Social contract theory is an early expression of what is now referred to as contractiarianism, a view according to which the legitimacy of political systems rests upon a mutual agreement amongst free, rational and equal people. A defining feature of early contractarianism is the belief that human beings are motivated, in some degree, by self-interest. Another defining feature is the characterization of the “state of nature” – a world without justice (and in some cases without any system of morality). Humans are driven to contractual agreement with others to escape an otherwise overly competitive or untenable situation. Humans cede decision-making power to the authority of government as a result of enlightened self-interest: we benefit, on balance, from cooperation with others.

This theory of political authority provides the basis for modern liberal systems of government. Without the works of such thinkers as Thomas Hobbes, John Locke and Jean Jacques Rousseau, modern systems of government may well look very different and the perception of the relationship between the interests of individuals and that of the state would likely be radically different.

In studying these early thinkers, we can come to appreciate the fundamental assumptions that drove the rise of modern Western governments. We are also driven to consider the nature of human motivation, the role of moral rules and rules of justice in state legislation, as well as to reflect upon the ways in which governmental structures shape our individual sense of rights, responsibilities and social duties.