The quality of our lives is determined by the quality of our thinking. The quality of our thinking, in turn, is determined by the quality of our questions, for questions are the engine, the driving force behind thinking. Without questions, we have nothing to think about. Without essential questions, we often fail to focus our thinking on the significant and substantive. When we ask essential questions, we deal with what is necessary, relevant, and indispensable to a matter at hand. We recognize what is at the heart of the matter. Our thinking is grounded and disciplined. We are ready to learn. We are intellectually able to find our way about. To be successful in life, one needs to ask essential questions: essential questions when reading, writing, and speaking; when shopping, working, and parenting; when forming friendships, choosing life-partners, and interacting with the mass media and the Internet. Yet few people are masters of the art of asking essential questions. Most have never thought about why some questions are crucial and others peripheral. Essential questions are rarely studied in school. They are rarely modeled at home. Most people question according to their psychological associations. Their questions are haphazard and scattered. The ideas we provide are useful only to the extent that they are employed daily to ask essential questions. Practice in asking essential questions eventually leads to the habit of asking essential questions. But we can never practice asking essential questions if we have no conception of them. This mini-guide is a starting place for understanding concepts that, when applied, lead to essential questions. We introduce essential questions as indispensable intellectual tools. We focus on principles essential to formulating, analyzing, assessing, and settling primary questions. You will notice that our categories of question types are not exclusive. There is a great deal of overlap

Of the four chapters in this book, the first two discuss (albeit in consider ably modified form) matters previously discussed in my papers 'On the Logic of Conditionals' [1] and 'Probability and the Logic of Conditionals' [2], while the last two present essentially new material. Chapter I is relatively informal and roughly parallels the first of the above papers in discussing the basic ideas of a probabilistic approach to the logic of the indicative conditional, according to which these constructions do not have truth values, but they do have probabilities (equal to conditional probabilities), and the appropriate criterion of soundness for inferences involving them is that it should not be possible for all premises of the inference to be probable while the conclusion is improbable. Applying this criterion is shown to have radically different consequences from the orthodox 'material conditional' theory, not only in application to the standard 'fallacies' of the material conditional, but to many forms (e. g. , Contraposition) which have hitherto been regarded as above suspi cion. Many more applications are considered in Chapter I, as well as certain related theoretical matters. The chief of these, which is the most important new topic treated in Chapter I (i. e.

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.

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.

This volume offers English translations of three early works by Ernst Schroeder (1841-1902), a mathematician and logician whose philosophical ruminations and pathbreaking contributions to algebraic logic attracted the admiration and ire of figures such as Dedekind, Frege, Husserl, and C. S. Peirce. Today he still engages the sympathetic interest of logicians and philosophers. The works translated record Schroeder's journey out of algebra into algebraic logic and document his transformation of George Boole's opaque and unwieldy logical calculus into what we now recognize as Boolean algebra. Readers interested in algebraic logic and abstract algebra can look forward to a tour of the early history of those fields with a guide who was exceptionally thorough, unfailingly honest, and deeply reflective.

This volume examines the role of logic in cognitive psychology in light of recent developments. Gonzalo Reyes's new semantic theory has brought the fields of cognitive psychology and logic closer together, and has shed light on how children master proper names and count nouns, and thus acquire knowledge. The chapters highlight the inadequacies of classical logic in its handling of ordinary language and reveal the prospects of applying these new theories to cognitive psychology, cognitive science, linguistics, the philosophy of language and logic.

This volume deals with formal, mechanizable reasoning in modal logics, that is, logics of necessity, possibility, belief, time computations etc. It is therefore of immense interest for various interrelated disciplines such as philosophy, AI, computer science, logic, cognitive science and linguistics. The book consists of 15 original research papers, divided into three parts. The first part contains papers which give a profound description of powerful proof-theoretic methods as applied to the normal modal logic S4. Part II is concerned with a number of generalizations of the standard proof-theoretic formats, while the third part presents new and important results on semantics-based proof systems for modal logic.

