Abstract
For centuries it has been a mainstay of European and American moral thought that keeping promises—and the allied activity of upholding contracts—is one of the most important requirements of morality. On some historically powerful views the obligation to uphold promises or contracts not only regulates private relationships, but also provides the moral foundation for our duty to support and obey legitimate governments. Some theorists believe that the concept of keeping promises has gradually moved to center stage in European moral thought. They see this movement as part of an historical shift from a moral conception in which an individual’s duties are mainly externally imposed and unalterable, to a conception in which duties are largely chosen by the individual.