"Bellum omnium contra omnes" is Latin for the war of all against all. It is the description that Thomas Hobbes gives to human existence in the state-of-nature thought experiment that he conducts in Leviathan. This thought experiment places people in a pre-social condition, and theorizes what would happen in such a condition. According to Hobbes, the outcome is that people choose to enter a social contract, giving up some of their liberties in order to enjoy peace. This thought experiment is a test for the legitimation of a state in fulfilling its role as "sovereign," and for comparing different types of states on that basis.

See also:

• Social contract theories
• Leviathan (book)