The idea behind this text is that, although legislation and regulation are the result of a political process, they can be the object of theoretical study. The focus is on problems common to most European legal systems, and the approach involves applying the tools of legal theory to legislative problems (hence ""legisprudence""). Traditional legal theory deals predominantly with the question of the application of law by the judge. Legisprudence enlarges the field of study so as to include the creation of law by the legislator. Following this approach a variety of questions and problems are raised, including the validity of norms, their meaning and the structure of the legal system, problems that are traditionally dealt with from the perspective of the judge or are taken for granted by classical legal theory. However, by shifting the attention to the legislator, the same questions arise, though traditional legal science covers many of these questions with the cloak of sovereignty. The essays in this volume expose and develop a range of insights into the relationship between legislative problems and legal theory in a way which should engage and interest legal scholars around the world.