In Medieval Trinitarian Thought from Aquinas to Ockham, Russell Friedman explores the trends and patterns of development in medieval approaches to the central problem of Trinitarian theology: In what way are the three Persons of the Trinity (Father, Son, and Holy Spirit) distinct from one another, such that they still constitute one single God? In order to address this problem, medieval theologians drew on all the resources of metaphysics and philosophy of mind at their disposal. Their treatments of this Trinitarian question, then, are of interest from both a theological and a philosophical perspective. Covering a wide range of well-known and lesser-known medieval figures, this book gives an excellent overview of the main trends in Trinitarian theology from 1200-1350, in a thorough, engaging, and accessible manner.
The book is divided into four chapters. Chapter 1, "The Trinity and the Aristotelian Categories: Different Ways of Explaining Identity and Distinction," examines what Friedman calls "the relation account" and "the emanation account" of personal distinction in the Trinity. The relation account, which can be traced back to Augustine and Boethius, and whose 13th-century formulation is typified in Aquinas and Bonaventure, holds that the distinction between the Persons of the Trinity is constituted by their opposed relations to each other: "That the Father has a Son and that the Son has a Father, these are the differences that make the Father and the Son personally distinct from each other" (9). The emanation account, championed by the Franciscans, holds that these relations must be grounded in some logically prior distinction between the way that each Person "emanates" or is originated. "On the emanation account, the Father is the divine essence in a fundamentally different way than the Son is, and the Holy Spirit is the very same divine essence in a third totally different way, these three different ways being how each one originates or has being" (17). Friedman describes the incipient stages of this emanation account in Bonaventure and traces its development in John Pecham (who reifies these emanations) and Henry of Ghent (whose emanation account completely excludes the role of relation in personal distinction). Of particular interest is his discussion of what implications the disagreement between these traditions holds for the Roman Catholic/Greek Orthodox disagreement over the Filioque.
The second chapter, "The Trinity and Human Psychology: 'In the Beginning Was the Word,'" examines the psychological model of the Trinity, which can be traced back to Augustine. While the psychological model appears in both relation and emanation accounts, Friedman argues that it became especially important to emanationist theologians, who needed an explanation for why the Trinitarian emanations were distinct prior to the relations that they grounded. The chapter begins with an admirably clear overview of Augustine's "verbum" theory and the way in which the Augustinian psychological model was used in Henry of Ghent and the Franciscan tradition to explain the Trinitarian emanations by reference to knowledge and love. According to this view, the Father emanates the Son in the way that the mind generates a self-concept or mental word, and the Spirit originates as the love exchanged between Father and Son. After reviewing a number of objections by thinkers of the Dominican tradition (Aquinas, John of Naples, Durand of Saint-Pourçain), the chapter concludes by showing how John Duns Scotus's adoption of the psychological model shaped crucial aspects of his philosophy of mind.
The third chapter, "The Trinity and Metaphysics: The Formal Distinction, Divine Simplicity, and the Psychological Model," continues the discussion of the psychological model. It begins with an interesting analysis of whether there is indeed a "shift" in Trinitarian theology at the turn of the 14th century--a question Friedman answers with a qualified yes and no. On the one hand, Scotus's theology provides a thread of continuity between the 13th and 14th centuries to the Franciscan Trinitarian discussions, a role that Aquinas's theology plays for the Dominican tradition. On the other hand, Friedman also notes a "discontinuous" tradition in the 14th-century Trinitarian theology, motivated by an increasing worry that the previous century's Trinitarian theology had failed in its duty to divine simplicity. This trend, which rejects the psychological, emanationist, and relational accounts, provides the matter for the second half of the book (chapters 3-4).
The third chapter, then, goes on to conduct the reader through the developing debate between the "strong version" of the psychological model (which argued that the Son's and Spirit's emanations really are acts of the divine intellect and will) and the "weak version" (which argued that acts of intellect and will are merely analogies for the Trinitarian emanations). At first, the debate partners assume that the strong psychological model implies a prior distinction between the divine essence, intellect, and will. The Dominican tradition cited this implication as a reason for rejecting this model. Scotus, in contrast, goes so far as to propose a formal (rather than real) distinction between God's essence and powers of intellect and will, in order to save the strong psychological model.
In the next stage of the debate, however, three 14th-century Franciscan thinkers--Peter Auriol, Francis of Marchia, and William of Ockham--object to Scotus's solution. Their divergent responses, all of which seek to explain the utter identity of essence, intellect, and will in God while maintaining some version of the psychological model, are strikingly innovative and metaphysically interesting, if sometimes less than convincing. For example, Auriol holds that the Trinitarian emanations do not rely on a prior distinction between the divine essence and the divine powers of intellect and will, Rather, the emanations, which occur according to the strong psychological model, are themselves the sources of that distinction (which Auriol nevertheless takes to be merely connotative). Marchia, on the other hand, completely rejects any distinction between the divine essence, intellect, and will, arguing that the perfections of intellect and will are found in God only eminently: "Their functional characteristics, i.e., what they can do, are contained in one indistinct divine essence" (122). Ockham, finally, is caught between a determination to uphold divine simplicity and the conviction that Scripture and the patristic tradition propose the strong psychological model (the Son as Word, the Spirit as Love) as a matter of faith. Characteristically, Ockham solves the problem semantically: the term "intellect," applied to God, merely refers to the divine essence as generating the Son, but we have no way of knowing why this term is used rather than any other (129-30). In these three thinkers, Friedman finds examples of a trend of Trinitarian thought that shies away from detailed explanations of the Trinitarian processions.
