In A Living Constitution or Fundamental Law?, distinguished scholar Herman Belz considers the concept of constitutionalism as the subject matter of constitutional history. He argues that the study of constitutionalism should be interdisciplinary, requiring the insights and methods of history, political science, and jurisprudence. Belz illuminates the evolution of American constitutionalism across the span of American history, from the Founding to Reconstruction to the Cold War and the rise of the bureaucratic state in the 1980s.