The purpose of this book is to present unpublished papers at the cutting edge of research on dialetheism and to reflect recent work on the applications of the theory. It includes contributions from some of the most respected scholars in the field, as well as from young, up-and-coming philosophers working on dialetheism. Moving from the fringes of philosophy to become a main player in debates concerning truth and the logical paradoxes, dialetheism has thrived since the publication of Graham Priest's In Contradiction, and several of the papers find their roots in a conference on dialetheism held in Glasgow to mark the 25th anniversary of Priest's book. The content presented here demonstrates the considerable body of work produced in this field in recent years. With a broad focus, this book also addresses the applications of dialetheism outside the more familiar area of the logical paradoxes, and includes pieces discussing the application of dialetheism in metaphysics, philosophy of language, and philosophy of mind.

Vagueness is the study of concepts that admit borderline cases: the property of being bald is vague because there are people who are neither definitely bald, nor definitely not bald. The epistemology of vagueness concerns the sorts of attitudes we ought to have towards propositions we know to be borderline. Is it possible to discover whether a borderline bald man is bald? Could two people with access to the same facts reasonably disagree about whether he is bald? Does it matter, when making practical decisions, whether he is bald? By drawing on such considerations, Andrew Bacon develops a novel theory of vagueness in which vagueness is fundamentally a property of propositions, and is explicated in terms of its role in thought. On this theory, language plays little role in explaining the central puzzles of vagueness. Part I of the book outlines some of the central questions regarding the logic and epistemology of vagueness, and criticizes some extant approaches to them. Part II concerns issues in the epistemology of vagueness, touching on the ramifications of vague thoughts on the study of evidence, ignorance, desire, probability theory, and decision theory. By examining the effects of vague information on one's beliefs about the precise, a positive theory of vagueness is proposed. Part III concerns the logic of vagueness, including the interaction between vagueness and modality, vague identity, and the paradoxes of higher-order vagueness. Bacon suggests that some familiar philosophical notions - including the concept of a fundamental proposition, a possible world and a precisification - need to be revised.

Fred Stoutland was a major figure in the philosophy of action and philosophy of language. This collection brings together essays on truth, language, action and mind and thus provides an important summary of many key themes in Stoutland's own work, as well as offering valuable perspectives on key issues in contemporary philosophy.

An agent often does not have precise probabilities or utilities to guide resolution of a decision problem. I advance a principle of rationality for making decisions in such cases. To begin, I represent the doxastic and conative state of an agent with a set of pairs of a probability assignment and a utility assignment. Then I support a decision principle that allows any act that maximizes expected utility according to some pair of assignments in the set. Assuming that computation of an option's expected utility uses comprehensive possible outcomes that include the option's risk, no consideration supports a stricter requirement.

This study of Plato's Phaedo promotes better understanding of its arguments for the soul's immortality by showing how Plato intended them, not as proofs, but as properly dialectical arguments functioning in accordance with the method of hypothesis. Unlike the argument for the soul's immortality in the Phaedrus, which does seem intended as a proof, the Phaedo arguments are proceeding toward the first principles that could serve as the basis for a proof - the most important being an account of the soul's own essential nature. This study attends to the substantial progress the Phaedo makes toward such an account. It also considers Socrates' epistemic situation in the dialogue and the problem of whether his confidence in the face of death is misplaced if his arguments have not been proofs before considering how the concluding myth draws together several of the dialogue's main themes.

Numbers and other mathematical objects are exceptional in having no locations in space or time and no causes or effects in the physical world. This makes it difficult to account for the possibility of mathematical knowledge, leading many philosophers to embrace nominalism, the doctrine that there are no abstract entitles, and to embark on ambitious projects for interpreting mathematics so as to preserve the subject while eliminating its objects. A Subject With No Object cuts through a host of technicalities that have obscured previous discussions of these projects, and presents clear, concise accounts, with minimal prerequisites, of a dozen strategies for nominalistic interpretation of mathematics, thus equipping the reader to evaluate each and to compare different ones. The authors also offer critical discussion, rare in the literature, of the aims and claims of nominalistic interpretation, suggesting that it is significant in a very different way from that usually assumed.

