What justifies differences in the acceptance of paternalism towards competent minors and older people? I propose two arguments. The first argument draws on the widely accepted view that paternalism is easier to justify the more good it promotes for the paternalizee. It argues that paternalism targeting young people generally promotes more good for the people interfered with than similar paternalism targeting older people. While promoting people's interests or well-being is essential to the justification of paternalism, the first argument has certain (...) unfair implications in that it disfavours paternalism towards the worse off. The second argument caters to such fairness concerns. It argues that priority or inequality aversion supports age-differentiated paternalism because young people, who act imprudently and thereby risk their interests or well-being, are worse off than older people who act in similar ways. I suggest that both arguments are pertinent in evaluating specific paternalistic acts and policies. (shrink)