Hume on Promises and the Peculiar Act of the Mind

Hume's account of the virtue of fidelity to promises contains two surprising claims:

1) Any analysis of fidelity that treats it as a natural (nonconventional) virtue is incorrect because it entails that in promising we perform a "peculiar act of the mind," an act of creating obligation by willing oneself to be obligated. No such act is possible.

2) Though the obligation of promises depends upon social convention, not on such a mental act, we nonetheless "feign" that whenever someone promises he performs such an act.

This paper explains both in light of the philosophical questions about promising that lie behind Hume's investigation, his virtue theory, and the general difficulties he believes we face trying to understand virtues that are in fact artificial in terms of our common-sense, natural conception of virtue. It extracts a lesson for contemporary virtue ethics about the motive of duty.