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.

How does Russell's realist conception of the proposition and its constituents inform the techniques for analysis which he adopted in mathematics? Jolen Galaugher's book sheds light on this perplexing issue. In this book, Galaugher provides a detailed treatment of Russell's early conception of analysis in the light of the philosophical doctrines to which it answered, and the demands imposed by existing mathematics on his early logicist program. She ties together the philosophical commitments which occasioned Russell's break with idealism and the problems which guided his selection of technical apparatus in his embrace of logicism. The result is a detailed synthesis of the primary materials from the emergence of Russell's realism in 1898 to his landmark theory of descriptions in 1905. Galaugher's broad thesis is that although Russell adopted increasingly refined techniques by which to carry out his logical analyses and avoid the Contradiction, the most crucial aspects of his philosophical conception of logical analysis were retained.

This book explains the first published consistency proof of PA. It contains the original Gentzen's proof, but it uses modern terminology and examples to illustrate the essential notions. The author comments on Gentzen's steps which are supplemented with exact calculations and parts of formal derivations. A notable aspect of the proof is the representation of ordinal numbers that was developed by Gentzen. This representation is analysed and connection to set-theoretical representation is found, namely an algorithm for translating Gentzen's notation into Cantor normal form. The topic should interest researchers and students who work on proof theory, history of proof theory or Hilbert's program and who do not mind reading mathematical texts. "

This volume describes and analyzes in a systematic way the great contributions of the philosopher Krister Segerberg to the study of real and doxastic actions. Following an introduction which functions as a roadmap to Segerberg's works on actions, the first part of the book covers relations between actions, intentions and routines, dynamic logic as a theory of action, agency, and deontic logics built upon the logics of actions. The second section explores belief revision and update, iterated and irrevocable beliefs change, dynamic doxastic logic and hypertheories. Segerberg has worked for more than thirty years to analyze the intricacies of real and doxastic actions using formal tools - mostly modal (dynamic) logic and its semantics. He has had such a significant impact on modal logic that "It is hard to roam for long in modal logic without finding Krister Segerberg's traces," as Johan van Benthem notes in his chapter of this book.

This volume is concerned with the concept of rationality and the interrelations between rationality, belief and desire in the explanation and evaluation of human action. The book is conceived and structured to represent some of the most important general differences of approach to these problems, and also to connect them with problems about the relation of individual to social behaviour which are of central interest to historians, social theorists and economists as well as to philosophers. The essays have all been commissioned for this volume and have not appeared elsewhere. The idea for the book arose from the meetings of philosophers and social scientists sponsored by the Thyssen Foundation, and is therefore a continuation of the informal series begun by C. Hookway and P. Pettit (eds.) Action and Interpretation (C. U. P. 1978).

This meticulous critical assessment of the ground-breaking work of philosopher Stanislaw Le niewski focuses exclusively on primary texts and explores the full range of output by one of the master logicians of the Lvov-Warsaw school. The author's nuanced survey eschews secondary commentary, analyzing Le niewski's core philosophical views and evaluating the formulations that were to have such a profound influence on the evolution of mathematical logic.

One of the undisputed leaders of the cohort of brilliant logicians that congregated in Poland in the early twentieth century, Le niewski was a guide and mentor to a generation of celebrated analytical philosophers (Alfred Tarski was his PhD student). His primary achievement was a system of foundational mathematical logic intended as an alternative to the Principia Mathematica of Alfred North Whitehead and Bertrand Russell. Its three strands-'protothetic', 'ontology', and 'mereology', are detailed in discrete sections of this volume, alongside a wealth other chapters grouped to provide the fullest possible coverage of Le niewski's academic output.

With material on his early philosophical views, his contributions to set theory and his work on nominalism and higher-order quantification, this book offers a uniquely expansive critical commentary on one of analytical philosophy's great pioneers. "

A Chance for Possibility defends the view that the objective modal realm is tripartite: truths about possible worlds supervene on modal truths, which in turn supervene on truths about objective chances. An understanding of supervenience in terms of grounding is developed which - unlike the standard modal characterization - allows the question of what modal truths supervene on to have a non-trivial answer. Relying on this understanding, a negative result is established: modal truths do not supervene on truths about possible worlds, whether possible worlds are conceived of as Lewisian concreta or as abstract objects of some kind. Instead, a conception of pleonastic possible worlds is developed that reverses the direction of supervenience. On the basis of linguistic considerations concerning our use of natural language 'might' and 'might have' sentences, Steinberg finally argues that truths about objective chances are able to provide a supervenience base for modal truths. A Chance for Possibility is an investigation in analytic metaphysics, drawing on related work in the philosophy of logic and language as well as linguistics. It provides a detailed case study for the fruitful use of a notion of grounding in the clarification and evaluation of longstanding philosophical issues.

