Contents:
Preface 1. Introduction 2. Argument and Evidence 3. Context, Convention and Communication 4. An informal Analysis of Arguments 5. Patterns of Reasoning 6. Establishing Validity 7. Critical Analysis in Practice 8.Assumptions 9. Evidence as Ground Belief 10. What Counts as Evidence? 11. Presenting and Summarising Evidence 12. Furthering Knowledge 13. Probability and Uncertainty 14. Probability Theory applied 15. Estimation and Reliability 16. Testing Hypotheses; Appendices; Glossery; References

This Element is an introduction to recent work proofs and models in philosophical logic, with a focus on the semantic paradoxes the sorites paradox. It introduces and motivates different proof systems and different kinds of models for a range of logics, including classical logic, intuitionistic logic, a range of three-valued and four-valued logics, and substructural logics. It also compares and contrasts the different approaches to substructural treatments of the paradox, showing how the structural rules of contraction, cut and identity feature in paradoxical derivations. It then introduces model theoretic treatments of the paradoxes, including a simple fixed-point model construction which generates three-valued models for theories of truth, which can provide models for a range of different non-classical logics. The Element closes with a discussion of the relationship between proofs and models, arguing that both have their place in the philosophers' and logicians' toolkits.

This Element takes a deep dive into Goedel's 1931 paper giving the first presentation of the Incompleteness Theorems, opening up completely passages in it that might possibly puzzle the student, such as the mysterious footnote 48a. It considers the main ingredients of Goedel's proof: arithmetization, strong representability, and the Fixed Point Theorem in a layered fashion, returning to their various aspects: semantic, syntactic, computational, philosophical and mathematical, as the topic arises. It samples some of the most important proofs of the Incompleteness Theorems, e.g. due to Kuratowski, Smullyan and Robinson, as well as newer proofs, also of other independent statements, due to H. Friedman, Weiermann and Paris-Harrington. It examines the question whether the incompleteness of e.g. Peano Arithmetic gives immediately the undecidability of the Entscheidungsproblem, as Kripke has recently argued. It considers set-theoretical incompleteness, and finally considers some of the philosophical consequences considered in the literature.

This Element is an exposition of second- and higher-order logic and type theory. It begins with a presentation of the syntax and semantics of classical second-order logic, pointing up the contrasts with first-order logic. This leads to a discussion of higher-order logic based on the concept of a type. The second Section contains an account of the origins and nature of type theory, and its relationship to set theory. Section 3 introduces Local Set Theory (also known as higher-order intuitionistic logic), an important form of type theory based on intuitionistic logic. In Section 4 number of contemporary forms of type theory are described, all of which are based on the so-called 'doctrine of propositions as types'. We conclude with an Appendix in which the semantics for Local Set Theory - based on category theory - is outlined.

Set theory is a branch of mathematics with a special subject matter, the infinite, but also a general framework for all modern mathematics, whose notions figure in every branch, pure and applied. This Element will offer a concise introduction, treating the origins of the subject, the basic notion of set, the axioms of set theory and immediate consequences, the set-theoretic reconstruction of mathematics, and the theory of the infinite, touching also on selected topics from higher set theory, controversial axioms and undecided questions, and philosophical issues raised by technical developments.

In the past 15 years a host of critical thinking books have appeared that teach students to find flaws in the arguments of others by learning to detect a number of informal fallacies. This book is not in that tradition. The authors of this book believe that while students learn to become vicious critics, they still continue to make the very mistakes they criticize in others. Thus, this book has adopted the approach of teaching the construction of good arguments first and then introducing criticism as a secondary skill. Moreover, the emphasis of the book is not on learning to name fallacies, but on being able to identify weaknesses in an argument so as to be able to construct an effective critique of that argument. The book is accompanied by a workbook featuring a wealth of examples to help students acquire the material.

In many ways set theory lies at the heart of modern mathematics, and it does powerful work both philosophical and mathematical - as a foundation for the subject. However, certain philosophical problems raise serious doubts about our acceptance of the axioms of set theory. In a detailed and original reassessment of these axioms, Sharon Berry uses a potentialist (as opposed to actualist) approach to develop a unified determinate conception of set-theoretic truth that vindicates many of our intuitive expectations regarding set theory. Berry further defends her approach against a number of possible objections, and she shows how a notion of logical possibility that is useful in formulating Potentialist set theory connects in important ways with philosophy of language, metametaphysics and philosophy of science. Her book will appeal to readers with interests in the philosophy of set theory, modal logic, and the role of mathematics in the sciences.

