Frege's Theorem collects eleven essays by Richard G Heck, Jr, one of the world's leading authorities on Frege's philosophy. The Theorem is the central contribution of Gottlob Frege's formal work on arithmetic. It tells us that the axioms of arithmetic can be derived, purely logically, from a single principle: the number of these things is the same as the number of those things just in case these can be matched up one-to-one with those. But that principle seems so utterly fundamental to thought about number that it might almost count as a definition of number. If so, Frege's Theorem shows that arithmetic follows, purely logically, from a near definition. As Crispin Wright was the first to make clear, that means that Frege's logicism, long thought dead, might yet be viable.
Heck probes the philosophical significance of the Theorem, using it to launch and then guide a wide-ranging exploration of historical, philosophical, and technical issues in the philosophy of mathematics and logic, and of their connections with metaphysics, epistemology, the philosophy of language and mind, and even developmental psychology. The book begins with an overview that introduces the Theorem and the issues surrounding it, and explores how the essays that follow contribute to our understanding of those issues. There are also new postscripts to five of the essays, which discuss changes of mind, respond to published criticisms, and advance the discussion yet further.

This book is a tribute to Professor Ewa Orlowska, a Polish logician who was celebrating the 60th year of her scientific career in 2017. It offers a collection of contributed papers by different authors and covers the most important areas of her research. Prof. Orlowska made significant contributions to many fields of logic, such as proof theory, algebraic methods in logic and knowledge representation, and her work has been published in 3 monographs and over 100 articles in internationally acclaimed journals and conference proceedings. The book also includes Prof. Orlowska's autobiography, bibliography and a trialogue between her and the editors of the volume, as well as contributors' biographical notes, and is suitable for scholars and students of logic who are interested in understanding more about Prof. Orlowska's work.

Gary Kemp presents a penetrating investigation of key issues in the philosophy of language, by means of a comparative study of two great figures of late twentieth-century philosophy. So far as language and meaning are concerned, Willard Van Orman Quine and Donald Davidson are usually regarded as birds of a feather. The two disagreed in print on various matters over the years, but fundamentally they seem to be in agreement; most strikingly, Davidson's thought experiment of Radical Interpretation looks to be a more sophisticated, technically polished version of Quinean Radical Translation. Yet Quine's most basic and general philosophical commitment is to his methodological naturalism, which is ultimately incompatible with Davidson's main commitments. In particular, it is impossible to endorse, from Quine's perspective, the roles played by the concepts of truth and reference in Davidson's philosophy of language: Davidson's employment of the concept of truth is from Quine's point of view needlessly adventurous, and his use of the concept of reference cannot be divorced from unscientific 'intuition'. From Davidson's point of view, Quine's position looks needlessly scientistic, and seems blind to the genuine problems of language and meaning. Gary Kemp offers a powerful argument for Quine's position, and in favour of methodological naturalism and its corollary, naturalized epistemology. It is possible to give a consistent and explanatory account of language and meaning without problematic uses of the concepts truth and reference, which in turn makes a strident naturalism much more plausible.

Now in a new edition --the classic presentation of the theory of computable functions in the context of the foundations of mathematics. Part I motivates the study of computability with discussions and readings about the crisis in the foundations of mathematics in the early 20th century, while presenting the basic ideas of whole number, function, proof, and real number. Part II starts with readings from Turing and Post leading to the formal theory of recursive functions. Part III presents sufficient formal logic to give a full development of G del's incompleteness theorems. Part IV considers the significance of the technical work with a discussion of Church's Thesis and readings on the foundations of mathematics. This new edition contains the timeline "Computability and Undecidability" as well as the essay "On mathematics."

Contents: Introduction; I. ONTOLOGY; 1. Existence (1987); 2. Nonexistence (1998); 3. Mythical Objects (2002); II. NECESSITY; 4. Modal Logic Kalish-and-Montague Style (1994); 5. Impossible Worlds (1984); 6. An Empire of Thin Air (1988); 7. The Logic of What Might Have Been (1989); III. IDENTITY; 8. The fact that x=y (1987); 9. This Side of Paradox (1993); 10. Identity Facts (2003); 11. Personal Identity: What's the Problem? (1995); IV. PHILOSOPHY OF MATHEMATICS; 12. Wholes, Parts, and Numbers (1997); 13. The Limits of Human Mathematics (2001); V. THEORY OF MEANING AND REFERENCE; 14. On Content (1992); 15. On Designating (1997); 16. A Problem in the Frege-Church Theory of Sense and Denotation (1993); 17. The Very Possibility of Language (2001); 18. Tense and Intension (2003); 19. Pronouns as Variables (2005)

