The social contract is an intellectual device intended to explain the appropriate relationship between individuals and their governments. Social contract arguments assert that individuals unite into political societies by a process of mutual consent, agreeing to abide by common rules and accept corresponding duties to protect themselves and one another from violence and other kinds of harm.^{[citation needed]}

Social contract theory played an important historical role in the emergence of the idea that political authority must be derived from the consent of the governed. The starting point for most social contract theories is a heuristic examination of the human condition absent from any political order, usually termed the “state of nature”. In this condition, individuals' actions are bound only by their personal power and conscience. From this shared starting point, social contract theorists seek to demonstrate, in different ways, why a rational individual would voluntarily give up his or her natural freedom to obtain the benefits of political order.

Thomas Hobbes (1651), John Locke (1689), and Jean-Jacques Rousseau (1762) are the most famous social contract thinkers. Each drew quite different conclusions about the nature of political authority. Hobbes advocated absolute monarchy, Locke advocated natural rights, and Rousseau advocated collective sovereignty in the name of "the general will".^{[citation needed]} The Lockean concept of the social contract was invoked in the United States Declaration of Independence, and social contract notions have recently been invoked, in a quite different sense, by thinkers such as John Rawls.

Although developed for understanding human societies, sociobiologists have found the notion illuminating for understanding societies of other social species and even interspecies symbiotic relationships.^[1]