Contractualism
Any theory basing either moral obligation in general, or the duty of political obedience, or the justice of social institutions, on a contract, usually called a ‘social contract’. The idea goes back at least as far as Plato’s Crito (c.395 BC), and contractualists (or contractarians) have also included Thomas Hobbes (1588-1679), John Locke (1632-1704), Jean Jacques Rousseau(1712-1778), and various modern