a gangue dos 18

8/17/2019 a gangue dos 18

http://slidepdf.com/reader/full/a-gangue-dos-18 1/25

The Death of Argument



PPLIED LOGIC SERIES

VOLUME32

Managing Editor

Dov M. Gab bay, Department of Computer Science, King's College, London,U K

Co-Editor

Jon Barwiset

Editorial AssistantJane Spurr, Department of Computer Science, King's College, London, U K

SCOPE OF THE SERIESLogic is applied in an increasingly wide variety of disciplines, from the traditional subjectsof philosophy and mathematics to the more recent disciplines of cognitive science, computer science, artificial intelligence, and linguistics, leading to new vigor in this ancient subject.Kluwer, through its Applied Logic Series, seeks to provide a home for outstanding books andresearch monographs in applied logic, and in doing so demonstrates the underlying unity andapplicability of logic.

The titles published in this series are listed at the end of this volume.



The Death of rgument

Fallacies in gent Based Reasoning

by

JOHN WOODSThe Abductive Systems Group,University o f British Columbia, Vancouver, Canadaand

Department o f Computer Science,King's College, London, EnglandandDepartment o f Philosophy,University o f Lethbridge, Canada

Springer-Science+Business Media, B.V.



A C.I.P. Catalogue record for this book is available from the Library of Congress.

ISBN 978-90-481-6700-5 ISBN 978-1-4020-2712-3 (eBook)DOI 10.1007/978-1-4020-2712-3

Printed on acid-free paper

All Rights Reserved© Springer Science+Business Media Dordrecht 2004Originally published by Kluwer AcademicPublishers in 2004Softcover reprint of the hardcover 1st edition 2004No part of this work may be reproduced, stored in a retrieval system, or transmittedin any form or by any means, electronic, mechanical, photocopying, microfilming, recordingor otherwise, without written permission from the Publisher, with the exceptionof any material supplied specifically for the purpose of being enteredand executed on a computer system, for exclusive use by the purchaser of the work.



For their unstinting support, their love and endless good humour,I dedicate this work to

Carol WoodsCatherine Armstrong

Kelly WoodsMichael Woods.



Contents

Dedication vPreface xiiiAcknowledgments XVll

Prologue XIX

Part I Metatheoretical Questions

1. WHO CARES ABOUT THE FALLACIES? 31 Questions About Fallacies. 3

2 The Current State of Fallacy Theory. 53 Light At The End Of The Tunnel? 7

4 Their Importance. 125 Is That All There Is? 15

6 Critical Thinking 197 So What? 20

2. THE NECESSITY OF FORMALISM 25

1 Methodological Pluralism 25

2 Formal Logic 26

3 Nomic Systematicity 304 Technical Information 31

5 Theory and Practice 325.1 Massey 335.2 McPeck 345.3 McP**k 355.4 Scriven 35



Vlll THE DE TH OF RGUMENT

6 Pedagogy 367 Conclusion 38

8 Appendix A 399 Appendix B 3910 Appendix C 41

3. THE INFORMAL CORE OF FORMAL LOGIC 43

1 Artificial Languages 43

2 The Language of PC 45

3 The Utility of PC 48

4 The Irreducible Informality 49

5 Quantum Logic 536 Further Work for Informal Logic 55

7 Informal Theories of Implication and Consistency 60

Part II Threats and Intimidation

4. D B CULUM AND PASCAL'S WAGER 651 The Standard Treatment 652 Prudential Argument 66

3 Case One: The Heist 674 Case Two: The Anti-smoking Commercial 675 Case Three: Pascal's Wager 686 Doxastic Surrender 697 Inaccessibility to Reason 708 The State, the Party and the Wager 7

5. APPEAL TO FORCE 751 Arguments From the Stick 752 Case One 763 Case Two 76

4 Case Three 765 Case Four: Risk A version Strategies 776 Case Five: The Stick-Up 787 Case Six: Negotiations 808 Case Seven: Veiled Threats 82



Contents ix

9 Practical Arguments 8410 d Baculum Reasoning 86

10.1 Collective Bargaining 8710.2 The Mugger 8910.3 Anti-smoking Arguments 8910.4 Utilities 90

11 Description of a Basic Model 9111.1 Example 9211.2 Example 9211.3 Propositions 93

11.4 Actions 93

Part III Arguments Involving Reference to Persons

6. DIALECTICAL BLINDSPOTS 971 Not Practising What You Preach 972 Insincerity and Irrationality 993 Explanatory Opacity 104

