Promises and Contract Law is the first modern work to explore the significance of promise to contract law from a comparative legal perspective. Part I explores the component elements of promise, its role in Greek thought and Roman law, the importance of the moral duty to keep promises and the development of promissory ideas in medieval legal scholarship. Part II considers the modern contract law of a number of legal systems from a promissory perspective. The focus is on the law of England, Germany and three mixed legal systems (Scotland, South Africa and Louisiana), though other legal systems are also mentioned. Major topics subjected to a promissory analysis include formation of contract, third party rights, contractual remedies and the renunciation of contractual rights. Part III analyses the future role which promise might play in contract law, especially within a harmonised European contract law.