Albertanus of Brescia is an important figure in the cultural history of late medieval and Renaissance Italy. He is best known among literary scholars for the influence of his writings on Brunetto Latini, John Gower, and Geoffrey Chaucer. In addition, his sermons have received attention as part of the history of lay confraternities and lay preaching in the twelfth and thirteenth centuries. James M. Powell shows that Albertanus's contributions considerably surpass even these notable attainments. Powell contends that Albertanus was an original social theorist, who drew on his experience with religious confraternities and with the law to develop a theory of consent. Albertanus developed the idea that society rested on voluntary acceptance of a rule, much as did religious life. This acceptance laid the foundation for social cohesion and legal enforcement. Albertanus's ideas were to find great prominence in the later Middle Ages. Powell's purpose in writing Albertanus of Brescia goes beyond the study of his eponymous subject. Through Albertanus, Powell examines how major developments of the twelfth century began to find expression in the mind of an early thirteenth-century secular thinker. In Albertanus, Powell perceives an individual bringing received, bookish authority into confrontation with lived experience. To Powell, the example of Albertanus suggests a much more complex picture of medieval approaches to social theory than that previously evident in the literature. This is the first book-length study of Albertanus and his works. It will be of particular interest to students and scholars of medieval, Italian, intellectual, and literary history, and political theory.