Luigi Gioia, The Theological Epistemology of Augustine's De Trinitate. Oxford Theological Monographs. Oxford/New York: Oxford University Press, 2008. Pp. xvi, 330. ISBN 9780199553464. $130.00.
Reviewed by Scott Carson, Ohio University
This revision of Gioia's Oxford dissertation presents a thought-provoking interpretation of Augustine's De Trinitate, providing one of the few book-length treatments in English of what is arguably one of Augustine's most important contributions to philosophy and philosophical theology.
The De Trinitate has been of interest to modern philosophers principally for what some like to think of as its "philosophy of mind", that is, Augustine's account of human cognition and how, and in what sense, humans come to have knowledge of God's Trinitarian nature. This is largely the topic of the latter half of the fifteen-book work, and so it has been this latter half that philosophers have mostly studied (indeed, Cambridge's recent  edition of Steven McKenna's translation contains only books 8-15). Among the principal virtues of Gioia's treatment is his careful argument for the unity of the treatise, showing how the epistemological sections of the latter half can only be properly understood in light of the theological explorations of the first half.
In his first chapter, "Augustine and His Critics", Gioia reviews some of the principal recent scholarship on the De Trinitate and situates his own thesis within the context of a Christological and pneumatological conception of epistemology. His focus is on three recent trends. First, the influence of O. Du Roy's L'Intelligence de la foi en la Trinité selon S. Augustin (Paris: Etudes Augustiniennes, 1966); second, the ongoing debate between Western and Eastern conceptions of the nature of the Trinity; and third, the work of Rowan Williams and Lewis Ayres. With regard to the first, Gioia writes (p. 10): "Our book as a whole shall be devoted to disproving Du Roy's conclusion not only with regard to his interpretation of the De Trinitate, but also to crucial aspects of his account of the genesis of Augustine's Trinitarian thought." It is this "account of the genesis of Augustine's Trinitarian thought" that provides the leaven for Gioia's project of showing the unity and coherence of the De Trinitate: the debate between East and West, and the work of Rowan and Lewis, provide a backdrop against which Gioia argues that, for Augustine, "theological epistemology is 'Trinitarian' because knowledge of the Father is possible only through Christ and the Spirit of the Father and the Son" (p. 23).
Chapter 2, "Against the 'Arians': Outline of Books 1 to 7", emphasizes Augustine's arguments against "Arians"1 in defense of orthodox Trinitarianism. Gioia's purpose is to highlight the unity of exposition in these first seven books and their connection to the remaining books in their heuristic concern for "unfolding the Trinitarian mystery" (p. 38). This chapter is perhaps the most philological in the book, drawing as it does upon rhetorical theory and structural analysis to uncover what Gioia calls "inner" and "outer layers" to the treatise. The "outer layer" is Augustine's explicit topic: an explanation of the nature of the Trinity; but Augustine's real purpose, according to Gioia, is to be found in the "inner layer", a Scripturally based explication of how humans come to know God by loving God through Christ. We encounter Christ most fully as mediator and redeemer, and Gioia argues that for Augustine revelation coincides with redemption: it is impossible to know God without first being reconciled to him through Christ the mediator. For Gioia it is here that the unity of the treatise can be found, since Christ's role as mediator and redeemer, first explored in Book 4, is reprised and more fully articulated in Book 13.
Turning from philology to philosophy, Chapter 3 assesses Augustine's well-known ambivalence towards pagan philosophy. On the one hand, he is clearly impressed with both Platonism and skepticism for their capacity to articulate and defend ethical principles that are consonant with the teachings of the faith. On the other hand, he recognizes the limitations of philosophers to go beyond the mere dialogical exploration of such issues and enter into genuine knowledge of the foundation of The Good. There is nothing about philosophy as such that could lead to knowledge of the Trinity, on Augustine's view, nor did he think that any non-Christian philosophers ever approached anything like trinitarianism in their ontologies, not even Plotinus. For Gioia, this inability of secular philosophy to make an approach to knowledge of God is the key to understanding Augustine's Christological epistemology in the De Trinitate: this is what makes it impossible for philosophy, on its own, to give an adequate account of human happiness.
This brings us to Gioia's principal argument, which is articulated most fully in Chapter 4, "The Trinitarian Character of Augustine's Approach to Knowledge of God". For Augustine, knowledge of God is dependent upon the Incarnation. Augustine rejects any form of adoptionism: for him, Christ is God, and everything Christ did for us is God's own action. The beginning of knowledge of God, then, is for Augustine rooted in the revelation, through Christ, of our need for a true mediator and a true sacrifice. What God reveals himself to us to be is central the argument: he reveals himself to us as he reconciles us to himself in the sacrifice of Christ, and drawn towards him through this sacrifice for our sake we recognize in our love of our own being the love that God has for all of creation. The human condition is one of blindness to this love, but the Son's love of the Father, which is the essence of Christ's sacrifice, heals our blindness and enables us to see God's nature to the extent that that is possible for us to do so given our nature. On Gioia's account, then, it is impossible to understand the epistemology of the De Trinitate apart from its Christology, a result that he claims is confirmed by the structure of the treatise itself, in which the two most Christological books, Book 4 and Book 13, occupy pivotal places in the unfolding of the overall argument of the treatise.
