The relation between logic and knowledge provoked a heated debate since the 1960s. The epistemic approaches, found their formal argument in the mathematics of Brouwer and intuitionistic logic. And following Michael Dummett - started to call themselves: antirealists'. Others persisted with the formal background of the Frege-Tarski tradition, where Cantorian set theory is linked via model theory to classical logic. Jaakko Hintikka tried to join both traditions by means of what is now known as explicit epistemic logic'. Here the epistemic content is introduced into the object language as an operator which yield propositions from propositions rather than as metalogical constraint on the notion of inference. The Realism-Antirealism debate had thus three players: classical logicians, intuitionists and explicit epistemic logicians. The editors of the present volume think that in these days and age of Alternative Logics, where manifold developments in logic happen in a breathtaking pace, this debate should be revisited. Using the most recent logical and epistemological tools, this book provides a novel and refreshing view on the most important topics of the Realism vs. Antirealism debate. Its general scope is to show the most recent developments in philosophical logic to deal with problems inherited from this debate. It is meant for researcher and advanced students in philosophy, logic, formal methods. It's complete collection with a variety of approaches, it is written by leading authors in the fields, every chapter is self-contained.

The main purpose of this work is to provide an English translation of and commentary on a recently published Arabic text dealing with con ditional propositions and syllogisms. The text is that of A vicenna (Abu represents his views on the subject as they were held throughout his life.

Individual objects have potentials: paper has the potential to burn, an acorn has the potential to turn into a tree, some people have the potential to run a mile in less than four minutes. Barbara Vetter provides a systematic investigation into the metaphysics of such potentials, and an account of metaphysical modality based on them. In contemporary philosophy, potentials have been recognized mostly in the form of so-called dispositions: solubility, fragility, and so on. Vetter takes dispositions as her starting point, but argues for and develops a more comprehensive conception of potentiality. She shows how, with this more comprehensive conception, an account of metaphysical modality can be given that meets three crucial requirements: (1) Extensional correctness: providing the right truth-values for statements of possibility and necessity; (2) formal adequacy: providing the right logic for metaphysical modality; and (3) semantic utility: providing a semantics that links ordinary modal language to the metaphysics of modality. The resulting view of modality is a version of dispositionalism about modality: it takes modality to be a matter of the dispositions of individual objects (and, crucially, not of possible worlds). This approach has a long philosophical tradition going back to Aristotle, but has been largely neglected in contemporary philosophy. In recent years, it has become a live option again due to the rise of anti-Humean, powers-based metaphysics. The aim of Potentiality is to develop the dispositionalist view in a way that takes account of contemporary developments in metaphysics, logic, and semantics.

First published in 2005. Routledge is an imprint of Taylor & Francis, an informa company.

This book presents an in-depth and critical reconstruction of Prawitz's epistemic grounding, and discusses it within the broader field of proof-theoretic semantics. The theory of grounds is also provided with a formal framework, through which several relevant results are proved. Investigating Prawitz's theory of grounds, this work answers one of the most fundamental questions in logic: why and how do some inferences have the epistemic power to compel us to accept their conclusion, if we have accepted their premises? Prawitz proposes an innovative description of inferential acts, as applications of constructive operations on grounds for the premises, yielding a ground for the conclusion. The book is divided into three parts. In the first, the author discusses the reasons that have led Prawitz to abandon his previous semantics of valid arguments and proofs. The second part presents Prawitz's grounding as found in his ground-theoretic papers. Finally, in the third part, a formal apparatus is developed, consisting of a class of languages whose terms are equipped with denotation functions associating them to operations and grounds, as well as of a class of systems where important properties of the terms can be proved.

This volume contains a selection of papers presented at a Seminar on Intensional Logic held at the University of Amsterdam during the period September 1990-May 1991. Modal logic, either as a topic or as a tool, is common to most of the papers in this volume. A number of the papers are con cerned with what may be called well-known or traditional modal systems, but, as a quick glance through this volume will reveal, this by no means implies that they walk the beaten tracks. In deed, such contributions display new directions, new results, and new techniques to obtain familiar results. Other papers in this volume are representative examples of a current trend in modal logic: the study of extensions or adaptations of the standard sys tems that have been introduced to overcome various shortcomings of the latter, especially their limited expressive power. Finally, there is another major theme that can be discerned in the vol ume, a theme that may be described by the slogan 'representing changing information. ' Papers falling under this heading address long-standing issues in the area, or present a systematic approach, while a critical survey and a report contributing new techniques are also included. The bulk of the papers on pure modal logic deal with theoreti calor even foundational aspects of modal systems."

