Formalizing Practical Argumentation

Universidad Nacional del Sur, Bahia Blanca, Argentina, June 1998

When people face a practical problem, on what to do, believe or decide, they often engage in practical argumentation. This takes place in daily life, law, bureacracies and organisations, etcetera. In practical argumentation (whether alone or debating with other people) arguments for and against a solution to a problem are constructed, attacked and compared, to see which solution is tenable. The aim of this course is to give insight in the problems and prospects of formalizing practical argumentation for the purpose of AI implementation. The main source of inspiration and examples will be legal reasoning. The general structure of the course is given by a four-layered picture of practical argumentation:

• The logical layer, that defines the construction of arguments;
• the dialectical layer, that defines when arguments attack each other, and which arguments prevail;
• the procedural layer, that states discourse norms for entering new information into or withdrawing old information from a dispute;
• the strategic layer, that defines rational strategies and heuristics for conducting a dispute

A crucial difference between the first two and the last two layers is that in the first two layers the information on which the reasoning operates is fixed, while in the last two layers the information is constructed dynamically in the course of a dispute.

• Course syllabus

• Slides:
  • Lecture 1 Introduction
  • Lecture 2 Logics for defeasible argumentation I. Semantics
  • Lecture 3 Logics for defeasible argumentation II. Dialectical proof theory
  • Lecture 4 AI & Law research on adversarial argumentation (partly available)
  • Lecture 5 Formalizing adversarial reasoning with precedents
  • Lecture 6a On formalizing the procedural layer: introduction
  • Lecture 6b
  On formalizing the procedural layer: Gordon (in reverse order)
  (Vreeswijk's slides are only available as hardcopy)
  • Lecture 7 Formalizing rules of order for meetings (most of the slides)
  • Lecture 8 A model of argumentation as negotiation