John Cassian (c. 360-435), whose demonological discourses in Conferences 7 & 8 are the subject of my MA Special Essay, is a character with whom few have any acquaintance. I hope to change that.
Cassian was born either in Gaul (now France) or in Dacia (now Romania). He seems to have received a Classical education and was fluent in both Latin and Greek. Around 382, he entered a monastery in Bethlehem. While there, he and his cellmate, Germanus, shared their cell for a while with Abba Paphnutius, an Egyptian abbot. Paphnutius was on the run from his monastery because he felt that the duties were too distracting from a life of humble contemplation of God. The two younger monks were thenceforth filled with zeal to visit Egypt and learn from the Egyptian abbas about the monastic way of life. They received permission from their monastery, and after a service in the Church of the Holy Nativity, they went off to Egypt.
John Cassian and Germanus were in Egypt from no later than 390 until 399/400, with one brief trip back to Bethlehem to obtain permission to resettle in Egypt. While there, they visited monks — a term comprising both coenobites (in community) and anchorites (solitaries) — in Upper Egypt from the Nile Delta to Nitria, Cellia, and Scetis listening to the elders and taking both their teachings and practices to heart. While there, they undoubtedly met Evagrius Ponticus, although he is not explicitly mentioned in Cassian’s writings.
In 399/400, during the First Origenist Controversy (click here for Origen & Origenism), Cassian and Germanus leave Egypt and turn up in Constantinople under the protection of St. John Chrysostom. Here John Cassian is ordained deacon by Archbishop Chrysostom. In 404, however, St. Chrysostom was exiled for the last time to the Black Sea. Cassian’s next appearance is in Rome, where he may have been ordained priest.
From Rome, he went to Gaul. Following the arguments of Goodrich in his book Contextualizing Cassian, I doubt that Cassian was in Marseilles at this time. He was, however, likely still in Gallia Narbonensis. During this time, at the request of Bishop Castor, he wrote his first work, On the Insititutes of the Coenobia and the Remedies for the Eight Principal Vices (that would be The Institutes, all but Book 6, “On the Spirit of Fornication” available at the CCEL, this link beginning at its Preface); this work was written for the edification of the monasteries of Gaul just then being founded. Subsequently, Cassian wrote The Conferences, a series of 24 “conferences” with 15 different Egyptian abbas, drawn from Cassian’s time in Egypt.
The Institutes deal with the practices of the Egyptians from dress to prayer as well as the eight vices (later the seven deadly sins); The Conferences are for those who have attained a certain amount of facility and mastery over the teachings of The Institutes. Through The Conferences, the monk is to seek to be perfected in prayer and find purity of heart, which is the monastic goal.
He later also wrote On the Incarnation Against Nestorius at the behest of Archdeacon Leo (later Pope Leo the Great). In this work, which I have yet to read, he notably sees connexions between Pelagianism and Nestorianism.
He died around 435. There has been much controversy surrounding him over the years, however; in the West, although canonised, he is not part of the regular calendar of saints, and in the East his feast day is February 29. In Marseilles, however, there is a local feast for him on July 23.
The controversy has also led to the impoverished state both of knowledge of this great spiritual writer as well as the websites about him. Recent research, however, has helped rehabilitate him, thus rendering The Catholic Encyclopedia’s entry out of date. That at the Christian Classics Ethereal Library is also outdated. Wikipedia‘s is pretty good, however; but note that the picture is currently of St. Jerome. Also worth reading is the unfortunately brief account at the OrthodoxWiki.