Chapter 7 offers a culminating test for competing rationalities, given how thoroughly Julian’s and Cyril’s texts are focused on re-narrating episodes from their rival. It returns to three specific arguments to consider if MacIntyre’s further claim about incommensurable forms of reasoning obtains in Julian’s and Cyril’s engagement. Three case studies in rationality, focusing on words (genētos, pronoia, and pistis) used by Julian and Cyril at crucial points in their reasoning, provide occasion to query whether non-intersecting forms of reasoning are at play in these specific arguments. Intellectual impasses on particular topics can suggest, after all, that the traditions inhabited by individuals engaged in intellectual conflict are more broadly incommensurable.

Chapter 4 turns to Cyril’s response to Julian in Against Julian. It provides an extensive overview of the narrative structure behind Cyril’s arguments against Julian. After surveying the setting, characters, and plot that frame Cyril’s arguments, it examines two leitmotifs that are crucial to Cyril’s reasoning and then provides examples of “narrative moments” in Against Julian. In broad outlines, the chapter reviews the well-known contours of emerging orthodoxy in the early church. But as a focused analysis of Against Julian, it also provides broad coverage of a text that has been understudied to date and further illustrates how a “narrative structure” lies implicit in something like a polemical treatise. It shows, finally, that despite Cyril’s exemplary status with most Christian communities he still had unique and idiosyncratic perspectives, some of which play noteworthy roles in Against Julian.

This chapter begins the more speculative part of the book. It responds to two objections to the instrument doctrine. The first objection is that a person cannot use a nature distinct from him as his instrument, even a divine person, because the created nature would lack some necessary feature for it to exist concretely. With the help of John Duns Scotus’s theology of the hypostatic union, the chapter argues that Christ’s humanity can be an instrument of his person because created personality is an extrinsic feature to the constitution of human nature. If Scotus is right, then a divine person can use a really distinct human nature as his instrument without any loss to the fullness of his humanity. The second objection argued that the instrument doctrine amounts to nothing other than the attribution of secondary causality to Christ’s humanity. The chapter argues that the hypostatic union means that the actions of Christ in the flesh are irreducibly distinct from ours, belonging as they do to a divine person.

This chapter argues that Augustine preaches on the Trinity both in sermons devoted particularly to particular trinitarian questions, and throughout his homiletic corpus insofar as Augustine’s understanding of creation and salvation as a whole is founded on his understanding of the inseparability and co-equality of Father, Son and Spirit. Through these different types of sermons Augustine also consistently emphasizes both the importance of accepting in faith knowledge handed on to us, but which we cannot yet comprehend, and the importance of struggling to think of God in terms beyond the material and the temporal. It is also noticeable that Augustine makes little use of the language of persona and natura in his preaching, preferring to define his belief through a series of Nicene principles (such as the inseparability of the divine three in their acts), and through presenting Nicene exegeses of key verses as hermeneutical keys.

Augustine’s liturgical preaching is integral to his conception of the liturgical celebration as rendering present the unrepeatable saving acts of Christ. During the liturgical season from Lent to Easter, the north African bishop is consistently preoccupied with the present effectiveness of the mysteries of Christ’s death and Resurrection. During Lent, he invites his congregation to fashion a cross for themselves – through prayer, fasting, and alms – for the sake of communion in Christ’s crucifixion. On Good Friday, he invites his listeners to contemplate the suffering of the impassible God and to safeguard the integrity of the Church that is the fruit of his suffering. In the Easter celebrations, he instructs his flock to be strengthened in their Easter faith through participation in the Eucharist and through performance of works of mercy, and to hold fast to the objective content of their faith in the genuine corporeality of the Risen Lord. He guides them into an experience of Easter joy as a proleptic participation in the eternal joy of the Church’s communion in the body of the Risen Lord, which can only be attained through a sharing in his Crucifixion.

Bishop Augustine probably preached countless sermons on the New Testament, but less than three hundred remain extant. Most of his New Testament preaching is found in his 124 Homilies on the Gospel of John, his ten Homilies on the First Epistle of John, and his Sermons 51–183. The richness of these sermons is astounding. This chapter samples them, offering a starting point for further analysis. The first section focuses on the pastoral goals that stand behind Augustine’s preaching on the Gospel of Matthew. Second, the chapter turns to his anti-Donatist Homilies on the First Epistle of John, where he intersperses his commentary on 1 John with extensive citations of the Psalms and the Gospels. Third, with respect to his Homilies on the Gospel of John, the chapter shows that Augustine preaches on John with a strong eye to his central theological interests, including his well-known arguments regarding grace and predestination.

This chapter offers a critical appraisal of two dominant approaches to pluralism, conflict, and difference in contemporary political theology, both of which draw on the thought of Augustine. Postliberal Augustinianism, represented by the “Radical Orthodoxy” of John Milbank, develops a highly sophisticated account of the metaphysics of human sociality, grounded in a creative reading of Trinitarian theology which construes political community in terms of harmonious difference. Augustinian civic liberalism, represented by Charles Mathewes and Eric Gregory, draws on Augustine’s understanding of love and difference in order to propose an ethics and ascetics of liberal citizenship. Both, however, thematize political community and difference in essentially oppositional terms, privileging one or the other, and reading conflict in decidedly negative terms. The limits of these political theological strategies reveal a need to reconceptualize the nature of political community and the place of conflict therein.

The book comes in three parts. In Part I I set out the full extent of incarnational theology, in terms of abundance, relationship, transfiguration and blessing. I explain seven ways in which my account seeks to correct the ways conventional theology departs from a truly theocentric approach. This is a story about God (rather than us). It is a story about Jesus (rather than overcoming sin and death). It is a story of abundance (not deficit). It is a story of God’s sovereignty (not rules God must obey). It is a story about Jesus from the beginning (not just from the annunciation). It is a story of flourishing (not inhibition). It is a story in which God’s means and ends are identical.

Here I begin my constructive account of a Christocentric incarnational theology. The Trinity has a chapter on its own: only thus may I express my insistence that this is fundamentally a story about God, and that creation, human beings and their divine destiny must stand in the light of that priority. My concern is to withstand the anthropocentrism of so much theology, which centres human existence and need, rather than God’s character and purpose, as the story’s focal point. The eight dimensions of being with provide a helpful structure through which to articulate the claims made about the Trinity.

This chapter considers the ways in which the classical credal and conciliar formulae provide a framework for understanding who Jesus Christ is and how God saves through the Incarnate Word. These credal and conciliar formulae provide the foundation for theologies across the spectrum of Christian traditions. The chapter is broadly divided into two sections, one focusing on the fourth century Trinitarian controversies, the second focusing on the christological controversies of the fifth to the seventh centuries. For classical Christian theology, only when Jesus is known as the Word made flesh, and as one coequal to Father and Spirit in the divine life, can the work of redemption be understood.

Many polytheists would be perfectly happy to borrow yet another god from Christianity, but only so long as they could demote Him from the One God to a god among gods: “What have you got against the others?” The naïve assumption is that God belongs to the genus “gods” – that He is just one more of those things (but in Christian belief, the real one). St. Thomas has argued that He is not that sort of thing at all – in fact, He is not a “sort of thing.” Moreover He is of such a nature that there could not be more than of Him. But how do we know He is one? Even someone who considers the many gods of polytheism false, foolish, base, demonic, or all too human may ask, “But is monotheism true?”