Hobbes wrote two books named after biblical beasts. One was Behemoth, his history of the English civil war. This, like the beast Behemoth himself, is still little known. The other was Leviathan. Both it, and its name, are much more familiar. After giving the work its title, the great beast first appears in the text itself in the chapter that explains the origin and nature of what we now normally call the state. A unity has to be produced from a multitude of people, and when this is done we have ‘a common-wealth, in Latin civitas. This is the generation of that great Leviathan, or rather (to speak more reverently) of that Mortal God, to which we owe under the Immortal God, our peace and defence’ [17.13, p. 87]. So Leviathan is what we now normally call the state, what Hobbes normally calls the commonwealth, and what he says should be thought of as a ‘mortal god’.

This is the first entry of the beast who gives his name to Hobbes's great work. One reason for the work's greatness is that it shows how a political philosophy could be constructed by the use of reason alone. Or so I claimed in the last chapter: Hobbes gives authority to reason at a time when there was not only deep conflicts that blunted the power of biblical or church authority, but also serious scepticism about the power of reason itself. We shall come later to the problem of scepticism about reason.