Quine's set theory, New Foundations, has often been treated as an anomaly in the history and philosophy of set theory. In this book, Sean Morris shows that it is in fact well-motivated, emerging in a natural way from the early development of set theory. Morris introduces and explores the notion of set theory as explication: the view that there is no single correct axiomatization of set theory, but rather that the various axiomatizations all serve to explicate the notion of set and are judged largely according to pragmatic criteria. Morris also brings out the important interplay between New Foundations, Quine's philosophy of set theory, and his philosophy more generally. We see that his early technical work in logic foreshadows his later famed naturalism, with his philosophy of set theory playing a crucial role in his primary philosophical project of clarifying our conceptual scheme and specifically its logical and mathematical components.

In this book we deal with combinations of concepts defining individuals in the Talmud. Consider for example Yom Kippur and Shabbat. Each concept has its own body of laws. Reality forces us to combine them when they occur on the same day. This is a case of "Identity Merging." As the combined body of laws may be inconsistent, we need a belief revision mechanism to reconcile the conflicting norms. The Talmud offers three options: 1 Take the union of the sets of the rules side by side 2. Resolve the conflicts using further meta-level Talmudic principles (which are new and of value to present day Artificial Intelligence) 3. Regard the new combined concept as a new entity with its own Halachic norms and create new norms for it out of the existing ones. This book offers a clear and precise logical model showing how the Talmud deals with these options.

This book articulates and defends Fregean realism, a theory of properties based on Frege's insight that properties are not objects, but rather the satisfaction conditions of predicates. Robert Trueman argues that this approach is the key not only to dissolving a host of longstanding metaphysical puzzles, such as Bradley's Regress and the Problem of Universals, but also to understanding the relationship between states of affairs, propositions, and the truth conditions of sentences. Fregean realism, Trueman suggests, ultimately leads to a version of the identity theory of truth, the theory that true propositions are identical to obtaining states of affairs. In other words, the identity theory collapses the gap between mind and world. This book will be of interest to anyone working in logic, metaphysics, the philosophy of language or the philosophy of mind.

Ideas about relativity underlie much ancient Greek philosophy, from Protagorean relativism, to Plato's theory of Forms, Aristotle's category scheme, and relational logic. In Ancient Relativity Matthew Duncombe explores how ancient philosophers, particularly Plato, Aristotle, the Stoics, and Sextus Empiricus, understood the phenomenon and how their theories of relativity affected, and were affected by, their broader philosophical outlooks. He argues that ancient philosophers shared a close-knit family of views referred to as 'constitutive relativity', whereby a relative is not simply linked by a relation but is constituted by it. Plato exploits this view in some key arguments concerning the Forms and the partition of the soul. Aristotle adopts the constitutive view in his discussions of relativity in Categories 7 and the Topics and retains it in Metaphysics Delta 15. Duncombe goes on to examine the role relativity plays in Stoic philosophy, especially Stoic physics and metaphysics, and the way Sextus Empiricus thinks about relativity, which does not appeal to the nature of relatives but rather to how we conceive of things as correlative.

Is mathematics 'entangled' with its various formalisations? Or are the central concepts of mathematics largely insensitive to formalisation, or 'formalism free'? What is the semantic point of view and how is it implemented in foundational practice? Does a given semantic framework always have an implicit syntax? Inspired by what she calls the 'natural language moves' of Goedel and Tarski, Juliette Kennedy considers what roles the concepts of 'entanglement' and 'formalism freeness' play in a range of logical settings, from computability and set theory to model theory and second order logic, to logicality, developing an entirely original philosophy of mathematics along the way. The treatment is historically, logically and set-theoretically rich, and topics such as naturalism and foundations receive their due, but now with a new twist.

This comprehensive account of the concept and practices of deduction is the first to bring together perspectives from philosophy, history, psychology and cognitive science, and mathematical practice. Catarina Dutilh Novaes draws on all of these perspectives to argue for an overarching conceptualization of deduction as a dialogical practice: deduction has dialogical roots, and these dialogical roots are still largely present both in theories and in practices of deduction. Dutilh Novaes' account also highlights the deeply human and in fact social nature of deduction, as embedded in actual human practices; as such, it presents a highly innovative account of deduction. The book will be of interest to a wide range of readers, from advanced students to senior scholars, and from philosophers to mathematicians and cognitive scientists.

