Building on his contributions to institutional legal theory in Institutional Legal Facts of 1993 (Law and Philosophy Library, volume 18), the author presents a comprehensive theory of legal institutions. To that end, the initial theoretical approach, which mainly concentrated on problems connected with legal powers and legal acts (acts-in-law), is widened to allow for the development of a theory of legal judgements capable of accounting not only for enacted but also unwritten law (legal principles and customary law). With the use of the concept of institutional legal facts, the...