The idea of a social contract as the basis for morality or political principles goes back a long way—there is, for example, a brief statement of it in Plato’s Republic. More notably, the great writers on political and moral philosophy of the 18th century were contractarians. In our own time, John Rawls’s work is regarded, both by him and those who are familiar with his writings, as falling within the general tradition of social contract theory, while David Gauthier’s “morals by agreement” present an elaboration of the principles of contractarianism.
Inasmuch as contractarianism has specific reference to a theory about the foundations of moral and political philosophy, its relation to libertarianism is somewhat indirect. Libertarianism is a theory regarding the general principles of justice. The underlying support for these principles, in the contractarian view, is that such theories are rational only if all agree to it. Additionally, contractarianism has no direct connection to any actual historical event, such as a Constitutional Convention; the idea is more abstract than that.
Two features of contract are crucial. First, one who enters into a contract does so for reasons of his own, usually reasons of self‐interest. We want to buy this car, we are willing to pay the proposed price, and we sign an agreement to that effect. Second, whereas self‐interest provides the motivation, agreement provides the moral basis for holding the parties to it. Having signed the contract for the car, I am now obligated to pay the price specified; my obligation is a function of my having voluntarily signed the relevant agreement. The obligation is thus self‐imposed. If we extend this notion to the project of founding a moral system, it follows that the “contract” is made between everyone and everyone else: We all agree with each other to do these things. However, in reality, such contracts have not been nor can be made. Rather, we can all understand that we are related to each other in such a way that agreeing with each other to act in certain ways is the thing to do: It is prescribed by reason—the reason that each person possesses.
What contractarian theory enables us to understand is why, given an initial situation in which there is as yet no morality and no law, people can nevertheless (a) see the need to have rules, and (b) shape the rules that will emerge in light of their own interests and their relation to all others. The contractarian idea is of enormous interest to libertarians because the theoretical project it envisages conceives of morality (and also government) as a set of restrictions that would be freely agreed to by people acting on their own without any antecedent constraints. By looking at how people stand in relation to each other and what kind of needs and problems their relationships entail, we can see what basic restrictions are needed.
The father of modern contractarian theory is Thomas Hobbes, who argued that any individual in a social situation where there were no rules imposing restrictions on anyone’s behavior would have a life that was “solitary, poor, nasty, brutish, and short.” The fundamental problem in a society without agreed‐on rules is that of interpersonal violence, which all of us can engage in and from which all of us can suffer. Violence impedes or makes impossible the victim’s pursuit of the good life as he sees it. Thus, the thing to do is agree on rules against such violence. All else requires agreement on particulars. So the basic contractarian rules are: nonviolence, which implies, in turn, that each is to have as much liberty as is possible for all, with no more for any individual or subset of individuals. Equal liberty implies that we are required to keep specific agreements of our own free making, subject to whatever restrictions and escape clauses may be built in.
Our incentive to live up to these agreements proceeds from our interests: We simply do better to live under these mutually advantageous rules than would otherwise be the case. We are constrained to obey these rules by two forces. The first is moral: We internally monitor our behavior to see to it that others have no complaint against us; and the second issues from whatever arrangements we may have made to help enforce these rules. Government, notoriously, is widely thought to be justified and required for this purpose. A number of theorists, however, argue that the necessity is by no means clear. What is required is third parties engaged by the original parties whose function is to wield the necessary force against those who renege on their agreement.
Proponents of the theory of a social contract argue that contractarianism alone can provide a genuine sense of moral constraint among free people. All other moral theories appeal to intuition or axioms that cannot be explained, lacking any clear reason that these theories should be embraced. The social contract, however, supplies a reason: It is the interests of people, given the exigencies of social life, which provide both the motivation and a rational method of determining the substance of moral requirements.
There have been many variants of the social contract idea, all of which, to a greater or lesser degree, modify this description. By far the most prominent recent theory is the one put forward by John Rawls, who argues that the social contract must originate from behind a “veil of ignorance,” in which the parties are unaware of what positions they will occupy after agreement. They then agree, he argues, to certain principles. However, it is unclear how a contract can exist that comprises only one party, albeit a supposedly universal one. It is more than unclear why real people would accept something that was made by “people” who don’t know what positions they might occupy after the contract came into force. In the end, it appears that Rawls is imposing a scheme of values on people whose characteristics cannot possibly include the attributes he demands of them. Rawls’s approach is in marked contrast to the contractarian idea that we must generate morals out of our separate, premoral interests.
The pure version of contract theory is of interest precisely because it proposes to derive and explain morals and politics from premises that merely reflect commonsense observations of what people are like, plus game‐theoretical results concerning their options. Each individual acts in his own interests, but when the interests of different people conflict, then the way is open for them to accept mutual constraints that will enable each to do as well as socially possible, thus motivating a real interest in moral and political principles and in the creation of institutions to enforce them.
Binmore, Ken. Game Theory and the Social Contract. 2 vols. Boston: MIT Press, 1994, 1998.
De Jasay, Anthony. Social Contract, Free Ride. Cambridge, MA: Blackwell, 1989.
Gauthier, David. Morals by Agreement. New York: Oxford University Press, 1986.
Hobbes, Thomas. Leviathan. New York: Everyman Library, 1960 .
Narveson, Jan. The Libertarian Idea. Peterborough, ON, Canada: Broadview Press, 2001.
Rawls, John. A Theory of Justice. Cambridge, MA: Harvard University Press, 1972.