First published in 1990 The Philosopher's Habitat introduces the subject by investigating a variety of the problems which are currently engaging philosophers, and which can be made intelligible to an absolute beginner. Rather than introducing philosophy by examining, in the traditional way, the writings of great philosophers, the author has inverted this procedure. The idea is that the reader will become absorbed in these dramas, will thereby come to appreciate the ways in which the stage was set by the great writers of the past, and will feel the urge to participate. Questions at the end of each chapter encourage the reader to push beyond the text. This book is a must read for students of philosophy.

Western philosophy and science are responsible for constructing some powerful tools of investigation, aiming at discovering the truth, delivering robust explanations, verifying conjectures, showing that inferences are sound and demonstrating results conclusively. By contrast reasoning that depends on analogies has often been viewed with suspicion. Professor Lloyd first explores the origins of those Western ideals, criticises some of their excesses and redresses the balance in favour of looser, admittedly non-demonstrative analogical reasoning. For this he takes examples both from ancient Greek and Chinese thought and from the materials of recent ethnography to show how different ancient and modern cultures have developed different styles of reasoning. He also develops two original but controversial ideas, that of semantic stretch (to cast doubt on the literal/metaphorical dichotomy) and the multidimensionality of reality (to bypass the realism versus relativism and nature versus nurture controversies).

Metamathematics and the Philosophical Tradition is the first work to explore in such historical depth the relationship between fundamental philosophical quandaries regarding self-reference and meta-mathematical notions of consistency and incompleteness. Using the insights of twentieth-century logicians from Goedel through Hilbert and their successors, this volume revisits the writings of Aristotle, the ancient skeptics, Anselm, and enlightenment and seventeenth and eighteenth century philosophers Leibniz, Berkeley, Hume, Pascal, Descartes, and Kant to identify ways in which these both encode and evade problems of a priori definition and self-reference. The final chapters critique and extend more recent insights of late 20th-century logicians and quantum physicists, and offer new applications of the completeness theorem as a means of exploring "metatheoretical ascent" and the limitations of scientific certainty. Broadly syncretic in range, Metamathematics and the Philosophical Tradition addresses central and recurring problems within epistemology. The volume's elegant, condensed writing style renders accessible its wealth of citations and allusions from varied traditions and in several languages. Its arguments will be of special interest to historians and philosophers of science and mathematics, particularly scholars of classical skepticism, the Enlightenment, Kant, ethics, and mathematical logic.

This book examines the birth of the scientific understanding of motion. It investigates which logical tools and methodological principles had to be in place to give a consistent account of motion, and which mathematical notions were introduced to gain control over conceptual problems of motion. It shows how the idea of motion raised two fundamental problems in the 5th and 4th century BCE: bringing together being and non-being, and bringing together time and space. The first problem leads to the exclusion of motion from the realm of rational investigation in Parmenides, the second to Zeno's paradoxes of motion. Methodological and logical developments reacting to these puzzles are shown to be present implicitly in the atomists, and explicitly in Plato who also employs mathematical structures to make motion intelligible. With Aristotle we finally see the first outline of the fundamental framework with which we conceptualise motion today.

Logical paradoxes - like the Liar, Russell's, and the Sorites - are notorious. But in Paradoxes and Inconsistent Mathematics, it is argued that they are only the noisiest of many. Contradictions arise in the everyday, from the smallest points to the widest boundaries. In this book, Zach Weber uses "dialetheic paraconsistency" - a formal framework where some contradictions can be true without absurdity - as the basis for developing this idea rigorously, from mathematical foundations up. In doing so, Weber directly addresses a longstanding open question: how much standard mathematics can paraconsistency capture? The guiding focus is on a more basic question, of why there are paradoxes. Details underscore a simple philosophical claim: that paradoxes are found in the ordinary, and that is what makes them so extraordinary.

Evidential Decision Theory is a radical theory of rational decision-making. It recommends that instead of thinking about what your decisions *cause*, you should think about what they *reveal*. This Element explains in simple terms why thinking in this way makes a big difference, and argues that doing so makes for *better* decisions. An appendix gives an intuitive explanation of the measure-theoretic foundations of Evidential Decision Theory.

