Fuzzy Logic and Its Application to Legal Reasoning — A Comment to Professor Zadeh

Abstract

Fuzzy logic, introduced by Professor Lotfi Zadeh more than thirty-five years ago, has become an established analytical tool in a variety of disciplines, including the study of legal reasoning. Fuzziness supplies a useful instrument for modeling various modes of uncertainty and vagueness, not dealt with by traditional probability calculus relying on the age-old structure of two-valued logic. The latter typically handles the uncertainty emanating from lack of information about the subject of interest, but has proved a poor method for modeling semantic vagueness. Fuzzy set theory,¹ and the logic constructed on its foundations, were designed to amend these shortcomings.