Abstract
This article aims to defend responsibility-sensitive egalitarianism by arguing for the rational capacities-based principle of responsibility as a plausible conception of an agent's responsibility for inequalities caused by his or her choice in responsibility-sensitive egalitarianism. I show that the rational capacities-based principle of responsibility is not only philosophically defensible as a conception of genuine choice, but also promising enough to ward off two common worries which cast doubt on responsibility-sensitive egalitarianism (qua luck egalitarianism): first, the rational capacities-based principle of responsibility allows the assignment of differential degrees of responsibility to rational agents in proportional terms, which may make it echo the adverse effects of their childhood environments. Second, its proportional construal essentially allows that nobody possesses a full degree of rational capacities. This enables responsibility-sensitive egalitarianism to refute the harshness objection.