John Cassian, Church Father (Unfortunately)
This is a [longer] paper I wrote for seminary that got filed away somewhere a long time ago over at monergism.com... hope it's helpful!
John Cassian's Response to Augustinianism
John Cassian was a zealous monk whose theology (unfortunately, one might say) has been massively influential on the churchâ€™s understanding of the whole of the gospel since the fifth century. His particular theology (commonly known as semi-Pelagianism), which was developed largely in response to Augustineâ€™s doctrines of predestination, grace, and free will, has been adopted by many Christiansâ€”academics, clergy and lay people alikeâ€”throughout the centuries. Two major influences were at work in Cassianâ€™s life and teachings. First, Greek neo-platonic philosophical theology shaped his understanding of anthropology in a way that prevented him from being able to engage Augustine on the level that he should have. And second, his intense devotion to the ascetic chastity of the monastery created a platform upon which his theology could develop, yet in a way that was almost entirely sub-biblical. The result of Cassianâ€™s theological contributions to the church has been the obscuring of the God of the Bible in the vision of His people.
Cassian and His Work
Cassianus was born (probably in Provence) around 360 A.D., and most likely assumed the name â€œIohannesâ€ (John) at his baptism or admittance to the monastic life.  He died in Massilia of Gaul (present-day Marseilles, France), where he had spent his most productive years as a monk, in 435.  His birthplace is uncertain, and little is known about his parents, education, or childhood, primarily because of his own silence regarding these in his writings.
It is known, however, that he had a rigorous education, as evidenced by his fluent bilingualism and familiarity with church fathers. Western-born, Latin was probably his native tongue; yet much of his thought is influenced by Greek writers, and much of his life was spent in the East, where he derived his perspective on monasticism. â€œ[H]is entire achievement was built onâ€ his bilingualism,  as it offered him access to all major writers, and undoubtedly enabled him to address any major audience. Much exposure to Greek philosophical theology, together with his zeal for ascetic chastity, would figure prominently in Cassianâ€™s response to Augustine, as shall be discussed later.
Cassian spent many years as a monk with his companion, Germanus, in Bethlehem of Palestine and various places in Egypt with the desert fathers before they went to Constantinople. There Cassian studied under Bishop Chrysostom, until the teacher was banished from Constantinople. Cassian and Germanus then carried a petition on his behalf from the clergy of Constantinople to Pope Innocent in Rome, where Cassian made the acquaintance of one Archdeacon Leo, later to become Pope Leo the Great.  Eventually Cassian removed to Massilia, where monastic life had become increasingly popular during more recent years, in order to develop monasticismâ€”he established two new monasteriesâ€”and to write. 
In Massilia Cassian, now an abbot, wrote his three major works: 1) his Institutes (De Institutis Coenobiorum et de Octo Principalium Vitiorum Remediis Libri XII), which detail rules for the monastic life; 2) his Conferences (Collationes XXIV), which record conversations with abbots during his time in Egypt;  and 3) On the Incarnation against Nestorius (De Incarnatione Domini contra Nestorium), a work of seven books written at the request of Pope Leo.  In this last writing Cassian is the first to point out similarities between Nestorianism and Pelagianism. Of certain Nestorians he writes, â€œin saying that Jesus Christ lived as a mere man without any stain of sin, they actually went so far as to declare that men could also be without sin if they liked.â€  The high estimation of manâ€™s sufficiency and strength of will that is pervasive in Pelagian writings is applied to the Jesus of Nestorianism, who was supposed to have overcome sin by the sheer power of His merely human will, becoming Christ only at His baptism.  This section of De Incarnatione clearly indicates Cassianâ€™s desire to distance himself from â€œthe teaching or rather the evil deeds of Pelagius.â€ 
The â€˜Problemâ€™ of Augustinianism
Augustineâ€™s influence and authority had been growing since the official defeat of Pelagianism, which was condemned in 418 at the 16th Council of Carthage.  The â€˜initial sparkâ€™ was provided for the Cassian controversy when one of Augustineâ€™s letters, concerning predestination and prevenient (and therefore irresistible) grace, came into the possession of monks at Adrumetum. Dispute arose among them over these doctrines, and they eventually sent a dispatch to Hippo to ask Augustine about the fuller meaning of his writings.  So Augustine wrote De Gratia et Libero Arbitrii (On Grace and Free Will) and De Correptione et Gratia (On Rebuke and Grace) in 426, with the hope of clarifying the matter. 
