Hans Kelsen is considered by many to be one of the foremost legal thinkers of the twentieth century. He made important contributions to many areas, but especially to legal theory and international law. Over a number of decades, he developed an important legal theory which found its first complete exposition in Reine Rechtslehre, 1934 (presently being translated by Stanley Paulson for OUP) and its fullest expression in the second edition of Reine Rechtslehre, 1960. During the last decade of his life he was working on what he called a general theory of norms. When he died in 1973, he left a lengthy manuscript, which was published in 1979 as Allgemeine Theorie der Normen. This book is the translation - General Theory of Norms. It is thus the last work of one of the most important legal theorists this century. In it, Kelsen develops his `pure theory of law' into a `general theory of norms'. In so doing, he provides a new basis for some of the positions he espoused earlier on, but also revises some of his earlier positions. The most important new topic is that of the applicability of logic to norms: Kelsen develops an original and extreme position some people have called `normative irrationalism'. In the book, Kelsen also examines the views of over 200 philosophers and legal theorists on law, morality and logic, ranging from Plato and Aristotle to contemporary thinkers.