This study looks to the work of Tarski's mentors Stanislaw Lesniewski and Tadeusz Kotarbinski, and reconsiders all of the major issues in Tarski scholarship in light of the conception of Intuitionistic Formalism developed: semantics, truth, paradox, logical consequence.

This book is intended to serve as an advanced text and reference work on modal logic, a subject of growing importance which has applications to philosophy and linguistics. Although it is based mainly on research which I carried out during the years 1969-1973, it also includes some related results obtained by other workers in the field (see the refer ences in Part 7). Parts 0, 1 and 2, can be used as the basis of a one year graduate course in modal logic. The material which they contain has been taught in such courses at Stanford since 1970. The remaining parts of the book contain more than enough material for a second course in modal logic. The exercises supplement the text and are usually difficult. I wish to thank Stanford University and Bar-Han University for making it possible for me to continue and finish this work, and A. Ungar for correcting the typescript. Bar-Ilan University, Israel Dov M. GABBA Y PART 0 AN INTRODUCTION TO GENERAL INTENSIONAL LOGICS CHAPTER 0 CONSEQUENCE RELATIONS Motivation We introduce the notions of a consequence relation (which is a generalization of the notion of a logical system) and of a semantics. We show that every consequence relation is complete for a canonical semantics. We define the notion of one semantics being Dian in another and study the basic properties of this notion. The concepts of this chapter are generalizations of the various notions of logical system and possible world semantics found in the literature."

During the last decade, argumentation has attracted growing attention as a means to elicit processes (linguistic, logical, dialogical, psychological, etc.) that can sustain or provoke reasoning and learning. Constituting an important dimension of daily life and of professional activities, argumentation plays a special role in democracies and is at the heart of philosophical reasoning and scientific inquiry. Argumentation, as such, requires specific intellectual and social skills. Hence, argumentation will have an increasing importance in education, both because it is a critical competence that has to be learned, and because argumentation can be used to foster learning in philosophy, history, sciences and in many other domains.

Argumentation and Education answers these and other questions by providing both theoretical backgrounds, in psychology, education and theory of argumentation, and concrete examples of experiments and results in school contexts in a range of domains. It reports on existing innovative practices in education settings at various levels.

Bringing together scholars from a broad range of theoretical perspectives, The Language of Argumentation offers a unique overview of research at the crossroads of linguistics and theories of argumentation. In addition to theoretical and methodological reflections by leading scholars in their fields, the book contains studies of the relationship between language and argumentation from two different viewpoints. While some chapters take a specific argumentative move as their point of departure and investigate the ways in which it is linguistically manifested in discourse, other chapters start off from a linguistic construction, trying to determine its argumentative function and rhetorical potential. The Language of Argumentation documents the currently prominent research on stylistic aspects of argumentation and illustrates how the study of argumentation benefits from insights from linguistic models, ranging from theoretical pragmatics, politeness theory and metaphor studies to models of discourse coherence and construction grammar.

This is a comprehensive study of the English word or, and the logical operators variously proposed to present its meaning. Although there are indisputably disjunctive uses of or in English, it is a mistake to suppose that logical disjunction represents its core meaning. Or is descended from the Anglo-Saxon word meaning second, a form which survives in such expressions as "every other day." Its disjunctive uses arise through metalinguistic applications of an intermediate adverbial meaning which is conjunctive rather than disjunctive in character. These conjunctive uses have puzzled philosophers and logicians, and have been discussed extensively under such headings as "free choice permission." This study examines the textbook myths that have clouded our understanding of how or and other "logical" vocabulary comes to have something approaching its logical meaning in natural languages. It considers the various historical conceptions of disjunction and its place in logic from the Stoics to the present day.

Reasoning is an integral part of intelligent systems in fields like databases, logic programming, robotics, knowledge engineering, human/computer interfaces, programming environments, etc. In reality any such system has to cope with a changing world and its dynamics. Hence it is of great importance that reasoning must account for coping with change in order to be truly useful in practice. The book comprises several contributions to current ways of approaching this problem. On the one hand it surveys and synthesizes recent research work, while on the other hand new research results are included. Among the topics treated are logics for reasoning about actions and planning, belief revision and the reconciliation of logically conflicting inputs, resolving of conflicts by merging of knowledge and issues in the evolution in object-oriented databases. The book is aimed at the researcher and advanced student active in this field.

This introduction to modality places the emphasis on the metaphysics of modality rather than on the formal semetics of quantified modal logic. The text begins by introducing students to the "de re/de dicto" distinction, conventionalist and conceptualist theories of modality and some of the key problems in modality, particularly Quine's criticisms. It then moves on to explain how possible worlds provide a solution to many of the problems in modality and how possible worlds themselves have been used to analyse notions outside modality such as properties and propositions. Possible worlds introduce problems of their own and the book argues that to make progress with these problems a theory of possible worlds is required. The pros and cons of various theories of possible worlds are then examined in turn, including those of Lewis, Kripke, Adams, Stalnaker and Plantinga.

