This book is a revised version of my dissertation 'DiaLaw - on legal th justification and dialog games' that I defended on June 5 1998 at the Universiteit Maastricht. The chapters 1, 4 & 5 (now: 1, 5 & 6) of my dissertation have remained largely unaltered. In chapter 2 I added explicitly the distinction between constructing legal justification and reconstructing it, and tried to elucidate the differences (and similarities) between the product and process of justification. Chapter 3 is divided into two chapters: one on the general characteristics of DiaLaw (now: chapter 3), and the other on specific, legal characteristics of DiaLaw (now: chapter 4). In order to improve readability, all rules in these chapters have been rewritten considerably. The section on the implementation of DiaLaw is moved to the appendix. In chapter 7 (the former chapter 6), a discussion of the notions 'procedural' and 'structural' arguments is added, and different layers in argumentation models are discussed. Finally, in chapter 8 (the former chapter 7) is added a recapitulation of my view on legal justification, and a discussion on the future use in legal practice of dialog models that represent argumentation in a natural way. The main thesis has remained unaltered: legal justification should be modeled as a procedural, dialogical model in which not only products of argumentation are allowed, but, even in formal models, rhetorical, psychological aspects of argument are dealt with.

Zusammenfassung
Finally, in chapter 8 (the former chapter 7) is added a recapitulation of my view on legal justification, and a discussion on the future use in legal practice of dialog models that represent argumentation in a natural way.

Inhalt
1 Introduction.- 1. Artificial Intelligence and Law.- 2. Legal justification.- 3. Outline of the book.- 2 From law to DiaLaw Why legal justification should be modeled dialogically.- 1. The product and the process of justification.- 2. Justification as a product.- 3. The defeasible nature of legal justification.- 4. The open nature of law.- 5. The Münchhausen Trilemma.- 6. Justification as a process: a dialogical model.- 7. Dealing with defeasibility, open nature, and the Münchhausen Trilemma in a dialogical model.- 8. Justification of dialog rules and altering protocols.- 9. How pure is the procedure of legal justification?.- 10. Conclusion.- 3 DiaLaw Framework and general rules.- 1. Justification in DiaLaw.- 2. Basic concepts of DiaLaw.- 3. DiaLaw's dialogical framework.- 4. General rules for communication.- 5. Towards legal justification.- 4 DiaLaw Special rules for communication.- 1. Special language elements.- 2. Special rules for communication - legal tools and forced commitment.- 3. Concluding remarks.- 5 DiaLaw in action.- 1. The Tyrell case.- 2. The Chabot case.- 3. Concluding remarks.- 6 Dialogical models of argumentation.- 1. The purpose of models.- 2. A short sample dialog.- 3. Mackenzie's DC and Hamblin's H.- 4. Rescher's Dialectics and the formal elaboration by Brewka.- 5. Gordon's Pleadings Game.- 6. Survey of moves and commitment.- 7. Other related research.- 8. Conclusion.- 7 What is an argument? Properties of procedural models of argumentation.- 1. Argumentation: two perspectives.- 2. Argumentation: two types.- 3. Towards combining the approaches.- 4. DiaLaw: rational and dia-rational argumentation.- 5. Procedural and structural arguments.- 6. Layers in models of legal argumentation.- 7. Conclusion.- 8 In conclusion.- 1. On legaljustification.- 2. The answers.- 3. The future: towards natural dialog models.- 4. Closing remarks.- Appendix- Prolog code of DiaLaw.- References.- Index of names.- Index of subjects.