A social contract theory of the state is any theory which says that the existence of the state is morally justified by some sort of agreement, often called a social contract, that is said hold among the residents of a particular geographical area over which the state has authority.

Sometimes this theory is called contractarianism. Why this contract is supposed to be necessary at all? Thomas Hobbes is famous for presenting a useful fiction in political philosophy, called the state of nature. The state of nature is, basically, the condition we all would be in if government did not exist. The way it's sometimes presented, it's the condition before the rule of law comes into being. Some have thought that there was a time before any government, any official monopoly on the initiation of the use of force, came into being. That might be wrong in point of historical fact. It is very rare, indeed, that a group of people lacks anything like a government at all, even if the "government" consists only of tribal elders.

Hobbes thought that the state of nature, the condition of having no government, would in effect be the war of all against all. We would all be fighting amongst ourselves for scarce resources, grabbing whatever we can. "The life of man," Hobbes said, would be "solitary, poor, nasty, brutish, and short." People in the state of nature, according to Hobbes, could not even correctly appeal to any sort of higher justice. There would be no justice at all. Hobbes thought that, in order to have justice, there must be a law. If there is no actual law against murder, then murder is not unjust.

Some people -- only some of the people who call themselves anarchists -- think that the state of nature as anarchy would definitely be better than any situation where there is a government. Against that is the thinking is at the heart of the social contract theory, that those conditions would lead to the formation of some leagues for self-defence, based on agreements. What Hobbes argued isn't that there is an actual agreement that anyone actually has made. It's a hypothetical agreement. What gives the state the right to exist is the fact that individuals would agree to establish it, and to give up their liberties, in the state of nature.

John Locke disagreed with Hobbes about the social contract. He didn't think the state of nature would be as bad as Hobbes envisioned. Locke also didn't think that the social contract was a hypothetical agreement; he thought it was an actual agreement. We actually have agreed to follow the laws of a government if we were born and raised, and come into adulthood in the country over which the government has authority. That gives the government its right the monopoly of the initiation of force.

There are other versions, such as those of Jean-Jacques Rousseau and, within the last thirty years, the American John Rawls.

Problems of social contract theories

First, there's the problem of the people who don't want to make the agreement, or who wouldn't even in the state of nature -- the problem of dissenters. Suppose that I wouldn't agree to the establishment of a government, in the state of nature. Do I have any obligation not to initiate force, according to the social contract theorist? Apparently not. Because the only thing that obligates me to give up my liberty to initiate force is that agreement. If you want to say that I owe allegiance to the state, then it's not a contract, real or imaginary, that's binding on me; it must be something else. The social contract theory, by itself, doesn't say what else.

Another problem is when we should dissolve the agreement with a government; when may we legitimately declare that we are not morally bound to do what the government says? The problem for social contractarianism comes in attempting to state the justification of breaking ties with a government. Surely, we would be justified in defying some governments that might arise. That seems clearly true. The question now is why we would be so justified -- what would justify us.

All that the social contract theory says is that, if we are party to a social contract, then we're morally bound to give up our liberty to initiate force, and the government that is given that same liberty is legitimate. By itself, that doesn't give clear grounds on which to dissolve a social contract.