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. Leviathan ranks as a classic western work on statecraft comparable to Machiavelli's The Prince. Written during the English Civil War (1642–1651), Leviathan 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 only be avoided by strong, undivided government.