. A new approach to the formalization of concepts used in legal reasoning such as obligation and cause is presented. The formalization is based on the linguistic use of the concepts both in legal language and in ordinary language, and has been motivated by work on a legal expert system with a natural language interface. Particularly for the concept of obligation this yields quite different results from those obtained by the usual approach of deontic logic: So‐called paradoxes are avoided, quantification (...) over obligations becomes possible, no restriction to a “single‐agent system” is required, and collisions of obligations can be formulated. (shrink)