A `slippery slope argument' is a kind of argument which warns you that, if you take a first step, you will find yourself caught up in a sequence of consequences from which you will be unable to extricate yourself, and that eventually you will end up speeding ever faster towards some disastrous outcome. Many textbooks on informal logic and critical thinking treat the slippery slope argument as a fallacy. Douglas Walton argues that slippery slope arguments can be used correctly in some cases as a reasonable type of argument to shift a burden of proof in a critical discussion, while in other cases they are used incorrectly. In the four central chapters he identifies and analyses four types of slippery slope argument. In each chapter he presents guidelines that show how each type of slippery slope argument can be used correctly or incorrectly, using over fifty case studies of argumentation on controversial issues. These include abortion, medical research on human embryos, euthanasia, the decriminalization of marijuana, pornography and censorship, and whether or not the burning of the American flag should be banned.

Of all philosophers of the 20th century, few built more bridges between academic disciplines than Karl Popper. He contributed to a wide variety of fields in addition to the epistemology and the theory of scientific method for which he is best known. This book illustrates and evaluates the impact, both substantive and methodological, that Popper has had in the natural and mathematical sciences. The topics selected include quantum mechanics, evolutionary biology, cosmology, mathematical logic, statistics, and cognitive science. The approach is multidisciplinary, opening a dialogue across scientific disciplines and between scientists and philosophers.

We share the capacity for knowledge with animals, but it is the nature and the scope of what we may rationally believe that makes us human. Yet what kind of beliefs do qualify as 'rational'? This challenging and refreshingly innovative book addresses certain fundamental questions concerning rational legitimacy of some widely held beliefs and provides argument-based answers to such questions, while at the same time encouraging the reader to actively engage with the views put forward and form his/her own judgement. The book is typically discursive rather than simply informative, and introduces philosophy by doing it.

This lucid and original book offers a detailed and critical exposition of German metaphysics and philosophy of logic during the past century. Julian Roberts sets his argument in the context of the current debate between "analytical" and "continental" philosophers. the book centers on the problem of reflection-exploration of the boundaries of rationality, or (in analytical terms) of the "limits of thought"-which Roberts claims lies at the heart of both traditions. Roberts concentrates on the work of Frege, Wittengenstein, Husserl, the Erlangen School, and Habermas. In the course of his examination, however, he also considers philosophers ranging from Russell and Quine to Putnam and Heidegger. Roberts argues that the technical advances of modern logic have not, as is sometimes believed by analytical thinkers, generated uniquely modern problems that can only be dealt with by a correspondingly modernist philosophy, for the problem of reflection was already at the heart of Kant's critical project and of his confrontation with Leibniz. If we recover this earlier debate, says Roberts, we can develop a more adequate understanding not merely of its echoes in the twentieth century, but of the role and contribution of metaphysics and of philosophy in general.

This book presents a systematic unifying-pluralist account-a "constructive-engagement" account-of how cross-tradition engagement in philosophy is possible. The goal of this "constructive-engagement" account is, by way of reflective criticism, argumentation, and methodological guiding principles, to inquire into how distinct approaches from different philosophical traditions can talk to and learn from each other for the sake of making joint contributions to the contemporary development of philosophy. In Part I of the book, Bo Mou explores a range of fundamental theoretic and methodological issues in cross-tradition philosophical engagement and philosophical interpretation. In Part II, he analyzes several representative case studies that demonstrate how relevant resources in the Western and Chinese philosophical traditions can constructively engage with each other. These studies cover issues in philosophical methodology, metaphysics, epistemology, philosophy of language and logic, and ethics. The book's theoretical and practical approaches expand the vision, coverage, and agenda of doing philosophy comparatively, and promote worldwide joint efforts of cross-tradition philosophical inquiries. Cross-Tradition Engagement in Philosophy will be of interest to graduate students and scholars interested in comparative philosophy and the intersection of Chinese and Western philosophy. It will also appeal to those who are interested in the ways in which cross-tradition philosophical engagement can enhance contemporary philosophical debates in metaphysics, epistemology, philosophy of language and logic, and ethics.

