Against Coherence - Truth, Probability, and Justification

## Abstract According to the popular coherence theory of knowledge and justification, if a person's beliefs are coherent, they are also likely to be true. This book is the most extensive and detailed study of coherence and probability to date. The book takes the reader through much of the history of the subject, from early theorists like A. C. Ewing and C. I. Lewis to contemporary figures like Laurence BonJour and C. A. J. Coady. The arguments presented are general enough to cover coherence between any items of information, including those deriving from belief, memory, or testimony. It is argued that coherence does not play the positive role that it is generally ascribed in the process whereby beliefs are acquired. The opposite of coherence, incoherence, is nonetheless the driving force in the process whereby beliefs are retracted. Contents......Page 12 1. Introduction......Page 16 Part I: Does Coherence Imply Truth?......Page 22 2.1 Why Coherence?......Page 24 2.2 Coherence—an Elusive Concept......Page 27 2.3 Pinning down the Coherence Theorist......Page 31 2.4 Truth and Agreement......Page 36 2.5 A Simple Witness Model......Page 39 2.6 Conditions for Convergence......Page 41 2.7 Convergence Parameters......Page 46 2.8 Challenges for the Coherence Theorist......Page 47 3.1 The Problem of Justifying Memory......Page 49 3.2 Lewisian Witness Scenarios......Page 50 3.3 Lewis on the Convergence Conditions......Page 63 3.4 The Individual Credibility ‘need not be Assigned’......Page 70 3.5 A Note on Lewis’s Definition of Independence......Page 73 4.1 The Problem of Justifying Beliefs......Page 76 4.2 BonJour on Justification from Scratch......Page 81 4.3 Lying and Individual Credibility......Page 84 4.4 Coordinated Lying and Independence......Page 87 4.5 Consequences for BonJour’s Anti-scepticism......Page 89 5.1 The Problem of Justifying Natural Testimony......Page 92 5.2 Hume’s ‘Fatal Ambiguity’......Page 94 5.3 The Argument for Individual Credibility......Page 96 5.4 The Invocation of Cohesion and Coherence......Page 99 5.5 Coady’s Fatal Ambiguity......Page 103 5.6 Closing Remarks on the Anti-sceptical Use of Coherence......Page 105 Part II: Does More Coherence Imply Higher Likelihood of Truth?......Page 108 6.1 Degrees of Coherence......Page 110 6.2 Coherence and Logical Closure......Page 116 6.3 Testimonial Truth Conduciveness......Page 117 6.4 Why the Klein–Warfield Argument Fails......Page 120 6.5 Testimonial vs. Explanatory Coherence......Page 123 7.1 Independence and Individual Credibility......Page 127 7.2 The Need for a Ceteris Paribus Clause......Page 131 7.3 Should Specificity (Strength) be Held Fixed?......Page 134 7.4 Should Size be Held Fixed?......Page 138 7.5 L. J. Cohen on the Influence of the Prior on the Posterior......Page 140 7.6 The Impossibility of Coherence......Page 149 Part III: Other Views......Page 156 8. How not to Regain the Truth Connection: A Reply to Bovens and Hartmann......Page 158 9.1 Nicholas Rescher......Page 171 9.2 Donald Davidson......Page 172 9.3 Keith Lehrer......Page 174 9.4 Paul Thagard......Page 177 Part IV: Scepticism and Incoherence......Page 186 10.1 Cartesian Scepticism......Page 188 10.2 Jamesian Wagering......Page 191 10.3 Peirce’s Reply to Scepticism......Page 202 10.4 More on Incoherence as a Reason for Doubt......Page 205 10.5 Three Roads to Scepticism......Page 208 10.6 Comparison with Other Contemporary Responses......Page 213 10.7 Conclusion......Page 218 Appendix A: Counter-example to the Doxastic Extension Principle......Page 220 Appendix B: Proof of the Impossibility Theorem......Page 226 Appendix C: Proofs of Observations......Page 231 References......Page 239 D......Page 244 L......Page 245 T......Page 246 W......Page 247 Contents 12 1. Introduction 16 Part I: Does Coherence Imply Truth? 22 2. Coherence, Truth, and Testimony 24 2.1 Why Coherence? 