In Leviathan, Hobbes set out his doctrine of the foundation of states and legitimate governments – originating social contract theory. Leviathan was written during the English Civil War; much of the book is occupied with demonstrating the necessity of a strong central authority to avoid the evil of discord and civil war.
Beginning from a mechanistic understanding of human beings and the passions, Hobbes postulates what life would be like without government, a condition which he calls the state of nature. In that state, each person would have a right, or license, to everything in the world. This, Hobbes argues, would lead to a "war of all against all" (bellum omnium contra omnes).