Hailing from North Africa, Lactantius was an imperial professor of Latin rhetoric, a position that brought him to the courts of the emperors Diocletian and Constantine. This chapter explores themes in his Divine Institutes that bear on his legal thought. In addition to setting out Lactantius’s conception of religious tolerance and its influence on the emperor Constantine’s religious policy, the chapter considers the role of “divine law” in Lactantius’s work. He found the first two principles of divine law in Matt 22:36–40 and considered them equivalent to pietas and aequitas in Cicero’s thought. Just as Roman citizens were defined by their access to Roman law, so adherence to divine law, for Lactantius, constituted both Christian and Roman identity. After Augustine of Hippo rejected Lactantius’s suggestion that the law of the state could be a faithful image of the divine law, Western medieval scholars largely ignored the legal thrust of Lactantius’s arguments. Nevertheless, his advocacy of religious tolerance gained currency in recent times, when the Second Vatican Council embraced it.

The Decretum of Burchard of Worms (d. 1025) was a popular and much copied canonical collection. Burchard drew on existing collections, which provided him with a mass of items that included conciliar decrees, patristic extracts, penitential prescriptions, and papal letters. He organized these into a coherent, relatively concise handbook designed for bishops to use in visitations and in their daily administrative lives. But he also intended his book to be used as a resource for teaching, as he explains in the preface. Coherence, clarity, and organization are the collection’s hallmarks. Whereas his predecessor, Regino, assumed that the reader would be able to derive an answer from multiple, sometimes conflicting texts, Burchard edited and assembled the texts to provide consistent, straightforward answers to a reader’s questions. The Decretum covers a wide range of topics that a bishop might need to address, including ritual, lay offenses, excommunication, penance, and even eschatology. Like Regino, Burchard sometimes forged new material, but for the most part he preferred to alter existing texts to make them consistent and to enhance their authority.