It will serve best this review if I begin by quoting what the author envisions the achievement of the book is as recapitulated in the opening lines of the conclusion: “this study has been an extended exercise in the art of reading Augustine's early Christian writings carefully, contextually, and with concern, above all, for his theology of the Holy Spirit. It has been, in other words, an effort to investigate the Spirit in Augustine's early theology within the spirit of Augustine's early theology” (201). This self-evaluation displays the importance of the subject at hand, the chosen methodology, and the style of argumentation. It also demonstrates the high and the low points of the execution. The book presents Gerber's (perhaps) revised doctoral thesis on Augustine's pneumatology and carries throughout the vestiges of its original inception more than anything else. While it is certainly a mark of distinction to publish one's doctoral thesis, the merits of which are easily spotted on the printed page, overall the study shows more potential than realization and it would have benefited from further “aging” down the road.

The rapidly increasing interest, in the last decade or so, in rethinking the relation between Hellenic philosophy—that is pagan Neoplatonism—and Christian philosophy (the avoidance of the term “theology” is intended here) makes the topic of this study propitiously timely, if not absolutely necessary. Inspired by and indebted to this new direction of research, Gerber rightly finds the scholarly opinion(s) on Augustine's understanding of pneumatology in his early writings and more particularly the strength of the Neoplatonic influence on it in need of serious re-examination. The author insists on using a balanced approach which takes into account the historical and conceptual specifics of Augustine's explicit pro-Nicene position which defends “the Spirit's coequality with the Father and his only (eternally) begotten son against the Pneumatomachians and other emergent groups with subordinationist theologies of the Holy Spirit” (1). Gerber's analysis systematically reveals that, pacé Augustine acknowledging his use of either Platonis or Plotinus paucisimi [sic] libri in De beata vita I.4 (14n28), there is no concrete textual evidence of how extensively he perused, if at all, these books. Moreover, any such use is trumped by the ample evidence that, in these early formative years, Augustine was most likely introduced to Neoplatonism through the Christian Neoplatonic theologians in Milan and Rome, respectively Simplicianus, Ambrose (22–24) and Marius Victorinus (47–48) rather than through direct contact with Neoplatonic texts.

The time frame under investigation is the period of five years between 386 and 391 when Augustine spent some time in Cassiciacum near Milan, Rome, and his home Thagaste. The narrative is divided in four chapters that diachronically follow the above-mentioned whereabouts in Augustine's life. Gerber wisely warns us that the neat overlap between the three stages of Augustine's writings and the equinumerous places of residence during this time is “largely accidental” (6). Chapter 1 focuses on the Cassiciacum dialogues (Contra Academicos, De beata vita, De ordine, Soliloquies) to show the deeply pro-Nicene roots of Augustine's early pneumatology while it still takes into account the direct and indirect influence of Neoplatonic philosophy, especially of the underlying principles of the One as the ultimate source of existence in the universe and Intellect as the intelligible principle of reality that immediately proceeds from the One (9). Gerber cautiously treads the waters between Neoplatonic philosophy, namely the tenets found in Plotinus' Enneads, and the Biblical scriptures. He finds Augustine's “confidence in philosophy” “somewhat naïve” (55) which allows him firmly to adhere to the greater influence of the philosophical elements espoused in the theological texts at Augustine's disposal. Chapter 2 continues Gerber's focus on the Cassiciacum dialogues but with particular attention to the Christian and Neoplatonic nature of Soul as presented in these writings and the specific views of Olivier du Roy in L'Intelligence de la foi en la Trinité selon Saint Augustin (Paris: Etudes Augustiniennes, 1966) and R. J. O'Connell in St. Augustine's Early Theory of Man (386–391) (Cambridge, Mass.: Belknap Press of Harvard University Press, 1968). The chapter exhaustively documents the various conceptual unfoldings of Augustine's commitment to working out what exactly the role and the place of the Holy Spirit are in the ontological relations within the Trinity. Relying heavily on the close reading of the text, Gerber is able to draw the major distinctions between Plotinus's view of Soul as the third underlying principle of reality and the Christian roots of Augustine's work in progress on his view of the Holy Spirit. Chapter 3 takes the journey of Augustine's early pneumatology to his Roman writings (De moribus ecclesiae catholicae, De moribus Manichaeorum, De quantitate animae, De libero arbitrio). This is the most original, and difficult, part of Gerber's analysis, aimed at teasing out Augustine's original contribution to the understanding of the Spirit based on and yet different from Plotinus's understanding of procession and reversion. Chapter 4 consolidates these findings in the Thagastan writings (De diversis quaestionibus, De Genesi adversus Manichaeos, De vera religione, De musica, De magistro) by showing the fruits of Augustine's intensive conceptual labor up to this point in forming his firm position that the Holy Spirit is the principle which orders the universe according to its divine model. The conclusion is followed by a brief appendix on The Spirit of the God and the Soul of the World: On the Compatibility of their Operations (De vera religione 12.24-5).

The above exposition, I hope, shows the ambition and the potential of this study. Indeed it has much to offer. Its most substantial drawbacks are the superficial and limited engagement with Neoplatonic philosophy the most symptomatic of which is the neglect of Porphyry's work on these issues, especially in light of Augustine's own reference to a number of Porphyry's treatises in De civitate dei (see: G. Catapano, “Augustine” in The Cambridge History of Philosophy in Late Antiquity, ed. L.P. Gerson, [New York: Cambridge University Press, 2010], 553); the uninformed use of Neoplatonic terminology and various names (“Mind” for “Intellect” [5], Pythagoreus for Pythagoras [51], the reference to Plotinus's three underlying principles of existence as “a cascading deity” [58], among others). The alarming kind of mistakes in the Latin as the one quoted in the second paragraph above (14n28) exceeds what could be considered normal and are distracting. The style of expression, as shown in the opening quote of this review, is at times unnecessarily burdensome, with misgauged touch of artistry. All in all, the book contains more kernels than fruits of ideas and indeed is what it says it is (201, quoted above): an exercise.