aim. For all actions that it had to execute in this her intention, and the whole regulation of its behaviour would have been able to be prescribed to it much more precisely by instinct, and (...) that aim thereby much more certainly maintained, than ever could happen through reason …. (shrink)

I reformulate the AGM-account of contraction (which would yield an account also of revision). The reformulation involves using introduction and elimination rules for relational notions. Then I investigate the extent to which the two main methods of partial meet contraction and safe contraction can be employed for theories closed under intuitionistic consequence.

While philosophy and psychoanalysis privilege language and conceptual distinctions and mistrust the image, the philosopher and psychoanalyst Julia Kristeva recognizes the power of art and the imagination to unblock important sources of meaning. She also appreciates the process through which creative acts counteract and transform feelings of violence and depression. Reviewing Kristeva's corpus, Elaine P. Miller considers the intellectual's "aesthetic idea" and "thought specular" in their capacity to reshape depressive thought on both the individual and cultural level. She revisits (...) Kristeva's reading of Walter Benjamin with reference to melancholic art and the imagination's allegorical structure; her analysis of Byzantine iconoclasm in relation to Freud's psychoanalytic theory of negation and Hegel's dialectical negativity; her understanding of Proust as an exemplary practitioner of sublimation; her rereading of Kant and Arendt in terms of art as an intentional lingering with foreignness; and her argument that forgiveness is both a philosophical and psychoanalytic method of transcending a "stuck" existence. Focusing on specific artworks that illustrate Kristeva's ideas, from ancient Greek tragedy to early photography, contemporary installation art, and film, Miller positions creative acts as a form of "spiritual inoculation" against the violence of our society and its discouragement of thought and reflection. (shrink)

We consider how a rational decision theorist would justify committing resources to an investigation designed to satisfy pure curiosity. We derive a strange result about the need to be completely open-minded about the outcome.