Second Treatise of Civil Government

Locke's Second Treatise (1689) argues that political authority derives from consent, not conquest or divine right. The state of nature, unlike Hobbes's war of all against all, is governed by natural law: reason reveals that all persons are free and equal, and none may harm another in life, liberty, or property. Government arises from a contract to protect these natural rights. Property, the securing of which requires government in the first place, is grounded in labor: a person mixes their labor with natural things and acquires a right to them, within limits.

The central move is the limitation of sovereign power. Where Hobbes's covenant produces an absolute sovereign who cannot be deposed, Locke's produces a trustee. If government violates the natural rights it was formed to protect, the people retain the right to dissolve it and form another. The legislative and executive powers are distinct, and the legislature answers to the people who created it. Concentration of both in a single hand is, by definition, tyranny.

The Second Treatise was written partly as a justification for the Glorious Revolution and became the theoretical foundation of liberal constitutionalism. Its arguments reappear nearly verbatim in the American Declaration of Independence and structure every subsequent debate about the limits of state power. Rousseau accepted the consent framework but rejected Locke's property theory, and the fork between them runs through the entire history of liberal and radical politics.