3 in philosophy, and therefore in metaphilosophy, cannot be based on rules that avoid spending time on pseudo-problems. Of course, this implies that, if one succeeds in demonstrating convincingly the pseudo-character of a problem by giving its 'solution', the time spent on it need not be seen as wasted. We conclude this section with a brief statement of the criteria for concept explication as they have been formulated in several places by Carnap, Hempel and Stegmiiller. Hempel's account ( 13J, Chapter 1) is still very adequate for a detailed introduction. The process of explication starts with the identification of one or more vague and, perhaps, ambiguous concepts, the so-called explicanda. Next, one tries to disentangle the ambiguities. This, however, need not be possible at once. Ultimately the explicanda are to be replaced (not necessarily one by one) by certain counterparts, the so-called explicata, which have to conform to four requirements. They have to be as precise as possible and as simple as possible. In addition, they have to be useful in the sense that they give rise to the formulation of theories and the solution of problems. The three requirements of preciseness, simplicity and usefulness. have of course to be pursued in all concept formation.

cians concerned with using logical tools in philosophy have been keenly aware of the limitations that arise from the original con centration of symbolic logic on the idiom of mathematics, and many of them have worked to create extensions of the received logical theories that would make them more generally applicable in philosophy. Carnap's Testability and Meaning, published in 1936 and 1937, was a good early example of this sort of research, motivated by the inadequacy of first-order formalizations of dis 'This sugar cube is soluble in water'. positional sentences like And in fact there is a continuous history of work on this topic, extending from Carnap's paper to Shoham's contribution to the present volume . . Much of the work in philosophical logic, and much of what has appeared in The Journal of Philosophical Logic, was mo tivated by similar considerations: work in modal logic (includ ing tense, deontic, and epistemic logic), intensional logics, non declaratives, presuppositions, and many other topics. In this sort of research, sin.ce the main point is to devise new formalisms, the technical development tends to be rather shallow in comparison with mathematical logic, though it is sel dom absent: theorems need to be proved in order to justify the formalisms, and sometimes these are nontrivial. On the other hand, much effort has to go into motivating a logical innovation."

The book investigates the ontology and logic of quantum physics. The first part discusses the relationship of theory and observation and different views on the ontological status of scientific theories. It introduces the fundamentals of quantum mechanics and some of its interpretations and their compatibility with various ontological positions. In the second part, implications of quantum mechanics on classical logic, especially on the distributive law and bivalence, as discussed by Garrett Birkhoff & John von Neumann (1936) and Hilary Putnam (1968), and their counterarguments are reconstructed and discussed. It is concluded that classical logic is sufficient for dealing with quantum mechanical propositions.

Recent work in argumentation theory has emphasized the nature of arguers and arguments along with various theoretical perspectives. Less attention has been given to the third feature of any argumentative situation - the audience. This book fills that gap by studying audience reception to argumentation and the problems that come to light as a result of this shift in focus. Christopher W. Tindale advances the tacit theories of several earlier thinkers by addressing the central problems connected with audience considerations in argumentation, problems that earlier philosophical theories overlook or inadequately accommodate. The main tools employed in exploring the central issues are drawn from contemporary philosophical research on meaning, testimony, emotion and agency. These are then combined with some of the major insights of recent rhetorical work in argumentation to advance our understanding of audiences and suggest avenues for further research.

Over the past few years, the tree model of time has been widely employed to deal with issues concerning the semantics of tensed discourse. The thought that has motivated its adoption is that the most plausible way to make sense of indeterminism is to conceive of future possibilities as branches that depart from a common trunk, constituted by the past and the present. However, the thought still needs to be further articulated and defended, and several important questions remain open, such as the question of how actuality can be understood and formally represented in a branching framework. The present volume is intended to be a 360 degree reflection on the tree model. The contributions is gathers concern the model and its alternatives, both from a semantic and from a metaphysical point of view.

