The Routledge Dictionary of Philosophy First published in 1976, the Dictionary of Philosophy has established itself as the best available text of its kind, explaining often unfamiliar, complicated and diverse terminology. Thoroughly revised and expan- ded, this fourth edition provides authoritative and rigorous definitions of a broad range of philosophical concepts. Concentrating on the Western philosophical tradition, The Routledge Dictionary of Philosophy offers an illuminating and informed introduc- tion to the central issues, ideas and perspectives in core fields such as metaphysics, epistemology and logic. It includes concise biographical entries for more than one hundred major philosophers, from Plato and Aristotle through to contemporary figures such as Dummett, McDowell, Parfit and Singer. All major entries are followed by helpful suggestions for further reading, including web links, and contain extensive cross-referencing to aid access and comprehension. This edition also features a brand new guide to the most useful philosophy sites on the internet. The Routledge Dictionary of Philosophy is an invaluable and up-to-date resource for all students of philosophy. Michael Proudfoot was Head of the Department of Philosophy at the University of Reading, UK, and is now an Honorary Fellow of the Department. A. R. Lacey is formerly a Senior Lecturer in the Department of Philosophy at King’s College, University of London, UK The Routledge Dictionary of Philosophy Fourth Edition Michael Proudfoot and A. R. Lacey First published 1976 Second edition 1986 Third edition 1996 Fourth edition 2010 by Routledge 2 Milton Park Square, Milton Park, Abingdon, OX14 4RN Simultaneously published in the USA and Canada by Routledge 270 Madison Ave, New York, NY 10016 Routledge is an imprint of the Taylor & Francis Group, an informa business This edition published in the Taylor & Francis e-Library, 2009. To purchase your own copy of this or any of Taylor & Francis or Routledge’s collection of thousands of eBooks please go to www.eBookstore.tandf.co.uk. © 1976, 1986, 1996 A.R. Lacey; 2010 Michael Proudfoot and A. R. Lacey All rights reserved. No part of this book may be reprinted or reproduced or utilised in any form or by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying and recording, or in any information storage or retrieval system, without permission in writing from the publishers. British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Library of Congress Cataloging in Publication Data Library of Congress Cataloging-in-Publication Data Proudfoot, Michael. The Routledge dictionary of philosophy / Michael Proudfoot and A.R. Lacey – 4th ed. p. cm. Rev. ed. of: Lacey, A. R. (Alan Robert) / A dictionary of philosophy. 1976. [etc.] 1. Philosophy–Dictionaries. I. Lacey, A. R. (Alan Robert) II. Lacey, A. R. (Alan Robert) Dictionary of philosophy. III. Title. B41.L32 2009 103–dc22 ISBN 0-203-42846-3 Master e-book ISBN ISBN10: 0-415-35644-X (hbk) ISBN 10: 0-415-35645-8 (pbk) ISBN 10: 0-203-42846-3 (ebk) ISBN 13: 978-0-415-35644-2 (hbk) ISBN 13: 978-0-415-35645-9 (pbk) ISBN 13: 978-0-203-42846-7 (ebk) Preface to the Fourth Edition This is an extensively revised edition of the Dictionary of Philosophy by A. R. Lacey which originally appeared in 1976, with new editions revised by Lacey appearing in 1986 and 1996. In this Preface I incorpo- rate material from Lacey’s three previous Prefaces, explaining something of the aim and nature of this book. The difference between an encyclopedia and a dictionary isn’t simply one of length. It is true that the Routledge Encyclopedia of Philosophy extends to ten substantial volumes, but there are admirable single volume encyclopedias (including the concise version of the Encyclopedia of Philosophy). Encyclopedias characteristically consist of essays of varying lengths, dealing with a variety of topics, often surveying the history of the treatment of that topic and discussing the various differ- ent theories forwarded by philosophers. The aim of a dictionary, on the other hand, is to clarify the meanings of terms, and to indicate issues and problems associated with those terms. The entries in a dictionary are not intended to be mini-essays, nor do they attempt to evaluate philosophers or theories, as an encyclopedia article might very well legitimately do. They are generally brief, explanatory and fairly neutral in tone. A dictionary will have, compared to an encyclopedia of the same length, more, but correspondingly shorter entries. This dictionary is intended for the general reader and university student. The earlier editions of the dictionary had a considerable emphasis on logic, metaphysics, philosophy of language and epistemol- ogy. I have increased the number of entries on other areas, for example, ethics, aesthetics and philosophy of religion, even though these