4 Blindspots 1065 Trust 107

7. D HOMINEM 111

1 Johnstone to Locke 1112 Aristotelian Refutations 1123 Falsifying Refutations 118

4Peirastic Refutations

1205 Proof d Hominem 122

8. AND SO INDEED ARE PERFECT CHEAT 1251 Fallacies that aren't Fallacies 1252 Bias 1263 Popular Appeals and Common Knowledge 1314 Preconception and Dogmatism 137

4.1 d Verecundiam 1384.2 Conservatism 1394.3 Inconsistency 141

5 Doxastic Loyalty 144



X THE DE TH OF RGUMENT

Part IV Pragma- Dialectics

9. PRAGMA-DIALECTICS 151

1 The Pragma-dialectical Approach 1512 Difficulties 153

3 Unification 155

4 Prospects for Pragma-dialectics 156

10. BUTTERCUPS, GNP'S AND QUARKS 161

1 Theory-dependency 161

2 Fallacies 163

3 Moderate Dependency 165

4 Theory and Analysis 168

11. UNIFYING THE FALLACIES? 171

1 Theory Reductions 171

2 Exemplar Theory 174

3 VEG as Theoretical Stipulation 177

4 Reconciling WW and VEG 179

Part V Intractable Disagreement

12. STANDOFFS IN PUBLIC POLICY 185

1 Degrees of Standoff, Force I-III 185

2 Extremism 187

3 Dealing with Standoffs of Force Five 194

4 Education as Strategy: Persuasion and Thought Control 197

13. STANDOFFS AND DEMORALIZATION 201

1 Demoralization 201

2 Spinning 208

3 Witnessing 211

4 Privatizing the Good 212

5 Indoctrination 214



Contents xi

Part VI How to Interpret Arguments

14. CHARITY: CAN WE FIND IT A HOME? 219

1 Slogans 2192 Radical Chari ty 222

3 Dialogical Charity 2264 Radical Chari ty Again 232

5 How Reliable is Charity? 233

15. MISSING PREMISSES 2391 Cooperative Conditions

2392 Validity 242

3 The Logical Minimum and Pragmatic Optimum 243

4 Genericity 246

5 Find the Premisses 249

Part VII Analogy

16. BY PARITY OF REASONING 2531 Parity of Reason 2532 Standoffs 2573 The Structure of Analogy 2604 Counterexample 2625 Relevance 2656 Analogical Predication 268

7 Deep Structure 269

17. VERDI IS THE PUCCINI OF MUSIC 2731 Analogies 273

1.1 The Method of Cases 2751.2 Analogical Prediction 2761.3 What the Cases Suggest 2791.4 Numerical Analogical Prediction 283

1.5 More Theory 2852 Analogical Semantics 2903 Concluding Reflections 296



xii THE DE TH OF RGUMENT

Part VIII Induction

18. SECUNDUM QUID 301

1 Omitting a Qualification 3012 DeMorgan's Approach 304

3 Extending the Reach of the Fallacy 3064 Petitio Principii 309

19. HASTY GENERALIZATION 3111 Hasty Generalization: The Basic Idea 311

2Primitive Induction

3143 Strategic Rationality 3154 Pract ical Reasoning 317

5 Notional and Behavioural Belief 319

6 The Raven Paradox 320

7 The Problem of Induction Again 324

8 Strategic Rationality Again 331

9 Conclusion 33320. THE PROBLEM OF ABDUCTION 335

1 Abduction 3352 Induction Has a Justification 3383 Objections 3414 Skepticism 345

Epilogue: The Way Ahead? 349

References 359

Index 373



Preface

The present work is a fair record of work I've done on the fallaciesand related matters in the fifteen years since 1986. The book may beseen as a sequel to Fallacies: Selected papers 1972-1982, which I wrotewith Douglas Walton, and which appeared in 1989 with Foris. This timeI am on my own. Douglas Walton has, long since, found his own voice,as the saying has it; and so have I Both of us greatly value the timewe spent performing duets, but we also recognize the attractions of solowork. f I had to characterize the difference that has manifested itselfin our later work, I would venture that Walton has strayed more, and Iless, from what has come to be called the Woods-Walton Approach tothe study of fallacies. Perhaps, on reflection stray is not the word forit, inasmuch as Walton's deviation from and my fidelity to the WWAare serious matters of methodological principle.

