For more than five hundred years the life and work of John of Damascus (c. 655-c.745) have been the subject of a very extensive literature, scholarly and popular, in which it is often difficult to get one's bearings. Through the studies included here (of which 6 appear in a translation into English made specially for this volume), Vassa Kontouma provides a critical review of this literature and attempts to answer several open questions: the author and date of composition of the official Life of John, the philosophical significance of the Dialectica (a study which has its first publication here), the original structure of the Exposition of the Orthodox faith, the identity of ps.-Cyril, the authenticity of the Letter on Great Lent, and questions of Mariology. She also opens new vistas for research along four main lines: the life of John of Damascus and its sources, Neochalcedonian philosophy, systematic theology in Byzantium, and Christian practices under the Umayyads.