Offers an extremely bold, far-reaching, and unsuspected thesis in the history of philosophy: Aristotelianism was a dominant movement of the British philosophical landscape, especially in the field of logic, and it had a long survival. British Aristotelian doctrines were strongly empiricist in nature, both in the theory of knowledge and in scientific method; this character marked and influenced further developments in British philosophy at the end of the century, and eventually gave rise to what we now call British empiricism, which is represented by philosophers such as John Locke, George Berkeley and David Hume. Beyond the apparent and explicit criticism of the old Scholastic and Aristotelian philosophy, which has been very well recognized by the scholarship in the twentieth century and which has contributed to the false notion that early modern philosophy emerged as a reaction to Aristotelianism, the present research examines the continuity, the original developments and the impact of Aristotelian doctrines and terminology in logic and epistemology as the background for the rise of empiricism.Without the Aristotelian tradition, without its doctrines, and without its conceptual elaborations, British empiricism would never have been born. The book emphasizes that philosophy is not defined only by the 'great names', but also by minor authors, who determine the intellectual milieu from which the canonical names emerge. It considers every single published work of logic between the middle of the sixteenth and the end of the seventeenth century, being acquainted with a number of surviving manuscripts and being well-informed about the best existing scholarship in the field.

A 'self-refutation argument' is any argument which aims at showing that (and how) a certain thesis is self-refuting. This study was the first book-length treatment of ancient self-refutation and provides a unified account of what is distinctive in the ancient approach to the self-refutation argument, on the basis of close philological, logical and historical analysis of a variety of sources. It examines the logic, force and prospects of this original style of argumentation within the context of ancient philosophical debates, dispelling various misconceptions concerning its nature and purpose and elucidating some important differences which exist both within the ancient approach to self-refutation and between that approach, as a whole, and some modern counterparts of it. In providing a comprehensive account of ancient self-refutation, the book advances our understanding of influential and debated texts and arguments from philosophers like Democritus, Plato, Aristotle, Epicurus, the Stoics, the Academic sceptics, the Pyrrhonists and Augustine.

Modern logic has Wldergone some remarkable developments in the last hun dred years. These have contributed to the extraordinary use of formal logic which has become essentially the concern of mathematicians. This has led to attempts to identify logic with formal logic. The claim has even been made that all non-formal reasoning, to the extent that it cannot be formalized, no longer belongs to logic. This conception leads to a genuine impoverishment of logic as well as to a narrow conception of reason. It means that as soon as demonstrative proofs are no longer available reason will no longer dominate. Even the idea of the 'reasonable' becomes foreign to logic and such expres sions as 'reasonable decisions', 'reasonable choice' or 'reasonable hypotheses' would be put aside as meaningless. The domain of action, including method ology and everything that is given over to deliberation or controversy - i.e., foreign to formal logic - would become a battleground where necessarily the reason of the strongest would always prevail."

Our ability to think, argue and reason is determined by our ability to question. Questions are a vital component of critical thinking, yet we underestimate the role they play. Using Questions to Think puts questioning back in the spotlight. Naming the parts of questions at the same time as we name parts of thought, this one-of-a-kind introduction allows us to see how questions relate to the definitions of propositions, premises, conclusions, and the validity of arguments. Why is this important? Making the role of questions visible in thinking reasoning and dialogue, allows us to: - Ask better questions - Improve our capability to understand an argument - Exercise vigilance in the act of questioning - Make explicit what you already know implicitly - Engage with ideas that contradict our own - See ideas in broader context Breathing new life into our current approach to critical thinking, this practical, much-needed textbook moves us away from the traditional focus on formal argument and fallacy identification, combines the Kantian critique of reason with Hans-Georg Gadamer's hermeneutics and reminds us why thinking can only be understood as an answer to a question.

J. Anthony Blair is a prominent international figure in argumentation studies. He is among the originators of informal logic, an author of textbooks on the informal logic approach to argument analysis and evaluation and on critical thinking, and a founder and editor of the journal Informal Logic. Blair is widely recognized among the leaders in the field for contributing formative ideas to the argumentation literature of the last few decades. This selection of key works provides insights into the history of the field of argumentation theory and various related disciplines. It illuminates the central debates and presents core ideas in four main areas: Critical Thinking, Informal Logic, Argument Theory and Logic, Dialectic and Rhetoric.

