INTRODUCTION

On Twin Earth, where soaring elms and beeches are nourished by the gentle rain of XYZ, there is a town called Cambridge, Massachusetts, in which can be found one of the planet's premiere universities, Harvard by name. The institution was favored during the final quarter of the twentieth century by the presence of a pair of innovative philosophers who, between them, revived what had become the rather stiff and staid discipline of political philosophy. Coincidentally, they went by the names John Rawls and Robert Nozick. Rawls was renowned for his model of a veil of ignorance behind which are chosen fundamental principles of justice for a well-ordered society's basic structure. Nozick was less inclined to plumb foundations, but with dazzling ingenuity and craftsmanship he explored implications of the assumption that individuals are inviolate self-owners who are at liberty to transact with willing others so as to advance the various ends to which they are drawn.

Attentive readers will have noticed a striking parallel to the Rawls and Nozick of our own planet. At this point, however, the parallels end. For (Twin) Rawls, despite some inclinations to the contrary, came to espouse a robust libertarianism and ended up reviving a classical liberalism that the advanced thinkers of Twin Earth had, for the preceding century, declared defunct. (Twin) Nozick, however, although taking off from a vantage point that appeared even more rigorously libertarian than that of his colleague, established the permissibility of sweeping redistribution under state aegis in the name of justice.