The idea of social contract which flourished in the 18th century found its roots and inspiration in three sources: the teaching of the Bible (which instructed that the powers that be are ordained of God, but also that David made a covenant with his people): the doctrines of Roman Law (which directed that "the people, by the Law of the Monarch passed in regard to his authority, confers upon him and into his hands all its authority and power"); and the principles of Aristotle's Politics (which favored a clear distinction between king and tyrant, and endorsed the right of the masses not only to elect the magistrate but also to call him to account).

These rudimentary principles became the political inheritance of the Middle Ages and took the form of a contract of government between feudal king and feudatory. "I will be to you faithful and true...on condition that you keep me as I am willing to deserve, and all that to fulfill that our agreement was, when I was to you submitted and chose your will."

Later, in the eighteenth century, these principles of "contracts of government" became transmuted into "contracts of society," and found their fullest expression in the writings of Locke, Hume, and Rousseau. The three essays collected in this volume proved to be as rich in their legacy to future political systems as they had been rich in their inheritance from the past. Their influence is seen in many revolutionary social treatises, in the writings of Thomas Paine, and, moreover, in the Constitutions of all free nations.