This monograph shows that, through a recourse to the concepts and methods of abstract algebraic logic, the algebraic theory of regular varieties and the concept of analyticity in formal logic can profitably interact. By extending the technique of Plonka sums from algebras to logical matrices, the authors investigate the different classes of models for logics of variable inclusion and they shed new light into their formal properties. The book opens with the historical origins of logics of variable inclusion and on their philosophical motivations. It includes the basics of the algebraic theory of regular varieties and the construction of Plonka sums over semilattice direct systems of algebra. The core of the book is devoted to an abstract definition of logics of left and right variable inclusion, respectively, and the authors study their semantics using the construction of Plonka sums of matrix models. The authors also cover Paraconsistent Weak Kleene logic and survey its abstract algebraic logical properties. This book is of interest to scholars of formal logic.

This volume contains papers on truth, logic, semantics, and history of logic and philosophy. These papers are dedicated to Jan Wolenski to honor his 60th birthday. Jan Wolenski is professor of philosophy at the Department of Philosophy of the Jagiellonian University in Cracow, Poland. He is likely to be the most well-known Polish philosopher of this time, best known for his work on the history of the philosophy and logic of the Lvov-Warsaw School.

One of the great minds of the English Renaissance, Francis Bacon was a scholar, politician, and early advocate of scientific thinking who set no limits on the scope of his enquiries. In these compact and vibrant essays, Bacon addresses an astonishingly diverse range of subjects including religion, politics, personal relationships, morality and even architecture. Evident throughout the volume is his considerable rhetorical skill, incisive wit, and an unwavering belief in the power of reason.

"Intuition" has perhaps been the least understood and the most abused term in philosophy. It is often the term used when one has no plausible explanation for the source of a given belief or opinion. According to some sceptics, it is understood only in terms of what it is not, and it is not any of the better understood means for acquiring knowledge. In mathematics the term has also unfortunately been used in this way. Thus, intuition is sometimes portrayed as if it were the Third Eye, something only mathematical "mystics," like Ramanujan, possess. In mathematics the notion has also been used in a host of other senses: by "intuitive" one might mean informal, or non-rigourous, or visual, or holistic, or incomplete, or perhaps even convincing in spite of lack of proof. My aim in this book is to sweep all of this aside, to argue that there is a perfectly coherent, philosophically respectable notion of mathematical intuition according to which intuition is a condition necessary for mathemati cal knowledge. I shall argue that mathematical intuition is not any special or mysterious kind of faculty, and that it is possible to make progress in the philosophical analysis of this notion. This kind of undertaking has a precedent in the philosophy of Kant. While I shall be mostly developing ideas about intuition due to Edmund Husser there will be a kind of Kantian argument underlying the entire book."

Model theory is used in every theoretical branch of analytic philosophy: in philosophy of mathematics, in philosophy of science, in philosophy of language, in philosophical logic, and in metaphysics. But these wide-ranging uses of model theory have created a highly fragmented literature. On the one hand, many philosophically significant results are found only in mathematics textbooks: these are aimed squarely at mathematicians; they typically presuppose that the reader has a serious background in mathematics; and little clue is given as to their philosophical significance. On the other hand, the philosophical applications of these results are scattered across disconnected pockets of papers. The first aim of this book, then, is to explore the philosophical uses of model theory, focusing on the central topics of reference, realism, and doxology. Its second aim is to address important questions in the philosophy of model theory, such as: sameness of theories and structure, the boundaries of logic, and the classification of mathematical structures. Philosophy and Model Theory will be accessible to anyone who has completed an introductory logic course. It does not assume that readers have encountered model theory before, but starts right at the beginning, discussing philosophical issues that arise even with conceptually basic model theory. Moreover, the book is largely self-contained: model-theoretic notions are defined as and when they are needed for the philosophical discussion, and many of the most philosophically significant results are given accessible proofs.

