This volume provides the first English translation of Hans Kelsen's and Carl Schmitt's influential Weimar-era debate on constitutional guardianship and the legitimacy of constitutional review. It includes Kelsen's seminal piece, 'The Nature and Development of Constitutional Adjudication', as well as key extracts from the 'Guardian of the Constitution' which present Schmitt's argument against constitutional review. Also included are Kelsen's review of Schmitt's 'Guardian of the Constitution', as well as some further material by Kelsen and Schmitt on presidential dictatorship under Article 48...