Augustine is a common source for any discussion of the Trinity. It helps that he wrote a book called On the Trinity. For good or bad, the consensus understands Augustine as a pivotal figure in early Trinitarianism, especially in a post-Nicene context.
The Donatist controversy is not discussed at quite the same level as Augustine and the Trinity, but is a common area of Augustine studies. Geoffrey G. Willis wrote on the issue, and the matter is addressed in any of the standard biographies. What we do not see often is a study that combines the two.
Adam Ployd’s Augustine, Trinity, and the Church (Oxford, 2015; source: publisher) falls in line with works on the relationship between the Trinity and the church. Examples of such studies are Miroslav Volf, After Our Likeness: The Church as the Image of the Trinity and Jürgen Moltmann, The Trinity and the Kingdom. Ployd’s study is not a progression of Volf or Moltmann, for to do so would be anachronistic. Rather, Ployd takes a look at Augustine within his post-Nicene context.
Ployd argues that Augustine’s 406-407 anti-Donatist sermons project a Trinitarian ecclesiology. Specifically, Augustine’s Trinitarian theology is characterized by a pro-Nicene quality. Ployd states:
I am referring to a complex of principles and exegetical concerns that govern the grammar and logic of trinitarian (as well as Christological and pneumatological) discourse as it develops in the second half of the fourth century in both the East and West among those who defend both the consubstantiality and the irreducibility of Father, Son, and Spirit (Augustine, Trinity, and the Church, 7).
Augustine’s primary influences, in these regards, are Hilary of Poitiers and Ambrose of Milan.
At the center of Augustine’s anti-Donatist sermons is a “moral epistemology.” Ployd defines moral epistemology as “Augustine’s account of how we advance in knowledge of God through the reformation of our desire” (Augustine, Trinity, and the Church, 19). The relationship between knowledge and love directs Augustine’s ecclesiology “by making the church an object of knowledge and love, as well as the primary vehicle whereby our minds and desires are reformed” (Augustine, Trinity, and the Church, 19).
This partnership is seen in Augustine’s exposition of the “intellectual” nature of Philippians 2:6-7 and the “moral” character of Matthew 5:8. This moral epistemology reveals its “teleological identity” in the church, as the earthly institution that seeks after the heavenly city of Jerusalem (Augustine, Trinity, and the Church, 35). Ployd ends the chapter with a discussion of humility. The argument is that the Donatist’s lack of humility betrays a moral epistemology, humility demonstrates that the church is the “vehicle” of moral epistemology, and that humility is Christological.
Augustine’s anti-Donatist sermons are based on his understanding that “the revelation of the Father’s Word through Christ’s incarnation is accomplished in our union with that Word through his body, the church” (Augustine, Trinity, and the Church, 57). By rejecting the church, the Donatist was rejecting Christ. Augustine used prosopological exegesis to argue that the Donatists were not part of the unus homo found in the Psalms singing to God. Nor are they unified with the ascending unus Christus.
The theme of unity is addressed in two final issues. First, the Holy Spirit’s ministry of love is what unifies the church. It is by this love that we are united to God. We recognize the unity within the Trinity, which is the source of the unity of the church. Second, the unity of the church is solidified by the sacrament of baptism. Contrary to the Donatists, Augustine argued that it is Christ who baptizes with the Holy Spirit. The efficacy of baptism, and its resulting unity, is Christ’s imparting of the Holy Spirit and not the church or bishop.
Readers will find a wealth of theological insight in Augustine, Trinity, and the Church. Ployd is attentive to the historical context of the Donatist controversy, but the unpacking of Augustine’s Trinitarian theology within ecclesiology is the heart of the work.
In addition to the Ployd’s strong argument for the relationship between the Trinity and church, Augustine, Trinity, and the Church contributes to the New Canon interpretation of Augustine. Rather than focusing on Augustine’s On the Trinity, especially trin. 8-15, New Canon scholarship (i.e. Lewis Ayres, Augustine and the Trinity) seeks to understand Augustine’s Trinitarian thought from his whole corpus. This results in a balanced depiction of the Trinity in the divine essence and the three persons. A study of the 406-407 anti-Donatist sermons highlights the exegetical development of Augustine’s theology and corrects the overstated role of Neoplatonism.