For the most part, the papers collected in this volume stern from presentations given at a conference held in Tucson over the weekend of May 31 through June 2, 1985. We wish to record our gratitude to the participants in that conference, as well as to the National Science Foundation (Grant No. BNS-8418916) and the University of Arizona SBS Research Institute for their financial support. The advice we received from Susan Steele on organizational matters proved invaluable and had many felicitous consequences for the success of the con ference. We also would like to thank the staff of the Departments of Linguistics of the University of Arizona and the University of Massachusetts at Amherst for their help, as weIl as a number of individuals, including Lin Hall, Kathy Todd, and Jiazhen Hu, Sandra Fulmer, Maria Sandoval, Natsuko Tsujimura, Stuart Davis, Mark Lewis, Robin Schafer, Shi Zhang, Olivia Oehrle-Steele, and Paul Saka. Finally, we would like to express our gratitude to Martin Scrivener, our editor, for his patience and his encouragement. Vll INTRODUCTION The term 'categorial grammar' was introduced by Bar-Rillel (1964, page 99) as a handy way of grouping together some of his own earlier work (1953) and the work of the Polish logicians and philosophers Lesniewski (1929) and Ajdukiewicz (1935), in contrast to approaches to linguistic analysis based on phrase structure grammars."

Writing is essential to learning. One cannot be educated and yet unable to communicate one's ideas in written form. But, learning to write can occur only through a process of cultivation requiring intellectual discipline. As with any set of complex skills, there are fundamentals of writing that must be internalized and then applied using one's thinking. This guide focuses on the most important of those fundamentals.

The essays in Powerful Arguments reconstruct the standards of validity underlying argumentative practices in a wide array of late imperial Chinese discourses, from the Song through the Qing dynasties. The fourteen case studies analyze concrete arguments defended or contested in areas ranging from historiography, philosophy, law, and religion to natural studies, literature, and the civil examination system. By examining uses of evidence, habits of inference, and the criteria by which some arguments were judged to be more persuasive than others, the contributions recreate distinct cultures of reasoning. Together, they lay the foundations for a history of argumentative practice in one of the richest scholarly traditions outside of Europe and add a chapter to the as yet elusive global history of rationality.

Klemens Szaniawski was born in Warsaw on March 3, 1925. He began to study philosophy in the clandestine Warsaw University during World War II. Tadeusz Kotarbinski, Jan Lukasiewicz, Maria and Stanislaw Ossowskis, Wladyslaw Tatarkiewicz, and Henryk Hii: were among his teachers. Sza- niawski was also a member of the Polish Home Army (AK), one of the young- est. He was arrested and spent the last period of the war as a prisoner in Auschwitz. After 1945, he continued his studies in the University of L6dz; his Master thesis was devoted to French moral thought of the 17th and 18th cen- turies. Then he worked in the Department of Ethics in L6dZ. In 1950, he received his Ph. D. on the basis of the dissertation on the concept of honour in knight groups in the Middle Ages; Maria Ossowska was the supervisor. In the early fifties he moved to Warsaw to the Department of Logic, directed by Kotarbinski. He took his habilitation exams in 1961. In 1969 he became a professor. Since 1970 he was the head of Department of the Logic at the Warsaw University. In the sixties Szaniawski was also the Dean of the Faculty of Philosophy and Sociology. In 1984 he was elected the Rector Magnificus of the Warsaw University but the Ministry overruled the autonomous democra- tic vote of the academic community. He served as the President of the Polish (since 1977) taking this post after Kotarbinski.

Frontiers in Belief Revision is a unique collection of leading edge research in Belief Revision. It contains the latest innovative ideas of highly respected and pioneering experts in the area, including Isaac Levi, Krister Segerberg, Sven Ove Hansson, Didier Dubois, and Henri Prade. The book addresses foundational issues of inductive reasoning and minimal change, generalizations of the standard belief revision theories, strategies for iterated revisions, probabilistic beliefs, multiagent environments and a variety of data structures and mechanisms for implementations. This book is suitable for students and researchers interested in knowledge representation and in the state of the art of the theory and practice of belief revision.

The purpose of this book is to highlight Carl Stumpf's contributions to philosophy and to assess some of the aspects of his work. This book is divided into four sections, and also includes a general introduction on Stumpf's philosophy. The first section examines the historical sources of his philosophy, the second examines some of the central themes of his work and the third examines his relationship to other philosophers. The fourth section consists of notes taken by Husserl during Stumpf's lectures on metaphysics in Halle, Stumpf's introduction to the edition of his correspondence with Brentano, which he prepared in 1929, and some important letters pertaining to this correspondence. This book also provides a comprehensive bibliography of the works of Stumpf.

