This book is about unity and distinction/diversity, in a twofold sense. First and foremost, it is about the Christian claim that the one God is Father, Son, and Holy Spirit, such that God is one substance (or essence) and three distinct persons who are this one thing (res). Second, this book is about the unity and diversity of medieval theologies of God. The latter constitutes the basic argument of this work, which is that while there is clearly a diversity of views regarding who God is and how the triune God can be talked about in the long medieval period (c. 1000–1550), there is also a profound unity or agreement.1 There is, one could say, a common or basic trinitarian theology held by almost all medieval and Reformation era Christians. Here it is perhaps useful to say a bit about both of these aspects.
First, this volume is focused on the long medieval period (c. 1000–1550) because of the richness of philosophical and theological argumentation about God that emerged during these centuries. As the recent work of Russell Friedman has masterfully demonstrated, the quality of theologizing about the Trinity in the medieval period is second to none and is an interesting source of theological and philosophical speculation. Further, as Lambertus de Rijk observed,
To study Christian theologizing about God, therefore, is to enter into the long debates in Western philosophy about the nature of God, the principle of individuation, substances and categories of accidental being, and other such topics.no student of medieval speculative thought can help being struck by the peculiar fact that whenever fundamental progress was made, it was theological problems which initiated the development. …speculation was, time and again, focused on how the notion of being and the whole range of our linguistic tools can be applied to God’s nature.2
Second, the present work defends the somewhat counter-intuitive thesis that medieval and Reformation era theologies of God remained remarkably consistent.3 Writing precisely at the hinge between the late medieval and early modern world, Martin Luther wrote in the first part of the Smalcald Articles in 1537 that with respect to trinitarian theology or Christology there is no contention or dispute with his Roman adversaries, because “both sides share the same confession.”4 Here Luther observes that his break with Rome is not over trinitarian doctrine or Christology, precisely because both Protestants and Catholics held similar beliefs about the one God and the incarnation of the Son. This, of course, is true in a rather stark sense; the Church divisions that emerged out of the sixteenth-century conflagration were not initially divisions grounded in divergent theologies of God or Christ (though whether divergent theologies of God and Christ eventually emerged is a rather different question), but about issues of salvation and the Church. Thus, the present volume will examine select topics of trinitarian theology in such a way as to demonstrate the basic normativity—shaped by common philosophical categories (Aristotelianism), Scripture, the Creeds of the Church, and Church tradition—that existed in trinitarian theology between the years 1000 and 1550.
In what remains of the introduction, we will consider some preliminary topics, including the sources of trinitarian speculation in this period, and the common language and categories employed by the majority of the thinkers discussed.
Sources
The theologians of the early Church held that the Christian doctrine of the Trinity is fundamentally a reflection upon Scripture. Augustine argued in De Trinitate that the Scriptures—both Old and New Testaments—bear witness to the fact that the one God is Father, Son, and Holy Spirit. Medieval theologians shared this view. According to William of St. Thierry, the Scriptures contain a biblical argument for both unity and diversity in God: (1) His unity is evident in the shema, “hear O Israel, the Lord your God, the Lord is one” (Deuteronomy 6:4); (2) and His trinitarian diversity is evident in the baptismal formula spoken by Christ, “Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit” (Matthew 28:19).5 For William, the Scriptures speak about the unity and diversity in God: the book of John, in particular (3:17, 14:26, 15:26), was understood to provide substantial evidence that God is both three and one.6 Here, following Augustine, William observes that the Christian Scriptures speak of three persons, and that the Father sends the Son and that the Father and Son send the Holy Spirit.
As William recognized, however, the doctrine of the Trinity is not explicitly stated in the Scriptures. The Christian doctrine uses lots of technical terms to describe how God is three and one that are not found in Scripture. In particular, William observes that the words ‘Trinity’ and ‘homoousios’ are not found in the Bible: the former being used to describe the three persons in one God and the latter to identify the Father, Son, and Spirit as one substance. William’s response is clear; the Christian doctrine of the Trinity is the Church’s interpretation of what the Scriptures present of the living God. While the doctrine, per se, is not found directly in the Scriptures, what the doctrine articulates is a theological model that can help one read and understand the complex statements made in Scripture.7
William’s approach was normative for theologians up through the medieval and Reformation eras, in that trinitarian theology presents, for these thinkers, a technical distillation of what is present in Scripture. John Calvin—often problematically labeled as one who would have preferred to reject such technical terms8—would claim that the use of the words ousia, hypostasis, essentia, and persona within trinitarian theology is often falsely decried by heretics as un-biblical and the product of human invention, when in fact such language merely articulates that which is found in the Scriptures. The Scriptures, Calvin thinks, are often unclear to the extent that they perplex or hinder our understanding, and in such cases why should one not explain the Scriptures by means of clearer words (verbis planioribus) to shed light upon the faith?9 In this sense trinitarian theology is a human attempt to bring clarity to the truths of the faith presented in Scripture by means of technical philosophical language.
Scripture, therefore, is the foundation of trinitarian theology for all of the medieval and Reformation era theologians. The fourteenth-century Augustinian theologian Peter Gracilis put it this way,
It is, as Gracilis attests, simply a fact that for all catholic authors the doctrine of the Trinity is understood to be fundamentally a distillation of Scripture. That said, trinitarian theology is not just a record of what is in Scripture, it is also a doctrine that was worked out in the Creeds of the Christian Church and by the numerous theologians of the Early Christian period. Here it is necessary to say a word or two about these sources.every Catholic writer who has written about the Trinity, which is God, intends to teach that Father, Son, and Holy Spirit are one substance/essence and are one God with an inseparable equality, and that this unity in essence, and Trinity in persons, is proved through many Scriptures.10
In its present form the Nicene Creed professed by the Western Churches goes back to the Councils of Nicaea (325) and Constantinople (381). This Nicene-Constantinopolitan Creed was accepted at the Council of Chalcedon (451) and would become a normative statement of belief for both Eastern and Western Christians.11 It is, therefore, a statement of faith that has governed the great majority of Christians throughout time and history, and it has a fundamentally trinitarian structure. First it speaks of the Father almighty who is the creator of the cosmos and the maker of things visible and invisible. Second, it turns to Jesus Christ, the Son of God, who is begotten from the Father, before all ages; and, lest one confuse the issue, it is clarified that the Son is begotten, not made, and is consubstantial (omousion Patri) with the Father. The Son is God from God, light from light, true God from true God. Third, the Creed speaks of the Holy Spirit, the Lord and giver of life (vivificatorem) who proceeds from the Father [and the Son]. This creedal statement is an articulation of the trinitarian faith professed by Christians throughout...