What was literary theory in the Middle Ages? What was literary criticism? How did medieval scholars record their interpretations of texts? What forms did those interpretations take? And how do the forms of medieval literary criticism contribute to the shape of medieval literary theory? By teasing out answers to these questions from a series of examples of medieval (chiefly twelfth-century) commentary on classical literature, this chapter offers an introduction to the study of literary texts, its norms, assumptions, sources and priorities in the Latin Middle Ages. It concludes with an overview of the volume as a whole, focusing on how the various chapters relate to three overarching concepts: interpretation, invention and imagination.