This volume deals with the connection between thinking-and-speaking and our form(s) of life. All contributions engage with Wittgenstein's approach to this topic. As a whole, the volume takes a stance against both biological and ethnological interpretations of the notion "form of life" and seeks to promote a broadly logico-linguistic understanding instead. The structure of this book is threefold. Part one focuses on lines of thinking that lead from Wittgenstein's earlier thought to the concept of form of life in his later work. Contributions to part two examine the concrete philosophical function of this notion as well as the ways in which it differs from cognate concepts. Contributions to part three put Wittgenstein's notion of form of life in perspective by relating it to phenomenology, ordinary language philosophy and problems in contemporary analytic philosophy.

Thomas Kuhn's The Structure of Scientific Revolutions offers an insightful and engaging theory of science that speaks to scholars across many disciplines. Though initially widely misunderstood, it had a profound impact on the way intellectuals and educated laypeople thought about science. K. Brad Wray traces the influences on Kuhn as he wrote Structure, including his 'Aristotle epiphany', his interactions, and his studies of the history of chemistry. Wray then considers the impact of Structure on the social sciences, on the history of science, and on the philosophy of science, where the problem of theory change has set the terms of contemporary realism/anti-realism debates. He examines Kuhn's frustrations with the Strong Programme sociologists' appropriations of his views, and debunks several popular claims about what influenced Kuhn as he wrote Structure. His book is a rich and comprehensive assessment of one of the most influential works in the modern sciences.

Are psychopaths morally responsible? Should we argue with them? Remonstrate with them, blame them, sometimes even praise them? Is it worth trying to change them, or should we just try to prevent them from causing harm? In this book, Jim Baxter aims to find serious answers to these deep philosophical questions, drawing on contemporary insights from psychiatry, psychology, neuroscience and law. Moral Responsibility and the Psychopath is the first sustained, book-length philosophical work on this important and fascinating topic, and will be of deep interest and importance to researchers in these fields - not to mention anyone who has had to interact with a psychopath in their everyday life.

I have been thinking about the philosophical issue of truth for more than two decades. It is one of several fascinating philosophical issues that motivated me to change my primary re ective interest to philosophy after receiving BS in mathem- ics in 1982. Some serious academic work in this connection started around the late eighties when I translated into Chinese a dozen of Donald Davidson's representative essays on truth and meaning and when I assumed translator for Adam Morton who gave a series of lectures on the issue in Beijing (1988), which was co-sponsored by my then institution (Institute of Philosophy, Chinese Academy of Social Science). I have loved the issue both for its own sake (as one speci c major issue in the phil- ophy of language and metaphysics) and for the sake of its signi cant involvement in many philosophical issues in different subjects of philosophy. Having been attracted to the analytic approach, I was then interested in looking at the issue both from the points of view of classical Chinese philosophy and Marxist philosophy, two major styles or frameworks of doing philosophy during that time in China, and from the point of view of contemporary analytic philosophy, which was then less recognized in the Chinese philosophical circle.

This collection of new essays presents cutting-edge research on the semantic conception of logic, the invariance criteria of logicality, grammaticality, and logical truth. Contributors explore the history of the semantic tradition, starting with Tarski, and its historical applications, while central criticisms of the tradition, and especially the use of invariance criteria to explain logicality, are revisited by the original participants in that debate. Other essays discuss more recent criticism of the approach, and researchers from mathematics and linguistics weigh in on the role of the semantic tradition in their disciplines. This book will be invaluable to philosophers and logicians alike.

This book argues that the meaning of negation, perhaps the most important logical constant, cannot be defined within the framework of the most comprehensive theory of proof-theoretic semantics, as formulated in the influential work of Michael Dummett and Dag Prawitz. Nils Kurbis examines three approaches that have attempted to solve the problem - defining negation in terms of metaphysical incompatibility; treating negation as an undefinable primitive; and defining negation in terms of a speech act of denial - and concludes that they cannot adequately do so. He argues that whereas proof-theoretic semantics usually only appeals to a notion of truth, it also needs to appeal to a notion of falsity, and proposes a system of natural deduction in which both are incorporated. Offering new perspectives on negation, denial and falsity, his book will be important for readers working on logic, metaphysics and the philosophy of language.

