This book studies one, highly important aspect of Augustine's understanding of language – as the vocal medium in which God discloses Himself to believers and discloses believers to themselves – and three works in which the theologian develops his ideas on this theme: the De trinitate, the De doctrina christiana, and the Confessiones. Familiar texts support a novel conclusion, that for Augustine ‘human utterance’ is ‘what keeps the mind going in its searching after God's reality’ (p. 13). The starting-point is De trinitate, Book 15, and Augustine's reading there of 1 Corinthians 13:12. The image of God within the human person is the enigmatic mirror in which alone we can see God darkly. In thought (an understanding present within the heart prior to any kind of inner speech, and not as a word in any given tongue) Augustine sees an image of the Divine Word in relationship to the Father whose Word and Wisdom He is. The opening chapter then turns to the analogy Augustine sets up between our utterance of a word in giving voice to thought and the incarnation of the Divine Word. Morgan holds (in a way we may question) that this unqualified analogy ‘opens up human discourse and language christologically, enabling them to stand as salvific in a way analogous (sicut) to the historical event of the incarnation of the Word’ (p. 44).

Chapters Two to Four switch away to the De doctrina. We follow Augustine's train of thought in Book I from the defence of theological writing on biblical exegesis as integral to the proper understanding of it, to the ineffability of the God of whom silence speaks louder than words, yet who has created people with the desire to praise Him in so far as we can and whose Word (unlike the Plotinian deity) became flesh for us and stands revealed in the Bible. We return to the fundamental analogy of the spoken word which now points to the significance of the incarnation as an act of communication by which God without change in Himself may enter into the heart and mind, just as thought is given voice so that it may enter unchanged into the hearer's consciousness. Again, Morgan's summary turns the analogy round: ‘Words, in their outwardly verbalized form, are mediators between God's transcendence and humanity's material embodiment’ (p. 53).

From Augustine's reading of inspired human lives and deeds as God's speech act, Morgan next explicates Books 2 and 3 of the De doctrina to show how Augustine understands Scripture as reflecting our fallen humanity back at us: ‘Reading for Augustine, or rather the task of learning not to misread, is itself part of providence's plan for human growth towards God’ (p. 63). We are taken through Augustine's seven-stage ascent towards God and the place of devout meditation upon Scripture in that progression. Within this process, Tobit's command – do not do to another what you would not have done to yourself – acts as a break on wilful misreading while it also requires the reader to apply the abstract command to practical circumstances. In the same way that Nathan's figurative address to David permits the King to repent of his murderous adultery, Scripture engages the reader in an exercise which brings home the meaning of his or her acts. Finally, in this central section of the book, Morgan sets out Augustine's understanding in De doctrina, Book 4, of wisdom's relationship to eloquence in Scripture, which the preacher is to explicate when himself inspired to wisdom by an eloquence that points beyond itself and transcends the classical canons. This eloquence is both divine and flows from the human authors of Scripture whose voices and virtues address us publicly, put us on the spot. This is perhaps the most attractive element of Morgan's presentation, directing us to a view of Biblical authority which sees us as both attentive and answerable to a historical community of holy interlocutors rather than simply to the book per se.

Chapter Five takes this rich account of how speech draws us towards God and applies it to the Confessions as ‘an act of exemplary speech’ (p. 101). Morgan deftly observes that Augustine's encounter with Neoplatonism in Book 7 is the point at which Augustine first considers himself to be addressed by God and drawn into a sustaining conversation with God. Morgan also suggests persuasively that Ambrose, the preacher par excellence, is described in the same terms as the biblical text he explicates and thus ‘represents an embodied paradigm of the characteristics of scripture’ (p. 109). Augustine's conversion – his acceptance of baptism and the chastity he understands as consequent upon it – is then described as the outcome of a crisis generated and negotiated by the harmonious interaction of Scripture and the social context of a Church invigorated by both the eloquence of its local bishop and the tale of a distant monk. Out of this crisis, in Book 9, emerges an Augustine seen to possess a new garrulity in addressing the God who first spoke to him (p. 121), when Augustine for the first and only time in the text directly addresses Jesus Christ.

The final part of this study, a hefty fifty pages, returns to the De trinitate, and Augustine's concern for the continuity between what Christ teaches and who He is as the Father's Word (De trinitate 1.12.27). Our engagement with this teaching is our entry into an understanding of the Trinity. The chapter takes a commonly accepted view of Augustine's account of what ‘person’ means in speaking of three ‘persons’ in the Trinity: Augustine does not mean what we do in using this term, and the term is nothing more than a convenience in the business of asserting that there are three who are the one God. Except, however, that Morgan also thinks that Augustine uses this empty term ‘as the reference point for our understanding the nature of identity and differentiation within the Trinity’ (p. 146). Much is meant to turn on this, though its sense is not entirely clear, and the issue is further problematized by the later claim that Augustine ‘meditated on the meaning of the word persona as exemplifying the Trinity’ (p. 157). At very least, however, the word keeps the conversation going and so makes possible the communication of the mystery. From here, the chapter moves to how love for God is deepened through our attraction towards what is good and just in holiness of life. St Paul, whom we know and love from his letters, attracts us towards the good which transcends himself. Knowledge and love of God cannot be had in isolation from exposure to, or participation in, such virtuous social contexts. Morgan then reflects briefly on Augustine's account of love as itself Trinitarian in form (with lover, beloved, and the love shared between them). The human being can image God ever more strongly in the practised recollection, knowledge, and love of God, but must ever acknowledge the dissimilarity between God's simplicity and our complexity, between image and reality, an admission that further prompts contemplative awe before the God who transcends both words and wordless thought.

There is much here to remind or teach us of the value of Augustine's theology, and of how far that theology builds upon a rich vision of the human person who is saved through listening and responding to the Divine Word which addresses him or her. However, this is also very much a book which betrays its origins as a doctoral thesis. Numerous and extensive summaries hope to persuade the reader that the different close readings, some of which are subtle and many of which are obscure, add up to a single and coherent argument. Despite, and to some extent because of this, the book remains hard going, and could not be recommended in toto to students of Augustine, let alone to the general reader. This reader at any rate fears that at several places along the way he may not have seen the wood for the trees.