This unique volume brings together leading academics and researchers from different legal traditions to discuss the work and impact of Hans Kelsen, the most influential legal philosopher with global reach. Using his Pure Theory of Law and his theory of democracy as a lingua franca, the book allows for dialogues between jurisdictions and legal traditions and serves as a point of departure for further research on several themes such as state, international, and non-state law. The volume covers four themes. The first part focuses on Kelsen's often overlooked assumptions and the resultant conception of law. The second section refers in particular to Kelsen's understanding of legal norms and some of its most salient elements and features such as sanction and validity. The third part explores a variety of questions concerning Kelsen's views on international and non-state law in general and their implications in some jurisdictions. The final section brings Kelsen's legal and political theory together by assessing its relevance to democracy.