It would seem that reason and morality are here blended into a simple, coherent picture in which reason serves morality and morality serves reason. But, I will argue, on closer examination an instability becomes apparent and, once identified, will prise apart the rational and the moral, and simultaneously separate justification and motivation. One of the merits of this argument, if it succeeds, is that it does not rely on the usual complaint against constrained maximisation, namely, that it is likely to be more rational to masquerade as a constrained maximiser than to become one. My argument concedes the possibility of constrained maximisation in all the senses Gauthier intends. There are two aspects of commonsense morality which seem to escape Gauthier's reduction of the moral to the rational.
Economic man lacks the capacity to be truly the just man.
The economic man is a reluctant participant in the game of moral cooperation, and if possible would escape the constraints morality imposes. Weakness and dependency in the face of competing others are obstacles to straightforward maximisation. If these obstacles could be overcome, economic man would have unlimited licence to exploit and benefit from others. Economic man is therefore the egoist forced to labour beneath the weight of an unwelcome moral order. The motives of economic man remain the motives of an exploiter, and the scope of his concerns does not stretch beyond the narrow limits of his present and future self.