Of course, though this may have settled the matter for the monks at Adrumetum, the doctrines were not so easily incorporated into the life of thought at Massilia. The monks there, of whom Cassian can be considered chief, agreed with Augustine on many issuesâ€”even against Pelagianism. But they distrusted his teachings on predestination, grace and free will as a result of his letters to the monks at Adrumetum.  â€œThey said that what Augustine taught as to the calling of Godâ€™s elect according to His own purpose was tantamount to fatalism, was contrary to the teaching of the fathers and the true Church doctrine, and, even if true, should not be preached, because of its tendency to drive men into indifference or despair.â€ 
Augustine taught that original sin had left humanity in a state of death (not just weakness), which necessitated the symmetrical actual giving of life in salvation by God. The will is alive and free, but its only function is to manifest the desire of a corrupt heart in a choice. So, in a sense, the will is utterly bound to sin, since men always and without exception love the darkness rather than the light, and this is death for them. The life came as Godâ€”of His own good pleasure, not motivated by anything He saw in sinnersâ€”regenerated the hearts of sinners, causing them to love God more than sin, by His Spirit (c.f. Ezek. 11:19-20; 36:22-28; Jer. 31:33-34; 32:38-41; 1 John 4:19). â€œThis grace, therefore, which is hiddenly bestowed in human hearts by the Divine gift, is rejected by no hard heart, because it is given for the sake of first taking away the hardness of the heart.â€  Augustine explained that God did this for some and not for others by referring to Romans 9, where God says that He is willing to exert His wrath, yet has patience in order to display the glory of His grace toward His elect.  These are the doctrines of predestination, grace and free will that Cassian felt jeopardized important truth about God and humanity. And though Augustine wrote convincing treatises on these doctrines in response to the complaint of the Massilians (De Praedestinatione Sanctorum and De Dono Perseverantiae; On the Predestination of the Saints and On the Gift of Perseverance  ), they would not be persuaded, and continued in their efforts to correct the doctrines they perceived as a threat to the life of the church.
Cassianâ€™s â€˜Solutionâ€™ Examined
Most of Cassianâ€™s relevant arguments are laid out in the 13th book of his Conferences, which is a record of a conversation with Abbot Chaeremon entitled â€œOn the Protection of God,â€ though he does touch upon the same doctrines, to lesser extents, in several other places. Methodologically, it must be saidâ€”to his commendationâ€”that he uses Scripture with great frequency.For Cassian, and others in opposition to strong Augustinianism, it seems there were two factors of primary concern in the debate. First, being a monk whose daily life consisted of disciplined asceticism for the sake of chastity (moral purity), Cassian feared that Augustineâ€™s doctrines would give an overwhelming sense of powerlessness and despondence in such pursuits. This, in turn, might lead to ethical irresponsibility (the lack of the feeling of accountability). 
It is of utmost importance to note that Cassian â€œpositions his analyses of grace and free will within his discussions of chastity.â€  The crucial issue for him was the empowerment for the pursuit of holiness. So great was his concern for chastity, in fact, that earlier in his life Cassian gave up the solitary life of an Anchorite monk in Egypt for that of a Coenobite in community with other monks, â€œin order that he might have the opportunity of practicing the virtues of obedience and subjection, which seemed out of the reach of the solitary.â€  Quite unlike Pelagius, however, Cassian insisted that divine grace was absolutely necessary for spiritual progress. â€œHow foolish and wicked then it is to attribute any good action to our own diligence and not to Godâ€™s grace and assistance, is clearly shown by the Lordâ€™s saying, which lays down that no one can show forth the fruits of the Spirit without His inspiration and co-operation.â€  Instead, he sought some middle ground of cooperation between manâ€™s willful initiative and Godâ€™s enabling grace (libero arbitrio semper co-operatur).
