In the late Roman Empire, complexity and uncertainty created demand for responsa from the apostolic see. After the eleventh-century papal turn, new legislation and a different society generated new complexities and uncertainties. Decretals were not the only way to resolve them, but given the prominence of the tradition launched by Siricius and Innocent I, they were an obvious way. An unbroken chain of communication links the first and second decretal ages. Late Antiquity and the central Middle Ages need not be kept in separate compartments.