Formalising debates about law-making proposals as practical reasoning

Abstract

In this paper the ASPIC+ framework for argumentation-based inference is used for formally reconstructing two legal debates about law-making proposals: an opinion of a legal scholar on a Dutch legislative proposal and a US commonlaw judicial decision on whether an existing common law rule should be followed or distinguished. Both debates are formalised as practical reasoning, with versions of the argument schemes from good and bad consequences. These case studies aim to contribute to an understanding of the logical structure of debates about lawmaking proposals. Another aim of the case studies is to provide new benchmark examples for comparing alternative formal frameworks for modelling argumentation. In particular, this paper aims to illustrate the usefulness of two features of ASPIC+: its distinction between deductive and defeasible inference rules and its ability to express arbitrary preference orderings on arguments.