In order to maintain his position that man must be capable of some motion toward God, he proposed that the will was not dead in sin. Instead, the free will was only severely weakened (infirmitas liberi arbitrii) as a result of the fall. Man was indeed capable of generating a small spark of initiative toward the good by the power of his own will, which must be then strengthened and aided by God to produce any actual good. Having a decidedly Eastern anthropology, it is understandable that Cassian would be more open to â€œnatural possibilityâ€ than the Western Augustine.  Strangely enough, Cassian saw examples in Scripture of both monergistic (i.e. Matthew and Paul) and synergistic (i.e. Zacchaeus) beginnings of faith without any apparent difficulty. This is interesting, since, as R. C. Sproul observes, â€œThe difference between Augustine and Cassian is the difference between monergism and synergism at the beginning of salvation.â€  Nevertheless, Cassian was able to write, â€œwhen He sees in us some beginnings of a good will, He at once enlightens it and strengthens it and urges it on towards salvation, increasing that which He Himself implanted or which He sees to have arisen from our own efforts.â€  This kind of assertion is common in his Conferences, and betrays his lack of understanding, at some level, of the issues at hand.
Second, and to a lesser degree, Cassian was concerned that the Augustinian view of particular (electing) grace stood in blatant opposition to the â€œclearâ€ biblical truth of the universal availability of salvation.  He saw Godâ€™s love being extended to all in the universal offering of salvation, and could not stand the idea that Godâ€™s love would be so arbitrarily selective. â€œFor if He willeth not that one of His little ones should perish, how can we imagine without grievous blasphemy that He does not generally will all men, but only some instead of all to be saved?â€ 
As a result, Cassianâ€™s theology of Godâ€™s love required something of a fair chance for all people. If God really loved people (in the way Cassian thought), He would not permit the unfairness of a completely disabled will while demanding moral perfection. So original sin could not really have had the effect that Augustine claimed. Concordantly, prevenient grace would really be quite unnecessary, if people had the ability to initiate their own faith. And if prevenient grace were not a reality, then neither would be an Augustinian understanding of predestination. If people could really turn themselves toward God by their own will (as they must be able to do, if God is really fair and wants all to be saved), then God would only have to see (or foresee) who would create in themselves the spark of faith, and predestine them to eternal life on that basis.
Cassianâ€™s â€˜Solutionâ€™ Refuted
Having ascertained Cassianâ€™s main reasons for disagreeing with Augustine in these matters, a few presuppositions or foundations of his perspective become evident which warrant critique. First, it is most apparent from his great concern for the advance of disciplined chastity that Cassianâ€™s view of salvation is more sanctification-oriented than justification- or reconciliation-oriented. Whereas Augustine is generally arguing for a specific soteriological position (i.e., who makes the first move to restore relationship between God and men?), Cassian seems not to be able to think in the same category. Columba Stewart attributes this to the fact that Western skills were honed by the Pelagian controversy, while Cassianâ€”being an Eastern thinkerâ€”has simply not been so influenced.  Thinking so much as he does about chastity, he almost seems to treat God as a means to the end of the perfection of holiness. This is a major fault, as it fosters a fundamentally more anthropocentric view of salvation than theocentric.
