In contrast to the numerous expositions and commentaries concerning the origin, history, and nature of the doctrine of the separation of powers, early theories of parliamentary government have failed to attract the attention of historians of political thought. This negligence arises from two factors which must not be under-estimated. In the first place, it is generally asserted that Walter Bagehot was the first to appreciate the true nature of parliamentarism. Indeed, the penetration and lucidity of his famous essay on the English constitution overshadowed earlier attempts to grasp theoretically the mechanism of parliamentary government. In the second place, historians of political theory have been less prone to trace the roots of the theory of parliamentarism than those of the doctrine of the separation of powers because parliamentary government, although gradually introduced into a number of countries in the course of the nineteenth century, was not reduced to writing in any organic law prior to the World War. The development of the theory of parliamentary government is, therefore, one of the most neglected chapters in the history of constitutional ideas.
While the English to the end of the fifties of the last century looked upon and appraised their constitution through the eyes of Montesquieu, Blackstone, and De Lolme, continental theorists were busy in elaborating a new theory about the nature of the English constitution. The early history of parliamentary theory is determined, therefore, to no small extent by the way in which continental theorists observed and conceived the operation of English government. It was in France and Germany that the true nature of the English constitution was first discovered and a theory of parliamentarism formulated for the direct purpose of introducing the parliamentary system into those two countries.