What did the ten commandments have to teach? Using the commentaries of a group of scholars from c. 1150-1350, such as Peter Lombard, Robert Grosseteste, and Bonaventure, along with confessors' manuals, mystery plays and sermon material, this book investigates the place of the Decalogue in medieval thought. Beginning with the overarching themes of law and number, it moves to consider what sort of God is revealed in the commandments of the first stone tablet, and uncovers the structure that lay behind the precepts dealing with one's neighbour. Interpreting the commandments allows us to look at issues of method and individuality in the medieval schools, and ask whether answers intended for the classroom could make an impression on the wider world.