DIALAW Law and Philosophy Library VOLUME 42 Managing Editors FRANCISCO J. LAPORTA, Department of Law, Autonomous University of Madrid, Spain ALEKSANDER PECZENIK, Department of Law, University of Lund, Sweden FREDERICK SCHAUER, John F. Kennedy School of Government, Harvard University, Cambridge, Mass., U.S.A. Former Managing Editors AULIS AARNIO, MICHAEL D. BAYLESt, CONRAD D. JOHNSONt, ALANMABE Editorial Advisory Board AULIS AARNIO, Research Institute for Social Sciences, University of Tampere, Finland ZENON BANKOWSKY, Centre for Criminology and the Social and Philosophical Study of Law, University of Edinburgh PAOLO COMANDUCCI, University of Genua, Italy ERNESTO GARZ6N VALDES, Institut fur Politikwissenschaft, Johannes Gutenberg Universitiit Mainz JOHN KLEINIG, Department of Law, Police Science and Criminal Justice Administration, John Jay College of Criminal Justice, City University of New York NEIL MacCORMICK, Centre for Criminology and the Social and Philosophical Study of Law, Faculty of Law, University of Edinburgh WOJCIECH SADURSKI, Faculty of Law, University of Sydney ROBERT S. SUMMERS, School of Law, Cornell University CARL WELLMAN, Department of Philosophy, Washington University ARNO R. LODDER Computer/Law Institute, Free University 01 Amsterdam, The Netherlands DIALAW On Legal ]ustification and Dialogical Models oiA rgumentation ..... " SPRINGER-SCIENCE+BUSINESS MEDIA, B.V. A C.I.P. Catalogue record for this book is available from the Library of Congress. ISBN 978-1-4020-0287-8 ISBN 978-94-011-3957-1 (eBook) DOI 10.1007/978-94-011-3957-1 Printed on acid-free paper All Rights Reserved © 1999 Spring~r Scjence+Business Media Dordrecht Originally published by Kluwer Academic Publishers in 1999 No part of the material protected by this copyright notice may be reproduced or utilized in any form or by any means, electronic or mechanical, inc1uding photocopying, recording or by any information storage and retrieval system, without written permission from the copyright owner. To Aimee Contents Preface .......................................................................................................................... xi Chapter 1 Introduction 1. Artificial Intelligence and Law ................................................................................. 2 2. Legal justification ..................................................................................................... 4 3. Outline of the book ................................................................................................... 5 Chapter 2 From law to DiaLaw Why legal justification should be modeled dialogically 1. The product and the process of justification ............................................................. 8 2. Justification as a product ......................................................................................... 11 3. The defeasible nature oflegal justification ............................................................. 13 3.1 Exceptions to rules .......................................................................................... 14 3.2 Conflicting norms ........................................................................................... 15 4. The open nature of law ............................................................................................ 17 4.1 Cases without an applicable norm ................................................................... 18 4.2 Vague legal language ...................................................................................... 19 5. The Miinchhausen Trilemma .................................................................................. 20 6. Justification as a process: a dialogical model... ....................................................... 23 7. Dealing with defeasibility, open nature, and the Miinchhausen Trilemma in a dialogical model ...................................................................................................... 25 8. Justification of dialog rules and altering protocols ................................................. 27 9. How pure is the procedure oflegaljustification? ................................................... 28 10. Conclusion .............................................................................................................. 31 Chapter 3 DiaLaw Framework and general rules 1. Justification in DiaLaw ........................................................................................... 33 2. Basic concepts ofDiaLaw ....................................................................................... 35 2.1. The participants ................................................................................................ 35 viii CONTENTS 2.2. The moves of the game .................................................................................... 36 2.3. Burden of proof. ............................................................................................... 38 2.4. Commitment .................................................................................................... 39 2.5. The dialog rules ................................................................................................ 39 2.6. Levels in the dialog .......................................................................................... 40 3. DiaLaw's dialogical framework .............................................................................. 41 3.1. The language .................................................................................................... 41 3.2. The dialog move .............................................................................................. 42 3.3. The commitment store ..................................................................................... 44 3.4. The dialog ........................................................................................................ 44 3.5. The dialog tree ................................................................................................. 45 4. General rules for communication ............................................................................ 47 4.1. The interaction in main lines ............................................................................ 48 4.2. Origin of commitment ...................................................................................... 49 4.3. General conditions ........................................................................................... 52 4.4. Moves after a claim .......................................................................................... 54 4.5. Moves after question ........................................................................................ 55 4.6. Moves after acceptance or withdrawal.. ........................................................... 55 5. Towards legal justification ...................................................................................... 61 Chapter 4 DiaLaw Special rules for communication 1. Special language elements ...................................................................................... 64 1.1. Introducing DiaLaw's Reason-Based Logic .................................................... 64 1.2. Formal properties of the special language elements ......................................... 66 2. Special rules for communication -legal tools and forced commitment.. ................ 