One of the difficulties social contract theorists have to tackle is how to make people with various preferences choose the same principles as a norm of conduct. In David Gauthier's contract theory of morality, the keystone for agreement is the Lockean Proviso, which prohibits taking advantage of others. The consensus among Gauthier's contractors is supposed to be possible when by accepting the Proviso, they resolve the conflicts in the Hobbesian state of nature and recognize the duty to respect the utility level each of them reaches without taking advantage of others. But it is doubtful whether the Proviso would enable us to settle the conflicts in the quasi-natural state which would emerge if all the moral and institutional ties we now have were abandoned. One of the reasons for the inadequancy of the Proviso is that our endowments have been shaped under the unequal influences of society. Another is that there are not enough goods to fulfil our many different desires and aims. Third, we very often have incompatible preferences concerning one another's lifestyles. If we are unable to determine the initial bargaining position by obeying the Proviso and thus unable to find a basis for agreement, Gauthier's whole moral system fails.