Chapter 5, "Trinity and Revelation", continues the exploration of this notion of God's self-manifestation by means of revelation in Christ. Because God the Son is fully God and fully man, God in Christ is no longer something invisible to human sight, but nevertheless does not cease to be Lord: "In the Incarnation, the Son of God truly is both visible and invisible and, through him, truly the Father makes himself visible, i.e. known while remaining visible" (p. 111). This chapter contains an interesting discussion of what Gioia calls the "inner life" of the Trinity grounded in the distinctions between "missions", that is, modes of being "God from God", a property that Trinitarians appeal to in order to keep the Persons of the Trinity distinct without sacrificing the unity of the Godhead. From a philosophical point of view this material is quite interesting in terms of the metaphysics on offer, though it is also rather difficult for the secular philosopher to make sense of. Each Person of the Trinity has the disjunctive property "either God or God from God". God the Father is distinct from God the Son and God the Holy Spirit by manifesting the first disjunct of this property, while God the Son is distinct from God the Holy Spirit by manifesting the second disjunct of this property in a different way than God the Holy Spirit manifests it. Both Son and Spirit are "God from God", but their "missions" differ as between begetting and proceeding. Since the property is disjunctive, all three Persons can be said, in a sense, to have the "same" property, yet it is nevertheless mysterious how such a property can, at the same time, serve to distinguish Persons and to maintain simplicity.
Gioia calls this analysis "the rule 'God from God'" (pp. 26-7, 120-3) and explains how Augustine derives it from Biblical texts, but given its centrality to Augustine's project as he understands it, it is a little disappointing that Gioia does not explore its philosophical ramifications more fully than he does. Chapter 6, "The Holy Spirit and the Inner-Life of the Trinity", is one place where one might have expected such an exploration, particularly in section II, "The Holy Spirit and the Unity of the Trinity" or, failing that, in Chapter 7, "Trinity and Ontology". One of the principal points of divergence between East and West after Augustine was on the question of God's simplicity (that is, the question of the metaphysical relationship between God the entity and the properties of that entity), with the Western tradition working much harder to defend absolute divine simplicity in the face of multiple property ascriptions. If God is a Trinity, there is some important work to be done to show just what it means to say that a single, metaphysical unity (such as God is said to be) not only can be said to have distinct properties (distinct in this sense: the property of being omniscient is not identical to the property of being omnipotent, etc.) but can also be said to subsist as three distinct Persons defined in terms of their relations to one another as given by the rule "God from God". The problem is a notorious one that has continued to puzzle metaphysicians up to the present, with even secular philosophers trying their hand at making sense of it.2 Augustine's own attempts to describe the nature of the Trinity in the De Trinitate never progress beyond arguments by analogy. We are asked to consider the set of relations, for example, that define the trinity-with-a-small-'t', "lover-beloved-love", or "knower-known-knowledge". The inseparability of each of the elements of these trinities from each other is supposed to illuminate the relations that define the Persons of the Trinity, with the "love" analogy adhering most closely to the Divine model since the Spirit and the Son are manifestations of the Father's love. For Gioia, this analysis amounts to the claim that the Father is the origin of the "inner life" of the Trinity, which is made known to us through the "outer life", that is, through God's self-manifestation in Christ through the Spirit.
In Chapters 6 and 7, Gioia is mostly just explicating Augustine's treatment of these difficult metaphysical issues in order to illustrate more fully his own thesis about the unity of the treatise as a whole and the centrality of Trinitarianism to Augustine's epistemology. There is an interesting and informative discussion of Augustine's use of technical Latin terms such as essentia, substantia, and persona in comparison with the Greek terms οὐσία and ὑπόστασις (pp. 154-7), but Gioia's point is to show that Augustine had no Scriptural resources to which he could appeal in disambiguating these relations. Gioia notes that "books 5 to 7 of the De Trinitate...do not aim to provide a systematic account of the doctrine of the Trinity with the help of ontological categories" (p. 158); rather, Augustine accepts the creedal commitment of the Church with respect to the ontological categories and focuses instead on explicating the unity of the Trinity in terms of unity of will-as-love.
On Gioia's reading of De Trinitate Augustine locates human knowledge of God in the transformation of the human person that takes place when one encounters God in Christ. Chapter 8, "Love and Knowledge of God", is a detailed examination of this thesis, with a concluding section on the theological roots of Augustine's argument. Chapter 9, "Knowledge and its Paradoxes", continues the explication of Augustine's theme of love as knowledge with a detailed account of Augustine's epistemology as found in the De Trinitate, including such important elements as his doctrine of illumination, his account of knowledge of other minds, and his views about the deleterious effects on human knowledge of covetousness and our fallen nature.
The final two chapters, Chapter 10, "Wisdom or Augustine's Ideal of Philosophy", and Chapter 11, "The Image of God", bring the argument full circle, explaining how knowledge of God is in fact a special case of what for Augustine is a general epistemological principle: genuine knowledge of any kind is possible only through Christ. True philosophy, on this view, is actually a form of worship, which for Gioia constitutes confirmation of his integrative reading of the treatise: "Reference to books 4 and 13 in [Augustine's] definition of proper philosophy confirms our claim as to the crucial role played by Christology not only with regard to knowledge of God, but also for the redefinition of the parameters of epistemology as such" (p. 229). To defend this integrative reading Gioia expands upon his theme in the eleventh and final chapter of the book, which is also by far the longest chapter. He departs from the De Trinitate to show how the theme of the image of God and knowledge as love is to be found in a wide range of Augustinian texts.
This book has much to recommend it to a wide range of readers -- philosophers, theologians, and philologists among them -- even though the work is clearly a theological monograph first and foremost. It is clearly an important contribution to the study of Augustine and to the history of epistemology.
1. Gioia refers to "Arians" within quotation marks to make clear that "for Augustine, as for his predecessors, [this term] had become a label for virtually any position at variance with what in the end became the mainstream orthodox confession of the mystery of the Trinity" (p. 26 n. 7).
2. See, for example, Richard Cartwright, "On the Logical Problem of the Trinity", reprinted in his Philosophical Essays (MIT, 1990). Cartwright specifically addresses Augustine's argument in the De Trinitate.