This book sets out for the first time in English and in the terms of modern logic the semantics of the Port Royal Logic (La Logique ou l'Art de penser, 1662-1685) of Antoine Arnauld and Pierre Nicole, perhaps the most influential logic book in the 17th and 18th centuries. Its goal is to explain how the Logic reworks the foundation of pre-Cartesian logic so as to make it compatible with Descartes' metaphysics. The Logic's authors forged a new theory of reference based on the medieval notion of objective being, which is essentially the modern notion of intentional content. Indeed, the book's central aim is to detail how the Logic reoriented semantics so that it centered on the notion of intentional content. This content, which the Logic calls comprehension, consists of an idea's defining modes. Mechanisms are defined in terms of comprehension that rework earlier explanations of central notions like conceptual inclusion, signification, abstraction, idea restriction, sensation, and most importantly within the Logic's metatheory, the concept of idea-extension, which is a new technical concept coined by the Logic. Although Descartes is famous for rejecting "Aristotelianism," he says virtually nothing about technical concepts in logic. His followers fill the gap. By putting to use the doctrine of objective being, which had been a relatively minor part of medieval logic, they preserve more central semantic doctrines, especially a correspondence theory of truth. A recurring theme of the book is the degree to which the Logic hews to medieval theory. This interpretation is at odds with what has become a standard reading among French scholars according to which this 16th-century work should be understood as rejecting earlier logic along with Aristotelian metaphysics, and as putting in its place structures more like those of 19th-century class theory.

This book defends the Direct Reference (DR) thesis in philosophy of language regarding proper names and indexical pronouns. It uniquely draws out the significant consequences of DR when it is conjoined with the fact that these singular terms sometimes fail to refer. Even though DR is widely endorsed by philosophers of language, many philosophically important and radically controversial consequences of the thesis have gone largely unexplored. This book makes an important contribution to the DR literature by explicitly addressing the consequences that follow from DR regarding failure of reference. Michael McKinsey argues that only a form of neutral free logic can capture a revised concept of logical truth that is consistent with the fact that any sentence of any form that contains a directly referring genuine term can fail to be either true or false on interpretations where that term fails to refer. He also explains how it is possible for there to be true (or false) sentences that contain non-referring names, even though this possibility seems inconsistent with DR. Consequences of Reference Failure will be of interest to philosophers of language and logic and linguists working on Direct Reference.

The central contention of this book is that second-order logic has a central role to play in laying the foundations of mathematics. In order to develop the argument fully, the author presents a detailed development of higher-order logic, including a comprehensive discussion of its semantics. Professor Shapiro demonstrates the prevalence of second-order notions in mathematics is practised, and also the extent to which mathematical concepts can be formulated in second-order languages . He shows how first-order languages are insufficient to codify many concepts in contemporary mathematics, and thus that higher-order logic is needed to fully reflect current mathematics. Throughout, the emphasis is on discussing the philosophical and historical issues associated with this subject, and the implications that they have for foundational studies. For the most part, the author assumes little more than a familiarity with logic as might be gained from a beginning graduate course which includes the incompleteness of arithmetic and the Lowenheim-Skolem theorems. All those concerned with the foundations of mathematics will find this a thought-provoking discussion of some of the central issues in this subject.

This book develops a new Wittgenstein interpretation called Wittgenstein's Metametaphysics. The basic idea is that one major strand in Wittgenstein's early and later philosophy can be described as undermining the dichotomy between realism and idealism. The aim of this book is to contribute to a better understanding of the relation between language and reality and to open up avenues of dialogue to overcome deep divides in the research literature. In the course of developing a comprehensive and in-depth interpretation, the author provides fresh and original analyses of the latest issues in Wittgenstein scholarship and gives new answers to both major exegetical and philosophical problems. This makes the book an illuminating study for scholars and advanced students alike.

