Few in antiquity or Byzantium would have questioned that angels have power. Portraying that power, however, posed a special challenge for Byzantines. In a world where both language and image were bound up in materiality, angels captured all that could and could not be said of God. If Christ was understood to be the Word of God made flesh, then there might be license for making pictures of Christ, at least in his earthly guise. But what exactly were angels? More than human, yet known for fleeting visitations in human form; like God, but created by God. Both “subtle” in body and slippery in categorization, angels perplexed Byzantine artists and writers. Glenn Peers calls our attention to this tension between the materiality that representation demands and the incorporeality that defines angels in this nuanced monograph on attitudes toward angels in Byzantine devotion, art, and theology. Like the angels, Peers is a category-crosser himself: an art historian by training, he combines subtle understandings of Byzantine theology and polemics with judicious use of critical theory to illumine the problem of angels as a crisis of illusion and representation.

Central to Peers’s study is the iconoclastic controversy, marked by intense polemic between those who defended the use of images in worship and those who sought their prohibition. If the controversy itself is still “in the grip of a crisis of over-explanation,” as Peter Brown famously declared almost thirty years ago (“A Dark Age Crisis: Aspects of the Iconoclastic Controversy,” English Historical Review 88 (1973): 1–34), then the study of angels opens up that tenacious grasp. Taking his cue from Averil Cameron, Peers focuses on the sixth and seventh centuries, a time when the emerging debate over sacred images spawned intense scrutiny of the ways humans can know God and the limits of those abilities. Knowing angels was equally problematic. Conflicting attitudes toward the veneration and depiction of angels reveal the deep fissures in the debate about images. Peers provides the novice with a helpful entrée into this debate and the expert with a fascinating case study.

The first chapter surveys the biblical evidence for angelic beings and how ancient biblical interpreters grappled with those transcendent figures that can assume human form, as in Abraham’s visitation by God’s messengers (Genesis 18) or the seraphim and cherubim from Isaiah’s vision of the divine throne (Isaiah 6). These biblical antecedents justified a variety of iconographic conventions: from flames and wings to anthropomorphic guises. Finding strategies for depicting that which is invisible, immaterial, and transcendent remained a problem in subsequent centuries, as Peers demonstrates in his careful analysis of ekphraseis, or verbal descriptions of art, and epigrams.

He devotes the second and third chapters to critics and defenders of images, respectively. Central to his analysis of the critics is the fourth-century bishop, Epiphanius of Salamis, who cautioned that angels’ divine nature and activity rendered all representation misleading and idolatrous. Such caveats, however, did not dissuade poets and theologians from defending and describing images of angels. The sixth-century Celestial Hierarchy, a seminal treatise on the nature and organization of angels, traditionally ascribed to Dionysius the Areopagite (fl. 500), charted the course for depicting angels’ illusory embodiment. For Pseudo-Dionysius, every image of an angel is a necessary dissimulation: humans need to know a suprasensory God through their senses and rely on angels, whose anthropomorphic simulations were temporary but effective to allow perception. The sixth-century epigrams of Agathias also carry forward this idea of dissimulation, as a poem that praises an image of the archangel Michael while apologizing for picturing what is known to be invisible. Peers develops a very interesting trajectory with this notion of dissimulation, showing how the eighth-century defender of images, John of Damascus, regarded all divine dissimulation as a gracious condescension to the limits of human perception, thereby justifying images of angels as well as Christ in worship. Peers also looks beyond texts to illustrate this dynamic of dissimulation-as-bridging: the sixth or seventh century Sinai icon of the virgin and child flanked by saints combines different stylistic conventions to differentiate angelic bodies from human ones, thereby reflecting the tensions between transcendence and embodiment. Inscriptions could also serve to destabilize angelic images, as in the ninth-century mosaics of angelic beings at the Church of the Dormition at Nicaea (modern Iznik). The fact that they are represented as identical but distinguished from each other by different labels signals that inscriptions point away from the image they “label.” Put simply, words safeguard the allusive and dissimulating functions of images.

In the fourth and fifth chapters, Peers turns his attention to how cultic writings, such as saints’ lives and miracle collections, came to terms with this tension between divinity and illusory materiality. To some, the most apt representation of an angel would be neither plastic nor verbal, but ethical, such that holy men (apparently, not women) could cultivate an image of the angelic life for others. Peers also takes a closer look at legends associated with the archangel Michael’s geological wonders. As an immaterial being, angels cannot leave material relics, such as a bone or garment. But they can leave an impression in matter, as the archangel Michael did when he rescued the town of Chonae in Asia Minor (modern Turkey) by leaving a cleft in the rock. (Here, Peers’s analysis invites further comparisons to other relic-less cults, as in contact relics associated with Christ, whose resurrection precluded the possibility of any bodily relics.) On another level, Peers claims, miracle stories are also a means of access, which make angels “apprehensible and proximate.” All representation, whether ethical, artistic, or poetic, then, is a means of approach.

Peers’s synthesis of textual and visual evidence, a hallmark of the book, reveals the “contingency of angelic nature” from several perspectives. He concludes that the most faithful image of an angel results from a process of dissimulation. Both poets and painters could express approaching the angel in order to reflect the angel’s ultimate absence from the world of embodied mortals. In short, angels are better known by their dissemblances than by any resemblance. To make this case, Peers marshals a rich array of textual evidence, both in the text and in footnotes. The cogent design of the book, with images well placed in the body of the text, is to be commended. In the final chapters, however, it would seem that the images cannot keep pace with the texts he examines. His analysis of angelic miracles is informed by a nuanced reading of saints’ lives. By contrast, the range of pictorial examples is limited primarily to images of angels. Just as stories about saints illumined stories about angels, what might a broader selection of images without angels reveal about representing immaterial beings?

Any desiderata, however, arise from the achievements that make this book shine. Peers offers a carefully integrated approach to devotional and polemical writing as they illumine angelic images. As he helps us see, iconoclasm was far more than a corpus of words about images. And images were far more than objects of contention; they elicited and engaged the very problems that prolonged the centuries-long controversy. With their power of resemblance through dissemblance, angels (or, more precisely, images of angels) problematize human attempts to know God.