It is fairly commonplace to think that the capacity for sentience need not be the only basis of moral status. Pluralists contend that moral status is grounded in several other valuable capacities as well as, or instead of, sentience, such as agency, empathy, or sociality. However, this contention contrasts with a standard assumption in animal ethics: that sentience should be the only basis of moral status. This article vindicates that assumption. Whilst classical utilitarians have defended a similar claim about sentience (...) in relation to ultimate value, the merits of this view have gone relatively unnoticed in contemporary debates about moral status and animal ethics. An account based on sentience alone avoids conceptual redundancy and has greater explanatory power than pluralist alternatives. An account of moral status based exclusively on sentience also yields two significant and revisionary implications that have not been recognised. First, the distinction between persons and nonpersons cannot hold, so all moral patients, including nonhuman animals, should feature as primary subjects in ethical theories, public policies, and research agendas. Second, we ought to favour nonhuman interests far more often than we tend to suppose. (shrink)