Computability and Logic has become a classic because of its accessibility to students without a mathematical background and because it covers not simply the staple topics of an intermediate logic course, such as Godel's incompleteness theorems, but also a large number of optional topics, from Turing's theory of computability to Ramsey's theorem. This 2007 fifth edition has been thoroughly revised by John Burgess. Including a selection of exercises, adjusted for this edition, at the end of each chapter, it offers a simpler treatment of the representability of recursive functions, a traditional stumbling block for students on the way to the Godel incompleteness theorems. This updated edition is also accompanied by a website as well as an instructor's manual.

Propositions are routinely invoked by philosophers, linguists, logicians, and other theorists engaged in the study of meaning, communication, and the mind. To investigate the nature of propositions is to investigate the very nature of our connection to each other, and to the world around us. As one of the only volumes of its kind, The Routledge Handbook of Propositions provides a comprehensive overview of the philosophy of propositions, from both historical and contemporary perspectives. Comprising 33 original chapters by an international team of scholars, the volume addresses both traditional and emerging questions concerning the nature of propositions, and our capacity to engage with them in thought and in communication. The chapters are clearly organized into the following three sections: I. Foundational Issues in the Theory of Propositions II. Historical Theories of Propositions III. Contemporary Theories of Propositions Essential reading for philosophers of language and mind, and for those working in neighboring areas, The Routledge Handbook of Propositions is suitable for upper-level undergraduate study, as well as graduate and professional research.

Godel's modal ontological argument is the centerpiece of an extensive examination of intensional logic. First, classical type theory is presented semantically, tableau rules for it are introduced, and the Prawitz/Takahashi completeness proof is given. Then modal machinery is added to produce a modified version of Montague/Gallin intensional logic. Finally, various ontological proofs for the existence of God are discussed informally, and the Godel argument is fully formalized. Parts of the book are mathematical, parts philosophical. "

Part I of this book presents a theory of modal metaphysics in the possible-worlds tradition. `Worlds' themselves are understood as structured sets of properties; this `Ersatzist' view is defended against its most vigorous competitors, Meinongianism and David Lewis' theory of existent concrete worlds. Related issues of essentialism and linguistic reference are explored. Part II takes up the question of lexical meaning in the context of possible-world semantics. There are skeptical analyses of analyticity and the notion of a logical constant; and an `infinite polysemy' thesis is defended. The book will be of particular interest to metaphysicians, possible-world semanticists, philosophers of language, and linguists concerned with lexical semantics.

Russell's first book on philosophy and a fascinating insight into his early thinking A classic in the history and philosophy of mathematics and logic by one of the greatest philosophers of the 20th century This Routledge Classics edition includes a new foreword by Michael Potter, a renowned expert on analytic philosophy

Brilliant introduction to the philosophy of mathematics, from the question 'what is a number?' up to the concept of infinity, descriptions, classes and axioms Russell deploys all his skills and brilliant prose to write an introductory book - a real gem by one of the 20th century's most celebrated philosophers New foreword by Michael Potter to the Routledge Classics edition places the book in helpful context and explains why it's a classic

Superb insight into the development of Russell's thinking by the master himself Clearly and engaging written, charting his intellectual development from young idealist to celebrated sceptic This Routledge Classics edition includes a new foreword by Nicholas Griffin Ideal companion to Russell's own Autobiography, which is concerned with his incredibly colourful life rather than philosophy

"The old logic put thought in fetters, while the new logic gives it wings." For the past century, philosophers working in the tradition of Bertrand Russell - who promised to revolutionise philosophy by introducing the 'new logic' of Frege and Peano - have employed predicate logic as their formal language of choice. In this book, Dr David Corfield presents a comparable revolution with a newly emerging logic - modal homotopy type theory. Homotopy type theory has recently been developed as a new foundational language for mathematics, with a strong philosophical pedigree. Modal Homotopy Type Theory: The Prospect of a New Logic for Philosophy offers an introduction to this new language and its modal extension, illustrated through innovative applications of the calculus to language, metaphysics, and mathematics. The chapters build up to the full language in stages, right up to the application of modal homotopy type theory to current geometry. From a discussion of the distinction between objects and events, the intrinsic treatment of structure, the conception of modality as a form of general variation to the representation of constructions in modern geometry, we see how varied the applications of this powerful new language can be.

This is a collection of Isaac Levi's philosophical papers. Over the period represented by the work here, Professor Levi has developed an interrelated set of views, in the tradition of Peirce and Dewey, on epistemology and the philosophy of science and social science. This focus has been on the problem of induction and the growth of knowledge, the foundations of probability and the theory of rational decision-making. His most important essays in these areas are assembled here, with an introduction setting out their main themes and connections. As a whole the volume presents a coherent, elaborated position which will be of great interest to a range of philosophers, decision theorists, welfare and social choice theorists and cognitive scientists.

