Saint John Cassian, Priest and founder of the Abbey of Saint Victor in Marseille († 435)
Feast Day: 23 July
Johannes Cassianus, commonly known as John Cassian, called “the Roman” or “the Romanian”, was born between 360 and 365 in Scythia (modern-day Romania) and died between 433 and 435 in Marseille. He was a monk and Churchman from the Mediterranean region who had a profound impact on the early Church in Provence in the 5th century. He is the founder of the Abbey of Saint Victor in Marseille.
He left behind a significant body of doctrinal work, including the Cenobitic Institutions (De Institutis coenobiorum et de octo principalium vitiorum remediis, written around 420) and the Conferences (Conlationes or Collationes), works dedicated to the monastic life. These had a deep influence on Western monasticism from the 5th century to the present day, notably because they were incorporated into the Rule of Saint Benedict, and also because they drew from Cassian’s own experience of the great Eastern monasticism of the deserts of Palestine and Egypt. Cassian built a bridge between Eastern and Western monasticism.
His original name was Cassian. The name John was likely added in homage to Saint John Chrysostom, of whom he was a devoted follower. According to an excerpt from De Viris Illustribus by the 5th-century historian Gennadius of Marseille, who refers to “…Cassianus, natione Scytha…”, he was born in Scythia, in Dobruja, in a region now shared between Romania and Bulgaria. This Romanian origin is acknowledged by the Catholic Church.
John Cassian left at a young age with his friend Germanus, with whom he was “one mind and one soul in two bodies” (Coll. 1, 1), to go to a monastery in Bethlehem (Inst. 3, 4), in the Province of Syria. This first encounter with cenobitic monasticism, which lasted only two years (Coll. 19, 2), allowed him to draw on the tradition of Palestinian monasticism, which lacked a mystical tradition and of which he retained little memory.
Around 390, he obtained permission to leave the monastery to travel with Germanus to Egypt to meet the anchorites of the Thebaid. When the monks who followed Evagrius Ponticus, a disciple of Origen, were dispersed in 400 by the bishop Theophilus of Alexandria, John Cassian left Egypt and briefly returned to Bethlehem before joining Constantinople.
The “Origenist” monks went to Constantinople, and John Cassian received instruction from Saint John Chrysostom, who ordained him deacon and entrusted him with the treasures of his cathedral. After the exile of his spiritual master in 404, Cassian travelled to Rome, where he was commissioned to seek the intercession of Pope Innocent I on behalf of the bishop. Around 415, he returned from Palestine with the former bishop of Aix-en-Provence, Lazarus.
He later settled in the West and founded, in 414 or 415, two monasteries in Marseille: Saint Victor for men and Saint Saviour for women. According to tradition, he asked the bishop of Marseille, Proculus—a friend of the Lazarus he had met in Palestine—for permission to found a monastery near the grotto where the relics of Saint Lazarus and Saint Victor were kept. He is even said to have built two churches near this grotto, one dedicated to Saints Peter and Paul, and the other to Saint John the Baptist. It is said that five thousand monks lived there under his discipline.
He is believed to have died around 435 in Marseille. Later, Blessed Urban V (Guillaume de Grimoald, 1362–1370) and Benedict XIV (Prospero Lorenzo Lambertini, 1740–1758) recognised his sanctity.
Main works of John Cassian
The Cenobitic Institutions (426): a treatise in twelve books dealing with the monks’ habit, the rule of prayer and psalms, and the obstacles to perfection: gluttony, impurity, avarice, anger, sadness, acedia, vainglory, and pride.
The Conferences (426): a collection of twenty-four conferences recounting Cassian’s memories of Egypt.
A Treatise on the Incarnation: Against Nestorius (430): in seven books, written at the instigation of Pope Leo I.
St. Benedict
Benedict of Nursia drew upon the works of John Cassian to establish his monastic rule. Some passages of the Rule of Saint Benedict are almost word-for-word repetitions of Cassian, and that Rule explicitly states that it must be complemented by the Conferences of the Fathers and Cassian’s Institutions. To this day, Western monks regard Cassian as one of the principal masters of the monastic life, who enabled the West to benefit from the rich experience of the first Eastern monks.
John Cassian is celebrated on 23 July in Marseille and in the universal Church, except in the East where his commemoration takes place on 29 February. His writings remain widely read, especially in Western monasteries. He also appears in the calendar of saints of the Orthodox Church, where he is greatly esteemed for his writings and his views on grace. In these, the Orthodox see far more affinity with the traditional teachings of the Orthodox Fathers than in Saint Augustine of Hippo. Thus, it is common for Orthodox monks and bishops to bear his name.
