Contemporary theories of justice fail to recognize that the concepts constitutive of our political practices ? including ?justice? itself? have historically mutable meanings. To recognize the fact of conceptual change entails an alteration in our understanding of justice between generations. Because there can be no transhistorical theory of justice, there can be no valid theory of intergenerational justice either ? especially where the generations in question are distant ones having very different understandings of justice. The upshot is that an earlier (...) generation cannot aspire to act justly toward a later distant generation whose members? understanding of justice differs radically from theirs. Conceptual change and incommensurability render the very idea of intergenerational justice incoherent. Even so, such radical relativism need not entail moral nihilism. (shrink)