Widely considered two of the most controversial legal scholars, Hans Kelsen and Carl Schmitt have been the subject of debate for almost a century. This book focuses on a limited, but extremely important, controversy between Kelsen and Schmitt: the answer to the question regarding the proper guardian of the constitution. This is a debate that goes to the heart of political power and legal thinking. The work presents a detailed examination of the three key documents from 1927 to 1933 regarding this controversy. An understanding of these writings will aid in comprehending the larger controversy between Kelsen and Schmitt regarding discussion or decisionism, law or power, and democracy or dictatorship. As much about the conflict between pluralism and unity and between democracy and autocracy as it is about a specific historical controversy, this study will be of interest to academics and researchers working in the areas of Jurisprudence and Legal Philosophy, Constitutional Law and Theory, Political Philosophy and Legal History.