St. Thomas Aquinas
Raised within the Benedictine tradition at Monte Cassino, Saint Thomas Aquinas was profoundly shaped by the spiritual and theological currents of monastic life. Among the authors he esteemed most was John Cassian, whose Conferences and Institutions had been integral to the Rule of Saint Benedict and to the monastic formation Thomas received in his youth. It is reported that Cassian’s works were always present on Aquinas’s desk, reflecting the deep influence they exercised on his spiritual and theological outlook. Cassian’s insights into the nature of the virtues, the dynamics of spiritual struggle, and the interior life resonated with Aquinas’s own synthesis of theology and spiritual anthropology. His frequent citations of Cassian, especially in the Summa Theologiae (e.g., ST II-II, q. 162, a. 3), bear witness to this lasting influence.¹
¹ See Jean Leclercq, L’amour des lettres et le désir de Dieu, Paris: Cerf, 1957; and Servais-Théodore Pinckaers, The Sources of Christian Ethics, trans. Mary Thomas Noble, Washington, D.C.: CUA Press, 1995, pp. 320–321. Cassian is cited by Aquinas especially on topics related to pride, acedia, and the stages of spiritual growth.
Stages of Growth in St. John Cassian
John Cassian discusses the stages of spiritual growth primarily in his Conferences (Collationes), a collection of dialogues with Egyptian desert monks. These texts are foundational for both Eastern and Western spiritual theology.
Where Cassian Discusses the Stages of Growth
The clearest treatments of spiritual progress appear in the following Conferences:
1. Conference 1 — Abbot Moses on the Goal and End of the Monk
Main theme: The purity of heart (puritas cordis) as the goal (scopos) of monastic life, and the Kingdom of God as its end (telos). Structure of growth: Cassian, influenced by Evagrius, describes the progressive purification of the heart through ascetic struggle and prayer. This conference introduces the practical (active) and contemplative life, corresponding to beginners and more advanced stages. 📖 “The end of our profession is the kingdom of God or the kingdom of heaven… But the immediate goal or scopos is purity of heart.” (Conf. 1.4)
English translation – Conference 1 (New Advent). 1st Conference (another translation)
2. Conference 2 — Abbot Moses on Discretion (Discernment)
Discusses discretion (discretio) as the guide of all virtues and the mark of spiritual maturity. The transition from: Beginners: struggle with passions. Proficients: acquire discretion and stability. Perfect: attain contemplative rest and divine love. 📖 “It is discretion alone that can keep us from excess on either side… and raise us to the heights of perfection.” (Conf. 2.4–6)
English translation – Conference 2 (New Advent)
3. Conference 18 — Abbot Piamun on the Three Renunciations
Here Cassian outlines a three-stage framework of spiritual renunciation:
Renunciation of worldly possessions and ties (the external world). Renunciation of one’s former ways, thoughts, and vices. Renunciation of one’s own will — the deepest interior surrender to God.
These stages correspond to: Initial conversion, Purification of the soul, Contemplative union.
“There are three kinds of renunciation… the third is the most difficult, where we no longer perform our own will.” (Conf. 18.6)
English translation – Conference 18 (New Advent)
4. Conference 23 — Abbot Theonas on Sinlessness and Perfection
Speaks of the gradual movement toward sinlessness, tranquility, and perfect charity, though not achievable by all in this life. Strong ties to the “third stage” of Evagrian teaching: apatheia (dispassion) leading to agape (divine love).
“Perfect love, which drives out fear, is not immediately possessed, but only through many labors and long perseverance.” (Conf. 23.8)
English translation – Conference 23 (New Advent)
Scholarly Commentary
Columba Stewart, OSB: Cassian adopts and adapts the threefold structure of the spiritual life (praktike → physike → theologia) from Evagrius Ponticus. See: Stewart, Cassian the Monk, Oxford University Press, 1998. OUP link Jean Leclercq, OSB notes that Cassian’s stages emphasize a pedagogical ascent rooted in praxis but oriented toward contemplation. Leclercq, The Love of Learning and the Desire for God.
Summary of Cassian’s Stages of Growth
| Stage | Description | Source |
|---|---|---|
| 1. External Renunciation | Leaving the world, external obedience | Conf. 18 |
| 2. Interior Renunciation | Combatting vices, achieving purity of heart | Conf. 1, 2 |
| 3. Discretion & Stability | Discernment and balance of life | Conf. 2 |
| 4. Dispassion (Apatheia) | Stillness, inner peace | Conf. 23 |
| 5. Love (Agape) | Spiritual maturity, union with God | Conf. 23 |
For further study
Related to the Prayer of the Heart:
St. John Cassian’s 10th Conference on Prayer
St. John Cassian’s 10th Conference 3 Videos (Father Benedict Croell OP)
St. John Cassian : The Conferences
On the goal of the life of the monk:
St. John Cassian: 1st Conference