The possibility of promising requires a determined obligation that distinguishes breaking a promise from merely failing to keep it, thus enabling both parties to know what the promise entails. In addition, a recognizable commitment must bind the promiser and justify the promisee's reliance. It is widely accepted that fulfilling these functions requires a rule of promises – either a convention or a moral principle. The paper criticizes this common view and presents an alternative. I introduce
... ive. I introduce the concept 'quamise'. Quamises are particular expressions of intentions to act, made within personal relationships which involve normative requirements. Given these requirements, quamising determines an obligation and justifies reliance sans rule. I argue that promises within relationships are in fact quamises. Consequently, a unified account of promises is available only if quamises can be made to strangers, without implicitly appealing to a rule. I show that an attempt to quamise can, under appropriate conditions, create the relationship needed for quamising. The conditions that enable quamising to strangers include the social emotion of shame, which provides the accountability to strangers required for reliance, as well as various salient precedents and practices the parties can designate in order to determine an obligation. Thus, a rule of promises is unnecessary. According to this view, the moral nature of promises resembles that of personal commitments: fidelity to promises is a virtue in the sense that friendship is.