At the radical extremity of this simplicity-preserving trend in medieval Trinitarian thought is the Praepositinianism, which provides the topic of the fourth chapter, "The Trinity, Divine Simplicity, and Fideism--or: Was Gilson Right about the Fourteenth Century after All?" This chapter returns to the debate between the relation and emanationist accounts of personal distinctions. Relation theologians and emanationist theologists agree on the project of identifying the unique feature that distinguishes persons of the Trinity, although they disagree as to whether this distinction is constituted by the opposition of relations or by prior emanations. The Achilles' heel of this view, according to Friedman, is made explicit in Henry of Ghent, an emanationist, and Godfrey of Fontaines, a relation theologian, both of whom describe the Trinitarian person as being quasi-hylomorphically constituted. For each person, the divine essence provides the "quasi-matter," with the relation or emanation providing the "quasi-form" that is constitutive of the distinct person (140-41). Consequently, for some thinkers, the very quest to identify the principle of personal distinction appeared as inherently threatening to Divine simplicity. The originator of this radically agnostic approach to Trinitarian theology is Praepositinus (d. 1210), who rejected the view that personal properties constitute the persons, arguing instead that the properties are the persons (i.e., the Father just is paternity). In other words, distinctness is a basic and unexplainable feature of the Trinity: "The divine persons just are distinct from each other, and no mechanism need be given to explain their distinction" (143). Praepositinianism was thoroughly rejected throughout the 13th century, but resurfaced as a minority position in the 14th century. The chapter traces the reemergence of Praepositinianism in three 14th-century thinkers: Walter Chatton, Robert Holcot, and Gregory of Rimini. The views of these thinkers all amounts to the same claim: "All that we are able to do is to repeat a fact that we know through revelation: one and the same God is three really distinct persons. The search for simplicity in these thinkers has ruled out any distinction, any analysis, and any explanation" (165). From this perspective, the role of Trinitarian theology is merely to find new and less ambiguous ways of restating what faith has received.
The final part of Chapter 4 provides a quasi-conclusion to the book. Here Friedman uses the Praepositinian meta-question of whether one should even seek an account of the personal distinctions, in order to address the "Gilsonian paradigm" of the 14th century: i.e., that 14th-century scholasticism is pervaded and corrupted by a pessimistic fideism. Agreeing with Gilson on the existence of a strong fideist strain in 14th-century thought, Friedman nevertheless makes a compelling case for a reevaluation of "the immense vitality and creativity of later-medieval theologians" (170). Appealing to the history of Trinitarian thought that he has just sketched, he points out that the fideist strain was just one among many creative and independent 14th-century solutions to the problem of personal distinctions in the Trinity. Of particular interest is Friedman's observation that Praepositinian Trinitarian theories in 14th-century thought is rooted, not in a blind fideism or mere skepticism in the power of reason, but in an adherence to the philosophical (and one might add, Neoplatonic) position that all explanation essentially involves a multiplicity that is incompatible with divine simplicity. From this perspective, explanation itself by its very nature violates the unity at the heart of the Trinity.
In this book, Friedman evinces a comprehensive knowledge of the texts and authors that are central to this 150-year debate over Trinitarian distinctions. By drawing less-familiar medieval figures back to their rightful places in the discussion, he restores a concrete shape and texture to the medieval debate on Trinitarian theology. In addition, by exploring how medieval contemporaries responded to the various theories he sketches, he is able to give a fuller sense of the lively spirit and innovative character of the historical debate, while offering philosophical evaluation of the merits of each theory.
Because of its wide-ranging scope and accessible presentation--reinforced by the inclusion of diagrams, an appendix that summarizes the main features of Franciscan vs. Dominican thought, and an annotated bibliography--this book can serve as a helpful point of introduction to Trinitarian thought during the 13th and 14th centuries. Those who study medieval Trinitarian thought will also find it useful for the orderly shape it gives to a dauntingly complex medieval debate and the access it provides to less-well-known authors and texts. For scholars of medieval philosophy, Friedman shows how medieval Trinitarian questions provide a base from which to explore an author's view on certain philosophical issues (relations, concept-formation, the nature of rational explanation, distinction and identity, essences, properties, and individation).
The origin of the book's four chapters in a set of four 2008 lectures, however, can pose some difficulties for the reader. The chapters remain relatively self-contained, and as subsequent chapters highlight different trends in medieval Trinitarian thought, it is not always clear how these trends are chronologically related, or whether they are all targeting the same or different aspects of the problem of Trinitarian distinction. For instance, the vocabulary of "relation account" vs. "emanation account" (ch. 1) and "psychological model" (chs 2-3) initially suggests distinct and mutually exclusive theories of Trinitarian distinction all on the same level. As becomes clear later, though, nearly all emanation accounts are also relation accounts, and both belong to a different order of explanation than the psychological model. (Indeed, Bonaventure's Trinitarian theology incorporates all three.) Nevertheless, the appendix does much to remedy this issue with its helpful summary of the key elements and flashpoints of the medieval debate.
In sum, this book brings clarity and insight to a very diverse set of theories, illuminating the contours of 150 years of Trinitarian thought. Readers will welcome the fascinating window it offers into the innovation and vitality of the medieval debate over the problem of Trinitarian distinctions.