1ARTIFICIAL INTELLIGENCE AND LAW USING RULE BASED EXPERT SYSTEMSEric Engle“formal symbolic logic and argumentation theory - have been developing separately, in reciprocal incomprehension if not in open clash.Scholars. have privileged the search for correctness, controllability, and certainty, and have therefor stressed the lack of rigour and the indeterminacy of theories of argumentation. . The theorists of argumentation have instead emphasized the conflict of opinions, the evaluation of alternatives. They have therefore condemned symbolic logic for its incapacity to capture these fundamental aspects of moral and legal reasoning. . The tension between logic and argumentation must instead be overcome by extending formal methods outside the domain of deduction, to the moments of dialectical conlict. which characterise legal and moral reasoning.“Giovanni Sartor, A Formal Model of Legal Argumentation, p 1.2TABLE OF CONTENTSI. Introduction .6A. Artificial intelligence in legal teaching and practice.6B. Limits of the theme.7C. Interest of AI in law .8D. Research Objectives.10E. Method and Problmatique.11F. Problem to be Solved: .13G. Definitions.16H. Outline.27I. Existing Solutions .29J. Existing Literature.30II. Extra-Legal Theories of Justification.37A. The problem of justification.37B. Contemporary Theories of Justification .38C. Law and Economics .42D. Formalism.43E. Realism .44F. Aristotle and Justification.46 1. Aristotle - Phronesis (Practical Reasoning: Prudence).46 2. Aristotle - Virtue and Vice .52III. An Extra-Legal Theory of Judgment.62A. How Do Judges Think?.62B. How Should Judges Think? Great Legal Minds .65C. Hard Cases and Easy Cases.66D. Four Cases to Illustrate Best and Worst Case Legal Interpretative Scenarios.69 1. Filartiga v. Pena Irala: .69 2. Bigio v. Coca Cola .71 3. Sampson v. Federal Republic of Germany.73 4. Byung Wha An et al. v. Doo-Hwan Chun, et. al. .74E. Interpolating multiple graphs to infer a general algorithm of judicial decision .75F. Describing, Explaining and Predicting Judicial Behavior Based on Interpolation of the Two Graphs.783IV. Infra-Legal Theories of Argumentation: Interpretive Methods .86A. Formal Rules of Statutory Construction.86 1. Literal or “plain meaning“ interpretation.