Motive and obligation in Hume's ethics

Abstract

Hume distinguishes natural obligation, the motive of self-interest, from moral obligation, the sentiment of approbation and disapprobation. I argue that his discussion of justice makes use of a third notion, in addition to the other two: rule-obligation. For Hume, the just person regulates her conduct by mutually advantageous rules of justice. Rule-obligation is the notion she requires to express her acceptance of these rules in so regulating herself. I place these ideas in relation to Hume’s official theory of the will and to early modern thinking about obligation and the will more generally.