Isidore was among the most representative and influential intellectuals of the early Middle Ages. He aimed to transform the Visigothic realm, which had converted from Arian to Nicene, or catholic, Christianity in 589, into a Christian respublica. To that end, the church needed to persuade the secular Gothic elites to join the project, and Isidore contributed to the construction of a common cultural setting. His most famous work, the Etymologies — an encyclopaedia in twenty books — is an attempt to present all human knowledge in an exposition that is both coherent and accessible, but it would become indispensable reading for students of law. Isidore moves within the tradition of Roman law, but he is not afraid to deviate from and to renew it. Although he was not a jurist by training or profession, he made original contributions to the theory of law — e.g., in relation to the ideal of the “two laws,” and by emphasizing the necessary ethical foundation of political power — and to the construction of a model of judicial procedure, which would be used by ecclesiastical as well as secular courts during the central Middle Ages.