Hellenistic philosophy concerns the thought of the Epicureans, Stoics, and Skeptics, the most influential philosophical groups in the era between the death of Alexander the Great (323 BCE) and the defeat of the last Greek stronghold in the ancient world (31 BCE). The Routledge Handbook of Hellenistic Philosophy provides accessible yet rigorous introductions to the theories of knowledge, ethics, and physics belonging to each of the three schools, explores the fascinating ways in which interschool rivalries shaped the philosophies of the era, and offers unique insight into the relevance of Hellenistic views to issues today, such as environmental ethics, consumerism, and bioethics. Eleven countries are represented among the Handbook's 35 authors, whose chapters were written specifically for this volume and are organized thematically into six sections: The people, history, and methods of Epicureanism, Stoicism, and Skepticism. Earlier philosophical influences on Hellenistic thought, such as Aristotle, Socrates, and Presocratics. The soul, perception, and knowledge. God, fate, and the primary principles of nature and the universe. Ethics, political theory, society, and community. Hellenistic philosophy's relevance to contemporary life. Spanning from the ancient past to the present, this Handbook aims to show that Hellenistic philosophy has much to offer all thinking people of the twenty-first century.

This book gathers the proceedings of the conference "Cultures of Mathematics and Logic," held in Guangzhou, China. The event was the third in a series of interdisciplinary, international conferences emphasizing the cultural components of philosophy of mathematics and logic. It brought together researchers from many disciplines whose work sheds new light on the diversity of mathematical and logical cultures and practices. In this context, the cultural diversity can be diachronical (different cultures in different historical periods), geographical (different cultures in different regions), or sociological in nature.

Godel's modal ontological argument is the centerpiece of an extensive examination of intensional logic. First, classical type theory is presented semantically, tableau rules for it are introduced, and the Prawitz/Takahashi completeness proof is given. Then modal machinery is added to produce a modified version of Montague/Gallin intensional logic. Finally, various ontological proofs for the existence of God are discussed informally, and the Godel argument is fully formalized. Parts of the book are mathematical, parts philosophical. "

Part I of this book presents a theory of modal metaphysics in the possible-worlds tradition. `Worlds' themselves are understood as structured sets of properties; this `Ersatzist' view is defended against its most vigorous competitors, Meinongianism and David Lewis' theory of existent concrete worlds. Related issues of essentialism and linguistic reference are explored. Part II takes up the question of lexical meaning in the context of possible-world semantics. There are skeptical analyses of analyticity and the notion of a logical constant; and an `infinite polysemy' thesis is defended. The book will be of particular interest to metaphysicians, possible-world semanticists, philosophers of language, and linguists concerned with lexical semantics.

This open access book is the first ever collection of Karl Popper's writings on deductive logic. Karl R. Popper (1902-1994) was one of the most influential philosophers of the 20th century. His philosophy of science ("falsificationism") and his social and political philosophy ("open society") have been widely discussed way beyond academic philosophy. What is not so well known is that Popper also produced a considerable work on the foundations of deductive logic, most of it published at the end of the 1940s as articles at scattered places. This little-known work deserves to be known better, as it is highly significant for modern proof-theoretic semantics. This collection assembles Popper's published writings on deductive logic in a single volume, together with all reviews of these papers. It also contains a large amount of unpublished material from the Popper Archives, including Popper's correspondence related to deductive logic and manuscripts that were (almost) finished, but did not reach the publication stage. All of these items are critically edited with additional comments by the editors. A general introduction puts Popper's work into the context of current discussions on the foundations of logic. This book should be of interest to logicians, philosophers, and anybody concerned with Popper's work.

This book puts forward an interpretation of rationality which is much broader than the one underlying the current polarity between analytic and continental philosophy. It will help to reaffirm a range of ideas which have long been pushed to the sidelines by the dominance of the geometric model of philosophical argument. Descartes's dream of attaining a `certitude equal to the demonstrations of Arithmetic and Geometry' reinforced the assumption that rationality must be assessed in terms of logical structure. Against this, Pascal invoked the notion of `finesse', and Warner extends Pascal's usage in this book to specify a related set of informal but legitimate styles of argument.