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

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

In this book, Veikko Rantala makes a systematic attempt to understand cognitive characteristics of translation by bringing its logical, pragmatic and hermeneutic features together and examining a number of scientific, logical, and philosophical applications. The notion of translation investigated here is called explanatory, but it is not a translation in the standard sense of the word since it admits of conceptual change. Such translations can take various degrees of precision, and therefore they can occur in contexts of different kinds: from everyday discourse to literary texts to scientific change. The book generalizes some earlier approaches to translation, especially the one presented in David Pearce's monograph Roads to Commensurability. Rantala argues that the notion has something in common with Thomas Kuhn's earlier conception of scientific change and his views of language learning, but it can be used to go beyond Kuhn's well-known ideas and challenge his criticism concerning the import of the correspondence relation.

The topic to which this book is devoted is reductionism, and not reduction. The difference in the adoption of these two denominations is not, contrary to what might appear at first sight, just a matter of preference between a more abstract (reductionism) or a more concrete (reduction) terminology for indicating the same sUbject matter. In fact, the difference is that between a philosophical doctrine (or, perhaps, simply a philosophical tenet or claim) and a scientific procedure. Of course, this does not mean that these two fields are separated; they are only distinct, and this already means that they are also likely to be interrelated. However it is useful to consider them separately, if at least to better understand how and why they are interconnected. Just to give a first example of difference, we can remark that a philosophical doctrine is something which makes a claim and, as such, invites controversy and should, in a way, be challenged. A scientific procedure, on the other hand, is something which concretely exists, and as such must be first of all described, interpreted, understood, defined precisely and analyzed critically; this work may well lead to uncovering limitations of this procedure, or of certain ways of conceiving or defining it, but it does not lead to really challenging it.

In this book, Livingston develops the political implications of formal results obtained over the course of the twentieth century in set theory, metalogic, and computational theory. He argues that the results achieved by thinkers such as Cantor, Russell, Godel, Turing, and Cohen, even when they suggest inherent paradoxes and limitations to the structuring capacities of language or symbolic thought, have far-reaching implications for understanding the nature of political communities and their development and transformation. Alain Badiou's analysis of logical-mathematical structures forms the backbone of his comprehensive and provocative theory of ontology, politics, and the possibilities of radical change. Through interpretive readings of Badiou's work as well as the texts of Giorgio Agamben, Jacques Lacan, Jacques Derrida, Gilles Deleuze, and Ludwig Wittgenstein, Livingston develops a formally based taxonomy of critical positions on the nature and structure of political communities. These readings, along with readings of Parmenides and Plato, show how the formal results can transfigure two interrelated and ancient problems of the One and the Many: the problem of the relationship of a Form or Idea to the many of its participants, and the problem of the relationship of a social whole to its many constituents.

This book, provides a critical approach to all major logical paradoxes: from ancient to contemporary ones. There are four key aims of the book: 1. Providing systematic and historical survey of different approaches - solutions of the most prominent paradoxes discussed in the logical and philosophical literature. 2. Introducing original solutions of major paradoxes like: Liar paradox, Protagoras paradox, an unexpected examination paradox, stone paradox, crocodile, Newcomb paradox. 3. Explaining the far-reaching significance of paradoxes of vagueness and change for philosophy and ontology. 4. Proposing a novel, well justified and, as it seems, natural classification of paradoxes. "

This book presents a constitutive approach to controversy based on a discourse analysis of news texts, focusing on the role of journalists as participants who shape public controversy for readers. Drawing data from the Reuters Corpus, the project identifies formulas that journalists use in reporting controversy and draws conclusions about how these serve professional and textual functions and how they shape public controversy as a natural, historical, and pragmatic event. While the traditions of dialectic and rhetoric have focused on the prescriptive aim of training participants to resolve controversies in philosophical dialogue or public debate settings, this orientation has tended to preempt questions about where controversy is located and how it is shaped. This project contributes to descriptive, ethnographic research about controversy, using discourse analysis to address a problem in argumentation.

Logic, the discipline that explores valid reasoning, does not need to be limited to a specific form of representation but should include any form as long as it allows us to draw sound conclusions from given information. The use of diagrams has a long but unequal history in logic: The golden age of diagrammatic logic of the 19th century thanks to Euler and Venn diagrams was followed by the early 20th century's symbolization of modern logic by Frege and Russell. Recently, we have been witnessing a revival of interest in diagrams from various disciplines - mathematics, logic, philosophy, cognitive science, and computer science. This book aims to provide a space for this newly debated topic - the logical status of diagrams - in order to advance the goal of universal logic by exploring common and/or unique features of visual reasoning.

