Dionysius the Areopagite is the peudonymous author of an influential body of early (about 500 AD) Christian theological texts. The Pseudo-Dionysian writings offer a synthesis of Christian dogma and Neo-platonic thought. Their leading idea which has made them the charter of Christian mysticism, is the intimate union between God and the soul and the progressive deification of man. In this book, Paul Rorem examines and elucidates these difficult texts and explores their profound influence on medieval theology both in the East and west. As Rorem shows, the Pseudo-Dionysian writings were regarded almost as a "Summa Theologica" in the Eastern Church. In the West, they were commented on by virtually all of the great medieval theologians. Thomas Aquinas alone cites Dionysius is some 1,700 places. Rorem is co-translator of the 1984 edition (Paulist Press) of the complete Pseudo-Dionysius (the first English-language edition in modern times) and provided the notes, indices, and bibliography. The present book will make these texts more accessible to both scholars and students. A comprehensive bibliography of secondary sources will be included.