This paper provides an ethical intepretation of the Nash choice rule. In a setting in which (cardinal) utilities are interpersonally comparable, this procedure is characterised by an impartiality requirement and by the assumption that choices are not responsive to the agents' relative ability to convert resources into utility.

Natural Justice is a bold attempt to lay the foundations for a genuine science of morals using the theory of games. Since human morality is no less a product of evolution than any other human characteristic, the book takes the view that we need to explore its origins in the food-sharing social contracts of our prehuman ancestors. It is argued that the deep structure of our current fairness norms continues to reflect the logic of these primeval social contracts, but the (...) particular fairness norm a society operates is largely a product of cultural evolution. In pursuing this point, the book proposes a naturalistic reinterpretation of John Rawls' original position that reconciles his egalitarian theory of justice with John Harsanyi's utilitarian theory by identifying the environment appropriate to each. (shrink)

The utilitarian economist and Nobel Laureate John Harsanyi and the liberal egalitarian philosopher John Rawls were two of the most eminent scholars writing on problems of social justice in the last century. This volume pays tribute to Harsanyi and Rawls by investigating themes that figure prominently in their work. In some cases, the contributors explore issues considered by Harsanyi and Rawls in more depth and from novel perspectives. In others, the contributors use the work of Harsanyi and Rawls as points (...) of departure for pursuing the construction of theories for the evaluation of social justice. The introductory essay by the editors provides background information on the relevant economics, game theory, philosophy, and social choice theory, as well as readers' guides to the individual contributions, to make this volume widely accessible to scholars in a wide range of disciplines. (shrink)

Though the revised edition of A Theory of Justice, published in 1999, is the definitive statement of Rawls's view, so much of the extensive literature on Rawls's theory refers to the first edition. This reissue makes the first edition once again available for scholars and serious students of Rawls's work.

If some external enforcement agency compels us to honor deals reached in the original position, then Harsanyi has shown that the outcome will be utilitarian. Under the same hypotheses, Rawls claims that the outcome will be egalitarian. This chapter confirms that Harsanyi is correct. It goes on to use the concept of an empathy equilibrium to predict the standard of interpersonal comparison needed to operate a utilitarian norm that will evolve in the medium run.