John Cassian

St. John Cassian was a monk who spent years in the Egyptian desert before founding monastic communities in Marseille. His Institutes (on monastic organization) and Conferences (accounts of conversations with the desert elders) transmitted the desert tradition to the Western Church. His account of the eight logismoi (later adapted by Gregory the Great into the seven deadly sins) and his theology of grace (opposed to Augustine's predestinarianism) were highly influential. He is venerated as a saint in the East.