Conventionalism and the Wrong of Promise-Breaking

A commonly made objection to conventionalist theories of promising is that they fail to adequately capture the way that breaking promises wrongs promisees in particular. If the wrong of promise-breaking is the wrong of undermining or free-riding on a useful social practice, as some conventionalist accounts hold, it appears that promissory obligations are not owed to promisees in particular, but instead to all those who contribute to the promising practice. This chapter argues that this “directionality objection” against conventionalism fails. First, it distinguishes between two forms of conventionalism, arguing that the objection does not gain a foothold against the first kind (“strong conventionalism”). The objection arises only on some versions of “weak conventionalism,” including Rawls’s, and stems from a particular way of applying the Principle of Fairness to the practice of promising. Second, the chapter argues that a more careful examination of the practice of promising reveals that the Principle of Fairness does not apply to it in the way that both Rawls and his critics tend to assume. The Principle of Fairness cannot explain why we owe it to all promise-keepers to keep our promises. Furthermore, there is an alternative interpretation of how the principle applies to the practice that explains why broken promises typically wrong promisees in particular. The upshot of the argument is that the directionality objection does not present a serious problem for conventionalism about promising. At the same time, the argument shows that there are limits to any attempt to use the Principle of Fairness to explain promissory obligation.