This is the first English translation of the most important work of political thought of the fifteenth century. The Catholic Concordance is the first major treatise to argue for consent through representative councils as a major prerequisite for legitimate law and government, and is the most learned and original work associated with the conciliar movement in the late medieval church. Cusa's arguments influenced such thinkers as Luther, Bruno and Locke, and Professor Sigmund's introduction places his work in its full historical and philosophical context.