This long book, at over 500 pages, is nonetheless tremendously readable and coherently structured into three major sections: “Riddles: Enigma as Play,” “Rhetoric: Enigma as Persuasion,” and “Theology: Enigma as Participation,” all exploring how the enigmatic, both in the form of literary riddles and in formal theology, is central to the experience of medieval Christian literature. So much more than a book about the various obtuse riddles in Piers Plowman, Gruenler’s book explores first the very nature of riddles as a source of “verbal creativity,” then how enigma as “figurative language” serves as “a kind of allegory distinguished by its obscurity,” and further how the “Bible’s own poetics” provokes a “dynamic understanding of the divine use of signs that both hide and reveal.” “At the juncture of these three realms of thought and language,” Gruenler continues, “theologians and poets reconceive the value of difficult reading in education and spiritual formation” (4).

Clearly this book was written by a deeply spiritual author, studying deeply spiritual texts in the Christian tradition, but it attends at times as well to “cultural universality” (7) and thus an anthropological approach to enigma, most prominently in chapter 2. Yet mostly the book meditates upon Latin religious writing and vernacular Christian poetry that confront the famous passage in 1 Corinthians 13 where Paul says, “We see now through a glass in a dark manner; but then face to face. Now I know in part; but then I shall know even as I am known,” verses, we learn, of incalculable influence in the Christian theological and literary traditions. “Interpreting the riddles of scripture gives meaning to the things of the sensible world as well,” writes Gruenler, for all the world in some way participates in “the long game,” that is, the eternal struggle to perceive and participate in the divine (10). In fact participation is the most important word in the book, for all the writers discussed here seek to join the faithful to the truths not clearly seen in the visible world—nor clearly expressed in the enigmas of poetic creation—but promised to be revealed finally in salvation. The book should be in libraries and on reserve for classes on Piers, but also on medieval spiritual literature more broadly, because its study of Augustine (plus Pseudo-Dionysius, Aquinas, Bonaventure, William of St. Thierry, and others) illuminates the expansive Latin tradition of commentary and contemplation upon the role of the enigmatic as a means of provoking human “participation” in the divine. Gruenler engages not only with Piers Plowman (the great storehouse of the enigmatic), but also with Chaucer, Dante, and Julian of Norwich, making this book of keen interest to anyone studying Middle English and European vernacular texts.

The writing is uncommonly calm, welcoming, and accessible, and the chapters unfold with studied yet guileless control. Chapter 1 focuses on “the old major texts in the Latin medieval tradition that articulate the value of enigmatic language” (28). Chapter 2 “gathers for the first time the scattered and heterogeneous evidence of Middle English riddles … and sorts it in relation to classical and Christian, Anglo-Saxon legacies of riddling” (28). Chapter 3 focuses on language in the banquet of Conscience scene in Piers, revealing “the theological and anti-institutional potential of play” in this drama of academic confrontation (28). Chapter 4 explores enigma as it was studied in medieval schools, while chapter 5 confronts the most enigmatic scene in Piers, the tearing of the pardon in B. Chapter 6 brings in Julian of Norwich, studying her important “parable of the Lord and the servant” (29). The final chapter “braids together the concepts of play, persuasion, and participation through the convention of riddles as an ending move” (29), comparing the elusive ending of Piers Plowman to that of other texts, such as Dante’s Commedia and the Romance of the Rose.

The book’s index is a well-engineered tool with detailed listings for such helpful headings as “Piers Plowman, characters and personifications,” “knowledge,” “participation,” “riddles and riddling,” “reading,” and many others. A fifty-page bibliography will be of great use, and the wise placement of 120 pages of notes at the back of the book allows for undistracted reading, highlighting the caring voice of a gifted teacher working in a natural, pastoral mode, at once profoundly genuine and generous.