In this essay I examine the obligation of promises according to Hume, giving special consideration to his view of the virtue of fulfilling one's promises as an artificial virtue. In this, Hume's position distinguishes itself from the Aristotelian and the Kantian views according to Anscombe and Herman, respectively. However, the main difficulty -that there is no natural motive to the fulfilling of promises, as there apparently should be for every natural obligation - divides the scholars of Hume: Cohon and Baier. I maintain, following Baier, that, in spite of the inexistence of a natural motive to the fulfillment of promises, there is a passion or effective motives - not natural as the natural motive that makes us care about our offspring - that can be called enlightened self-interest: it is a self-interest, and thus far real and natural; it is enlightened because of the recognition of its correspondence in others, which links it to a "common benefit" in the sense of a "mutual advantage".
Hume; obligation of promises; artificial virtues; enlightened self-interest