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 AristotlethroughtocontemporaryfiguressuchasDummett,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 usefulphilosophysiteson theinternet.The Routledge DictionaryofPhilosophyisaninvaluableandup-to-dateresourceforall 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 Firstpublished1976 Secondedition1986 Thirdedition1996 Fourthedition2010 byRoutledge 2MiltonParkSquare,MiltonPark,Abingdon,OX144RN Simultaneously published in the USA and Canada byRoutledge 270MadisonAve,NewYork,NY10016 RoutledgeisanimprintoftheTaylor&FrancisGroup,aninformabusiness 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. ©1976,1986,1996A.R.Lacey;2010MichaelProudfootandA.R.Lacey Allrightsreserved.Nopartofthisbookmaybereprintedor reproducedorutilisedinanyformorbyanyelectronic,mechanical, orothermeans,nowknownorhereafterinvented,including photocopyingandrecording,orinanyinformationstorageor retrievalsystem,withoutpermissioninwritingfromthepublishers. BritishLibraryCataloguinginPublicationData AcataloguerecordforthisbookisavailablefromtheBritishLibrary LibraryofCongressCataloginginPublicationData LibraryofCongressCataloging-in-PublicationData Proudfoot,Michael. The Routledge dictionary of philosophy / Michael Proudfoot and A.R.Lacey–4thed. p.cm. Rev.ed.of:Lacey,A.R.(AlanRobert)/Adictionaryofphilosophy. 1976. [etc.] 1.Philosophy–Dictionaries.I.Lacey,A.R.(AlanRobert)II.Lacey, A.R.(AlanRobert)Dictionaryofphilosophy.III.Title. B41.L322009 103–dc22 ISBN 0-203-42846-3 Master e-book ISBN ISBN10:0-415-35644-X(hbk) ISBN10:0-415-35645-8(pbk) ISBN10:0-203-42846-3(ebk) ISBN13:978-0-415-35644-2(hbk) ISBN13:978-0-415-35645-9(pbk) ISBN13:978-0-203-42846-7(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- ratematerialfromLacey’sthreepreviousPrefaces,explainingsomething 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 Prefaceto theFourth 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,asitisused inphilosophy. Thisisspecificallyadictionary of philosophy, so it is not concerned with the meanings that some of these wordshaveingeneraluse,wherethatconflictswiththephilosophicaluse. 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 whichoccurattheendofentries,precededby‘Seealso’mayrefertothe 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 guidanceto areader 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 PrefacetotheFourthEdition 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 whichhave provided astandardto beaimed for,ifnot 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. For very substantial help on individual items I am grateful to Dr K. Hossack, Prof. M. Machover, Dr C. Hughes, Mr J. Hopkins, Prof. R.M. Sainsbury and Prof. G. Segal. Others who provided invaluable help on individual entries or questions include Dr S. Botros, Dr D.M. Edgington, Prof. D.A. Gillies, Dr S. Guttenplan, Prof. D.W. Hamlyn, Miss R.L Meager, Prof. D. Papineau, Prof. A.B. Savile, Prof. P. Simons, Dr L. Siorvanes, Dr R. Spencer-Smith, Dr A. Thomas, Mr J.D. Valen- tine, Mr P. Wesley (who translated the second edition into Dutch) and Prof. P.G. Winch. The following among my non-philosophical colleagues took great troublein getting me to communicate comprehensively: Mrs J.H. Bloch, Prof. D.F. Cheesman, Dr G. Darlow, Dr D.R. Dicks, Dr M.R. Hoare, Dr E. Jacobs, Mr. T. Taylor, Miss E.C. Vollans, Dr G.H. Wright and Mrs. Helen Marshall. Naturally none of all these people is responsible for the remaining faults, especially as I did not always follow their advice, or not fully. I was also helped at various points by Mrs M. Blackburn of the University of London Library – to say nothing of the indispensable resources of that library itself. Prof. T. Honderich helped me greatly at various stages throughout, and I am grateful to various typists and secretaries who came to my aid in time of need, as I am to Bedford viii Prefatorynote tothepreviouseditions College Philosophy Department for allowing me two sabbatical terms (and Kings College Philosophy Department for allowing me one) at relevant times. Among written sources my main debts apart from the items men- tionedinthebibliographies aretoP.Edwards(ed.)TheEncyclopediaof Philosophy (8 vols., Macmillan 1967), J.O. Urmson (ed.) The Concise Encyclopedia of Western Philosophy and Philosophers (Hawthorn 1960) and D. Runes (ed.) Dictionary of Philosophy (Littlefield Adams 1942) for mainly its logical entries. The intermittent ‘recent work in … ’ sur- veys in the American Philosophical Quarterly should also be mentioned. I am grateful as well to Gale Research International for letting me re- use some of the material I contributed to their Dictionary of Theories (1993), and to the sources mentioned in the acknowledgments to that volume. Just to repeat one paragraph from my original preface: The wide- ranging reader must be prepared to find almost any term used in ways I have not mentioned. In particular, it can only mislead to offer brief and precise definitions of philosophical ‘-isms’. I have thus tried instead to bring out something of the general spirit of such terms, which often refer to features oraspects rather than to people or systems. Precision is similarly inapposite in recommending the use of a term like ‘the causal theory of meaning’ rather than ‘causal theories of meaning’. Context or even whim will often decide whether one talks of different theories, or of variants of a single theory. Words like ‘principle’, ‘law’, ‘rule’, ‘thesis’, ‘axiom’, again, are used almost indifferently in phrases like ‘the principle of … ’. Finally, for the present edition my main indebtedness is of course to Michael Proudfoot, both for undertaking the somewhat thankless task of revising someone else’s work and for making such an excellent job of it.Ihavelearntquitealotmyselffromthenearly150newentrieshehas contributedandhavebeenagreeablysurprisedattheamountofmyown work he has felt able to leave standing despite pressures on space. A. R. Lacey ix