The WWA was always conceived of as a way of handling the analysisof various kinds of fallacious argument or reasoning. It was a response

to a particular challenge [Hamblin, 1970]. The challenge was that sincelogicians had allowed the investigation of fallacious reasoning to fall intodisgraceful disarray, it was up to them to put things right. Accordingly,the WWA sought these repairs amidst the rich pluralisms of logic in the1970s and beyond. The WWA was never intended as a general theoryof argument or a comprehensive articulat ion of an informal logic. t wasa dominantly logical approach to the study of fallacies, an approachthat emphasized the utility of nonstandard systems of logic, including dialogue logic. Neither was it supposed by the WWA that fallacieswere intrinsically dialogical, as is now supposed by Douglas Walton incompany with the pragma-dialecticians of the Amsterdam School. Norwas the WWA much interested in finding a unified theoretical structurewithin which everything bearing the name of fallacy would have a wellelucidated home. This was not a decision borne by failed attempts at



xiv THE DE TH OF RGUMENT

federal amity, but rather one that grew out of the conviction that anysuch unification was destined to end up as theoretically thin. Here, too,as with our friends in Amsterdam, Walton's present inclination is to see

in unification prospects of greater theoretical robustness than do I; and Ion the other hand remain unconvinced, and so an unrepentant pluralist,at least for now, about the structure of fallacious reasoning.

There remains a point on which Walton and I remain in perfect accord.It is that getting the fallacies right is an extremely important task forlogic, indeed a central part of its mandate, and that it is a task muchmore avowed than performed. I hope that I might be forgiven a briefshudder of impatience over the slapdash work that still makes its way

into basic textbooks in logic and critical thinking.In one way or another, everything in this book has been influenced

by the Netherlands, my intellectual home away from home. Some chapters first took shape at the Netherlands Institute for Advanced Study,where under the direction of Frans van Eemeren I was part of the Research Group on Fallacies, toge ther with Rob Grootendorst, Sally Jackson, Scott Jacobs, Agnes van Rees, Agnes Verbiest, Douglas Walton andCharles Willard. The remaining chapters were all written in whole or

part when for portions of most of the years in this period I was Adjunct Professor in Frans van Eemeren's Leerstoelgroep Taalbeheersing,Argumentatietheorie en Rhetorica at the University of Amsterdam. Igreatly value my intellectual association with Holland, and am gratifiedthat over the years it has been the occasion of enduring friendships.For their interest and support of my work I warmly thank my Dutchcolleagues and friends, Frans van Eemeren, the late Rob Grootendorst,Else Barth, Erik Krabbe, Agnes van Rees, Eveline Feteris, FrancescaSnoeck Henkemans, Peter Houtlosser, Bart Garsen, Johan van Benthem,Jeanne Peijnenburg, and Frank Veltman. I am no less grateful to mynon-Dutch supporters and critics: In Canada, J.A. Blair, Ralph Johnson, Robert Pinto, Hans Hansen, David Hitchcock, Christopher Tindale,Trudy Govier, Andrew Irvine, Leslie Burkholder, Leo Groarke, MarkVorobej, Thomas, Hurka, George Englebretsen, J.J. Macintosh, MichaelStingl, Ian Hacking, and Douglas Walton; in the United States, thelate Henry Johnstone, Jonathan Adler, Harvey Siegel, Michael Wreen,Lawrence Powers, Mark Weinstein, Michael Scriven, James Freeman,

Jaakko Hintikka, William Lycan, Alvin Goldman, Jonathan Bennett,Jonathan Bennett, Julius Moravcsik, Patrick Suppes, Bas van Fraassen,Sally Jackson, Scott Jacobs, Joseph Wenzel, Charles Willard, IsaacLevi, Dale Jacquette, and John Hoaglund; and Dov Gabbay, JonathanCohen, Chris Reed, Peter McBurney, Timothy Williamson, Jim Cunningham and Alec Fisher (U.K.); Harald Wohlrapp and Hans Jiirgen



PREF CE XV

Ohlbach (Germany); Jean-Paul van Bendegem and Paul Gochet (Belgium); Gabriella Pigozzi (Italy); Lorenzo Peiia (Spain); Graham Priest,Greg Restall, the late Richard Sylvan and Robert Meyer (Australia);and Roderic Girle (New Zealand).

