Stig Kanger on Deontic Logic

Abstract

The year 1957 saw the publication of two ground-breaking contributions to deontic logic, Stig Kanger’s ‘New Foundations for Ethical Theory’ (Kanger 1957/71)1 and Jaakko Hintikka’s ‘Quantifiers in Deontic Logic’ (Hintikka 1957).2 Superficially the papers look very different, but they contain many significant similarities: 1. Both papers contain a semantic analysis of the basic normative concepts the obligatory, the permitted, and the prohibited (or the concepts of ought, may, and may not). The semantical theories proposed by Kanger and Hintikka are closely related to, or variants of, the possible worlds semantics for modal concepts. 2. Kanger and Hintikka discuss the applicability of the concepts of truth and consequence to normative discourse, that is, to imperatives, norms, and normative statements. 3. Both authors analyze the role of quantifiers in deontic logic and the interplay of quantifiers and deontic operators. 4. The concepts and results of deontic logic are applied to conceptual problems in ethics and the philosophy of law. 5. In these papers, Kanger and Hintikka discuss the importance of the representation of actions and agency in deontic logic and, more generally, the role of actions and action descriptions in normative discourse. In the present paper I shall briefly discuss Kanger’s contributions to these topics.