Though the monastic writings of St John Cassian have been enduringly popular, his reputation (not least as a theological author) has been seriously compromised. A. M. C. Casiday begins with an evaluation of conventional ideas about Cassian and, finding them seriously flawed, offers the first sustained attempt at re-reading Cassian's works for their theological significance. Specific attention is called to the Christological aspects of Cassian's monastic anthropology. Throughout, reference is made to Cassian's contemporaries - both well-known figures like Augustine of Hippo, Evagrius Ponticus, Vincent of Lérins, and Nestorius, and lesser-known figures such as Prosper of Aquitaine, Valerian of Cimiez, and Paul of Tamma - in order to offer an analysis of Cassian's writings and their significance that is unencumbered by anachronism.