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). The description contains what has been called one of the best known passages in English philosophy, which describes the natural state mankind would be in, were it not for political community: In such condition, there is no place for industry; because the fruit thereof is uncertain: and consequently no culture of the earth.

The Introduction
Nature (the art whereby God hath made and governes the world) is by the art of man, as in many other things, so in this also imitated, that it can make an Artificial Animal. For seeing life is but a motion of Limbs, the begining whereof is in some principall part within; why may we not say, that all Automata (Engines that move themselves by springs and wheeles as doth a watch) have an artificiall life? For what is the Heart, but a Spring; and the Nerves, but so many Strings; and the Joynts, but so many Wheeles, giving motion to the whole Body, such as was intended by the Artificer? Art goes yet further, imitating that Rationall and most excellent worke of Nature, Man.