Research for these chapters has been supported financially by, in addition to the Netherlands Institute for Advanced Study and the Leerstoelgroep Taalbeheersing, Argumentatietheorie en Rhetorica, the SocialScience and Humanities Research Council of Canada, the University ofLethbridge Research Fund, the Dean of Arts and Science, University ofLethbridge, and King's College, London. My thanks to all.

My research assistants in Lethbridge, Dawn Collins, Ethan Toombs

and David Graham, have put the book into camera-ready form andprepared the index. I am most grateful for this excellent help. Mythanks also to the publisher, Charles Erkelens and his assistant, LucyFleet as well as Deborah Doherty, from Author Support, for technicalassistance and direction.



Acknowledgments

I would like to thank the following co-author, editors, and publishersfor their permissions to reprint material in this book.

• Co-author Brent Hudak for Verdi is the Puccini of Music , Synthese, 92 (1992), 189-220; and By Parity of Reasoning , InformalLogic, 11 (1990), 135-139.

• Kluwer Academic Publishers for Verdi is the Puccini of Music ,Synthese, 92 (1992), 189-220; And So Indeed Are Perfect Cheat ,Argumentation 9 (1995), 645-668; and The Necessity of Formalismin Informal Logic , Argumentation 3 (1989) 149-167.

• Royal Netherlands Academy of Arts and Sciences for Public Policy and Standoffs of Force Five , in E.M. Barth and E.C.W.Krabbe (eds.), Logic and Politics of Culture, 1992, 9-108.

• Informal Logic for By Parity of Reasoning , Informal Logic, XI(1990), 125-139; Buttercups, GNP's and Quarks: Are Fallacies Theoretical Entities? , Informal Logic, X(1989), 67-77; and Is the Theoretical Unity of the Fallacies Possible? , Informal Logic, XVI (1994),77-85.

• Springer Verlag GmbH Co. KG for Deep Disagreements andPublic Demoralization , in Dov M. Gabbay and Hans Jiirgen Ohlbach(eds.), Practical Reasoning: Springer Notes on Artific ial Intelligence,1996, 650-662.

• Logique et Analyse for Missing Premisses in Pragma-Dialectics ,Logique et Analyse, 129-130 (1993), 155-168.



XVll l T HE D E T H O RGUM E NT

• U itgev er oninkl ijk e Van Go rcum BV Asse n for T he Pr ob -le m o f A b d u c t io n , Algem e en Nederl a nds Tijdsc h rift voor Wijsbegeer te ,jaarg ang 93 nr. 4 p p . 265-27 3.

• Sic Sat P ress fo r W h o C a re s About th e Fallac ies ? , in F .H . vanE e m e ren , Ro b G ro o t end o rs t , J. Anthon y Blair , C har les A. Wi l l a rd (eds. ), Argumenta t ion Il lumi n ated, A m ste rdam : S ic Sat P re ss, 1992,22-48; A d B a c u lum is N o t a Fal lacy , Procee d ings of th e FourthI n ternat ion a l Confere n ce of the Internat io n al Societ y for the S tudyof Argum entation, i n F r an s H . van E em eren , R ob G r o o t e n do rs t , J .A n t h o n y Bla i r an d Cha r l e s A. W il la rd (eds.) , A ms te rda m : Sic S atPress , 199 9, 2 21-224 ; and A d H ominem: F r o m J oh ns tone to Locketo Ar i s to t le , in F ra ns H . v an Eemere n , e t al (eds .), Analys is andEva luation, A m ste r d a m : Sic Sa t P r ess , 1995, 295 -408.

• Edi tions Ro dop i B V for Secu n dum Qu i d as a R e search Pro -g r a m m e , in E . C . W. K rab be et a l (eds.) , E m pirical L ogic and P u b-lic Debate, A m ste r d a m : R o do pi, 199 3, 27-3 6 .

• Penn State Un iversity Press for Dialec tic al Bl ind sp ots Phi-loso p hy and R h etoric, 26 (19 93), 2 51-2 65; an d A pp ea l to For cein Ha n s H a n s e n an d Rob ert P into (eds .), Fallaci es : Classic a l andContemp orary Rea d ings, U niv ers i ty Park , PA: Pen n S tate U n iversity P ress , 1999, 18 1-196.