68 2.1. On reasons to apply a rule ................................................................................ 68 2.2. On applies, reason, and exc1uded ..................................................................... 70 2.3. On outweighs and reason ................................................................................. 71 2.4. On il claim ....................................................................................................... 76 3. Concluding remarks ................................................................................................ 80 Chapter 5 DiaLaw in action 1. The Tyrell case ........................................................................................................ 82 2. The Chabot case ...................................................................................................... 88 2.1. On reasons to apply a rule ................................................................................ 89 2.2. On applies, reason, and exc1uded ..................................................................... 90 2.3. On reasons and outweighs ................................................................................ 92 CONTENTS IX 3. Concluding remarks ................................................................................................ 94 Chapter 6 Dialogical models of argumentation 1. The purpose of models ............................................................................................ 98 2. A short sample dialog ............................................................................................. 99 3. MacKenzie's DC and Hamblin's H ...................................................................... 102 3.1. The moves ...................................................................................................... 103 3.2. Commitment .................................................................................................. 105 3.3. Concluding remarks ....................................................................................... 106 4. Rescher's Dialectics and the formal elaboration by Brewka ................................. 107 4.1. The moves ...................................................................................................... 108 4.2. Dialog rules .................................................................................................... 109 4.3. Commitment .................................................................................................. 112 4.4. Concluding remarks ....................................................................................... 114 5. Gordon's Pleadings Game .................................................................................... 115 5.1. An informal description of the Pleadings Game ............................................ 116 5.2. The moves ...................................................................................................... 118 5.3. Dialog rules .................................................................................................... 119 5.4. Relevancy and issues ..................................................................................... 123 5.5. Commitment .................................................................................................. 125 5.6. Suggestions and Concluding remarks ............................................................ 126 6. Survey of moves and commitment ........................................................................ 128 6.1. Moves ............................................................................................................. 128 6.2. Commitment .................................................................................................. 131 7. Other related research ........................................................................................... 133 7 .1. Van Eemeren and Grootendorst.. ................................................................... 133 7.2. Vreeswijk's argument-based dialectics .......................................................... 135 7.3. The HELIC systems ....................................................................................... 140 7.4. Loui c.s.: protocols and rationales .................................................................. 141 7.5. Farley and Freeman's levels of burden of proof ............................................ 143 8. Conclusion ............................................................................................................ 145 Chapter 7 What is an argument? Properties of procedural models of argumentation 1. Argumentation: two perspectives .......................................................................... 147 1.1. The logical perspective .................................................................................. 148 1.2. The psychological perspective ....................................................................... 149 2. Argumentation: two types ..................................................................................... 150 x CONTENTS 2.1. Rational and dia-rational argumentation ........................................................ 151 2.2. (Di)a-rational argumentation in case law ....................................................... 152 3. Towards combining the approaches ...................................................................... 154 4. DiaLaw: rational and dia-rational argumentation ................................................. 155 5. Procedural and structural arguments ..................................................................... 157 6. Layers in models oflegal argumentation .............................................................. 159 7. Conclusion ............................................................................................................ 162 Chapter 8 In conclusion 1. On legal justification ............................................................................................. 163 2. The answers .......................................................................................................... 165 2.1 How can be determined whether a legal statement is justified, and are there criteria a legal statement must satisfy in order to be justified? ...................... 165 2.2. What model oflegaljustification is satisfactory, and is it possible to defme and implement this model? ............................................................................ 166 2.3. How do comparable models represent argumentation? ................................. 166 2.4. What is acceptable as an argument in legal justification? .............................. 167 3. The future: towards natural dialog models ............................................................ 168 4. Closing remarks .................................................................................................... 170 Appendix-Prolog code of DiaLaw ...................................................................... 171 References ................................................................................................................. 185 Index of names ......................................................................................................... 193 Index of subjects ...................................................................................................... 195