This volume consists of papers delivered at the conference 'The Lvov-Warsaw School and Contemporary Philosophy', organised in celebration of the hun- dredth anniversary ofKazimierz Twardowski's first lecture as Professor of Phi- losophy at Lvov University. This lecture can be regarded as the starting point of the development of analytic philosophy in Poland, which culminated in the Warsaw School of Logic. The conference was held in Lvov (15-17 November) and Warsaw (19-21 November 1995). It was organised jointly by the Ukrainian Academy of Sci- ences and the Polish Academy of Sciences. The general organisation was un- dertaken by Professor Andrzej Grzegorczyk (polish Academy of Sciences) and Professor Marat Vernikov (Ukrainian Academy of Sciences). Professors Jaroslaw Isaievich (Ukrainian Academy of Sciences) and Jan Wolenski (Jagiel- Ionian University) were responsible for the scientific programme. Over 100 philosophers participated in the conference. Papers published in this volume are organised according to the sections of the conference and rep- of the papers delivered. resent a selection The editors would like to express their gratitude to Professor Andrzej Grze- gorczyk, spiritus movens of the conference, who, by including the present vol- ume in a programme of publications connected with the hundredth anniversary of the Lvov-Warsaw School, provided financial support for its preparation. Fi- nally, we express our gratitude to Dr Timothy Childers of the Academy of Sciences of the Czech Republic for correcting the English of the papers.

This book puts forward an interpretation of rationality which is much broader than the one underlying the current polarity between analytic and continental philosophy. It will help to reaffirm a range of ideas which have long been pushed to the sidelines by the dominance of the geometric model of philosophical argument. Descartes's dream of attaining a `certitude equal to the demonstrations of Arithmetic and Geometry' reinforced the assumption that rationality must be assessed in terms of logical structure. Against this, Pascal invoked the notion of `finesse', and Warner extends Pascal's usage in this book to specify a related set of informal but legitimate styles of argument.

This book argues that there is a common cognitive mechanism underlying all indexical thoughts, in spite of their seeming diversity. Indexical thoughts are mental representations, such as beliefs and desires. They represent items from a thinker's point of view or her cognitive perspective. We typically express them by means of sentences containing linguistic expressions such as 'this (F)' or 'that (F)', adverbs like 'here', 'now', and 'today', and the personal pronoun 'I'. While generally agreeing that representing the world from a thinker's cognitive perspective is a key feature of indexical thoughts, philosophers disagree as to whether a thinker's cognitive perspective can be captured and rationalized by semantic content and, if so, what kind of content this is. This book surveys competing views and then advances its own positive account. Ultimately, it argues that a thinker's cognitive perspective - or her indexical point of view - is to be explained in terms of the content that is believed and asserted as the only kind of content that there is which thereby serves as the bearer of cognitive significance. The Indexical Point of View will be of interest to philosophers of mind and language, linguists, and cognitive scientists.

This Handbook offers students and more advanced readers a valuable resource for understanding linguistic reference; the relation between an expression (word, phrase, sentence) and what that expression is about. The volume's forty-one original chapters, written by many of today's leading philosophers of language, are organized into ten parts: I Early Descriptive Theories II Causal Theories of Reference III Causal Theories and Cognitive Significance IV Alternate Theories V Two-Dimensional Semantics VI Natural Kind Terms and Rigidity VII The Empty Case VIII Singular (De Re) Thoughts IX Indexicals X Epistemology of Reference Contributions consider what kinds of expressions actually refer (names, general terms, indexicals, empty terms, sentences), what referring expressions refer to, what makes an expression refer to whatever it does, connections between meaning and reference, and how we know facts about reference. Many contributions also develop connections between linguistic reference and issues in metaphysics, epistemology, philosophy of mind, and philosophy of science.

The present monograph is a slightly revised version of my Habilitations schrift Proof-theoretic Aspects of Intensional and Non-Classical Logics, successfully defended at Leipzig University, November 1997. It collects work on proof systems for modal and constructive logics I have done over the last few years. The main concern is display logic, a certain refinement of Gentzen's sequent calculus developed by Nuel D. Belnap. This book is far from offering a comprehensive presentation of generalized sequent systems for modal logics broadly conceived. The proof-theory of non-classical logics is a rapidly developing field, and even the generalizations of the ordinary notion of sequent listed in Chapter 1 can hardly be presented in great detail within a single volume. In addition to further investigating the various approaches toward generalized Gentzen systems, it is important to compare them and to discuss their relative advantages and disadvantages. An initial attempt at bringing together work on different kinds of proof systems for modal logics has been made in [188]. Another step in the same direction is [196]. Since Chapter 1 contains introductory considerations and, moreover, every remaining chapter begins with some surveying or summarizing remarks, in this preface I shall only emphasize a relation to philosophy that is important to me, register the sources of papers that have entered this book in some form or another, and acknowledge advice and support.

