 Individuals “faced with the costs of natural or market interaction in the face of externalities agree to a different, cooperative mode of interaction.” Rational individuals do so to “maximize their own utility” (Gauthier 1986, 145–6). The goal is to show why anyone should accept moral restraints on their behavior. Gauthier proposes that even instrumental rationality can justify ethical constraints to all. A citizen can be subject to state coercion in certain respects because it is in his interests. Gauthier does not base public justification on the total utility it produces. Parties strike bargains where each person provides the minimum relative concession of rents. Publicly justified rules maximize each person’s share, but joint maximization constrains each person’s claim. Each side seeks the best bargain they can get.