Christopher McLaughlin received his Ph. D. in Historical Theology from Boston College. His dissertation, "The Pneumatology of Marius Victorinus: A Rhetorical, Philosophical, and Theological Commentary on Adversus Arium III," details Victorinus's contribution to Nicene pneumatology in the early 360s. Christopher's areas of expertise are in Greek and Latin patristics and Platonism through the fourth century.
Caius Marius Victorinus is known today primarily through Augustine’s account of his conversion, presented in the eighth book of the Confessions. After telling Simplicianus that he had read Victorinus’s Latin translations of the “books of the Platonists” (likely works by Plotinus and Porphyry), Simplicianus, while endorsing the Platonic philosophy, narrated the edifying story of Victorinus’s baptism. Victorinus would often tell Simplicianus in private that he was a Christian, but had not been interested in formally joining the Church. Converting to Christianity meant damaging his relationship to the pagan aristocracy while undergoing the humiliation of repudiating the gods of the Roman pantheon whom he had “with thundering eloquence defended so many years” (Conf. 8.2.3); indeed, to do so in order to follow Jesus Christ and the apostles who had been the object of such ridicule in Porphyry’s Against the Christians. When Victorinus finally and suddenly determined to join the sacramental and ritual life of the Church, he elected to profess his faith and be baptized before the whole assembled body of Christ (Conf. 8.2.5). The story of the pagan rhetor’s courageous conversion made such an impression on Augustine that he burned to imitate his predecessor (Conf. 8.5.10).
Outside of Augustine’s colorful narration, few biographical sources on Victorinus have come down to us. From Jerome we know that Victorinus converted to Christianity sometime between 355 and 357, being then in extrema senectute (perhaps between 75 and 85 years old). He may have lived another decade after his conversion, which would give him time to compose his theological writings, but anything over a decade is rather unlikely given his advanced age. From these clues, scholars suggest Victorinus was born between 281 and 291 and died circa 365. The place of his birth was Roman North Africa where Michael von Albrecht says he was educated before moving to Rome. He was teacher of rhetoric in Rome during the reign of Constantius II. He had a granddaughter, Accia Maria Tulliana, whose epitaph alludes to Victorinus as rhetor and one who had brought honor to the family, which suggests both that Victorinus was married and had an ongoing public reputation at least two generations after his death. It has been suggested that his granddaughter’s agnomen, Tulliana, is a gesture to Victorinus’s distinguished efforts at expounding Cicero’s rhetorical works. For his rhetorical achievement and service, Victorinus was honored in 354 with a bust statue in Trajan’s Forum. When he converted to Christianity in Rome c. 355, he began putting his talents to use for the cause of Nicene Christianity.
Victorinus’s theological output was remarkable both in quantity and quality when one considers how briefly he had been Christian, as well as how theologically turbulent the period was for Christians across the empire, and the difficulty of the theological problem he set out to solve. He articulated his interpretation of Nicene homoousian theology over against the homoiousians led by Basil of Ancyra - homoians whose perspective was in favor with emperor Constantius from 358 until the emperor’s death in 361 - and against a kind of modalist interpretation of homoousios associated with the thought of Marcellus of Ancyra. His theological treatises are distinctive in their extensive and foundational use of philosophical resources for the working out of Christian theological doctrine. Perhaps the most important philosophical concepts he uses are the model of the noetic triad, Plotinus’s theory of two-acts, and the Platonic idea of predominance.
Victorinus writes of the Father as the potentia to which the Son relates as the actio, the power enacted. The potentia in question is the Plotinian idea of power-to-act rather than the Aristotelian unactualized potency. The enactment of the divine potentia is a manifestation of the divine power which had always been perfect in its own repose. The potentia and actio of God, that is, the Father and the Son, are one in essence (homoousios) as the power of vision and vision in act are of one essence. He also uses the model of substantia-motus, explaining that the Father is the primary substance as possessed by the subject, the Son is the substance as moving in accord with its nature, which is to say, the substance enacting its essential power.
Having established the relation between this dyad of Father and Son, he then develops an account of a second dyad, comprising Son and Holy Spirit. This second dyad is based on the divine actio and divine motus. Beginning from the Son of the first dyad, he differentiates the Son into the second dyad of Son and Holy Spirit. This second dyad is characterized by the two distinct actions of vivere and intellegere, ascribed to Son and Holy Spirit respectively. Putting these two dyads together, Victorinus develops his noetic triad of esse-vivere-intellegere. The Father is esse as the cause of being in all things, but this esse goes forth in a twofold activity of living and understanding which correspond to Son and Holy Spirit respectively. Each of these aspects of the Trinity is and lives and understands, but each is properly associated with the power which predominates in it, so that the Father both lives and understands in His own right, but as the power of living and understanding is most properly associated with pure esse, and the Son is predominantly associated with life (vivere), the Holy Spirit with understanding (intellegere).