Offering a bold new vision on the history of modern logic, Lukas M. Verburgt and Matteo Cosci focus on the lasting impact of Aristotle's syllogism between the 1820s and 1930s. For over two millennia, deductive logic was the syllogism and syllogism was the yardstick of sound human reasoning. During the 19th century, this hegemony fell apart and logicians, including Boole, Frege and Peirce, took deductive logic far beyond its Aristotelian borders. However, contrary to common wisdom, reflections on syllogism were also instrumental to the creation of new logical developments, such as first-order logic and early set theory. This volume presents the period under discussion as one of both tradition and innovation, both continuity and discontinuity. Modern logic broke away from the syllogistic tradition, but without Aristotle's syllogism, modern logic would not have been born. A vital follow up to The Aftermath of Syllogism, this book traces the longue duree history of syllogism from Richard Whately's revival of formal logic in the 1820s through the work of David Hilbert and the Goettingen school up to the 1930s. Bringing together a group of major international experts, it sheds crucial new light on the emergence of modern logic and the roots of analytic philosophy in the 19th and early 20th centuries.

This book applies the formal discipline of logic to everyday discourse. It offers a new analysis of the notion of individual, suggesting that this notion is linguistic, not ontological, and that anything denoted by a proper name in a well-functioning language game is an individual. It further posits that everyday discourse is non-compositional, i.e., its complex expressions are not just the result of putting simpler ones together but react on the latter, modifying their meaning through feedback. The book theorizes that in everyday discourse, there is no algebra of truth values, but the latter can be both input and output of something which has no truth value at all. It suggests that an elementary proposition of everyday discourse (defined as having exactly one predicate) can, in principle, be indefinitely expanded by adding new components, belonging neither to subject nor to predicate, but remain elementary. This book is of interest to logicians and philosophers of language.

By drawing on the insights of diverse scholars from around the globe, this volume systematically investigates the meaning and reality of the concept of negation in Post-Kantian Philosophy-German Idealism, Early German Romanticism, and Neo-Kantianism. The reader benefits from the historical, critical, and systematic investigations contained which trace not only the significance of negation in these traditions, but also the role it has played in shaping the philosophical landscape of Post-Kantian philosophy. By drawing attention to historically neglected thinkers and traditions, and positioning the dialogue within a global and comparative context, this volume demonstrates the enduring relevance of Post-Kantian philosophy for philosophers thinking in today's global context. This text should appeal to graduate students and professors of German Idealism, Post-Kantian philosophy, comparative philosophy, German studies, and intellectual history.

This book features mathematical and formal philosophers' efforts to understand philosophical questions using mathematical techniques. It offers a collection of works from leading researchers in the area, who discuss some of the most fascinating ways formal methods are now being applied. It covers topics such as: the uses of probable and statistical reasoning, rational choice theory, reasoning in the environmental sciences, reasoning about laws and changes of rules, and reasoning about collective decision procedures as well as about action. Utilizing mathematical techniques has been very fruitful in the traditional domains of formal philosophy - logic, philosophy of mathematics and metaphysics - while formal philosophy is simultaneously branching out into other areas in philosophy and the social sciences. These areas particularly include ethics, political science, and the methodology of the natural and social sciences. Reasoning about legal rules, collective decision-making procedures, and rational choices are of interest to all those engaged in legal theory, political science and economics. Statistical reasoning is also of interest to political scientists and economists.

This book intends to unite studies in different fields related to the development of the relations between logic, law and legal reasoning. Combining historical and philosophical studies on legal reasoning in Civil and Common Law, and on the often neglected Arabic and Talmudic traditions of jurisprudence, this project unites these areas with recent technical developments in computer science. This combination has resulted in renewed interest in deontic logic and logic of norms that stems from the interaction between artificial intelligence and law and their applications to these areas of logic. The book also aims to motivate and launch a more intense interaction between the historical and philosophical work of Arabic, Talmudic and European jurisprudence. The publication discusses new insights in the interaction between logic and law, and more precisely the study of different answers to the question: what role does logic play in legal reasoning? Varying perspectives include that of foundational studies (such as logical principles and frameworks) to applications, and historical perspectives.

Free logic - i.e., logic free of existential presuppositions in general and with respect to singular terms in particular- began to come into its own as a field of research in the 1950s. As is the case with so many developments in Western philosophy, its roots can be traced back to ancient Greek philo sophy. It is only during the last fifty years, however, that it has become well established as a branch of modern logic. The name of Karel Lambert is most closely connected with this development: he gave it its name and its profile as a well defined field of research. After a development of fifty years, it is time to look back and take stock while at the same time scanning for new perspectives. This is the purpose of the papers collected in this volume. The first paper is written by Karel Lambert himself who also comments on all the papers of the other authors. In an introductory essay we give a survey of the present status of and new directions in free logic."

