Those who live during epochs that are later interpreted by historians as “transitional” usually share a common fate, regardless of their uniqueness: they tend to be viewed as representative of whatever preceded them or as harbingers of things to come, or as an evolutionary link of sorts between the old and the new. The religious movement commonly known as the Devotio Moderna has long been a prime example of this tendency. Dismissed by Johann Huizinga in his Autumn of the Middle Ages (1919) as dour world-denying representatives of a waning culture, but praised by Albert Hyma as agents of change and the very embodiment of the essence of a new era in The Christian Renaissance (1924), the Modern-Day Devout became a Rorschach test of sorts for scholars throughout the twentieth century, in which all descriptions of the contours of the subject were couched in terms of polarities and mixtures: old versus new.

Steering clear of any such teleological reductionism, John Van Engen has written a history of this complex movement that places it squarely in the context of its own time, roughly from the 1370s to the 1530s, a span which he prefers to call “the long fifteenth century” (307). He has also chosen to analyze the Modern Devotion in its social and geographic context, as an urban phenomenon centered in the Low Countries, and as a community whose ethos was best summarized in Thomas von Kempen's Imitation of Christ rather than as a movement with a trajectory that led ineluctably to the establishment of the Collège de Montaigu in Paris and to the ascendancy of its three most famous and most dissimilar pupils: the reformers Erasmus of Rotterdam, John Calvin, and Ignatius Loyola. Given that Van Engen is a medievalist, and that tracing the transition to modernity is very much in vogue nowadays (with an emphasis on secularism as the essence of modernity), this is one book that swims against strong currents. And it does so successfully, with great skill.

Employing an impressive array of archival documents, chronicles, and contemporary texts of all sorts, from letters to devotional treatises, Van Engen paints a highly nuanced portrait of the Brothers and Sisters of the Common Life—as the adepts of the Modern Devotion were known—a portrait that is at once as detailed a rendition of certain individuals as of the whole community to which they belonged. The most significant contribution of this study lies not so much in the portraiture, however, as in the change in background: no longer is this community posed against a “medieval” or “modern” backdrop, or some combination of those two. The backdrop in Van Engen's admirable survey is the immensely complex environment that these men and women inhabited: a world in which church and state were inseparably intertwined, and in which individuals and corporations were expected to fulfill well-defined roles. Consequently, much of the narrative here—the bulk of this book—centers on how a movement that challenged traditional roles managed not only to survive, but to thrive.

The New Devotion and the Modern-Day Devout, as Van Engen prefers to call them, were hard to classify: neither fully lay nor fully clerical. Taking no vows, they lived celibate quasi-monastic lives in communal households, eschewing private property, producing textiles and books, and establishing and running schools for the children of the rising burger class. Living in a way that placed them outside established hierarchical structures of authority, aiming at mystical intimacy with the divine, and challenging local economies in various ways, the Modern-Day Devout attracted many different kinds of opposition, yet managed to create their own special niche successfully, both civil and ecclesiastic. Sisters and Brothers of the Common Life provides us with a very detailed account of how it was that such a determined urban minority carved out a place for themselves in the material and spiritual landscape of their day and time, against great odds, and how it was that a very specific kind of piety, focused on enabling individuals to find the inner connection between themselves and God, gave rise to communal households that challenged the status quo but at the same time provided a series of valuable services to their cities and towns in return.

This is a painstakingly detailed narrative into which the analysis is seamlessly woven. When all is said and done, it is a major contribution on several fronts. First and foremost, as a definitive history of the New Devotion, it not only takes its place at the top of any reading list on the subject, but also announces a shift in terminology, as well as a shift in our understanding of the place of this movement in its day and time. This is also a very complete survey of urban life and institutional structures in the Low Countries, lay and clerical, during the “long” fifteenth century. To a lesser extent, this magisterial survey also plumbs the spiritual life of these men and women, providing some furtive glimpses of the ways in which the goals of contemplative monastics made their way out of the cloister and out into the streets.

Written with advanced specialists in mind rather than neophytes, Sisters and Brothers of the Common Life pays meticulous attention to detail. This may make it less attractive to non-specialists, or even some impatient specialists, but in the long run no one who subscribes to this journal should pass up this book. If nothing else—even for those who do not focus on this time period—it serves as a primer in the interweaving of social, political, economic, cultural, and intellectual history. So, while it may be as difficult to pigeonhole as the Modern-Day Devout themselves, Van Engen's latest offering, much like all of his work, is a timely exemplar of religious history at its very best.