The perception of what he calls 'aspects' preoccupied Wittgenstein and gave him considerable trouble in his final years. The Wittgensteinian aspect defies any number of traditional philosophical dichotomies: the aspect is neither subjective (inner, metaphysically private) nor objective; it presents perceivable unity and sense that are (arguably) not (yet) conceptual; it is 'subject to the will', but at the same time is normally taken to be genuinely revelatory of the object perceived under it. This Element begins with a grammatical and phenomenological characterization of Wittgensteinian 'aspects'. It then challenges two widespread ideas: that aspects are to be identified with concepts; and that aspect perception has a continuous version that is characteristic of (normal) human perception. It concludes by proposing that aspect perception brings to light the distinction between the world as perceived and the world as objectively construed, and the role we play in the constitution of the former.

W. V. Quine was one of the most influential figures of twentieth-century American analytic philosophy. Although he wrote predominantly in English, in Brazil in 1942 he gave a series of lectures on logic and its philosophy in Portuguese, subsequently published as the book O Sentido da Nova Logica. The book has never before been fully translated into English, and this volume is the first to make its content accessible to Anglophone philosophers. Quine would go on to develop revolutionary ideas about semantic holism and ontology, and this book provides a snapshot of his views on logic and language at a pivotal stage of his intellectual development. The volume also includes an essay on logic which Quine also published in Portuguese, together with an extensive historical-philosophical essay by Frederique Janssen-Lauret. The valuable and previously neglected works first translated in this volume will be essential for scholars of twentieth-century philosophy.

The proceedings of the Los Angeles Caltech-UCLA 'Cabal Seminar' were originally published in the 1970s and 1980s. Large Cardinals, Determinacy and Other Topics is the final volume in a series of four books collecting the seminal papers from the original volumes together with extensive unpublished material, new papers on related topics and discussion of research developments since the publication of the original volumes. This final volume contains Parts VII and VIII of the series. Part VII focuses on 'Extensions of AD, models with choice', while Part VIII ('Other topics') collects material important to the Cabal that does not fit neatly into one of its main themes. These four volumes will be a necessary part of the book collection of every set theorist.

A relative change occurs when some item changes a relation. This Element examines how Plato, Aristotle, Stoics and Sextus Empiricus approached relative change. Relative change is puzzling because the following three propositions each seem true but cannot be true together: (1) No relative changes are intrinsic changes; (2) Only intrinsic changes are proper changes; (3) Some relative changes are proper changes. Plato's Theaetetus and Phaedo property relative change. I argue that these dialogues assume relative changes to be intrinsic changes, so denying (1). Aristotle responds differently, by denying (3) that relative change is proper change. The Stoics claimed that some non-intrinsic changes are changes (denying (2)). Finally, I discuss Sextus' argument that relative change shows that there are no relatives at all.

In the twenty-first century there are two ways to study logic. The more recent approach is symbolic logic. The history of teaching logic since World War II, however, casts doubt on the idea that symbolic logic is best for a first logic course. Logic as a Liberal Art is designed as part of a minority approach, teaching logic in the "verbal" way, in the student's "natural" language, the approach invented by Aristotle. On utilitarian grounds alone, this "verbal" approach is superior for a first course in logic, for the whole range of students. For millennia, this "verbal" approach to logic was taught in conjunction with grammar and rhetoric, christened the trivium. The decline in teaching grammar and rhetoric in American secondary schools has led Rollen Edward Houser to develop this book. The first part treats grammar, rhetoric, and the essential nature of logic. Those teachers who look down upon rhetoric are free, of course, to skip those lessons. The treatment of logic itself follows Aristotle's division of the three acts of the mind (Prior Analytics 1.1). Formal logic is then taken up in Aristotle's order, with Parts on the logic of Terms, Propositions, and Arguments. The emphasis in Logic as a Liberal Art is on learning logic through doing problems. Consequently, there are more problems in each lesson than would be found, for example, in many textbooks. In addition, a special effort has been made to have easy, medium, and difficult problems in each Problem Set. In this way the problem sets are designed to offer a challenge to all students, from those most in need of a logic course to the very best students.

Wittgenstein's 'middle period' is often seen as a transitional phase connecting his better-known early and later philosophies. The fifteen essays in this volume focus both on the distinctive character of his teaching and writing in the 1930s, and on its pivotal importance for an understanding of his philosophy as a whole. They offer wide-ranging perspectives on the central issue of how best to identify changes and continuities in his philosophy during those years, as well as on particular topics in the philosophy of mind, religion, ethics, aesthetics, and the philosophy of mathematics. The volume will be valuable for all who are interested in this formative period of Wittgenstein's development.