Our preferences determine how we act and think, but exactly what the mechanics are and how they work is a central cause of concern in many disciplines. This book uses techniques from modern logics of information flow and action to develop a unified new theory of what preference is and how it changes. The theory emphasizes reasons for preference, as well as its entanglement with our beliefs. Moreover, the book provides dynamic logical systems which describe the explicit triggers driving preference change, including new information, suggestions, and commands. In sum, the book creates new bridges between many fields, from philosophy and computer science to economics, linguistics, and psychology. For the experienced scholar access to a large body of recent literature is provided and the novice gets a thorough introduction to the action and techniques of dynamic logic.

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.

In "God, Mind and Logical Space" Istvan Aranyosi takes the reader on a journey for the mind by revisiting the fundamental questions and the everlasting debates in philosophy of religion, ontology, and the philosophy of mind. The first part deals with issues in ontology, and the author puts forward a radical view according to which all thinkable objects and states of affairs have an equal claim to existence in a way that renders existence a relative notion. In the second part another radical view is argued for, according to which some objects and states of affairs that do not exist in our world are nevertheless present in our surroundings by being real in their consequences. The final part argues that the only way to prove the existence of God is to accept a view called Logical Pantheism, according to which God is identical to Logical Space.

"A remarkable book capable of reshaping what one takes philosophy to be." -Cora Diamond, Kenan Professor of Philosophy Emerita, University of Virginia Could there be a logical alien-a being whose ways of talking, inferring, and contradicting exhibit an entirely different logical shape than ours, yet who nonetheless is thinking? Could someone, contrary to the most basic rules of logic, think that two contradictory statements are both true at the same time? Such questions may seem outlandish, but they serve to highlight a fundamental philosophical question: is our logical form of thought merely one among many, or must it be the form of thought as such? From Descartes and Kant to Frege and Wittgenstein, philosophers have wrestled with variants of this question, and with a range of competing answers. A seminal 1991 paper, James Conant's "The Search for Logically Alien Thought," placed that question at the forefront of contemporary philosophical inquiry. The Logical Alien, edited by Sofia Miguens, gathers Conant's original article with reflections on it by eight distinguished philosophers-Jocelyn Benoist, Matthew Boyle, Martin Gustafsson, Arata Hamawaki, Adrian Moore, Barry Stroud, Peter Sullivan, and Charles Travis. Conant follows with a wide-ranging response that places the philosophical discussion in historical context, critiques his original paper, addresses the exegetical and systematic issues raised by others, and presents an alternative account. The Logical Alien challenges contemporary conceptions of how logical and philosophical form must each relate to their content. This monumental volume offers the possibility of a new direction in philosophy.

This volume comprises a selection of papers that were contributed to the 7th International Congress of Logic, Methodology and Philosophy of Science, which was held in Salzburg from the 11th - 16th July, 1983. There were 14 sections in this congress: 1. proof theory and foundations of mathematics 2. model theory and its applica ti on 3. recursion theory and theory of computation 4. axiomatic set theory 5. philosophical logic 6. general methodology of science 7. foundations of probability and induction 8. foundations and philosophy of the physical sciences 9. foundati ons and phi 1 osophy of biology 10. foundations and philosophy of psychology foundations and philosophy 11. of the social sciences 12. foundati ons and philosophy of linguistics 13. history of logic, methodology and philosophy of science 14. fundamental principles of the ethics of science In each section, three or four invited addresses were given, which will be published in the Congress Proceedings (Ruth Barcan Marcus, Georg J. W. Dorn and Paul Weingartner, eds. : Logic, Metho dology and Philosophy of Science VII. Proceedings of the Seventh International Congress of Logic, Methodology and Philosophy of v PREFACE Science, Salzburg, 1983. - Amsterdam, New York, Oxford: North-Holland Publishing 'Company, 1985. ) Every section with the exception of section 14 also contained contributed papers.

This book is an essay on the epistemology of classifications. Its main purpose is not to provide an exposition of an actual mathematical theory of classifications, that is, a general theory which would be available to any kind of them: hierarchical or non-hierarchical, ordinary or fuzzy, overlapping or non-overlapping, finite or infinite, and so on, establishing a basis for all possible divisions of the real world. For the moment, such a theory remains nothing but a dream. Instead, the authors essentially put forward a number of key questions. Their aim is rather to reveal the "state of art" of this dynamic field and the philosophy one may eventually adopt to go further. To this end they present some advances made in the course of the last century, discuss a few tricky problems that remain to be solved, and show the avenues open to those who no longer wish to stay on the wrong track. Researchers and professionals interested in the epistemology and philosophy of science, library science, logic and set theory, order theory or cluster analysis will find this book a comprehensive, original and progressive introduction to the main questions in this field.

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.

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.

This is a title on the foundations of defeasible logic, which explores the formal properties of everyday reasoning patterns whereby people jump to conclusions, reserving the right to retract them in the light of further information. Although technical in nature the book contains sections that outline basic issues by means of intuitive and simple examples. This book is primarily targeted at philosophers interested in the foundations of defeasible logic, logicians, and specialists in artificial intelligence and theoretical computer science.

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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