The Pigou-Dalton (PD) principle recommends a non-leaky, non-rank-switching transfer of goods from someone with more goods to someone with less. This Article defends the PD principle as an aspect of distributive justice—enabling the comparison of two distributions, neither completely equal, as more or less just. It shows how the PD principle flows from a particular view, adumbrated by Thomas Nagel, about the grounding of distributive justice in individuals’ “claims.” And it criticizes two competing frameworks for thinking about justice that less (...) clearly support the principle: the veil-of-ignorance framework, and Larry Temkin’s proposal that fairer distributions are those concerning which individuals have fewer “complaints.” -/- The Article also clarifies the relation between the PD principle and prioritarianism. Prioritarians will surely endorse the PD principle (with the “good” individual well-being), but they are also committed to a distinct axiom of separability: the moral value of someone’s well-being change does not depend upon her position relative to others. The PD principle neither implies separability, nor is implied by it. Although prioritarianism is very plausible, the case for the PD principle is yet more compelling than for the combination of that principle with separability. In discussing prioritarianism, we should differentiate between these two, logically independent aspects of the view. -/- . (shrink)