The book presents a thoroughly elaborated logical theory of generalized truth-values understood as subsets of some established set of (basic) truth values. After elucidating the importance of the very notion of a truth value in logic and philosophy, we examine some possible ways of generalizing this notion. The useful four-valued logic of first-degree entailment by Nuel Belnap and the notion of a bilattice (a lattice of truth values with two ordering relations) constitute the basis for further generalizations. By doing so we elaborate the idea of a multilattice, and most notably, a trilattice of truth values - a specific algebraic structure with information ordering and two distinct logical orderings, one for truth and another for falsity. Each logical order not only induces its own logical vocabulary, but determines also its own entailment relation. We consider both semantic and syntactic ways of formalizing these relations and construct various logical calculi.

Though the subject of this work, "nominalism and contemporary nom inalism," is philosophical, it cannot be fully treated without relating it to data gathered from a great variety of domains, such as biology and more especially ethology, psychology, linguistics and neurobiology. The source of inspiration has been an academic work I wrote in order to obtain a postdoctoral degree, which is called in Belgium an "Aggregaat voor het Hoger Onderwijs" comparable to a "Habilitation" in Germany. I want to thank the National Fund of Scientific Research, which accorded me several grants and thereby enabled me to write the academic work in the first place and thereafter this book. I also want to thank Prof. SJ. Doorman (Technical University of Delft) and Prof. G. Nuchelmans (University of Leiden), who were members of the jury of the "Aggre gaatsthesis," presented to the Free University of Brussels in 1981 and who by their criticisms and suggestions encouraged me to write the present book, the core of which is constituted by the general ideas then formulated. I am further obliged to Mr. X, the referee who was asked by Jaakko Hintikka to read my work and who made a series of constructive remarks and recom mendations. My colleague Marc De Mey (University of Ghent) helped me greatly with the more formal aspects of my work and spent too much of his valuable time and energy to enable me to deliver a presentable copy. All remaining shortcomings are entirely my responsibility. I asked Prof."

by the question in its being an answer, if only in a circumstantial (i. e. inessential) manner. One indeed must question oneself in order to remember, says Plato, but the dialectic, which would be scientific, must be something else even if it remains a play of question and answer. This contradiction did not escape Aristotle: he split the scientific from the dialectic and logic from argumentation whose respective theories he was led to conceive in order to clearly define their boundaries and specificities. As for Plato, he found in the famous theory of Ideas what he sought in order to justify knowledge as that which is supposed to hold its truth only from itself. What do Ideas mean within the framework of our approach? In what consists the passage from rhetoric to ontology which leads to the denaturation of argumentation? When Socrates asked, for example, "What is virtue?," he thought one could not answer such a question because the answer refers to a single proposition, a single truth, whereas the formulation of the question itself does not indicate this unicity. For any answer, another can be given and thus continuously, if necessary, until eventually one will come across an incompatibility. Now, to a question as to what X, Y, or Z is, one can answer in many ways and nothing in the question itself prohibits multiplicity. Virtue is courage, is justice, and so on.

It is the aim of the present study to introduce the reader to the ways of thinking of those contemporary philosophers who apply the tools of symbolic logic to classical philosophical problems. Unlike the "conti nental" reader for whom this work was originally written, the English speaking reader will be more familiar with most of the philosophers dis cussed in this book, and he will in general not be tempted to dismiss them indiscriminately as "positivists" and "nominalists." But the English version of this study may help to redress the balance in another respect. In view of the present emphasis on ordinary language and the wide spread tendency to leave the mathematical logicians alone with their technicalities, it seems not without merit to revive the interest in formal ontology and the construction of formal systems. A closer look at the historical account which will be given here, may convince the reader that there are several points in the historical develop ment whose consequences have not yet been fully assessed: I mention, e. g., the shift from the traditional three-level semantics of sense and deno tation to the contemporary two-level semantics of representation; the relation of extensional structure and intensional content in the extensional systems of Wittgenstein and Carnap; the confusing changes in labelling the different kinds of analytic and apriori true sentences; etc. Among the philosophically interesting tools of symbolic logic Lesniewski's calculus of names deserves special attention."

