The development of Anglo-American law has been greatly influenced by certain theories and doctrines which have directed and conditioned the evolution of administrative law. Foremost among these are the political and legal theory of the separation of governmental powers and a juridical doctrine relating to the nature and scope of law itself. Briefly, the theory of the separation of powers, which is commonly announced as a fundamental principle of American constitutional law, and is implicit in some phases of English law, is to the effect that laws are made by the legislature, executed by the executive, and interpreted and applied by the courts. As a correlative of this doctrine, it is understood as essential that none of these departments may delegate powers which properly belong to it to either of the other departments, in order that, as the Massachusetts constitution expresses it, “there shall be a government of laws and not of men.”
