Amazon.com description: Product Description: This book provides the Greek text of the "Oratio catechetica" by Gregory of Nyssa. It is a critical edition based on the examination of all 59 known manuscripts. Their relationship is extensively analyzed in the preface. The latest edition of the "Oratio catechetica" was prepared by J.H. Srawley in 1903. Many more manuscripts have since been discovered including several ancient ones. Thus, Srawley's text has been improved. Being part of the well-known series "Gregorii Nysseni Opera" the edition sets a further standard for editing the highly complex text transmission of the Church Fathers. The "Oratio catechetica" is a summary of Christian doctrine written at the end of the 4th century. The penetrating mind of its author, Gregory of Nyssa, elaborates a coherent theological system and was of great influence.