Abstract

Genuine norms have no truth-value. This makes their \logic" peculiar. Norms which are prescriptions have, moreover, a history. They come into being, are \in force" for some time, and then pass out of existence. By a corpus of norms we understand a nite set of temporally co- existing norms. A corpus is satised if, and only if, all states of aairs which the norms of the corpus pronounce obligatory obtain throughout the history of the corpus { and every state which the norms pronounce permitted obtains some time in this history. And a corpus is satisable if if is logically possible that it is satised.