Leviathan or The Matter, Forme and Power of a Commonwealth Ecclesiasticall and Civil

Commonly referred to as Leviathan, this is a book written by Thomas Hobbes (1588–1679) and published in 1651 (revised Latin edition 1668). Its name derives from the biblical Leviathan.

The work concerns the structure of society and legitimate government, and is regarded as one of the earliest and most influential examples of social contract theory. Written during the English Civil War (1642–1651), it argues for a social contract and rule by an absolute sovereign.

Hobbes wrote that civil war and the brute situation of a state of nature ("the war of all against all") could be avoided only by a strong, undivided government.