"The old logic put thought in fetters, while the new logic gives it wings." For the past century, philosophers working in the tradition of Bertrand Russell - who promised to revolutionise philosophy by introducing the 'new logic' of Frege and Peano - have employed predicate logic as their formal language of choice. In this book, Dr David Corfield presents a comparable revolution with a newly emerging logic - modal homotopy type theory. Homotopy type theory has recently been developed as a new foundational language for mathematics, with a strong philosophical pedigree. Modal Homotopy Type Theory: The Prospect of a New Logic for Philosophy offers an introduction to this new language and its modal extension, illustrated through innovative applications of the calculus to language, metaphysics, and mathematics. The chapters build up to the full language in stages, right up to the application of modal homotopy type theory to current geometry. From a discussion of the distinction between objects and events, the intrinsic treatment of structure, the conception of modality as a form of general variation to the representation of constructions in modern geometry, we see how varied the applications of this powerful new language can be.

This book analyzes the uses of emotive language and redefinitions from pragmatic, dialectical, epistemic and rhetorical perspectives, investigating the relationship between emotions, persuasion and meaning, and focusing on the implicit dimension of the use of a word and its dialectical effects. It offers a method for evaluating the persuasive and manipulative uses of emotive language in ordinary and political discourse. Through the analysis of political speeches (including President Obama's Nobel Peace Prize address) and legal arguments, the book offers a systematic study of emotive language in argumentation, rhetoric, communication, political science and public speaking.

This volume consists of papers delivered at the conference 'The Lvov-Warsaw School and Contemporary Philosophy', organised in celebration of the hun- dredth anniversary ofKazimierz Twardowski's first lecture as Professor of Phi- losophy at Lvov University. This lecture can be regarded as the starting point of the development of analytic philosophy in Poland, which culminated in the Warsaw School of Logic. The conference was held in Lvov (15-17 November) and Warsaw (19-21 November 1995). It was organised jointly by the Ukrainian Academy of Sci- ences and the Polish Academy of Sciences. The general organisation was un- dertaken by Professor Andrzej Grzegorczyk (polish Academy of Sciences) and Professor Marat Vernikov (Ukrainian Academy of Sciences). Professors Jaroslaw Isaievich (Ukrainian Academy of Sciences) and Jan Wolenski (Jagiel- Ionian University) were responsible for the scientific programme. Over 100 philosophers participated in the conference. Papers published in this volume are organised according to the sections of the conference and rep- of the papers delivered. resent a selection The editors would like to express their gratitude to Professor Andrzej Grze- gorczyk, spiritus movens of the conference, who, by including the present vol- ume in a programme of publications connected with the hundredth anniversary of the Lvov-Warsaw School, provided financial support for its preparation. Fi- nally, we express our gratitude to Dr Timothy Childers of the Academy of Sciences of the Czech Republic for correcting the English of the papers.

This book offers a plurality of perspectives on the historical origins of logicism and on contemporary developments of logicist insights in philosophy of mathematics. It uniquely provides up-to-date research and novel interpretations on a variety of intertwined themes and historical figures related to different versions of logicism. The essays, written by prominent scholars, are divided into three thematic sections. Part I focuses on major authors like Frege, Dedekind, and Russell, providing a historical and theoretical exploration of such figures in the philosophical and mathematical milieu in which logicist views were first expounded. Part II sheds new light on the interconnections between these founding figures and a number of influential other traditions, represented by authors like Hilbert, Husserl, and Peano, as well as on the reconsideration of logicism by Carnap and the logical empiricists. Finally, Part III assesses the legacy of such authors and of logicist themes for contemporary philosophy of mathematics, offering new perspectives on highly debated topics-neo-logicism and its extension to accounts of ordinal numbers and set-theory, the comparison between neo-Fregean and neo-Dedekindian varieties of logicism, and the relation between logicist foundational issues and empirical research on numerical cognition-which define the prospects of logicism in the years to come. This book offers a comprehensive account of the development of logicism and its contemporary relevance for the logico-philosophical foundations of mathematics. It will be of interest to graduate students and researchers working in philosophy of mathematics, philosophy of logic, and the history of analytic philosophy.

