Book excerpt: Promises and agreements are everywhere; we make, receive, keep, and break them on a daily basis. The quest to understand these social practices is integral to understanding ourselves as social creatures. The study of promises and agreements is enjoying a renaissance in many areas of social philosophy, including philosophy of language, action theory, normative ethics, value theory, and legal philosophy. This volume is the first collection of philosophical papers on promises and agreements, bringing together sixteen original self-standing contributions to the philosophical literature. The contributors highlight some of the more interesting aspects of the ubiquitous social phenomena of promises and agreements from different philosophical perspectives.