1. Main assumptions, objectives and conditionings 1.1. The present book is concerned with certain problems in the logical philosophy of language . It is written in the the Polish logical, philosophical, and semiotic spirit of syntax of tradition, and shows two conceptions of the categorial languages : the theory of simple languages, i.e ., languages which do not include variables nor the operators that bind them (for instance, large fragments of natural languages, calculi, the language of languages of well-known sentential Aristotle's traditional syllogistic, languages of equationally definable algebras), and the theory of w-languages, i.e., languages which include operators and variables bound by the latter

The general aim of this book is to provide an elementary exposition of some basic concepts in terms of which both classical and non-dassicallogirs may be studied and appraised. Although quantificational logic is dealt with briefly in the last chapter, the discussion is chiefly concemed with propo- gjtional cakuli. Still, the subject, as it stands today, cannot br covered in one book of reasonable length. Rather than to try to include in the volume as much as possible, I have put emphasis on some selected topics. Even these could not be roverrd completely, but for each topic I have attempted to present a detailed and precise t'Xposition of several basic results including some which are non-trivial. The roots of some of the central ideas in the volume go back to J.Luka- siewicz's seminar on mathematicallogi

This book intends to show that radical naturalism (or physicalism), nominalism and strict finitism account for the applications of classical mathematics in current scientific theories. The applied mathematical theories developed in the book include the basics of calculus, metric space theory, complex analysis, Lebesgue integration, Hilbert spaces, and semi-Riemann geometry (sufficient for the applications in classical quantum mechanics and general relativity). The fact that so much applied mathematics can be developed within such a weak, strictly finitistic system, is surprising in itself. It also shows that the applications of those classical theories to the finite physical world can be translated into the applications of strict finitism, which demonstrates the applicability of those classical theories without assuming the literal truth of those theories or the reality of infinity. Both professional researchers and students of philosophy of mathematics will benefit greatly from reading this book.

"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."

George Berkeley's Principles of Human Knowledge is a crucial text in the history of empiricism and in the history of philosophy more generally. Its central and seemingly astonishing claim is that the physical world cannot exist independently of the perceiving mind. The meaning of this claim, the powerful arguments in its favour, and the system in which it is embedded, are explained in a highly lucid and readable fashion and placed in their historical context. Berkeley's philosophy is, in part, a response to the deep tensions and problems in the new philosophy of the early modern period and the reader is offered an account of this intellectual milieu. The book then follows the order and substance of the Principles whilst drawing on materials from Berkeley's other writings. This volume is the ideal introduction to Berkeley's Principles and will be of great interest to historians of philosophy in general.

Although the study of reasons plays an important role in both epistemology and moral philosophy, little attention has been devoted to the question of how, exactly, reasons interact to support the actions or conclusions they do. In this book, John F. Horty attempts to answer this question by providing a precise, concrete account of reasons and their interaction, based on the logic of default reasoning. The book begins with an intuitive, accessible introduction to default logic itself, and then argues that this logic can be adapted to serve as a foundation for a concrete theory of reasons. Horty then shows that the resulting theory helps to explain how the interplay among reasons can determine what we ought to do by developing two different deontic logics, capturing two different intuitions about moral conflicts. In the central part of the book, Horty elaborates the basic theory to account for reasoning about the strength of our own reasons, and also about the related concepts of undercutting defeaters and exclusionary reasons. The theory is illustrated with an application to particularist arguments concerning the role of principles in moral theory. The book concludes by introducing a pair of issues new to the philosophical literature: the problem of determining the epistemic status of conclusions supported by separate but conflicting reasons, and the problem of drawing conclusions from sets of reasons that can vary arbitrarily in strength, or importance.

