From the events recorded in the Acts of the Apostles during the years following Christ's ascension through to the end of late antiquity, the apologetic efforts of early Christian authors exhibit some of the most sophisticated expositions of Christian faith and life. Recognition of the power of early Christian apologetic literature to aid in our understanding of the history, theology and experience of early Christian communities has left few stones unturned. Not to be deterred, D. H. Williams contends that among the many surveys, studies of individual authors and their apologetic writings, and investigations of early Christian identity formation and boundary construction, there has yet to be a critical overview of pre- and post-Constantinian Christian apologetics that explains the relevant texts, their theology and what they reveal about the surrounding culture. This lacuna describes precisely what Williams intends to contribute in Defending and defining the faith.

The book's eighteen chapters include an introduction (ch. i), four chapters of prolegomena to early Christian apologetics (chs ii–v), and thirteen chapters of thematised analysis of early Christian apologetic literature from the New Testament through the fifth-century apologetic labours of Theodoret of Cyrus (chs vi–xviii). Williams makes it clear in his introductory chapter that he takes a critical stance regarding the looseness with which some refer to ‘apologetics’ or ‘the apologists’ in referring to certain early Christian texts. Yet, he proposes that rather than there being a discrete literary genre of apology, early Christians authored apologetic writings that shared ‘a common content’ (p. 9), which held them together. Limiting the focus of his analysis to anti-pagan apologetic texts, which were almost always intended principally for the Christian community, Williams suggests that they consistently (1.) responded to provocation(s) by pagans that somehow endangered the life of the Church; (2.) aspired to present the Christian faith with greater sophistication in order to defend its tenets more credibly; and (3.) aided in the processes of identity formation and ecclesial expansion through the use of enduring exegetical and theological themes.

Williams continues to lay the groundwork for his analysis of early Christian apologetic literature in the following four chapters. Chapter ii provides a more formal assessment of the concept of apologia in pre-Christian antiquity and early Christianity, specifying (1.) why it is not a genre; (2.) how it differs from contiguous forms of discourse (e.g., invective, polemic, protreptic); (3.) that there was no conscious ‘Apologetic tradition’ in the second century; (4.) for whom and what occasions it was written; and (5.) what material means and social networks made its publication and dissemination possible. Williams exhibits in the third chapter the religious character of the Greco-Roman world in which Christianity arose. He walks the reader through Roman religio and pietas; Varro's famous conceptualisation of mythical, natural and civic theology; the perceptible forms of religious expression in everyday life; and the contrast between the divine unity affirmed by the philosophers and the common belief in an array of daimones among ordinary citizens. Williams takes a stand on the contested question of pagan monotheism by following Mark Edwards's distinction of Christian monotheism from the kind of divine unity affirmed among Neoplatonists, for example, and by suggesting that the closest pagans get to monotheism is actually a modalism for which there is a supreme God variously manifested in the ‘localized and multiple’ gods (p. 66). In considering the way apologetics contributed to ‘The construction of Christian self-definition’, the fourth chapter details the history and development of arguments for authority on the basis of antiquity, the Jewish claim that the Greeks borrowed from Moses and the frequent appropriation of such arguments in early Christian apologetic discourse. In addition to outlining borrowed strategies for accruing authority, Williams posits that apologies helped Christians to develop their own culture that depended upon and yet opposed both Judaism and Greco-Roman society. The apologia's function as a vehicle for the evolution of Christian theology and exegesis formed a central part of this process of forming Christian identity. Chapter v offers a clear answer to the questions of how much early Christians were persecuted and what was the legal status of Christianity before the Decian persecution (249–51 ce). Showing little patience for Candida Moss's argument that early Christians exaggerated the extent of their persecution, Williams details the extant pagan accusations made against Christians, analyses evidence for earlier forms of legal suppression and concludes that, on balance, the evidence suggests there were no earlier imperial policies against Christians, but that by consequence local persecution was likely not uncommon.

The remaining chapters of Williams's book offer critical analysis of the trajectory of early Christian anti-pagan apologetic literature, adjudicating which works are best understood as apologies; providing helpful historical, social and cultural context; showing attentiveness to manuscript difficulties; attending to theological complexities; and guiding readers through the existing bodies of secondary literature. Rather than retracing Williams's circuitous path through early Christian apologetic literature, allow me to mention a number of contentions made, implicitly or explicitly, concerning the nature and development of early Christian apologetic literature: (1.) there were many literary, philosophical and cultural norms and tropes that early Christian apologists borrowed from Jewish literature and the Greco-Roman world; (2.) around the middle of the fourth century (for example, Arnobius, Ambrose), Christian apologists began writing from a position of greater strength, adding to the principal focus on supporting fellow Christians the overt criticism of their pagan neighbors; (3.) although the decades following the reign of Constantine left Christians within the empire feeling more secure, they could not be certain about the stability or longevity of their station in the empire; (4.) the apologetic task always included, to some extent, the defence and definition of Christian faith and life; and (5.) although the early Christian apologia is best understood not as an ancient literary genre so much as a literary expression that contains a common occasion, purpose and content, it must be distinguished from proximate literary forms. Readers should take note that these summary observations provide a mere glimpse at what is a feast of careful descriptive analysis.

From start to finish, Defending and defining the faith displays Williams's erudition as a historian of early Christianity; his expansive knowledge of sources far and wide, primary and secondary; and his methodological determination to offer a critically informed discussion of the matters, formal and material, of early Christian anti-pagan apologetics. The book bears as much value for its sober discussions of issues pertinent to relations between pagans and Christians during late antiquity as it does for its learned analysis of apologetic literature itself.

To avoid offering prospective readers only effusive praise of the book's many merits, allow me to raise two residual questions and to make two minor comments. First, since historical narration is always an exercise in critical selectivity, might some organising divisions in the book's contents have helped to situate the book more as a historical construal of and less as a running commentary on this literature? As it stands, readers are faced with the challenge of constructing their own sense of what Williams takes to be the beginning, middle and end of this period of apologetic literature. Second, how does the conclusion that apologia is not a literary genre (or is a ‘subgenre’; p. 32) recast how it is related to known genres such as, for instance, dialogue, polemic and protreptic? To my surprise, Williams gives much attention to differentiating the apologetic from the forms of speech in which it was conveyed. My own sense is that working with a slightly more elastic notion of what comprises apologetic discourse would encourage a welcome shift of focus from the tasks of form criticism to analysis of the purpose, content and context that decide whether a text is in fact apologetic. Third, while I can appreciate the needs and the benefits of delimiting the scope of the project to anti-pagan apologetics in particular, the title of the book suggests that its purview is more all-encompassing. The actual interest of this book is in the relationship of Christianity to pagan culture, philosophy and religion. Those interested in intra-Christian apologetic efforts will need to look elsewhere. Finally, the presence of regular typographical infelicities throughout the book (for example, missing and misplaced words and punctuation, in one case the presence of ‘???’ in an incomplete sentence [p. 329]) stands in unfortunate contrast with the ostensibly meticulous and scrupulous care evident in Williams's scholarship itself.

All things considered, Defending and defining the faith will serve as a longstanding resource for experts in early Christianity, scholars interested in pagan-Christian relations during late antiquity, church historians curious about the significance of early Christian apologetics and, finally, those interested in the pairing of sensible historiography with careful attention to the lived faith of religious communities.