24 2.2 Coherence—an Elusive Concept 27 2.3 Pinning down the Coherence Theorist 31 2.4 Truth and Agreement 36 2.5 A Simple Witness Model 39 2.6 Conditions for Convergence 41 2.7 Convergence Parameters 46 2.8 Challenges for the Coherence Theorist 47 3. C. I. Lewis’s Radical Justification of Memory 49 3.1 The Problem of Justifying Memory 49 3.2 Lewisian Witness Scenarios 50 3.3 Lewis on the Convergence Conditions 63 3.4 The Individual Credibility ‘need not be Assigned’ 70 3.5 A Note on Lewis’s Definition of Independence 73 4. Laurence BonJour’s Radical Justification of Belief 76 4.1 The Problem of Justifying Beliefs 76 4.2 BonJour on Justification from Scratch 81 4.3 Lying and Individual Credibility 84 4.4 Coordinated Lying and Independence 87 4.5 Consequences for BonJour’s Anti-scepticism 89 5. C. A. J. Coady’s Radical Justification of Natural Testimony 92 5.1 The Problem of Justifying Natural Testimony 92 5.2 Hume’s ‘Fatal Ambiguity’ 94 5.3 The Argument for Individual Credibility 96 5.4 The Invocation of Cohesion and Coherence 99 5.5 Coady’s Fatal Ambiguity 103 5.6 Closing Remarks on the Anti-sceptical Use of Coherence 105 Part II: Does More Coherence Imply Higher Likelihood of Truth? 108 6. Making the Question Precise 110 6.1 Degrees of Coherence 110 6.2 Coherence and Logical Closure 116 6.3 Testimonial Truth Conduciveness 117 6.4 Why the Klein–Warfield Argument Fails 120 6.5 Testimonial vs. Explanatory Coherence 123 7. A Negative Answer 127 7.1 Independence and Individual Credibility 127 7.2 The Need for a Ceteris Paribus Clause 131 7.3 Should Specificity (Strength) be Held Fixed? 134 7.4 Should Size be Held Fixed? 138 7.5 L. J. Cohen on the Influence of the Prior on the Posterior 140 7.6 The Impossibility of Coherence 149 Part III: Other Views 156 8. How not to Regain the Truth Connection: A Reply to Bovens and Hartmann 158 9. Other Coherence Theories 171 9.1 Nicholas Rescher 171 9.2 Donald Davidson 172 9.3 Keith Lehrer 174 9.4 Paul Thagard 177 Part IV: Scepticism and Incoherence 186 10. Pragmatism, Doubt, and the Role of Incoherence 188 10.1 Cartesian Scepticism 188 10.2 Jamesian Wagering 191 10.3 Peirce’s Reply to Scepticism 202 10.4 More on Incoherence as a Reason for Doubt 205 10.5 Three Roads to Scepticism 208 10.6 Comparison with Other Contemporary Responses 213 10.7 Conclusion 218 Appendix A: Counter-example to the Doxastic Extension Principle 220 Appendix B: Proof of the Impossibility Theorem 226 Appendix C: Proofs of Observations 231 References 239 Index 244 A 244 B 244 C 244 D 244 E 245 F 245 G 245 H 245 I 245 J 245 K 245 L 245 M 246 N 246 O 246 P 246 R 246 S 246 T 246 U 247 V 247 W 247 This Book Is The Most Extensive And Detailed Study Of Coherence And Probable Truth To Date. Erik Olsson Argues That The Value Of Coherence Has Been Generally Overestimated; It Is Severely Problematic To Maintain That Coherence Has A Role To Play In The Process Whereby Beliefs Are Acquired Or Justified. He Proposes That The Opposite Of Coherence, I.e. Incoherence, Can Still Be The Driving Force In The Process Whereby Beliefs Are Retracted, So That The Role Of Coherence In Our Enquiries Is Negative Rather Than Positive.--jacket. Part I. Does Coherence Imply Truth? -- Coherence, Truth, And Testimony: Why Coherence? ; Coherence: An Elusive Concept ; Pinning Down The Coherence Theorist ; Truth And Agreement ; A Simple Witness Model ; Conditions For Convergence ; Convergence Parameters ; Challenges For The Coherence Theorist -- C.i. Lewis's Radical Justification Of Memory: The Problem Of Justifying Memory ; Lewisian Witness Scenarios ; Lewis On The Convergence Conditions ; The Individual Credibility 'need Not Be Assigned' ; A Note On Lewis's Definition Of Independence -- Laurence Bonjour's Radical Justification Of Belief. The Problem Of Justifying Beliefs ; Bonjour On Justification From Scratch ; Lying And Individual Credibility ; Coordinated Lying And Independence ; Consequences For Bonjour's Anti-scepticism -- C . A.j. Coady's Radical Justification Of Natural Testimony: The Problem Of Justifying Natural Testimony ; Hume's 'fatal Ambiguity' ; The Argument For Individual Credibility ; The Invocation Of Cohesion And Coherence ; Coady's Fatal Ambiguity ; Closing Remarks On The Anti-sceptical Use Of Coherence -- Part Ii. Does More Coherence Imply Higher Likelihood Of Truth? -- Making The Question Precise: Degrees Of Coherence ; Coherence And Logical Closure ; Testimonial Truth Conduciveness ; Why The Klein-warfield Argument Fails ; Testimonial Vs. Explanatory Coherence -- A Negative Answer: Independence And Individual Credibility ; The Need For A Ceteris Paribus Clause ; Should Specificity (strength) Be Held Fixed? ; Should Size Be Held Fixed? ; L.j. Cohen On The Influence Of The Prior On The Posterior ; The Impossibility Of Coherence -- Part Iii. Other Views -- How Not To Regain The Truth Connection: A Reply To Bovens And