Strong reasoning skills are an important aspect to cultivate in life, as they directly impact decision making on a daily basis. By examining the different ways the world views logic and order, new methods and techniques can be employed to help expand on this skill further in the future. Philosophical Perceptions on Logic and Order is a pivotal scholarly resource that discusses the evolution of logical reasoning and future applications for these types of processes. Highlighting relevant topics including logic patterns, deductive logic, and inductive logic, this publication is an ideal reference source for academicians, students, and researchers that would like to expand their understanding of how society currently employs the use of logical reasoning techniques.

This book offers insight into the nature of meaningful discourse. It presents an argument of great intellectual scope written by an author with more than four decades of experience. Readers will gain a deeper understanding into three theories of the logos: analytic, dialectical, and oceanic. The author first introduces and contrasts these three theories. He then assesses them with respect to their basic parameters: necessity, truth, negation, infinity, as well as their use in mathematics. Analytic Aristotelian logic has traditionally claimed uniqueness, most recently in its Fregean and post-Fregean variants. Dialectical logic was first proposed by Hegel. The account presented here cuts through the dense, often incomprehensible Hegelian text. Oceanic logic was never identified as such, but the author gives numerous examples of its use from the history of philosophy. The final chapter addresses the plurality of the three theories and of how we should deal with it. The author first worked in analytic logic in the 1970s and 1980s, first researched dialectical logic in the 1990s, and discovered oceanic logic in the 2000s. This book represents the culmination of reflections that have lasted an entire scholarly career.

Necessary Beings is concerned with two central areas of metaphysics: modality-the theory of necessity, possibility, and other related notions; and ontology-the general study of what kinds of entities there are. Bob Hale's overarching purpose is to develop and defend two quite general theses about what is required for the existence of entities of various kinds: that questions about what kinds of things there are cannot be properly understood or adequately answered without recourse to considerations about possibility and necessity, and that, conversely, questions about the nature and basis of necessity and possibility cannot be satisfactorily tackled without drawing on what might be called the methodology of ontology. Taken together, these two theses claim that ontology and modality are mutually dependent upon one another, neither more fundamental than the other. Hale defends a broadly Fregean approach to metaphysics, according to which ontological distinctions among different kinds of things (objects, properties, and relations) are to be drawn on the basis of prior distinctions between different logical types of expression. The claim that facts about what kinds of things exist depend upon facts about what is possible makes little sense unless one accepts that at least some modal facts are fundamental, and not reducible to facts of some other, non-modal, sort. He argues that facts about what is absolutely necessary or possible have this character, and that they have their source or basis, not in meanings or concepts nor in facts about alternative 'worlds', but in the natures or essences of things.

Many systems of logic diagrams have been offered both historically and more recently. Each of them has clear limitations. An original alternative system is offered here. It is simpler, more natural, and more expressively and inferentially powerful. It can be used to analyze not only syllogisms but arguments involving relational terms and unanalyzed statement terms.

This is an open access title available under the terms of a CC BY-NC-ND 4.0 International licence. It is free to read at Oxford Scholarship Online and offered as a free PDF download from OUP and selected open access locations. We need to understand the impossible. Francesco Berto and Mark Jago start by considering what the concepts of meaning, information, knowledge, belief, fiction, conditionality, and counterfactual supposition have in common. They are all concepts which divide the world up more finely than logic does. Logically equivalent sentences may carry different meanings and information and may differ in how they're believed. Fictions can be inconsistent yet meaningful. We can suppose impossible things without collapsing into total incoherence. Yet for the leading philosophical theories of meaning, these phenomena are an unfathomable mystery. To understand these concepts, we need a metaphysical, logical, and conceptual grasp of situations that could not possibly exist: Impossible Worlds. This book discusses the metaphysics of impossible worlds and applies the concept to a range of central topics and open issues in logic, semantics, and philosophy. It considers problems in the logic of knowledge, the meaning of alternative logics, models of imagination and mental simulation, the theory of information, truth in fiction, the meaning of conditional statements, and reasoning about the impossible. In all these cases, impossible worlds have an essential role to play.