A Theory of Argument is an advanced textbook intended for students in philosophy, communications studies and linguistics who have completed at least one course in argumentation theory, information logic, critical thinking or formal logic. Containing nearly 400 exercises, Mark Vorobej develops a novel approach to argument interpretation and evaluation. One of the key themes of the book is that we cannot succeed in distinguishing good argument from bad arguments until we learn to listen carefully to others. Part I develops a relativistic account of argument cogency that allows for rational disagreement. Part II offers a comprehensive and rigorous account of argument diagramming. Hybrid arguments are contrasted with linked and convergent arguments, and a novel technique is introduced for graphically recording disagreements with authorial claims.

This second and extended edition of Priest's classic includes new chapters on Heidegger and Nagarjuna, as well as reflections on reactions to the first edition.
Praise for previous edition: "a splendid tour de force, one which should be read by every philosopher..."--Philosophical Quarterly
" H]ighly entertaining and provocative...an engaging and instructive tour through some of the most perplexing features of our own conceptual finitude..."--TLS

Berkeley: Ideas, Immaterialism, and Objective Presence offers a novel interpretation of the arc of George Berkeley's philosophical thought, from his theory of vision through his immaterialism and finally to his proof of God's existence. Keota Fields unifies these themes to focus on Berkeley's use of the Cartesian doctrine of objective presence, which demands causal explanations of the content of ideas. This is particularly so with respect to Berkeley's arguments for immaterialism. One of those arguments is typically read as a straightforward transitivity argument. After identifying material bodies with sensible objects, and the latter with ideas of sense, Berkeley concludes that putative material bodies are actually identical to collections of ideas of sense. George Pappas has recently defended an alternative reading that grounds Berkeley's immaterialism in his rejection of what Pappas calls category-transcendent abstract ideas: abstract ideas of beings, entia, or existence. Fields uses Pappas's interpretation as a framework for understanding Berkeley's immaterialism in terms of transcendental arguments. Early moderns routinely used the doctrine of objective presence to justify transcendental arguments for the existence of material substance. The claim was that physical qualities are necessary for any causal explanation of the content of sensory ideas; since those qualities are represented to perceivers as ontologically dependent, material substance is the necessary condition for the existence of physical qualities and a fortiori any causal explanation of the content of sensory ideas. On the reading defended here, Berkeley rejects Locke's transcendental argument for the existence of material substratum on the grounds that it turns decisively on the aforementioned category-transcendent abstract ideas, which Berkeley rejects as logically inconsistent. In its place, Berkeley offers his own transcendental argument designed to show that only minds and ideas exist. He uses that argument as a

This book brings together a selection of essays by one of the pre-eminent scholars of informal logic. Following an approach that is empirical but not psychological; dialectical but not dialogical, and focused on interpretation without neglecting evaluation, Maurice Finocchiaro defines concepts such as reasoning, argument, argument analysis, critical reasoning, methodological reflection, judgment, critical thinking, and informal logic. He defends ideas about the rarity of fallacies but frequently of fallacious reasoning; the asymmetry of positive and negative in argumentation, interpretation and evaluation and the role of critical thinking in science, among other topics. Containing extended critiques of the views of many contemporary scholars, he also integrates into the discussion Arnauld's Post-Royal Logic, Gramsci's theory of intellectuals, and case studies from the history of science, particularly the work of Galileo, Newton, Huygens, and Lavoisier.

This is a title on the foundations of defeasible logic, which explores the formal properties of everyday reasoning patterns whereby people jump to conclusions, reserving the right to retract them in the light of further information. Although technical in nature the book contains sections that outline basic issues by means of intuitive and simple examples. This book is primarily targeted at philosophers interested in the foundations of defeasible logic, logicians, and specialists in artificial intelligence and theoretical computer science.

This book defends the Direct Reference (DR) thesis in philosophy of language regarding proper names and indexical pronouns. It uniquely draws out the significant consequences of DR when it is conjoined with the fact that these singular terms sometimes fail to refer. Even though DR is widely endorsed by philosophers of language, many philosophically important and radically controversial consequences of the thesis have gone largely unexplored. This book makes an important contribution to the DR literature by explicitly addressing the consequences that follow from DR regarding failure of reference. Michael McKinsey argues that only a form of neutral free logic can capture a revised concept of logical truth that is consistent with the fact that any sentence of any form that contains a directly referring genuine term can fail to be either true or false on interpretations where that term fails to refer. He also explains how it is possible for there to be true (or false) sentences that contain non-referring names, even though this possibility seems inconsistent with DR. Consequences of Reference Failure will be of interest to philosophers of language and logic and linguists working on Direct Reference.