• C ommun i cation a n d Cogni ti on for P r agma-D ial ect ics : A R adical Depa rt ure in F alla c y T h e o ry , C o m m u n ication an d Cognitio n , 24(1 9 91), 43-53.

• Wa lter de G r uyter G mbH C o. KG for A d B a c ulum, Sel f

In te re s t a nd P asc a l ' s W ag e r , in F .H . van E m e e ren et al (eds. ) ,Ar gumentat i o n: Across the Lines of Discipl in e, 1987, 343 -349.



Prologue

In 1970, the Australian logician C.L. Hamblin published a book entitled Fallacies. It was a bombshell. Hamblin marshalled some verystrong criticisms against what he called the Standard Treatment in fallacy theory. Here is part of that attack:

We have no theory of fallacy.... In some respects... we are in the position ofthe medieval logicians before the twelfth century: we have lost the doctrine offallacy, and need to rediscover it [Hamblin, 1970, p. 12].

Speaking of the treatment of fallacies in logic textbooks at the time ofwriting, Hamblin insisted that

what we find in most cases... is as debased, worn-out and dogmatic treatmentas could be imagined - incredibly tradition-bound, yet lacking in logic andin historical sense alike, and almost without connection to anything else inmodern Logic at all [Hamblin, 1970, p. 12].

Hamblin's criticisms proved to be a fruitful provocation. To a large

extent, three intellectual developments can claim some degree of origination in Hamblin's goading. These three are informal logic, fallacytheory and argumentation theory. A good sense of the development ofinformal logic can be got from Ralph Johnson's The Rise of InformalLogic [Johnson, 1996], as well as Fundamentals of argumentation theory[van Eemeren et al., 1996]. Fallacies: Selected Papers, 1972-1982 byJohn Woods and Douglas Walton [Woods and Walton, 1989] renders asimilar service for fallacy theory, as does Hansen and Pinto [Hansen andPinto,

1995]. A usefulentre

into argumenttheory

isthe

collection ofessays, Studies in Pragma Dialectics, edited by Frans van Eemeren andRob Grootendorst [van Eemeren and Grootendorst, 1994]. t is hard toknow what Hamblin would have thought of the work done on fallaciesduring the past thirty years, but there can be little doubt that he wouldnot in the year 2003 see occasion to lodge the same criticisms that he



XX THE DE TH OF RGUMENT

levelled in 1970. Fallacy theory may not yet have achieved the theoretical maturity that Hamblin called for, but it has come a long wayfrom the despised Standard Treatment. The present book is a further

attempt to take the fallacies research programme in a direction which,as I hope, Hamblin might have approved of.

I am a traditionalist about fallacy theory. I accept the traditionalnotion of fallacy as an argument or piece of reasoning which seems to begood in a certain way but isn't in fact good in that way. I also tend tothink of fallacy theory as a branch of logic. I am moreover something ofa traditionalist about logic. I yield to no one in the respect I have formodern mathematical logic in its four princely domains of model theory,proof theory, set theory and recursion theory. But no one seriouslybelieves that modern mathematical logic is much good for the analysisof real-life argument and reasoning, nor that it is the best place in whichto transact the business of fallacy theory.

Mathematical logic has achieved a hegemony that is scarcely a hundred years old, whereas logic itself has been a dominant intellectual forcein the tradition that ensues from Athens for two and half thousand years.What logic has always been until comparatively recently is the theoretical core of general theories of argument and inference. t was so withthe first logician and remained so, with litt le variation, until Frege. Onething that the old logic could not do is capture the structure of mathematics, not even Greek mathematics. Centuries later Descartes wouldcelebrate algebra as a universal method of mathematical problem solving. After 1879, adequate logic would inherit this hegemonic character.

t would purport to be wholly for the representation of the structure ofmathematics. In this fateful transformation, logic lost its customary tie

to the agora.There is some evidence that the mathematical hold on logic is re

laxing its grip. Informal logic, investigations into critical thinking, argumentation theory and fallacy theory itself are underwriting researchprogrammes of considerable power. Computer scientists have led theway in re-jigging logic in ways that cater to more realistic models ofactual human practice. Default logic [Reiter, 1980], nonmonotonic logic[Sandewall, 1972] and [McCarthy, 1980] and autoepistemic logic [Moore,