Friedrich Ueberweg (1826-71) is best remembered for both his compendious "History of Philosophy" and his "System of Logic", both of which went through several editions in the original German. It was the latter's remarkable popularity as a textbook in Germany that led Lindsay to translate it to fill a gap in the English market. As well as incorporating the most up-to-date revisions and additons to the German edition he inserted the opinions of the more important English logicians. As such this is a valuable textbook for the understanding of logic systems as taught in England and Germany before symbolic logic was a formal and distinct discipline.

This volume examines the entire logical and philosophical production of Nicolai A. Vasil'ev, studying his life and activities as a historian and man of letters. Readers will gain a comprehensive understanding of this influential Russian logician, philosopher, psychologist, and poet. The author frames Vasil'ev's work within its historical and cultural context. He takes into consideration both the situation of logic in Russia and the state of logic in Western Europe, from the end of the 19th century to the beginning of the 20th. Following this, the book considers the attempts to develop non-Aristotelian logics or ideas that present affinities with imaginary logic. It then looks at the contribution of traditional logic in elaborating non-classical ideas. This logic allows the author to deal with incomplete objects just as imaginary logic does with contradictory ones. Both logics are objects of interesting analysis by modern researchers. This volume will appeal to graduate students and scholars interested not only in Vasil'ev's work, but also in the history of non-classical logics.

The aim of this volume is to collect original contributions by the best specialists from the area of proof theory, constructivity, and computation and discuss recent trends and results in these areas. Some emphasis will be put on ordinal analysis, reductive proof theory, explicit mathematics and type-theoretic formalisms, and abstract computations. The volume is dedicated to the 60th birthday of Professor Gerhard Jager, who has been instrumental in shaping and promoting logic in Switzerland for the last 25 years. It comprises contributions from the symposium "Advances in Proof Theory", which was held in Bern in December 2013. Proof theory came into being in the twenties of the last century, when it was inaugurated by David Hilbert in order to secure the foundations of mathematics. It was substantially influenced by Goedel's famous incompleteness theorems of 1930 and Gentzen's new consistency proof for the axiom system of first order number theory in 1936. Today, proof theory is a well-established branch of mathematical and philosophical logic and one of the pillars of the foundations of mathematics. Proof theory explores constructive and computational aspects of mathematical reasoning; it is particularly suitable for dealing with various questions in computer science.

"You've Got to Be Kidding : How Jokes Can Help You Think" is a thoughtful and accessible analysis of the ways in which jokes illustrate how we think critically, and how the thinking process goes awry in everyday human situations Uses jokes to illustrate the various mistakes or fallacies that are typically identified and discussed in courses on critical reasoningProvides an effective way to learn critical thinking skills since jokes often describe real-life situations where it really matters whether a person thinks well or notDemonstrates how philosophy is actually very practical and clearly related to real- life human experiencesExplains how developing good reasoning habits can make a real difference in all aspects of one's life

This is a concise and readable study of five intertwined themes at the heart of Wittgenstein's thought, written by one of his most eminent interpreters. David Pears offers penetrating investigations and lucid explications of some of the most influential and yet puzzling writings of twentieth-century philosophy. He focuses on the idea of language as a picture of the world; the phenomenon of linguistic regularity; the famous "private language argument"; logical necessity; and ego and the self.

This book presents the state of the art in the fields of formal logic pioneered by Graham Priest. It includes advanced technical work on the model and proof theories of paraconsistent logic, in contributions from top scholars in the field. Graham Priest's research has had a considerable influence on the field of philosophical logic, especially with respect to the themes of dialetheism-the thesis that there exist true but inconsistent sentences-and paraconsistency-an account of deduction in which contradictory premises do not entail the truth of arbitrary sentences. Priest's work has regularly challenged researchers to reappraise many assumptions about rationality, ontology, and truth. This book collects original research by some of the most esteemed scholars working in philosophical logic, whose contributions explore and appraise Priest's work on logical approaches to problems in philosophy, linguistics, computation, and mathematics. They provide fresh analyses, critiques, and applications of Priest's work and attest to its continued relevance and topicality. The book also includes Priest's responses to the contributors, providing a further layer to the development of these themes .

