Promise as Practice Reason

Abstract

To promise someone to do something is to commit oneself to that person to do that thing, but what does that commitment consist of? Some think a promissory commitment is an obligation to do what’s promised, and that while promising practices facilitate the creation of promissory obligations, they are not essential to them. I favor the broadly Humean view in which, when it comes to promises (and so promissory obligations), practices are of the essence. I propose the Practice Reason Account of promises, according to which a promise is basically to give oneself a self-interested practice reason to do what’s promised. One achieves this feat by invoking self-enforcing independent practice rules thanks to which one’s doing what’s promised preserves one’s promissory trust(worthiness) and promising power. However, nothing in this account supports the Hume-Rawls claim that promise-keeping or promise-breaking is right just when and because it conforms to practice rules that are justified by their good- or right-making properties.