Proof, Computation and Agency: Logic at the Crossroads provides an overview of modern logic and its relationship with other disciplines. As a highlight, several articles pursue an inspiring paradigm called 'social software', which studies patterns of social interaction using techniques from logic and computer science. The book also demonstrates how logic can join forces with game theory and social choice theory. A second main line is the logic-language-cognition connection, where the articles collected here bring several fresh perspectives. Finally, the book takes up Indian logic and its connections with epistemology and the philosophy of science, showing how these topics run naturally into each other.

From the author of Wittgenstein's Poker and Would You Kill the Fat Man?, the story of an extraordinary group of philosophers during a dark chapter in Europe's history On June 22, 1936, the philosopher Moritz Schlick was on his way to deliver a lecture at the University of Vienna when Johann Nelboeck, a deranged former student of Schlick's, shot him dead on the university steps. Some Austrian newspapers defended the madman, while Nelboeck himself argued in court that his onetime teacher had promoted a treacherous Jewish philosophy. David Edmonds traces the rise and fall of the Vienna Circle-an influential group of brilliant thinkers led by Schlick-and of a philosophical movement that sought to do away with metaphysics and pseudoscience in a city darkened by fascism, anti-Semitism, and unreason. The Vienna Circle's members included Otto Neurath, Rudolf Carnap, and the eccentric logician Kurt Goedel. On its fringes were two other philosophical titans of the twentieth century, Ludwig Wittgenstein and Karl Popper. The Circle championed the philosophy of logical empiricism, which held that only two types of propositions have cognitive meaning, those that can be verified through experience and those that are analytically true. For a time, it was the most fashionable movement in philosophy. Yet by the outbreak of World War II, Schlick's group had disbanded and almost all its members had fled. Edmonds reveals why the Austro-fascists and the Nazis saw their philosophy as such a threat. The Murder of Professor Schlick paints an unforgettable portrait of the Vienna Circle and its members while weaving an enthralling narrative set against the backdrop of economic catastrophe and rising extremism in Hitler's Europe.

This volume, "The Brazilian Studies in the Philosophy and History of Science, "is the first attempt to present to a general audience, works from Brazil on this subject. The included papers are original, covering a remarkable number of relevant topics of philosophy of science, logic and on the history of science. The Brazilian community has increased in the last years in quantity and in quality of the works, most of them being published in respectable international journals on the subject. The chapters of this volume are forwarded by a general introduction, which aims to sketch not only the contents of the chapters, but it is conceived as a historical and conceptual guide to the development of the field in Brazil. The introduction intends to be useful to the reader, and not only to the specialist, helping them to evaluate the increase in production of this country within the international context.

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This monograph first presents a method of diagramming argument macrostructure, synthesizing the standard circle and arrow approach with the Toulmin model. A theoretical justification of this method through a dialectical understanding of argument, a critical examination of Toulmin on warrants, a thorough discussion of the linked-convergent distinction, and an account of the proper reconstruction of enthymemes follows.

The study of information-based actions and processes has been a vibrant - terface between logic and computer science for several decades now. Indeed, several natural perspectives come together here. On the one hand, logical s- tems may be used to describe the dynamics of arbitrary computational p- cesses as in the many sophisticated process logics available today. But also, key logical notions such as model checking or proof search are themselves informational processes involving agents with goals. The interplay between these descriptive and dynamic aspects shows even in our ordinary language. A word like proof hdenotes both a static certificate of truth, and an activity which humans or machines engage in. Increasing our understanding of l- ics of this sort tells us something about computer science, and about cognitive actions in general. The individual chapters of this book show the state of the art in current - vestigations of process calculi such as linear logic, and with mainly two major paradigms at work, namely, linear logic and modal logic. These techniques are applied to the title themes of concurrency and synchronisation, but there are also many repercussions for topics such as the geometry of proofs, categorial semantics, and logics of graphs. Viewed - gether, the chapters also offer exciting glimpses of future integration, as the reader moves back and forth through the book."