A contractarian moral theory states that an action (practice, social structure, etc.) is morally permissible if and only if it (or rules to which if conforms) would be agreed to by the members of society under certain circumstances. What people will agree to depends on what their desires are like. Most contractarian theories --for example those of Rawls (1971) and Gauthier (1986) --specify that parties to the agreement are mutually unconcerned (take no interest in each other's interests). Contractarian theorists, do not, of course, believe that this is true of real people, but they insist (with Kant) that the basic moral constraints on conduct (if there are any) apply independently of whether individuals care about each other.
I shall here argue against the appropriateness of the assumption of mutual unconcern for contractarian theories, such as Gauthier's, that are supposed to ground morality solely in rationality.
Gauthier's project is to "generate, strictly rational principles for choice,.., without introducing prior moral assumptions" (p. 6). Unlike Rawls, Gauthier does not merely want to apply the principles of rational choice to some morally privileged choice situation (i.e., a choice situation, such as Rawls' original position, in which morally irrelevant features of reality have been screened off). He wants to apply the principles of rational choice to real life choice situations. Consequently, on Gauthier's theory "the parties to agreement are real, determinate individuals, distinguished by their capacities, situations, and concerns" (p. 9). In particular, no veil of ignorance is imposed on the parties.
Gauthier assumes, however, that the parties are mutually unconcerned (take no interest in each other's interests) (pp. 10--11, 102--103). Note that there are two different places that assumptions about people's preferences (desires, utility functions) may enter in contrac-