This book proposes a novel theory of truth and falsity. It argues that truth is a form of reference and falsity is a form of reference failure. Most of the philosophical literature on truth concentrates on certain ontological and epistemic problems. This book focuses instead on language. By utilizing the Fregean idea that sentences are singular referring expressions, the author develops novel connections between the philosophical study of truth and falsity and the huge literature in in the philosophy of language on the notion of reference. The first part of the book constructs the author's theory and argues for it in length. Part II addresses the ways in which the theory relates to, and is different from, some of the basic theories of truth. Part III takes up how to account for the truth of sentences with logical operators and quantifiers. Finally, Part IV discusses the applications and implications of the theory for longstanding problems in philosophy of language, metaphysics, and epistemology. A Referential Theory of Truth and Falsity will appeal to researchers and advanced students working in philosophy of language, epistemology, metaphysics, and linguistics.

Berkeley: Ideas, Immaterialism, and Objective Presence offers a novel interpretation of the arc of George Berkeley's philosophical thought, from his theory of vision through his immaterialism and finally to his proof of God's existence. Keota Fields unifies these themes to focus on Berkeley's use of the Cartesian doctrine of objective presence, which demands causal explanations of the content of ideas. This is particularly so with respect to Berkeley's arguments for immaterialism. One of those arguments is typically read as a straightforward transitivity argument. After identifying material bodies with sensible objects, and the latter with ideas of sense, Berkeley concludes that putative material bodies are actually identical to collections of ideas of sense. George Pappas has recently defended an alternative reading that grounds Berkeley's immaterialism in his rejection of what Pappas calls category-transcendent abstract ideas: abstract ideas of beings, entia, or existence. Fields uses Pappas's interpretation as a framework for understanding Berkeley's immaterialism in terms of transcendental arguments. Early moderns routinely used the doctrine of objective presence to justify transcendental arguments for the existence of material substance. The claim was that physical qualities are necessary for any causal explanation of the content of sensory ideas; since those qualities are represented to perceivers as ontologically dependent, material substance is the necessary condition for the existence of physical qualities and a fortiori any causal explanation of the content of sensory ideas. On the reading defended here, Berkeley rejects Locke's transcendental argument for the existence of material substratum on the grounds that it turns decisively on the aforementioned category-transcendent abstract ideas, which Berkeley rejects as logically inconsistent. In its place, Berkeley offers his own transcendental argument designed to show that only minds and ideas exist. He uses that argument as a

The present monograph is a slightly revised version of my Habilitations schrift Proof-theoretic Aspects of Intensional and Non-Classical Logics, successfully defended at Leipzig University, November 1997. It collects work on proof systems for modal and constructive logics I have done over the last few years. The main concern is display logic, a certain refinement of Gentzen's sequent calculus developed by Nuel D. Belnap. This book is far from offering a comprehensive presentation of generalized sequent systems for modal logics broadly conceived. The proof-theory of non-classical logics is a rapidly developing field, and even the generalizations of the ordinary notion of sequent listed in Chapter 1 can hardly be presented in great detail within a single volume. In addition to further investigating the various approaches toward generalized Gentzen systems, it is important to compare them and to discuss their relative advantages and disadvantages. An initial attempt at bringing together work on different kinds of proof systems for modal logics has been made in [188]. Another step in the same direction is [196]. Since Chapter 1 contains introductory considerations and, moreover, every remaining chapter begins with some surveying or summarizing remarks, in this preface I shall only emphasize a relation to philosophy that is important to me, register the sources of papers that have entered this book in some form or another, and acknowledge advice and support.

Originally published in 1987, this volume reflects the diversity in Hegelianism and every branch of philosophy which he contributed to. It includes essays on his contribution to contemporary social philosophy, logic and the philosophy of religion. His work is examined in relation to Marx, Wittgenstein and his social philosophy discussed from a feminist standpoint.