CONTRACTUALISM'S (NOT SO) SLIPPERY SLOPE

Familiar questions about whether or how far to impose risks of harm for social benefit present a fundamental dilemma for contractualist moral theories. If contractualism allows “ex post” objections by considering actual outcomes, it becomes difficult to justify the risks created by most public policy, leaving contractualism at odds with moral commonsense in much the way utilitarianism is. But if contractualism instead takes a fully “ex ante” form by considering onlyexpectedoutcomes, it becomes unclear how it recommends something other than aggregative cost-benefit decision-making. Focusing on T.M. Scanlon's version, this paper develops this basic choice of interpretation and recommends theex anteversion. The paper explains how contractualism is inconsistent with John Harsanyi–style utilitarianism and how contractualism supplies a principled framework for walking a careful line between the “bad aggregation” characteristic of utilitarianism and the “good aggregation” that is both unavoidable and fully appropriate in public life.