1985] are all products of work done by computer scientists. Even mainstream logicians have been involved in making logic more realistic, whatwith developments in dynamic logic [van Benthem, 1994], labelled deductive systems [Gabbay, 1996], situation logic [Barwise and Etchemendy,1984], paraconsistent logic [Batens et al., 2000], among numbers of othersuch developments. Nor should we overlook the burgeoning literature



xxi

on dialogue logic ([MacKenzie, 1990; Girle, 1993; Girle, 1996; Waltonand Krabbe, 1995; Lorenzen and Lorenz, 1978; Gabbay and Woods,2001c; Barth and Krabbe, 1982], to name just a few).

Mine therefore is both a more traditional and a more liberal view oflogic. (A more detailed account of this conception than I have spacefor here can be found in Woods, Johnson, Gabbay and Ohlbach [Woodset al., 2002].) One of the virtues of this liberalism is that it makeswholly unnecessary (in fact, wholly impossible) fruitless wrangles aboutwhether fallacy theory is logic or something else (dialectic, for example).And if we heed Hamblin's wish that fallacy theory achieve at least somesort of connection with modern logic, 1 we have taken a stand against

those who think that ordinary reasoning and everyday argument shouldnot be subjected to accounts that are technically theoretical.

Though I favour the more traditional conception of logic, I am notinclined to be greedy about it. I am far from believing that everythinggood in argumentation theory and fallacy theory is logic. Though mynotion of logic is already something of an interdisciplinary concept, thedisciplines required for the production of deep and mature theories ofhuman cognitive and argumentative practice significantly outreach thestretch of anything deserving of the name of logic. I welcome the needfor interdisciplinary cooperation, linking up all branches of logic withcomputer science, cognitive psychology, neurobiology, forensic science,linguistics (including conversation analysis and discourse analysis) andargumentation theory.

t is important that we be aware that there has been a considerableconceptual shift in fallacy theory since Aristotle's original classificationin On Sophistical Refutations. In some cases the name persists whilewhat it denotes has changed. Aristotle defined a fallacy as an argument

that appears to be a syllogism, but isn't a syllogism in fact. But noone today, even those who take the traditional approach, would define afallacy in just this way. This is because hardly anyone is much inclinedto think the theory of syllogisms as a serious rival of modern systemsof logic. (Perhaps the dismissal is too abrupt. The logic of the syllogism was the first intuitionistic, relevant, nonmonotonic and paraconsistent logic ever. See below). Similarly, present-day accounts of the adhominem fallacy have nothing to do with Aristotle's discussion (interestingly the ad hominem did not make Aristotle's original list of thirteen)or with Locke's treatment of it [Locke, 1961]. Nor do our accounts ofbegging the question have the same breadth as Aristotle's, or our ac-

1 A case in point is Woods and Walton's modelling of question-begging in the Kripke-semanticsfor intuitionistic modal logic [Woods and Walton, 1989, ch. 10].



xxii THE DE TH OF RGUMENT

counts of the complex question fallacy bear the slightest resemblance towhat Aristotle said about it. Then, too, the inductive and statisticalfallacies are comparatively new, arising in the 17th century with the

birth of probability theory and the emergence of inductive methods inscience. (See here [Woods, 1999b; Woods, 2002a; Woods, 1999d; Woods,1999a; Woods, 1999c].)

'Dialectic' is also a word with a history. In Aristotle's On Sophistical Refutations, a dialectical argument is a question-and-answer exercisewith respect to some received view or dialectical proposition. A dialectical proposition is one that expresses an endoxon. An endoxon is anopinion held by everyone, or by most people, or by experts. Today a

dialectic argument is generally understood as one in which an issue is indispute, with the parties attempting to prevail on each other with regardto that issue. However, in some cases, modern theorists understand a dialectical argument as little more than a dialogue in which the parties arehaving a rational discussion. (See here [van Eemeren and Grootendorst,1984] and [Hamblin, 1970, p. 320].)