Second, and closely related to the first, is the weak view of sin and grace in Cassian. Sin for him seems to be only a violation of command and conscience. For Augustine, and in Scripture, the essence of sin is more than thisâ€”it is a rejection of the supremacy of the glory of God for delight in things of infinitely less worthâ€¦ and therefore much more dishonoring to God. Accordingly, Cassianâ€™s view of grace is more Pelagian than Augustinian. For him grace is merely an agent of enabling unto holiness (seeing Christ more as an instructor than a savior). He would likely have a low view of the substitutionary atonement of Christ. Third, there seems to be in Cassian the attempt to maintain some level of autonomy from God in the process of salvation. This is perhaps the point where Augustine sees Cassianism â€œas necessarily implying the basal idea of Pelagianism,â€  thereby referring to it as â€œsemi-Pelagianism.â€ Indeed, prior to regeneration we are all born Pelagians,  at our religious â€œbestâ€ hoping to commend ourselves to God by some means other than Christ and the total reliance upon the sovereign grace of God.
Fourth, and more commonly ignored among historical and systematic theologians than the other points, is the pernicious error of an unexamined, confused, unbiblical anthropology. It is obvious from Cassianâ€™s Conferences that he sees the will as self-moved, self-initiated, and able to incline itself (albeit only slightly and weakly) toward the good. Also, he muddles the functions of the faculties of the soul in various places, not demonstrating any clear understanding of the will as a function of the heart, or of the desires as determining the direction of the will. For him, a manâ€™s being and doing are reversed from the biblical perspective: â€œfor each man must incline to one side or the other in accordance with the character of his actions.â€
The Official Outcome
Prosper of Aquitaine, lay friend of Augustine, took up the defense of monergism against Cassianâ€™s synergism from the beginning. He had alerted Augustine to the trouble in Massilia, motivating the bishop to write the two last works of his life against semi-Pelagianism (De Praedestinatione Sanctorum and De Dono Perseverantiae). And shortly after Augustineâ€™s death he, with his (otherwise unknown) companion, Hilary, petitioned Pope Celestine to condemn Cassianâ€™s teachings. However, they encountered difficulty in
â€¦trying to secure a condemnation of someone (Cassian) who had just written the anti-Nestorian treatise The Incarnation of the Lord at the behest of Leo, archdeacon of Rome. Cassian had, surely not coincidentally, linked Nestorius to Pelagius and attached both vigorously. His stock was high in Rome. 
In 432 Prosper wrote Contra Collatorem (Against the Author of the Conferences) as he saw Cassianism spreading in Gaul, expressing the hope that Pope Sixtus would condemn the teachings.  In this work he focuses on Cassianâ€™s Eastern tendencies as detrimental to a right understanding of the human will.
Semi-Pelagianism experienced some small official successes in Gaul at the Synods of Arles and Lyons in 472, but in 496 â€œPope Gelasius I sanctioned the writings of Augustine and Prosper and condemned those of Cassianâ€¦.â€  Eventually, at the Council of Arausiacum (Orange: 529) semi-Pelagianism was officially condemned, and the church adopted a mostly-Augustinian stance. 
The Abiding Influence
Tragically for the church, Augustinianism was being softened by the bishopâ€™s successors before semi-Pelagianism was even officially condemned.  It was not held to strongly enough for the fundamental tenets of Augustineâ€™s theology to take deeper root in the church. The resulting influence of Cassian has been widespread and long lasting. For, while it is true that the Council of Orange was a triumph over the â€œsemi-Pelagian denial of the necessity of prevenient grace for salvation,â€ Robert L. Reymond observes,
â€¦that same council betrayed the church into the semi-semi-Pelagian denial of the irresistibility of that prevenient grace by human free will, which theological vision, in spite of the recurring protests through the centuries of such men as Gottschalk, Bradwardine, Wycliff, and Hus, eventually an Aquinas was to systematize and the Council of Trent (1545) was to declare the official position of those churches in communion with Counter-Reformation Rome. 
And so the more complete majesty of Godâ€™s work in saving a people for Himself out of sin has gone through the centuries half-veiled, until the Day when the last vestiges of our self-reliance are stripped away, and all the earth trembles at the total sovereignty of the God whose pleasure it was to save some, sola gratia.