Propositions has two main goals. The first is to show that there are propositions. The second is to defend an account of their nature. While pursuing these goals, Trenton Merricks draws a variety of controversial conclusions about related issues, including, among others, supervaluationism, the nature of possible worlds, truths about non-existent entities, and whether and how logical consequence depends on modal facts. An argument is modally valid just in case, necessarily, if its premises are true, then its conclusion is true. Propositions begins with the assumption that some arguments are modally valid. Merricks then argues that the premises and conclusions of modally valid arguments are not sentences. Instead, he argues, they are propositions. So, because there are modally valid arguments, there are propositions. Merricks defends the claim that propositions are not structured and are not sets of possible worlds. He thereby presents arguments against the two leading accounts of the nature of propositions. Those arguments are intended not only to oppose those accounts, but also to deliver conclusions about what a satisfactory account of the nature of propositions should say. Of particular importance in this regard are arguments concerning the alleged explanations of how a set of possible worlds or a structured proposition would manage to represent thing as being a certain way. Merricks then defends his own account of the nature of propositions, which says only that each proposition is a necessary existent that essentially represents things as being a certain way.

This is a collection of, mostly unpublished, papers on topics surrounding decision theory. It addresses the most important areas in the philosophical study of rationality and knowledge, for example: causal vs. evidential decision theory, game theory, backwards induction, bounded rationality, counterfactual reasoning in games and in general, and analyses of the famous common knowledge assumptions in game theory.

Paris of the year 1900 left two landmarks: the Tour Eiffel, and David Hilbert's celebrated list of twenty-four mathematical problems presented at a conference opening the new century. Kurt Goedel, a logical icon of that time, showed Hilbert's ideal of complete axiomatization of mathematics to be unattainable. The result, of 1931, is called Goedel's incompleteness theorem. Goedel then went on to attack Hilbert's first and second Paris problems, namely Cantor's continuum problem about the type of infinity of the real numbers, and the freedom from contradiction of the theory of real numbers. By 1963, it became clear that Hilbert's first question could not be answered by any known means, half of the credit of this seeming faux pas going to Goedel. The second is a problem still wide open. Goedel worked on it for years, with no definitive results; The best he could offer was a start with the arithmetic of the entire numbers. This book, Goedel's lectures at the famous Princeton Institute for Advanced Study in 1941, shows how far he had come with Hilbert's second problem, namely to a theory of computable functionals of finite type and a proof of the consistency of ordinary arithmetic. It offers indispensable reading for logicians, mathematicians, and computer scientists interested in foundational questions. It will form a basis for further investigations into Goedel's vast Nachlass of unpublished notes on how to extend the results of his lectures to the theory of real numbers. The book also gives insights into the conceptual and formal work that is needed for the solution of profound scientific questions, by one of the central figures of 20th century science and philosophy.

Games, Norms, and Reasons: Logic at the Crossroads provides an overview of modern logic focusing on its relationships with other disciplines, including new interfaces with rational choice theory, epistemology, game theory and informatics. This book continues a series called "Logic at the Crossroads" whose title reflects a view that the deep insights from the classical phase of mathematical logic can form a harmonious mixture with a new, more ambitious research agenda of understanding and enhancing human reasoning and intelligent interaction. The editors have gathered together articles from active authors in this new area that explore dynamic logical aspects of norms, reasons, preferences and beliefs in human agency, human interaction and groups. The book pays a special tribute to Professor Rohit Parikh, a pioneer in this movement.

This book offers readers a collection of 50 short chapter entries on topics in the philosophy of language. Each entry addresses a paradox, a longstanding puzzle, or a major theme that has emerged in the field from the last 150 years, tracing overlap with issues in philosophy of mind, cognitive science, ethics, political philosophy, and literature. Each of the 50 entries is written as a piece that can stand on its own, though useful connections to other entries are mentioned throughout the text. Readers can open the book and start with almost any of the entries, following themes of greatest interest to them. Each entry includes recommendations for further reading on the topic. Philosophy of Language: 50 Puzzles, Paradoxes, and Thought Experiments is useful as a standalone textbook, or can be supplemented by additional readings that instructors choose. The accessible style makes it suitable for introductory level through intermediate undergraduate courses, as well as for independent learners, or even as a reference for more advanced students and researchers. Key Features: Uses a problem-centered approach to philosophy of language (rather than author- or theory-centered) making the text more inviting to first-time students of the subject. Offers stand-alone chapters, allowing students to quickly understand an issue and giving instructors flexibility in assigning readings to match the themes of the course. Provides up-to-date recommended readings at the end of each chapter, or about 500 sources in total, amounting to an extensive review of the literature on each topic.