When names don't change, underlying conceptual change is likely togo unnoticed, except for investigators who have tried to master the history of fallacy theory. Since these are patently in the minority, bloopersare bound to be made. One is that John Stuart Mill charged that every deductively valid argument committed the fallacy of begging thequestion. Aristotle considered the possibility, and then rejected it; andSextus Empiricus made the complaint and stuck by it. But not onlydid Mill not make the claim, he actually and emphatically denied it.Another blooper is one in which Locke is credited with originating theterms ad verecundiam and ad ignorantiam (and borrowing the term adhominem), which he then used to denote the fallacies that have borne

those names ever since. But Locke in fact does not think that argumentsof these kinds are fallacious at all. Conceptual shifts and historical inaccuracies can mar a theorist's best efforts. I have tried to avoid thesedifficulties here, but I can't claim a perfect result. Conceptual shifts andhistorical mistakes are a little like fallacies. They don't in the generalcase announce themselves.

A word or two would be in order about the title of this book. At176a10- 12 of Sophistical Refutations Aristotle writes as follows:

For it is possible for it to be true to say 'Yes' or 'No' without qualificationto countless different questions; but still one should not answer them witha single answer for that is the death of argument ([Barnes, 1984, p. 299];emphasis added).

Aristotle is here discussing the fallacy of several questions or, as ithas come to be called, the fallacy of many questions or complex ques-



xxiii

tion. In its modern sense, the many question fallacy is exemplified byqueries such as, Have you stopped beating your dog? in the contextof interrogation arguments in which questions must always be answered

by 'Yes' or 'No'. On some accounts, the fallacy involves the question'spresupposition, You have beaten or used to beat your dog . f thequestion is allowed to stand, then since it must be answered 'Yes' or'No', each answer presupposes that the answerer has beaten his dog. Inthis way, the questioner commits the respondent to a proposition whichthe respondent has not conceded (and in most real-life cases would emphatically reject if he could). This is not, however, Aristotle's analysis.His view is that

[t]hose fallacies that depend upon the making of several questions into one consist in our failure to articulate the account of a proposition. For a propositionpredicates a single thing of a single thing Now since a deduction [= syllogism] starts from propositions and a refutation is a deduction, a refutation,too, will start from propositions [Barnes, 1984, pp. 286;169a6- 14].

Aristotle 's example is the question Are Coriscus and Callias at home ornot at home?'' But what goes wrong with this question? To understandAristotle's position it is necessary to emphasize that he is discussing

the thirteen fallacies in the context of a kind of argument called refutation. In a refutation there are two participants, a questioner and ananswerer. The answerer puts forward a thesis T (e.g., that all virtues canbe taught), which he then defends by answering critical queries put bythe questioner. Aristotle requires that the answerer's responses be either'Yes' or 'No' and therefore that the questioner's questions be answerablein this way. The further task of the questioner is to take the concessions made by the answerer as premisses and to construct from thosepremisses a syllogism whose conclusion is not- T, i.e., the contradictoryof the thesis that the questioner was attempting to defend. Syllogismsfor Aristotle are a special kind of valid argument. They are valid arguments that satisfy additional constraints. One is that the argumentcontain no redundant premisses (which make syllogistic logic a kind ofnonomontonic relevance logic); another is that no premiss may occuras the conclusion, and derivatively, that premiss-sets must always beconsistent (which makes syllogistic logic a paraconsistent logic); a further requirement is that syllogisms not have multiple conclusions (which

makes the system a kind of intuitionistic logic). (See [Woods, 2001].) Arefutation, then, is an argument that satisfies these conditions (amongothers) and whose conclusion is the contradictory of the questioner'soriginal thesis. A further requirement imposed by Aristotle on syllogisms is that they be constructed from a special kind of statement, forwhich Aristotle reserves the technical term proposition . As we have



XXIV THE DE TH OF RGUMENT

seen, a proposition is a statement that predicates a single thing of a single thing. Propositions therefore cannot be molecular constructions ofpairs of statements. f we examine the question that Aristotle discusses,

Are Coriscus and Callias at home or not at home?'', it is clear thatit admits of a 'Yes' or 'No' answer. The 'Yes' answer concedes to thequestioner the statement, Coriscus and Callias are at home or are notat home . A negative answer concedes to the questioner the statement,

It is not so that Coriscus and Callias are at home or not at home .Neither of these statements is of any use to the questioner. They arenot propositions. The first is equivalent to Coriscus is at home andCallias is not at home, or Coriscus is at home and Callias is at home,

or Coriscus is not at home and Callias is at home, or Coriscus is not athome and Callais is not at home . And the second is equivalent to thenegation of the first. Since they are not propositions in Aristotle's technical sense, they are ineligible for use in constructing syllogisms; hencethey cannot be used in constructing a refutation.