In 1911, Bertrand Russell began a historically formative interchange about the nature of logic and cognition with his student, Ludwig Wittgenstein. In 1913, Russell set to work on a manuscript, the "Theory of Knowledge", designed to move from the analysis of perception to judgement and on to knowledge of the world. After Wittgenstein interrupted Russell's daily writing with a series of objections to his doctrine of judgement and conception of logic, Russell abandoned his project in despair, leaving it unfinished. His subsequent work can be understood largely as an attempt to assimilate and respond to Wittgenstein's challenge in 1913. "Russell and Wittgenstein on the Nature of Judgement" is the first book-length treatment of Russell's decisive 1913 exchanges with Wittgenstein. Rosalind Carey incorporates little-known notes and diagrams into a new analysis of the problems Russell was facing. She also evaluates the numerous interpretations of Russell's positions and Wittgenstein's objections to them. The result is a new perspective on both these great thinkers, at a crucial point in the development of twentieth-century philosophy.

This book focuses on logic and logical language. It examines different types of words, terms and propositions in detail. While discussing the nature of propositions, it illustrates the procedures used to determine the truth and falsity of a proposition, and the validity and invalidity of an argument. In addition, the book provides a clear exposition of the pure and mixed form of syllogism with suitable examples. The book encompasses sentential logic, predicate logic, symbolic logic, induction and set theory topics. The book is designed to serve all those involved in teaching and learning courses on logic. It offers a valuable resource for students and researchers in philosophy, mathematics and computer science disciplines. Given its scope, it is an essential read for everyone interested in logic, language, formulation of the hypotheses for the scientific enquiries and research studies, and judging valid and invalid arguments in the natural language discourse.

ways of doing it, but it is wrong to project it far into the past: it did not exist at the turn of the century and only became clearly apparent after the Second World War. I recently taught at an American university on the his tory of philosophy from Balzano to Husserl. The course title had to come from a fixed pool and gave trouble. Was it philosophical logic, the nine teenth century, or phenomenology? A logic title would connote over this period Frege, Russell, Carnap, perhaps a mention of Boole: not continental enough. The nineteenth century? The century of Kant's successors: Fichte, Hegel, Schopenhauer, Feuer bach, Marx, Nietzsche? What have they to do with Balzano, Lotze, Brentano, Meinong, Husserl and Twardowski? Even tually 'Phenomenology' was chosen, misdescribing more than half of the course. That illustrates the problems one faces in trying to work against the picture of the period which is ingrained in minds and syllabuses. This book arises from my efforts to combat that picture. I backed into writing about the history of recent philosophy rather than setting out to do so. The beginning was chance. In Manchester in the early seventies, at a time when most English philosophy departments breathed re cycled Oxford air, the intellectual atmosphere derived from Cambridge and Warsaw, spiced with a breath of Freiburg and Paris."

Logical consequence is the relation that obtains between premises and conclusion(s) in a valid argument. Orthodoxy has it that valid arguments are necessarily truth-preserving, but this platitude only raises a number of further questions, such as: how does the truth of premises guarantee the truth of a conclusion, and what constraints does validity impose on rational belief? This volume presents thirteen essays by some of the most important scholars in the field of philosophical logic. The essays offer ground-breaking new insights into the nature of logical consequence; the relation between logic and inference; how the semantics and pragmatics of natural language bear on logic; the relativity of logic; and the structural properties of the consequence relation.

This book attempts to explicate and expand upon Frank Ramsey's notion of the realistic spirit. In so doing, it provides a systematic reading of his work, and demonstrates the extent of Ramsey's genius as evinced by both his responses to the Tractatus Logico-Philosophicus, and the impact he had on Wittgenstein's later philosophical insights.

This book examines the nature, sources, and implications of fallacies in philosophical reasoning. In doing so, it illustrates and evaluates various historical instances of this phenomenon. There is widespread interest in the practice and products of philosophizing, yet the important issue of fallacious reasoning in these matters has been effectively untouched. Nicholas Rescher fills this gap by presenting a systematic account of the principal ways in which philosophizing can go astray.

The present volume of the "Handbook of the History of Logic" is designed to establish 19th century Britain as a substantial force in logic, developing new ideas, some of which would be overtaken by, and other that would anticipate, the century's later capitulation to the mathematization of logic.
"British Logic in the Nineteenth Century" is indispensable reading and a definitive research resource for anyone with an interest in the history of logic.
- Detailed and comprehensive chapters covering the entire range of modal logic
- Contains the latest scholarly discoveries and interpretative insights that answer many questions in the field of logic