This page intentionally left blank P1:KAE 0521854318pre CUNY272B/Vorobej 0521573726 January12,2006 9:28 ATheoryofArgument A Theory of Argument is an advanced textbook intended for students inphilosophy,communicationstudies,andlinguisticswhohavecom- pleted at least one course in argumentation theory, informal logic, criticalthinking,orformallogic.Thetextcontains400exercises. In this book, Mark Vorobej develops a novel approach to argu- ment interpretation and evaluation that synthesizes subjective con- cerns about the personal points of view of individual arguers, with objectiveconcernsaboutthestructuralpropertiesofarguments.One ofthekeythemesofthebookisthatwecannotsucceedindistinguish- inggoodargumentsfrombadonesuntilwelearntolistencarefully toothers. PartOnedevelopsarelativisticaccountofargumentcogencythat allowsforrationaldisagreement.Anargumentcanbecogentforone person without being cogent for someone else, provided we grant thatitcanberationalforindividualstoholddifferentbeliefsabout theobjectivepropertiesoftheargumentinquestion. Part Two offers a comprehensive and rigorous account of argu- ment diagraming. An argument diagram represents the evidential structure of an argument as conceived by its author. Hybrid argu- mentsarecontrastedwithlinkedandconvergentones,andanovel techniqueisintroducedforgraphicallyrecordingdisagreementswith authorialclaims. MarkVorobejisassociateprofessorofphilosophyanddirectorofthe CentreforPeaceStudiesatMcMasterUniversityinCanada. i P1:KAE 0521854318pre CUNY272B/Vorobej 0521573726 January12,2006 9:28 ii P1:KAE 0521854318pre CUNY272B/Vorobej 0521573726 January12,2006 9:28 A Theory of Argument MARK VOROBEJ McMasterUniversity iii P1:KAE 0521854318pre CUNY272B/Vorobej 0521573726 January12,2006 9:28 cambridge university press Cambridge,NewYork,Melbourne,Madrid,CapeTown,Singapore,SãoPaulo Cambridge University Press TheEdinburghBuilding,Cambridgecb22ru,UK Published in the United States of America by Cambridge University Press, New York www.cambridge.org Information on this title: www.cambridge.org/9780521854313 ©MarkVorobej2006 Thispublicationisincopyright.Subjecttostatutoryexceptionandtotheprovisionof relevantcollectivelicensingagreements,noreproductionofanypartmaytakeplace withoutthewrittenpermissionofCambridgeUniversityPress. Firstpublishedinprintformat 2006 isbn-13 978-0-511-19006-3 eBook (Adobe Reader) isbn-10 0-511-19006-9 eBook (Adobe Reader) isbn-13 978-0-521-85431-3 hardback isbn-10 0-521-85431-8 hardback isbn-13 978-0-521-67025-8 paperback isbn-10 0-521-67025-x paperback CambridgeUniversityPresshasnoresponsibilityforthepersistenceoraccuracyofurls forexternalorthird-partyinternetwebsitesreferredtointhispublication,anddoesnot guaranteethatanycontentonsuchwebsitesis,orwillremain,accurateorappropriate. P1:KAE 0521854318pre CUNY272B/Vorobej 0521573726 January12,2006 9:28 Tomymother FranckaVorobej(ne´eRupar) August25,1929–November4,1998 v P1:KAE 0521854318pre CUNY272B/Vorobej 0521573726 January12,2006 9:28 Listeningisthebeginningofpeace. –EliseBoulding vi P1:KAE 0521854318pre CUNY272B/Vorobej 0521573726 January12,2006 9:28 Contents Preface page ix part one: macrostructure 1 Arguments 3 1.1 AuthorsandAudiences 3 1.2 Propositions 8 1.3 CanonicalForms 11 1.4 ListeningtoPersons 18 1.5 ClarityandAccuracy 23 1.6 Charity 27 1.7 AnIllustration 38 2 Cogency 47 2.1 TheFourCogencyConditions 47 2.2 RationalBelief 58 2.3 ReflectiveStability 61 2.4 “Bad”CogentArguments 73 2.5 “Good”Non-CogentArguments 79 2.6 EpistemicStatesandContexts 97 2.7 Egalitarianism 103 3 Normality 111 3.1 TheNormalityAssumption 111 3.2 StrengthasCogency 125 3.3 Validity 131 3.4 Reliability 138 3.5 MethodologicalMatters 149 vii P1:KAE 0521854318pre CUNY272B/Vorobej 0521573726 January12,2006 9:28 viii Contents part two: microstructure 4 Convergence 161 4.1 Diagrams 161 4.2 ConvergentArguments 163 4.3 ModalDiagramsandPooledPremises 174 4.4 CharitableChoices 192 4.5 SquigglyDiagrams 198 4.6 Illustrations 214 5 Linkage 224 5.1 LinkedArguments 224 5.2 StructuralOptions 232 5.3 VulnerableArguments 245 5.4 RelationalVulnerability 251 5.5 Illustrations 259 6 Supplementation 271 6.1 HybridArguments 271 6.2 StructuralAmbiguity 290 6.3 EpistemicComplications 295 6.4 MoralHybrids 308 6.5 Ignorance 314 Index 323