Hartmann -- Other Coherence Theories: Nicholas Rescher ; Donald Davidson ; Keith Lehrer ; Paul Thagard -- Part Iv. Scepticism And Incoherence -- Pragmatism, Doubt, And The Role Of Incoherence: Cartesian Scepticism ; Jamesian Wagering ; Peirce's Reply To Scepticism ; More On Incoherence As A Reason For Doubt ; Three Roads To Scepticism ; Comparison With Other Contemporary Responses ; Conclusion. Erik J. Olsson. Includes Bibliographical References (p. [224]-228) And Index. "It is tempting to think that, if a person's beliefs are coherent, they are also likely to be true. Indeed, this truth-conduciveness claim is the cornerstone of the popular coherence theory of knowledge and justification. Hitherto much confusion has been caused by the inability of coherence theorists to define their central concept. Nor have they succeeded in specifying in unambiguous terms what the notion of truth-conduciveness involves. This book is the most extensive and detailed study of coherence and probable truth to date. Erik Olsson argues that the value of coherence has been generally overestimated; it is severely problematic to maintain that coherence has a role to play in the process whereby beliefs are acquired or justified. He proposes that the opposite of coherence, i.e. incoherence, can still be the driving force in the process whereby beliefs are retracted, so that the role of coherence in our enquiries is negative rather than positive. Another innovative feature of Olsson's book is its unified, interdisciplinary approach to the issues at hand. The arguments are equally valid for coherence among any items of information, regardless of their sources (beliefs, memories, testimonies, and so on). Writing in accessible, non-technical language, Olsson takes the reader through much of the history of the subject, from early theorists like A.C. Ewing and C.I. Lewis to contemporary figures like Laurence BonJour and C.A.J. Coady. Against Coherence will make stimulating reading for epistemologists and anyone with a serious interest in truth."--Book cover It is tempting to think that, if a person's beliefs are coherent, they are also likely to be true. Indeed, this truth-conduciveness claim is the cornerstone of the popular coherence theory of knowledge and justification. Hitherto much confusion has been caused by the inability of coherence theorists to define their central concept. Nor have they succeeded in specifying in unambiguous terms what the notion of truth-conduciveness involves. This book is the most extensive and detailed study of coherence and probable truth to date. Erik Olsson argues that the value of coherence has been generally overestimated; it is severely problematic to maintain that coherence has a role to play in the process whereby beliefs are acquired or justified. He proposes that the opposite of coherence, i.e. incoherence, can still be the driving force in the process whereby beliefs are retracted, so that the role of coherence in our enquiries is negative rather than positive. Another innovative feature of Olsson's book is its unified, interdisciplinary approach to the issues at hand. The arguments are equally valid for coherence among any items of information, regardless of their sources (beliefs, memories, testimonies, and so on). Writing in accessible, non-technical language, Olsson takes the reader through much of the history of the subject, from early theorists like A. C. Ewing and C. I. Lewis to contemporary figures like Laurence BonJour and C. A. J. Coady. Against Coherence will make stimulating reading for epistemologists and anyone with a serious interest in truth. It is tempting to think that, if a person's beliefs are coherent, they are also likely to be true. This truth conduciveness claim is the cornerstone of the popular coherence theory of knowledge and justification. Erik Olsson's new book is the most extensive and detailed study of coherence and probable truth to date. Setting new standards of precision and clarity, Olsson argues that the value of coherence has been widely overestimated. Provocative and readable, Against Coherence will make stimulating reading for epistemologists and anyone with a serious interest in truth. Erik Olsson's book is an extensive and detailed study of coherence and probable truth. Setting new standards of precision and clarity, Olsson argues that the value of coherence has been widely overestimated