Granting an original state of anarchy and internecine hostility, there is, according to Hobbes, only one way out of it, which is a joint resolution of the whole community to surrender their rights of individual sovereignty into the hands of one man, who thenceforth becomes absolute ruler of the State, with authority to defend its citizens against mutual aggressions, and the whole community against attacks from a foreign Power. This agreement constitutes the famous Social Contract, of which so much was to be heard during the next century and a-half. It holds as between the citizens themselves, but not between the subjects and their sovereign, for that would be admitting a responsibility which there is no power to enforce. And anyone refusing to obey the sovereign justly forfeits his life; for he thereby returns to the State of Nature, where any man that likes may kill his neighbour if he can. All this theory of an original institution of the State {27} by contract impresses a modern reader as utterly unhistorical. But its value, if any, does not depend on its historical truth. Even if the remote ancestors of the seventeenth-century Europeans had surrendered all their individual rights, with certain trifling exceptions, into the hands of an autocrat, no sophistry could show that their mutual engagements were binding on the subjects of Charles I. and Louis XIV. And it is really on expediency, understood in the largest sense, that the claims of the New Monarchy are based by Hobbes. What he maintains is that nothing short of a despotic government exercised by one man can save society from relapsing into chaos. But even under this amended form the theory remains amenable to historical criticism. Had Hobbes pursued his studies beyond Thucydides, he would have found that other polities besides the Athenian democracy broke down at the hour of trial. Above all, Roman Imperialism, which seems to have been his ideal, failed to secure its subjects either against internal disorder or against foreign invasion.