The essays collected in this book address legislation from the viewpoint of legal theory and provide an overview of current research in legisprudence as a new scholarly approach to lawmaking. The overall focus of the volume is on the justification of legislation, with a special emphasis on the intricate notion of legislative rationality. With the rational justification of legislation as their central theme, the essays elaborate on the foundations and bounds of legislation and the search for a more principled lawmaking, discuss the role of legislation within the framework of democratic constitutionalism, analyze legislation as implementation of constitutional law, and explore how legislative argumentation in parliament can be construed as a source of justification of laws.