The main aim of this Element is to introduce the topic of limited awareness, and changes in awareness, to those interested in the philosophy of decision-making and uncertain reasoning. While it has long been of interest to economists and computer scientists, this topic has only recently been subject to philosophical investigation. Indeed, at first sight limited awareness seems to evade any systematic treatment: it is beyond the uncertainty that can be managed. On the one hand, an agent has no control over what contingencies she is and is not aware of at a given time, and any awareness growth takes her by surprise. On the other hand, agents apparently learn to identify the situations in which they are more and less likely to experience limited awareness and subsequent awareness growth. How can these two sides be reconciled? That is the puzzle we confront in this Element.

The conditional, if...then, is probably the most important term in natural language and forms the core of systems of logic and mental representation. It occurs in all human languages and allows people to express their knowledge of the causal or law-like structure of the world and of others' behaviour, e.g., if you turn the key the car starts, if John walks the dog he stops for a pint of beer; to make promises, e.g., if you cook tonight, I'll wash up all week; to regulate behaviour, e.g., if you are drinking beer, you must be over 18 years of age; to suggest what would have happened had things been different, e.g., if the match had been dry it would have lit, among many other possible uses. The way in which the conditional is modelled also determines the core of most logical systems. Unsurprisingly, it is also the most researched expression in the psychology of human reasoning.
Cognition and Conditionals is the first volume for over 20 years (On Conditionals, 1986, CUP) that brings together recent developments in the cognitive science and psychology of conditional reasoning. Over the last 10 to 15 years, research on conditionals has come to dominate the psychology of reasoning providing a rich seam of results that have created new theoretical possibilities. This book shows how these developments have led researchers to view people's conditional reasoning behaviour more as succesful probabilistic reasoning rather than as errorful logical reasoning. It shows how the multifarious, and apparently competing, theoretical positions developed over the last 50 years in this area - mental logics, mental models, heuristic approaches, dual process theory, and probabilistic approaches-have responded to these insights. Its organisation reflects the view that an integrative approach is emerging that may need to exploit aspects of all these theoretical positions to explain the rich and complex phenomenon of reasoning with conditionals. It includes an introductory chapter relating the development of the psychology of reasoning to developments in the logic and semantics of the conditional. It also includes chapters by many of the leading figures in this field.
Cognition and Conditionals will be a valuable resource for cognitive scientists, psychologists and philosophers interested how people actually reason with conditionals.

This Element presents a concise and accessible view of the central arguments of Wittgenstein's Tractatus Logico-Philosophicus. Starting from the difficulties found in historical and current debates, drawing on the background of Russell's philosophy, and grounded in the ladder structure expressed in the numbering system of the book, this Element presents the central arguments of the Tractatus in three lines of thought. The first concerns the role of the so-called 'ontology' and its relationship to the method of the Tractatus and its logical symbolism, which displays the formal essence of language and world. The second deals with the symbolic unity of language and its role in the 'ladder structure' and explains how and why the book is not self-defeating. The third elucidates Wittgenstein's claim to have solved in essentials all philosophical problems, whose very formulation, he says, rests on misunderstandings.

Sets are central to mathematics and its foundations, but what are they? In this book Luca Incurvati provides a detailed examination of all the major conceptions of set and discusses their virtues and shortcomings, as well as introducing the fundamentals of the alternative set theories with which these conceptions are associated. He shows that the conceptual landscape includes not only the naive and iterative conceptions but also the limitation of size conception, the definite conception, the stratified conception and the graph conception. In addition, he presents a novel, minimalist account of the iterative conception which does not require the existence of a relation of metaphysical dependence between a set and its members. His book will be of interest to researchers and advanced students in logic and the philosophy of mathematics.

Our minds have physical effects. This happens, for instance, when we move our bodies when we act. How is this possible? Thomas Kroedel defends an account of mental causation in terms of difference-making: if our minds had been different, the physical world would have been different; therefore, the mind causes events in the physical world. His account not only explains how the mind has physical effects at all, but solves the exclusion problem - the problem of how those effects can have both mental and physical causes. It is also unprecedented in scope, because it is available to dualists about the mind as well as physicalists, drawing on traditional views of causation as well as on the latest developments in the field of causal modelling. It will be of interest to a range of readers in philosophy of mind and philosophy of science. This book is also available as Open Access.