This volume collects the most important articles on the metaphysics of modality by noted philosopher Alvin Plantinga. The book chronicles Plantinga's thought from the late 1960's to the present. Plantinga is here concerned with fundamental issues in metaphysics: what is the nature of abstract objects like possible worlds,properties, propositions, and such phenomena? Are there possible but non-actual objects? Can objects that do not exist exemplify properties? In this thorough and searching book, Plantinga addresses these and many other questions that continue to preoccupy philosophers in the field. This volume contains some of the best work in metaphysics from the past 30 years, and will remain a source of critical contention and keen interest among philosophers of metaphysics and philosophical logic for years to come.

Barry Taylor's book mounts an argument against one of the fundamental tenets of much contemporary philosophy, the idea that we can make sense of reality as existing objectively, independently of our capacities to come to know it. Part One sets the scene by arguings that traditional realism can be explicated as a doctrine about truth - that truth is objective, that is, public, bivalent, and epistemically independent. Part Two, the centrepiece of the book, shows how a form of Hilary Putnam's model-theoretic argument demonstrates that no such notion of truth can be founded on the idea of correspondence, as explained in model-theoretic terms (more traditional accounts of correspondence having been already disposed of in Part One). Part Three argues that non-correspondence accounts of truth - truth as superassertibility or idealized rational acceptability, formal conceptions of truth, Tarskian truth - also fail to meet the criteria for objectivity; along the way, it also dismisses the claims of the latterday views of Putnam, and of similar views articulated by John McDowell, to constitute a new, less traditional form of realism. In the Coda, Taylor bolsters some of the considerations advanced in Part Three in evaluating formal conceptions of truth, by assessing and rejecting the claims of Robert Brandom to have combined such an account of truth with a satisfactory account of semantic structure. He concludes that there is no defensible notion of truth which preserves the theses of traditional realism, nor any extant position sufficiently true to the ideals of that doctrine to inherit its title. So the only question remaining is which form of antirealism to adopt.

Kit Fine has since the 1970s been one of the leading contributors to work at the intersection of logic and metaphysics. This is his eagerly-awaited first book in the area. It draws together a series of essays, three of them previously unpublished, on possibility, necessity, and tense. These puzzling aspects of the way the world is have been the focus of considerable philosophical attention in recent decades. Fine gives here the definitive exposition and defence of certain positions for which he is well known: the intelligibility of modality de re; the primitiveness of the modal; and the primacy of the actual over the possible. But the book also argues for several positions that are not so familiar: the existence of distinctive forms of natural and normative necessity, not reducible to any form of metaphysical necessity; the need to make a distinction between the worldly and the unworldly, analogous to the distinction between the tensed and the tenseless; and the viability of a non-standard form of realism about tense, which recognizes the tensed character of reality without conceding that there is any privileged standpoint from which it is to be viewed. Modality and Tense covers a wide range of topics from many different areas: the possible-worlds analysis of counterfactuals; the compatibility of special relativity with presentism; the implications of ethical naturalism; and the nature of first-personal experience. A helpful introduction orients the reader and offers a way into some of the most original work in contemporary philosophy.

A comprehensive philosophical introduction to set theory. Anyone wishing to work on the logical foundations of mathematics must understand set theory, which lies at its heart. Potter offers a thorough account of cardinal and ordinal arithmetic, and the various axiom candidates. He discusses in detail the project of set-theoretic reduction, which aims to interpret the rest of mathematics in terms of set theory. The key question here is how to deal with the paradoxes that bedevil set theory. Potter offers a strikingly simple version of the most widely accepted response to the paradoxes, which classifies sets by means of a hierarchy of levels. What makes the book unique is that it interweaves a careful presentation of the technical material with a penetrating philosophical critique. Potter does not merely expound the theory dogmatically but at every stage discusses in detail the reasons that can be offered for believing it to be true.

F. H. Bradley was the greatest of the British Idealists, but for much of this century his views have been neglected, primarily as a result of the severe criticism to which they were subjected by Russell and Moore. In recent years, however, there has been a resurgence of interest in and a widespread reappraisal of his work. W. J. Mander offers a general introduction to Bradley's metaphysics and its logical foundations, and shows that much of his philosophy has been seriously misunderstood. Dr Mander argues that any adequate treatment of Bradley's thought must take full account of his unique dual inheritance from the traditions of British empiricism and Hegelian rationalism. The scholarship of recent years is assessed, and new interpretations are offered of Bradley's views about truth, predication, and relations, and of his arguments for idealism. This book is a clear and helpful guide for those new to this difficult but fascinating thinker, and at the same time an original and stimulating contribution to the re-evaluation of his work.