 Edgar C. S. Gibson, preface to The Works of John Cassian, by John Cassian, trans. Edgar C. S. Gibson, in The Nicene and Post-Nicene Fathers, 2nd ser., vol. 11, ed. Philip Schaff, accessed through The Master Christian Library, ver. 8 (Rio, WI: AGES Software, Inc., 2000), 375.
 The New Schaff-Herzog Encyclopedia of Religious Knowledge (Grand Rapids: Baker Book House, 1954), s.v. â€œCassianus Johannus,â€ http://www.ccel.org/php/disp.php?authorID=schaff&bookID=encyc02&page=435&view=
 Columba Stewart, Cassian the Monk, Oxford Studies in Historical Theology (Oxford:
Oxford University Press, 1998), 5.
 Gibson, 383.
 Stewart, 5.
 The Catholic Encyclopedia, 1908 ed., s.v. â€œJohn Cassian,â€ http://www.newadvent.org/cathen/03404a.htm
 Gibson, 383.
 John Cassian, On the Incarnation against Nestorius, in The Works of John Cassian, trans. with preface Edgar C. S. Gibson, in The Nicene and Post-Nicene Fathers, 2nd ser., vol. 11, ed. Philip Schaff, accessed through The Master Christian Library, ver. 8 (Rio, WI: AGES Software, Inc., 2000), 1:3.
 Gibson., 387.
 Cassian., Against Nestorius, 1:4.
 Robert L. Reymond, A New Systematic Theology of the Christian Faith, 2d ed. rev. & updated (Nashville: Thomas Nelson, 1998), 468-9.
 B. B. Warfield, introduction to Saint Augustineâ€™s Anti-Pelagian Works, by St. Augustine, trans. Peter Holmes & Robert Ernest Wallis, rev. B. B. Warfield, in The Nicene and Post-Nicene Fathers, 1st ser., vol. 5, ed. Philip Schaff, accessed through The Master Christian Library, ver. 8 (Rio, WI: AGES Software, Inc., 2000), 89-90.
 Gibson, 388.
 Ibid., 389.
 Warfield, 97-8.
 St. Augustine, The Predestination of the Saints, in Saint Augustineâ€™s Anti-Pelagian Works, by St. Augustine, trans. Peter Holmes & Robert Ernest Wallis, rev. with intro. B. B. Warfield, in The Nicene and Post-Nicene Fathers, 1st ser., vol. 5, ed. Philip Schaff, accessed through The Master Christian Library, ver. 8 (Rio, WI: AGES Software, Inc., 2000), ch. 13, emphasis mine.
 Ibid., ch. 14. See Rom. 9:22-23. For an excellent treatment of the righteousness of God in His sovereign election based on this passage, see John Piper, The Justification of God: An Exegetical & Theological Study of Romans 9:1-23, 2nd ed. (Grand Rapids: Baker Books, 1993), especially pp. 183-216.
 Gibson, 389
 Earle E. Cairns, Christianity through the Centuries, 3rd ed. rev. & expanded (Grand Rapids: Zondervan, 1996), 132.
 Stewart, 76.
 Gibson, 378.
 Cassian, The Conferences of John Cassian, in The Works of John Cassian, 3:16.
 Stewart, 19.
 R. C. Sproul, Willing to Believe (Grand Rapids: Baker Books, 1997), 73.
 Cassian, Conferences, 13:8.
 Sproul, 70.
 Cassian, Conferences, 13:7.
 Stewart, 78.
 Warfield, 93.
 Reymond, 469.
 Stewart, 20-21.
 Gibson, 390-391.
 Sproul, 75.
 J. N. D. Kelly, Early Christian Doctrines, rev. ed. (San Francisco: Harper Collins, 1978), 371-2.
 Sproul, 75.
 Reymond, 469