The Latin treatise Adversus Manichaeos has been preserved in manuscript anthologies containing polemical works of Augustine of Hippo and Quodvultdeus of Carthage. One family of those manuscripts contains the notation of authorship “whether it is of Augustine or of Evodius, is not known.” Jacques Sirmond advocated for the latter's authorship in 1648, and that view has prevailed in subsequent scholarship and is affirmed after further examination by Vanspauwen, still largely on circumstantial evidence, since Evodius otherwise has nothing more than a few letters to his name. Never before translated, the work has been mostly cited in studies of Manichaeism, typically under the name De fide contra manichaeos, the designation reflected in this volume's main title but demonstrated by Vanspeuwen to be the result of a copying accident: the closing formula of the previous treatise in the anthology (Augustine's De fide et symbolo) runs onto the following page in one of the manuscripts, where it was mistakenly read by a subsequent copyist together with the opening formula of this treatise (57–59). Vanspeuwen's methodical and comprehensive presentation of Adversus Manichaeos puts the work on a much better footing than it has ever had before as a source for the study of early fifth-century North African Christianity and Manichaeism.

Vanspeuwen's new edition surpasses all predecessors in its comprehensive basis in the thirty surviving manuscripts, plus records of lost manuscripts in earlier editions, whose interrelationship have been worked out in detail (45–69). An appendix provides descriptions of every manuscript (421–440). The edition is fully annotated, allowing readers access to all variants, and most significant editorial decisions are reviewed in further notes following the edition (407–417). The author generally resolves textual difficulties convincingly, resorting to conjectural emendation rarely. A few editorial decisions might be questioned, however: 16,13–14 princeps . . . soluuntur should be principes . . . soluuntur as context requires and attested in multiple manuscripts across the three principal branches of transmission; 44,15 ipsa yields a perhaps too clever expression compared to the more logical and equally attested ipsam; the choice of two different verbs turbo in 48,14–15 and turpo in 49,4–5 defies the latter passage's explicit remark “as was said before,” and turbo is to be preferred in both places. These examples all stem from the author's occasional overreliance on the lectio difficilior at the expense of other considerations of scribal inattentiveness or slips of the pen. The translation is generally clear and elegant, with only a few infelicitous clauses (e.g., 20,3 “then he is rather be found evil who . . .”).

Vanspeuwen's edition and translation is preceded by detailed, clearly written studies of the manuscript tradition, evidence regarding authorship, what else is known about Evodius, the structure and rhetorical techniques of Adversus Manichaeos, the sources on which it draws, the theology of the author, and the work's value as a source on Manichaeism. The work shows familiarity with, but not exclusive dependence on, Augustine's anti-Manichaean treatises (172–189). Its author also had independent access to both Manichaean and anti-Manichaean sources (189–197). This gives the work utmost importance as another representative of early fifth-century North African Catholic Christianity alongside Augustine, who may be compared to the latter in his understanding of the issues dividing his church from the Manichaeans and precisely what form of faith he saw himself defending. Scholars working in Augustinian studies now have a new avenue through which to assess just how far Augustine's theological innovations had been received by his contemporary associates.

One may well ask why one of those figures felt the need to compose a treatise against Manichaeism, since the ground had been so thoroughly covered already by Augustine. Vanspeuwen points out the systematic character of the work, covering the nature of God (sections 1–3), origin and character of evil as a substance or as a product of free will (4–10), the Manichaean myth (11–20), Christology (21–36), harmony of OT and NT (37–39), and resurrection and eschatology (40–49). None of Augustine's anti-Manichaean works have such a sweeping agenda, except his entry on Manichaeism in haer, which Vanspeuwen suggests may have been written after Evodius’ treatise since the latter shows no knowledge of that particular Augustinian work. Decret previously noted the prominence of Christological issues in comparison to Evodius’ related inquiries to Augustine in Epistle 161, suggesting that the letter signaled a key motivation behind the work. Augustine's own Christology remained underdeveloped through most of the period of his anti-Manichaean production, and Evodius may have sought to address that deficit. As with Augustine's own anti-Manichaean works, mostly completed by 405 CE, Adversus Manichaeos employs free will arguments against dualism and does not contain the developed ideas on original sin and grace of Augustine's later period. Those later ideas significantly erode the contrast between Catholic and Manichaean Christianity on human agency, as “Pelagian” opponents pointed out.

Since Adversus Manichaeos has found its predominant modern use within Manichaean studies, Vanspeuwen's chapter on the work as a source on Manichaeism (225–292) holds particular importance. He effectively engages with all relevant scholarship and provides original, close textual analyses of the work's valuable quotations from known Manichaean texts, such as the Fundamental Epistle and the Thesaurus independent of those made by Augustine. In a very impressive appendix, the author compares passages of the Adversus Manichaeos to “parallel and source passages” from other anti-Manichaean works by Augustine and others (441–491). The treatise itself, while showing obvious dependence on Augustine, also contains unique points of debate between the author and real or imagined Manichaeans, fleshing out certain Manichaean positions that, in careful comparison to primary Manichaean sources, might further illuminate this extinct variety of the Christian faith.