Constructibility and complexity play central roles in recent research in computer science, mathematics and physics. For example, scientists are investigating the complexity of computer programs, constructive proofs in mathematics and the randomness of physical processes. But there are different approaches to the explication of these concepts. This volume presents important research on the state of this discussion, especially as it refers to quantum mechanics. This foundational debate' in computer science, mathematics and physics was already fully developed in 1930 in the Vienna Circle. A special section is devoted to its real founder Hans Hahn, referring to his contribution to the history and philosophy of science. The documentation section presents articles on the early Philipp Frank and on the Vienna Circle in exile. Reviews cover important recent literature on logical empiricism and related topics.

This introduction to modality places the emphasis on the metaphysics of modality rather than on the formal semetics of quantified modal logic. The text begins by introducing students to the "de re/de dicto" distinction, conventionalist and conceptualist theories of modality and some of the key problems in modality, particularly Quine's criticisms. It then moves on to explain how possible worlds provide a solution to many of the problems in modality and how possible worlds themselves have been used to analyse notions outside modality such as properties and propositions. Possible worlds introduce problems of their own and the book argues that to make progress with these problems a theory of possible worlds is required. The pros and cons of various theories of possible worlds are then examined in turn, including those of Lewis, Kripke, Adams, Stalnaker and Plantinga.

Paradoxes are more than just intellectual puzzles - they raise substantive philosophical issues and offer the promise of increased philosophical knowledge. In this introduction to paradox and paradoxes, Doris Olin shows how seductive paradoxes can be, why they confuse and confound, and why they continue to fascinate. Olin examines the nature of paradox, outlining a rigorous definition and providing a clear and incisive statement of what does and does not count as a resolution of a paradox. The view that a statement can be both true and false, that contradictions can be true, is seen to provide a challenge to the account of paradox resolution, and is explored. With this framework in place, the book then turns to an in-depth treatment of the Prediction Paradox, versions of the Preface/Fallibility Paradox, the Lottery Paradox, Newcomb's Problem, the Prisoner's Dilemma and the Sorites Paradox. Each of these paradoxes is shown to have considerable philosophical punch. Olin unpacks the central arguments in a clear and systematic fashion, offers original analyses and solutions, and exposes further unsettling implications for some of our most deep-seated principles and convictions.

This book seeks to arrive at a better understanding of the relationships between the objective and subjective aspects of time. It discusses the existence of fluent time, a controversial concept in many areas, from philosophy to physics. Fluent time is understood as directional time with a past, a present and a future. We experience fluent time in our lives and we adopt a temporal perspective in our ways of knowing and acting. Nevertheless, the existence of fluent time has been debated for both philosophical and scientific reasons, thus creating a rift between the subjective and objective aspects of time. Starting from the basic notion of points of view, or perspectives, this book explores the relationships between objective or external time, as it has been conceptualized by science, and subjective or internal time, which is involved in our lived experiences. It establishes a general framework encompassing the nature, structure and mode of existence of points of view, in which the objective and subjective aspects of time can be integrated. The book mainly addresses researchers and postgraduates in philosophy and logic. Additionally, it offers inspiration for physicists and computer scientists involved in the modeling and simulation of complex behaviors for which the representation of internal time should be considered together with the notion of objective, external time.

Paradoxes are more than just intellectual puzzles - they raise substantive philosophical issues and offer the promise of increased philosophical knowledge. In this introduction to paradox and paradoxes, Doris Olin shows how seductive paradoxes can be, why they confuse and confound, and why they continue to fascinate. Olin examines the nature of paradox, outlining a rigorous definition and providing a clear and incisive statement of what does and does not count as a resolution of a paradox. The view that a statement can be both true and false, that contradictions can be true, is seen to provide a challenge to the account of paradox resolution, and is explored. With this framework in place, the book then turns to an in-depth treatment of the Prediction Paradox, versions of the Preface/Fallibility Paradox, the Lottery Paradox, Newcomb's Problem, the Prisoner's Dilemma and the Sorites Paradox. Each of these paradoxes is shown to have considerable philosophical punch. Olin unpacks the central arguments in a clear and systematic fashion, offers original analyses and solutions, and exposes further unsettling implications for some of our most deep-seated principles and convictions.

