Grounding Moral Obligations in Aquinas's Metaethics <sup/>

Philosophers across a range of historical traditions and in contemporary metaethics have debated how nature relates to moral obligations. This debate among interpreters of Aquinas has seemed particularly intransigent. The present essay proposes an interpretation of Aquinas's view of moral obligations that embraces elements of both the neoscholastic view and the New Natural Law view, standard moral naturalism and non-naturalism, by holding together two things typically thought to be in opposition: there is a necessary role for facts about human nature in the very grounds of moral obligations, and those facts are insufficient to determine what specific obligations there are, so a person's practical reasoning must operate to generate obligations. Practical reason's role in grounding moral obligations does not make the natural facts morally inert, and the place of natural facts in the grounds of obligations does not jeopardize the place of non-natural facts about individuals’ practical reasoning on those grounds.