addi- tions had to be kept brief if the book were to remain a reasonable size. The emphasis has been on the commonest terms and notions that are likely to come up in philosophy courses in the English speaking world. I have not attempted to cover non-Western philosophy, impor- tant though that may be, except, in one or two instances, where there v Preface to the Fourth Edition have been significant connections with the Western tradition (Avicenna, for example). There are over 100 entries on individual philosophers. These are very brief guides to their major works and dates, with cross-references to other entries and, where appropriate, to useful introductory works about that philosopher. Some of the longer entries start with a brief definition: this should be understood only as an attempt to give the general character of the term concerned, as it is used in philosophy. This is specifically a dictionary of philosophy, so it is not concerned with the meanings that some of these words have in general use, where that conflicts with the philosophical use. Cross-references are denoted by small capitals, and are of two kinds, within entries and self-standing. The former are only given when they seem useful. The term referred to is often mentioned in an approximate or abbreviated, but obvious, form. For example, the entry called ‘con- version’ might be referred to within the context of an entry as ‘converse’. The self-standing cross-references are not a guarantee that a term is treated fully, but they may be thought of as forming a sort of index. Terms with more than one word normally appear only once. RUSSELL’S PARADOX appears under R but not under P, and the discussion of innate ideas can be traced through IDEA. Cross-references which occur at the end of entries, preceded by ‘See also’ may refer to the preceding entry as a whole, not just the last paragraph. The bibliographies are by no means intended to be comprehensive, nor necessarily to include the latest twists and turns in continuing debates on issues. Rather, they are intended to give guidance to a reader who wishes to pursue further reading on a topic. The items in the bib- liographies are included for various reasons. They may be the original source of the concept concerned, or a good introductory discussion of the issues, or a collection of relevant articles on the topic. From these sources, further bibliographical help can be found. The information in parentheses after the work gives some indication of why they are included. Asterisked items might be particularly helpful as an introduc- tion. In this edition, I have included, for the first time, references in the bibliographies to sources on the internet. For further information about philosophy on the internet, please see the ‘Guide to Philosophy Online’. In the earlier editions, A.R. Lacey quite rightly acknowledged by name the many colleagues and friends who had helped him with advice and suggestions. I, too, am in debt to many sources and people. I have found the Routledge Encyclopedia of Philosophy, and the Concise ver- sion in particular, and the online Stanford Encyclopedia of Philosophy very useful. I was enormously helped by the four anonymous readers vi Preface to the Fourth Edition whom the publishers asked to look at the previous edition for their suggestions about deletions, additions and changes, the vast majority of which I have incorporated into this edition, and sometimes verbatim. I also wish to thank the following for their help: Emma Borg, Jonathan Dancy, Max de Gaynesford, Simon Glendinning, Hanjo Glock, Brad Hooker, Søren Landkildehus, Rick Momeyer, David Oderberg, John Preston, Severin Schroeder, Philip Stratton-Lake, Mark Tebbit, Nigel Warburton and Daniel Whiting. In some cases, their help extended to drafting a whole entry for me, but in all cases I must take the entire responsibility for the final entries and therefore for any errors that there may be in them. But my greatest thanks must be to A.R. Lacey, whose entries in the original editions of this Dictionary, most of which are retained in this edition, are examples of knowledge, clarity and conci- sion, and which have provided a standard to be aimed for, if not always reached. Michael Proudfoot vii Prefatory note to the previous editions All three of the previous editions owed so much to other people as almost to constitute a joint work in themselves. Dr J.L. Watling, Dr D.M. Tulloch and Mr D.A. Lloyd Thomas sent me detailed comments on the entire manuscript, and Dr Watling discussed innumerable points with me over innumerable lunches. For the third edition Prof. T. Crane and Prof. J. Cargile sent me detailed comments, both general and par- ticular, on the complete draft, Prof. Crane also doing so on my initial revisions and adding a hundred or more bibliographic suggestions, virtually all of which I adopted.