Normative Systems, Rationality Requirements, and Deductive Closure

Abstract

This paper examines Berislav Žarnić’s social-pragmatic approach to deontic logic and its account of rationality in normative activities. It reviews the rationality requirements governing norm-givers, norm-recipients, and norm-appliers, with particular attention to consistency, completeness, and deductive closure. The paper argues that issuing conflicting norms does not necessarily make a norm-giver irrational, since conflicts may serve substantive or formal purposes. It also shows that sealing principles intended to complete normative systems can produce problematic consequences in certain cases. Most importantly, the paper distinguishes deductive instantiation from the combination of general norms and argues that the latter can constitute a rationality requirement for norm-givers.