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.

Luciano Floridi presents an innovative approach to philosophy, conceived as conceptual design. He explores how we make, transform, refine, and improve the objects of our knowledge. His starting point is that reality provides the data, to be understood as constraining affordances, and we transform them into information, like semantic engines. Such transformation or repurposing is not equivalent to portraying, or picturing, or photographing, or photocopying anything. It is more like cooking: the dish does not represent the ingredients, it uses them to make something else out of them, yet the reality of the dish and its properties hugely depend on the reality and the properties of the ingredients. Models are not representations understood as pictures, but interpretations understood as data elaborations, of systems. Thus, he articulates and defends the thesis that knowledge is design and philosophy is the ultimate form of conceptual design. Although entirely independent of Floridi's previous books, The Philosophy of Information (OUP 2011) and The Ethics of Information (OUP 2013), The Logic of Information both complements the existing volumes and presents new work on the foundations of the philosophy of information.

This volume presents different conceptions of logic and mathematics and discuss their philosophical foundations and consequences. This concerns first of all topics of Wittgenstein's ideas on logic and mathematics; questions about the structural complexity of propositions; the more recent debate about Neo-Logicism and Neo-Fregeanism; the comparison and translatability of different logics; the foundations of mathematics: intuitionism, mathematical realism, and formalism. The contributing authors are Matthias Baaz, Francesco Berto, Jean-Yves Beziau, Elena Dragalina-Chernya, Gunther Eder, Susan Edwards-McKie, Oliver Feldmann, Juliet Floyd, Norbert Gratzl, Richard Heinrich, Janusz Kaczmarek, Wolfgang Kienzler, Timm Lampert, Itala Maria Loffredo D'Ottaviano, Paolo Mancosu, Matthieu Marion, Felix Muhlhoelzer, Charles Parsons, Edi Pavlovic, Christoph Pfisterer, Michael Potter, Richard Raatzsch, Esther Ramharter, Stefan Riegelnik, Gabriel Sandu, Georg Schiemer, Gerhard Schurz, Dana Scott, Stewart Shapiro, Karl Sigmund, William W. Tait, Mark van Atten, Maria van der Schaar, Vladimir Vasyukov, Jan von Plato, Jan Wolenski and Richard Zach.

A comprehensive collection of historical readings in the philosophy of mathematics and a selection of influential contemporary work, this much-needed introduction reveals the rich history of the subject. An Historical Introduction to the Philosophy of Mathematics: A Reader brings together an impressive collection of primary sources from ancient and modern philosophy. Arranged chronologically and featuring introductory overviews explaining technical terms, this accessible reader is easy-to-follow and unrivaled in its historical scope. With selections from key thinkers such as Plato, Aristotle, Descartes, Hume and Kant, it connects the major ideas of the ancients with contemporary thinkers. A selection of recent texts from philosophers including Quine, Putnam, Field and Maddy offering insights into the current state of the discipline clearly illustrates the development of the subject. Presenting historical background essential to understanding contemporary trends and a survey of recent work, An Historical Introduction to the Philosophy of Mathematics: A Reader is required reading for undergraduates and graduate students studying the philosophy of mathematics and an invaluable source book for working researchers.

This book returns to the discussion in volume 1 on analogy and induction, and analyses their substance. The first part distinguishes between two kinds of logic: One kind based on union of the common features, and the other kind based on synthesis of different features. In the second part of the book we propose a formal scheme for synthesis of concepts. The third part analyses various mechanisms for kidushin and kinyan, which form a mathematical group.

Driven by an intercultural vision and comparative research, this is the first volume to bring together African and Western philosophical approaches to current issues in language, logic, metaphysics and ethics. Featuring contributions from an international line up of scholars across four continents including leading contemporary African philosophers, and new work from Saul Kripke in collaboration with Romina Padro, these chapters cover a wide range of topics. They advance our understanding of the linguistic, logical, metaphysical and ethical contributions of African philosophical thought in comparison with Western traditions, fostering discussion about how they relate, and are distinct, from one another. Reinvigorating the debate in cross-cultural and global philosophy, this is a groundbreaking resource for any scholar or student of each sub-discipline.