Prospective Possibilism

There has been considerable debate regarding the relative merits of two theses about moral obligation known as actualism and possibilism. Both theses seek to give expression to the general idea that one ought to do the best one can. According to actualism, one’s obligations turn on what would happen if one chose some course of action, whereas, according to possibilism, they turn on what could happen if one chose some course of action. There are two strands to the debate: the substantive verdicts that the two theses render in particular cases, and the accounts that they yield of the conceptual structure of moral obligation. Possibilism is conceptually appealing, whereas actualism is not, but the latter may seem to render superior substantive verdicts. In this paper, it is argued that, by turning from the objectivist’s emphasis on what is actually best to the prospectivist’s emphasis on what one’s evidence indicates is best, possibilists can provide an account of moral obligation that is both conceptually and substantively attractive.