Both Locke and Rousseau developed social contract theories in Two Treatises of Government and Discourse on Inequality, respectively. While quite different works, Locke, Hobbes, and Rousseau agreed that a social contract, in which the government's authority lies in the consent of the governed, is necessary for man to live in civil society. Locke defines the state of nature as a condition in which humans are rational and follow natural law; in which all men are born equal and with the right to life, liberty and property. However, when one citizen breaks the Law of Nature, both the transgressor and the victim enter into a state of war, from which it is virtually impossible to break free. Therefore, Locke said that individuals enter into civil society to protect their natural rights via an "unbiased judge" or common authority, such as courts, to appeal to. Contrastingly, Rousseau's conception relies on the supposition that "civil man" is corrupted, while "natural man" has no want he cannot fulfill himself. Natural man is only taken out of the state of nature when the inequality associated with private property is established. Rousseau said that people join into civil society via the social contract to achieve unity while preserving individual freedom. This is embodied in the sovereignty of the general will, the moral and collective legislative body constituted by citizens.

What did Locke, Hobbes, and Rousseau agree was necessary for a man to live in civil society?