Many recent political and economic transformations pose difficult questions of legal and social theory. Yet, although these questions are now raised with new urgency, the basic questions are not new. They have long been central features of legal and social philosophy in its most general form. What principles explain or justify legal institutions or decisions, thereby transforming coercion to authority? Are there or could there be any such universal principles? Can any philosophical theory account for such principles? How, if at all, do philosophical theories of law and politics apply to particular issues? And finally, what, if any, do such practical applications tell us about general theories and principles? The essays in this volume represent the efforts of an international group of scholars to understand these general aspects of legal philosophy.