John Cassian is considered by the Church in the East and West to be one of the greatest of the early monastic writers. The breadth of his experience of eremitical life in the Egyptian desert, his distinction as a theologian and churchman, and his veneration for the Desert Fathers are conveyed in the ‘Institutes’ and ‘Conferences’. Augustine Casiday provides a new translation of the two classic conferences on ‘Prayer’, together with a critical introduction.