Using both Father Kevin Wall's eidetic matrix of "the relational unity of being" and Edith Stein's remarkable synoptic view of intentionality in both Aquinas and Husserl, this book uncovers purely logical ground for a subalternate eidetic science called "convergent phenomenology," itself located at the inmost depths of Husserlian phenomenology. Convergent phenomenology emerges as a distinctively new discipline dealing with relation-like objectivity as opposed to the thing-like objectivity of traditional phenomenology. This has grand implications for the way we as humans conceive of God and being. The book thus benefits theologians, logicians, and phenomenologists by revealing the constitutive interrelationality of transcendental logic in an utterly new light as already flowering forth into formal ontology itself. What emerges is a rich conception of divinity and humanity.

This book is a study in the logic of questions (sometimes called erotetic logic). The central topics in erotetic logic have been the structure of questions and the question-answer relationship. This book doesn't neglect these problems, but much of it is focussed on other issues. The main subject is the logical analysis of certain relations between questions and the contexts of their appearance. And our aim is to elaborate the conceptual apparatus of the inferential approach to the logic of questions. Questions are asked for many reasons and for different purposes. Yet, before a question is asked or posed, a questioner must arrive at it. In many cases arriving at a question resembles coming to a conclusion: there are some premises involved and some inferential thought processes take place. If we agree that a conclusion need not be "conclusive," we may say that sometimes questions can play the role of conclusions. But questions can also perform the role of premises: we often pass from some "initial" question to another question. In other words, there are inferential thought processes - we shall call them erotetic inferences - in which questions play the roles of conclusions or conclusions and premises. The inferential approach to the logic of questions focusses its attention on the analysis of erotetic inferences. This book consists of eight chapters.

This book defines a logical system called the Protocol-theoretic Logic of Epistemic Norms (PLEN), it develops PLEN into a formal framework for representing and reasoning about epistemic norms, and it shows that PLEN is theoretically interesting and useful with regard to the aims of such a framework. In order to motivate the project, the author defends an account of epistemic norms called epistemic proceduralism. The core of this view is the idea that, in virtue of their indispensable, regulative role in cognitive life, epistemic norms are closely intertwined with procedural rules that restrict epistemic actions, procedures, and processes. The resulting organizing principle of the book is that epistemic norms are protocols for epistemic planning and control. The core of the book is developing PLEN, which is essentially a novel variant of propositional dynamic logic (PDL) distinguished by more or less elaborate revisions of PDL's syntax and semantics. The syntax encodes the procedural content of epistemic norms by means of the well-known protocol or program constructions of dynamic and epistemic logics. It then provides a novel language of operators on protocols, including a range of unique protocol equivalence relations, syntactic operations on protocols, and various procedural relations among protocols in addition to the standard dynamic (modal) operators of PDL. The semantics of the system then interprets protocol expressions and expressions embedding protocols over a class of directed multigraph-like structures rather than the standard labeled transition systems or modal frames. The intent of the system is to better represent epistemic dynamics, build a logic of protocols atop it, and then show that the resulting logic of protocols is useful as a logical framework for epistemic norms. The resulting theory of epistemic norms centers on notions of norm equivalence derived from theories of process equivalence familiar from the study of dynamic and modal logics. The canonical account of protocol equivalence in PLEN turns out to possess a number of interesting formal features, including satisfaction of important conditions on hyperintensional equivalence, a matter of recently recognized importance in the logic of norms, generally. To show that the system is interesting and useful as a framework for representing and reasoning about epistemic norms, the author applies the logical system to the analysis of epistemic deontic operators, and, partly on the basis of this, establishes representation theorems linking protocols to the action-guiding content of epistemic norms. The protocol-theoretic logic of epistemic norms is then shown to almost immediately validate the main principles of epistemic proceduralism.

This book deals with a previously neglected episode in the history of logic and theories of cognition: the way in which conceptions of inference changed during the 17th century. Gaukroger focuses on the work of Descartes, contrasting his explanation of inference as an instantaneous grasp in accord with the natural light of reason with the Aristotelian view of inference as a discursive process. He offers a new interpretation of Descartes' contribution to the question, revealing it to be a significant advance over humanist and late Scholastic conceptions, and argues that the Cartesian account played a pivotal role in the development of our understanding of the nature of inference.

This complete collection of Francis Bacon's essays is superbly presented and meticulously faithful to the original publication. An intellectual possessed of a staggering breadth of knowledge and learning, Francis Bacon wrote many essays on a range of topics. Subjects such as married life, child rearing, the sins of envy and vainglory, and the virtues of friendship, love and good counsel are all thoughtfully expounded upon and detailed in these essays. Cautionary writings on the subjects of anger and revenge are also present; Bacon notably makes an impassioned plea for true justice, noting that the quality of mercy is a far higher virtue than the 'wild justice' born of angry revenge. Reflecting the early colonial times in which Francis Bacon lived, we also witness essays upon the subjects of travel, Empire, ambition and commerce. Well-traveled and curious about distant lands, it is also with experience that Bacon imbues color and depth to his essays.