The purpose of this essay is to defend utilitarianism from the popular objection that it makes moral theory depend improperly upon uncertain factual information and calculations which may produce violations of individual rights or liberties. This objection is a more subtle variant of the general Kantian complaint that utilitarianism makes morality improperly contingent upon empirical facts about historical, socioeconomic circumstances, the consequences of actions, institutions, etc., thereby allowing individual liberties to be sacrificed in order to maximize the collective welfare. Three main arguments connected with the uncertainty-objection are delineated in Rawls' work, and are seen to be fallacious. It is concluded that a suitably sophisticated form of rule-utilitarianism need not base liberty on any impermissible kind of uncertainty in moral theory. This analysis is contrary not only to what Rawlsians and other Kantians nowadays typically argue or assume in criticizing utilitarianism, but also to what some of the leading critics of Rawls have said about his anti-utilitarian stance.