Victorinus insists on the full divinity and full humanity of Christ, over against the Christology of Photinus of Sirmium and of Marcellus of Ancyra (Paul of Samosata he includes as well) which he repudiates explicitly. Concerning the humanity of Christ, he argues that Jesus has a real body and a full rational soul with all emotional and intellectual powers intact, basing himself on scriptural passages in which Christ is sad, desires, is angered, and reasons. He understands the incarnation in Platonic terms as the Logos taking up the logos of flesh and the logos of soul. Ellen Scully has argued recently that Victorinus’s soteriology is “physicalist,” meaning that by the Logos taking on the universal form (the logos) of humanity, he has implicitly and automatically saved every particular human. Yet however we interpret Victorinus’s account of the objective conditions for salvation, it is certain that the subjective reception of eternal life is for Victorinus dependent on the individual’s faith in Jesus Christ. He articulates this position most clearly in his commentaries on the Pauline epistles.
Victorinus wrote at least six commentaries on the Pauline corpus, namely on Romans, 1 and 2 Corinthians, Ephesians, Galatians, and Philippians.Only the latter three of these have come down to us. All six were composed, it is thought, after Victorinus resigned from his chair of rhetoric under Emperor Julian’s proscription of Christian teachers. These were the first commentaries on Paul in the Latin language. Victorinus’s exegesis is spare, committed to the bare expositio verborum. He allows himself few philosophical and theological digressions (these are more frequent in his commentary on Cicero’s De inventione), concerning only topics Victorinus deemed necessary for a full knowledge of soteriology and anthropology. These digressions include treatments of the soul which he envisioned especially in Platonic terms (see In Eph. 1:4), and discussions of the preexistence of souls in Christ (see In Gal. 3:20).
Victorinus emphasizes Paul’s soteriology and Christology, insisting that the believer is saved through faith in Christ alone, not through good works. Salvation is a matter of being set free “from the lords of the world and of the flesh, so as to have Christ now as Lord and be his slave” and of coming to knowledge of God through Christ. Psychologically, this is a matter of thinking spiritually rather than corporeally, of contemplating heavenly things enabled by Christ’s gift of faith. Victorinus prioritizes (logically and temporally) the agency of God in calling people to Himself, but gives equal weight to the necessity of the believer’s response of faith, so that both grace and freedom are required for salvation.
The following passage is taken from one of Victorinus’s later theological treatises, Adversus Arium III, written c. 361. It contains a concentration of Victorinus’s distinctive treatments of trinitarian theology, Christology, and anthropology. The context of the quotation, which begins here in media res, is a digression from his theological defense of applying Nicaea’s homoousios to the whole Trinity, in order to discuss how the Logos takes on soul in the incarnation. He is commenting on John 10:17-18. The translation is that of Mary Clark.
It is clear enough that Christ has never been called soul, no more than God is called soul. Indeed, the Father is called God, is called spirit; likewise, the Son is called Logos, is called spirit, and without doubt God, indeed since both are one God. Therefore these realities, the Logos, the Pneuma are above the soul by their own superior substance; the substance of the soul is far different and inferior to them, since it is breathed in by God and begotten and is alone properly called substance, because it depends on the forms which are in it and proper to it, and in the same manner as matter. To this is added that God is life, that Christ is life, and each of the two has life from himself, but so that, by the Father’s gift, Christ has life from himself. Therefore life is superior to the soul. For zoe and zootes, that is, life and vitality, are prior to the soul. Therefore, these realities there are homoousia, namely, God and the Logos, the Father and the Son, for, certainly, as the former is spirit, the latter is spirit, and as the latter is life, the former is also life . . . The spirit, therefore, has also the “power of taking, of leaving, and taking up again the soul.” Indeed, this is life, and life which is life from itself has the “power of taking, of leaving” that which, by its own power, by participation in it, it causes to live.
Indeed, the soul has been made according to the image of the image of God: “Let us make humanity according to our image and likeness.” Therefore, the soul is inferior; in addition, it originated or was created by God and the Logos, never God himself or the Logos, but a certain logos, not the Logos who is Son, not the general and universal seed, origin, source of all those things “which through him were made” . . .