This book is about the idea that some true statements would have been true no matter how the world had turned out, while others could have been false. It develops and defends a version of the idea that we tell the difference between these two types of truths in part by reflecting on the meanings of words. It has often been thought that modal issues-issues about possibility and necessity-are related to issues about meaning. In this book, the author defends the view that the analysis of meaning is not just a preliminary to answering modal questions in philosophy; it is not merely that before we can find out whether something is possible, we need to get clear on what we are talking about. Rather, clarity about meaning often brings with it answers to modal questions. In service of this view, the author analyzes the notion of necessity and develops ideas about linguistic meaning, applying them to several puzzles and problems in philosophy of language. Meaning and Metaphysical Necessity will be of interest to scholars and advanced students working in metaphysics, philosophy of language, and philosophical logic.

This book presents a systematic unifying-pluralist account-a "constructive-engagement" account-of how cross-tradition engagement in philosophy is possible. The goal of this "constructive-engagement" account is, by way of reflective criticism, argumentation, and methodological guiding principles, to inquire into how distinct approaches from different philosophical traditions can talk to and learn from each other for the sake of making joint contributions to the contemporary development of philosophy. In Part I of the book, Bo Mou explores a range of fundamental theoretic and methodological issues in cross-tradition philosophical engagement and philosophical interpretation. In Part II, he analyzes several representative case studies that demonstrate how relevant resources in the Western and Chinese philosophical traditions can constructively engage with each other. These studies cover issues in philosophical methodology, metaphysics, epistemology, philosophy of language and logic, and ethics. The book's theoretical and practical approaches expand the vision, coverage, and agenda of doing philosophy comparatively, and promote worldwide joint efforts of cross-tradition philosophical inquiries. Cross-Tradition Engagement in Philosophy will be of interest to graduate students and scholars interested in comparative philosophy and the intersection of Chinese and Western philosophy. It will also appeal to those who are interested in the ways in which cross-tradition philosophical engagement can enhance contemporary philosophical debates in metaphysics, epistemology, philosophy of language and logic, and ethics.

This book sets out for the first time in English and in the terms of modern logic the semantics of the Port Royal Logic (La Logique ou l'Art de penser, 1662-1685) of Antoine Arnauld and Pierre Nicole, perhaps the most influential logic book in the 17th and 18th centuries. Its goal is to explain how the Logic reworks the foundation of pre-Cartesian logic so as to make it compatible with Descartes' metaphysics. The Logic's authors forged a new theory of reference based on the medieval notion of objective being, which is essentially the modern notion of intentional content. Indeed, the book's central aim is to detail how the Logic reoriented semantics so that it centered on the notion of intentional content. This content, which the Logic calls comprehension, consists of an idea's defining modes. Mechanisms are defined in terms of comprehension that rework earlier explanations of central notions like conceptual inclusion, signification, abstraction, idea restriction, sensation, and most importantly within the Logic's metatheory, the concept of idea-extension, which is a new technical concept coined by the Logic. Although Descartes is famous for rejecting "Aristotelianism," he says virtually nothing about technical concepts in logic. His followers fill the gap. By putting to use the doctrine of objective being, which had been a relatively minor part of medieval logic, they preserve more central semantic doctrines, especially a correspondence theory of truth. A recurring theme of the book is the degree to which the Logic hews to medieval theory. This interpretation is at odds with what has become a standard reading among French scholars according to which this 16th-century work should be understood as rejecting earlier logic along with Aristotelian metaphysics, and as putting in its place structures more like those of 19th-century class theory.

1. Metaphors and Logic Metaphors are among the most vigorous offspring of the creative mind; but their vitality springs from the fact that they are logical organisms in the ecology of l- guage. I aim to use logical techniques to analyze the meanings of metaphors. My goal here is to show how contemporary formal semantics can be extended to handle metaphorical utterances. What distinguishes this work is that it focuses intensely on the logical aspects of metaphors. I stress the role of logic in the generation and int- pretation of metaphors. While I don't presuppose any formal training in logic, some familiarity with philosophical logic (the propositional calculus and the predicate c- culus) is helpful. Since my theory makes great use of the notion of structure, I refer to it as the structural theory of m etaphor (STM). STM is a semant ic theory of m etaphor : if STM is correct, then metaphors are cognitively meaningful and are n- trivially logically linked with truth. I aim to extend possible worlds semantics to handle metaphors. I'll argue that some sentences in natural languages like English have multiple meanings: "Juliet is the sun" has (at least) two meanings: the literal meaning "(Juliet is the sunkIT" and the metaphorical meaning "(Juliet is the sun)MET". Each meaning is a function from (possible) worlds to truth-values. I deny that these functions are identical; I deny that the metaphorical function is necessarily false or necessarily true.