This leaves us with two rather pressing questions. Why did Aristotlethink that he was justified in requiring that syllogisms be constructedexclusively out of propositions? And what is it about the concessionof non-propositions in the context of refutation-arguments that justifiesAristotle's passionate denunciation? ( the death of argument ). Thefirst question is more easily answered than the second. Aristotle imposes the proposition-only condition on syllogisms because he holds thethesis of propositional simplification. According to this thesis, anythingstateable in any natural language is also stateable without relevant lossin the sublanguage of propositions. Propositions in turn are statementsof the form All A are B , No A are B , Some A are B and SomeA are not-B . f the thesis of propositional simplification is true, this

works a substantial economy into Aristotle 's logic. For Aristotle can nowclaim that he can capture a complete theory of deduction in this veryeconomical sublanguage of propositions. Aristotle states the theory atOn Interpretation l7a13, 18a19ff. and 18a24 [Barnes, 1984, pp. 26-28].There is no known extant proof.

Our second question asks for what justifies Aristotle's claim that allowing non-propositions into refutation-arguments would be the death ofargument. Aristotle does not answer this question, or anyhow does not

answer it in any direct way. Even so, an answer can be conjectured. Takeas a second example the rather more interesting (and modern-sounding)

Have you stopped beating your dog? It is equivalent to Do you havea dog you have beaten and, if you have a dog you have beaten, haveyou stopped beating it? As Aristotle correctly notes, the question isanswerable 'Yes' or 'No'. f the answer is affirmative it concedes the



X X V

statement I have a dog that I have beaten and I still beat it . But nowconsider what a negative reply gives us: It is not the case that I havea dog that I've beaten and that I still beat it , or symbolically,

not-((D and B) and S).

Let me say again that Aristotle rightly recognizes that this statementcould be true, that it could be a fact that not-((D and B) and S). But it isnot a fact that the questioner can make use of as long as he is interestedin determining the questioner's status as a (potential) past and presentdog-beater. Imagine a dialogue in which every question were complexin this sort of way, and every answer were (as might well be the casein real-life interrogation-argument) in the negative. Then it would be

impossible for the questioner to get to the particular facts of the case athand. This indeed would be the death of argument with regard to anythesis which itself is a proposition (e.g., The questioner is not a violentperson ). f every fact of the case is complex in the kind of way that thefact not-((D and B) and S is, then no fact will imply any statement inthe form The questioner is a violent person which is the contradictoryof the thesis we are present ly considering. Hence no refutat ion can beconstructed.

t is arguable that Aristotle would have been prepared to extend thedeath-of-argument metaphor to all fallacies. There is no doubt thatAristotle thinks that fallacies are serious mistakes. This is also my ownview, but it is subject to a tautologous seeming qualification: Fallaciesare serious mistakes when they are indeed fallacies Whether we arethinking of Aristotle's original thirteen or what I call the gang of eighteen(see chapter 1), it is apparent that rarely are arguments of these varioustypes fallacies just because they are of that type. So, for example, whenan ad hominem argument or an ad verecundiam argument is a fallacy,it is not so merely because it has the form of an ad hominem or anad verecundiam argument. That is to say, fallaciousness is not intrinsicto arguments of these kinds; and the same is true for nearly them all,whether Aristotle's thirteen or the gang of eighteen. This is both aset back and an attraction. The set back is that the fallacy theorist mustbe able to specify the varying conditions under which an argument of agiven kind is and is not fallacious. This is more easily said than done;but doing it, even so, is filled with interesting challenges, which are the

potent ial occasion of theoretical depth. And that is the attraction offallacy theory.

A word or two about my subtit le would also be in order. Since all reasoning is agent-based, Fallacies in Agent-Based Reasoning might strikethe reader as rather pleonastic. Of course. But not all theories of reasoning make express provision for agents in their working vocabularies. In



xxvii

Strange as it might initially strike us, such arguments, though they arein one straightforward sense of the term non-cooperative, are not, just so,irrational or stupid. Part of their importance lies in the emphasis they

lend to a distinction between what might be called alethic rationalityand strategic rationality, the one an intellectual virtue and the other apractical virtue. This is a distinction which we shall repeatedly find itprofitable to engage.

a gangue dos 18

Documents