In Anarchy, State, and Utopia, Robert Nozick made the argument that income redistribution violates the Kantian categorical imperative. Nozick’s retrospective enslavement argument is still used today in discussions about the moral justification of taxation. This article explicates four implicit premises of Nozick’s argument: the self-ownership principle, its fullness, the absence of restrictions on the appropriation of natural resources, and the absence of restrictions on the distribution of the fruits of cooperation. Without additional justification for each of these premises, Nozick’s argument (...) cannot show that income redistribution violates the categorical imperative. (shrink)