Therefore the universal Logos, because he is spirit and life, not soul, has “the power from himself to leave soul,” and again to take soul. . . . When the soul is taken by divine beings—that is, by the Logos; for it was not taken by God, for the Logos is movement, the soul is also movement, and movement which is self-movement, hence the soul is “image” and “likeness” of the Logos; therefore when the soul is taken by divine beings, this taking adds nothing to life, since it is through life, that is, through the power of living that the soul possesses its own life. Therefore, when the spirit takes soul, it projects, so to speak, its power towards inferiors and towards actions, while it fills the world and worldly things. Therefore, the spirit, and especially the Logos, the spirit who is life, has in its power both the taking and the leaving of soul.
But when the Spirit takes soul, it is born, so to speak, in the world, and its power enters into dialogue with the world. When, in fact, it leaves the soul, it withdraws from the world and does not act in the world in a bodily mode, nor does it yet act spiritually. This is what we call his death, and then he is said to be in hell, not certainly without the soul. Hence he prays that God “may not abandon his soul in hell.” Therefore, because he must return to the world and to his action, he leads with him his soul from hell. Therefore, he retakes, as it were, his soul, that is, he retakes it for the sake of action in the world. And because only the full and total Logos, that is, he who is spirit and soul and body, can exercise an activity in the world, it was necessary then that he be newly sanctified, since he had newly assumed all that. He went, therefore, to the spirit and he returned sanctified, conversed with the apostles, then sent the Holy Spirit. Who therefore is the Holy Spirit? It is the Logos. For there is one movement. And for that reason it was said: “And if I go and prepare a place for you, I shall come again.” For who came after the departure of Christ except the Holy Spirit, the Paraclete?
 Jerome, De viris illustribus 101, 739.
 A. H. Travis, “Marius Victorinus,” Harvard Theological Review 36 (1943): 83-90; and Pierre Hadot, Marius Victorinus: Recherches sur sa vie et ses œuvres (Paris: Études Augustiniennes, 1971), 24.
 Afer appears in Jean Sicard’s 1528 edition of Victorinus’s theological works (see Hadot, Marius Victorinus, 24). Jerome begins his entry “Victorinus, natione Afer,” in De viris illustribus 101, 739. Michael von Albrecht and G. L. Schmeling, A History of Roman Literature: from Livius Andronicus to Boethius: with Special Regard to its Influence on World Literature (New York: E.J. Brill, 1997), 1616.
 Jerome, De viris illustribus 101, 739. Constantius reigned in the East from 337 and as sole ruler of the empire from 353-361.
 Hadot, Marius Victorinus, 16-17; Chiara Tommasi, “Marius Victorinus,” in Routledge Companion of Early Christian Philosophy, ed. Mark Edwards (2020): 475-489, here 476.
 Hadot, Marius Victorinus, 17 n. 21.
 Jerome, Chronicon 2370, 239.7-17; cf. Augustine, Confessions 8.2.3.
 For an account of the complexities of the theological landscape in the 350s as well as the crystallization of theological perspectives in the late 350s see, inter alia, Lewis Ayres, Nicaea and Its Legacy: An Approach to Fourth-Century Trinitarian Theology (Oxford: Oxford University Press, 2004).
 See Adv. Ar. III 5 (CSEL 83.1, 199-200).
 See Adv. Ar. IA 28, 30-41 (CSEL 83.1, 104).
 Adv. Ar. III 3, 34-46 (CSEL 83.1, 196-197).
 Ellen Scully, “Physicalism as the Soteriological Extension of Marius Victorinus's Cosmology,” Journal of Early Christian Studies 26 (2018): 221-248; see also Wendy Elgersma Helleman, “Victorinus’ Soteriology as a Philosophical, Theological and Exegetical Project,” Vigiliae Christianae (2021): 1-42.
 Hadot, Marius Victorinus, 287.
 Hadot, Marius Victorinus, 285-286.
 In Gal. 4.18, 23-25 (CSEL 83.2, 151); see also In Eph. 1.11, 25-26 (CSEL 83.2, 18).
 Cooper, Galatians, 116.
 See especially In Gal. praef. (Cooper, Galatians, 249-250); In Gal. 1:3-7 (Cooper, Galatians, 253-255)
 In Gal. 1:10; Cooper, Galatians, 257.
 Adv. Ar. III, 11, 26-12, 46 (CSEL 83.1, 210-213; ET: Marius Victorinus: Theological Treatises on the Trinity, tr. Mary T. Clark, FC 69 [Washington, DC: Catholic University of America Press, 1981], 238-241).