The concept of promise stirs many to write. Among ethical theorists, a cottage industry flourishes, devoted to answering Hume’s skeptical questions: What are promises? and Why are they binding? Among jurists and legal philosophers, the leading questions have been: When should promises be enforced? and What is the relationship between promissory and other forms of obligation? Among linguists and philosophers of language, the focus is different still. These scholars ask: What is the logical structure of the speech act of promising? and To what extent is promising a universal linguistic phenomenon?
This widespread interest in promises and promising is driven by several factors. One is a belief that the moral and political stakes are high. Promising is not only a common way by which we come to have obligations. It is the simplest, most direct, and most individualistic way in which we voluntarily come to have obligations. If one wishes to account for social, political or moral obligation in a way that maximizes the scope of individual liberty, one likely will focus on promissory obligation and its potential to serve as basis for more complex—even non-voluntary—types of obligation.
Another factor contributing to the interest in promising is the emergence of speech act theory as a framework for philosophical, linguistic, and to some extent jurisprudential, analysis. Speech act theory treats language as a system of verbal acts that effect changes in the world. A person cannot utter “Let there be light,” and bring it about that there is light. But he might be able to utter “I hereby declare you husband and wife” and bring it about that Jones and Smith are married to each other. This perspective on language quickly leads to an interest in promising, since promising appears to be one of the most straightforward ways of altering the world through words. What seems simpler than changing one’s relationship by uttering “I promise to ϕ”?