Traditional narratives of the Reformation have long held that Protestants rejected the sensory splendor of traditional Christianity and ushered in a modern, rational religion of the Word. Jacob M. Baum argues that this narrative is ultimately a mythic one. The sensory world of medieval Christianity, Baum reveals, was much more variegated than later accounts have suggested, and German reformers did not break with the past as radically as they claimed. Rather, Baum argues that the Reformation of the senses was not a historical reality so much as a narrative that was produced by Reformation-era thinkers and uncritically accepted and perpetuated ever since.

Baum's argument is grounded in thorough research using manuscripts in more than twenty German archives and a wealth of printed primary sources. The book is divided into two parts, the first focusing on fifteenth-century Christianity and the second on the Reformation in Germany up to circa 1600. Baum makes a compelling case for the importance of returning to the early Reformation and its late medieval roots, an important intervention in light of several decades of scholarship that has focused heavily on the later period of confessionalization.

By examining church inventories, Baum reveals the diversity of sensory experiences of worship that prevailed in fifteenth-century communities. While wealthy patrons in urban areas endowed churches with multiple altars and devotional objects, the local political economies of the average rural community provided most German churches with fewer resources to support sensuous worship. Consequently, the late medieval church was less uniformly sensuous than either Reformation-era critics or modern scholars have claimed. This did not mean, however, that the senses were unimportant to medieval Christian theologians. In subsequent chapters, Baum reveals how learned theologians saw sensory worship as a means of shaping Christian souls and extending church authority. Yet at the same time, sensuous worship proved extraordinarily difficult to control, and through a rich prosopographical study of fifteenth-century prayer books, Baum shows that vernacular theologians understood the spiritual role of the senses in ways that were related to the ideas of their learned counterparts but also fundamentally distinct from them. Consequently, sensuous worship became the subject of tension in the years before the Reformation, and by the turn of the sixteenth century, it was increasingly gendered female and associated with non-Christians.

Reformation-era critiques of spiritual sensuality, as a result, did not fully reflect the complexity of medieval sensory cultures, nor were they without precedent. Baum thus reframes the Reformation of the senses not as a radical break from the medieval past, but as a narrative through which evangelicals articulated their own identity. The second half of the book takes up these dynamics of continuity and change, with particular consideration of the emerging Lutheran tradition and a secondary focus on Reformed Christianity. Early evangelicals, Baum argues, stressed their departure from the hyper-sensuality of medieval Christianity. Yet Protestant authorities maintained much of the basic Aristotelian understanding of the function of the senses, and Lutheran worship was marked by as much continuity with medieval practice as it was by change.

Again, local circumstance often mattered more than evangelical ideals as most communities continued to work with the materials they had inherited and, as Baum reveals through an examination of Lutheran church orders, early evangelicals’ strident critiques gave way to a careful position of indifference toward sensuous worship. The narrative of sensory Reformation, as a result, was not consistently borne out in practice, nor did it result in markedly different views of the senses across Protestant confessional lines. As Baum suggests in the book's final chapter, Lutheran and Reformed theologians in the later sixteenth century understood the efficacy of the senses in worship in fundamentally similar ways, even if their practical implementation of sensuous worship differed.

In place of a single narrative of the decline of sensuous worship, Baum thus reveals a story of “ambivalence, paradox, and outright contradictions” (203). Although Baum seeks to paint a picture of complexity, his analysis at times obscures it. For example, Baum's thematic focus on the Eucharist sometimes skims the surface of Eucharistic theology and its implications for the sensory experience of ritual, and the book as a whole treats sensory worship as an intellectual problem more than an embodied experience. This is particularly apparent in the treatment of the medieval Eucharist, to which Baum refers to at several instances as a “ritual show” (45). For those who participated in that sacrament, the Mass was no mere performance, and those who critiqued it took aim at much more than the outward trappings of bells and vestments. Instead, the profound sensory experiences invoked in the Eucharist, no matter the opulence or austerity of its setting, were fundamentally bound up with the doctrines of Incarnation and transubstantiation and, in turn, with their implications for how the human body might mediate the divine—concepts that Baum references but does not fully explore.

Although The Reformation of the Senses does much to advance our understanding of the material conditions of sensory worship, it pays less attention to those deeper relationships among body, matter, and divinity, which might have revealed significant ruptures alongside the continuities that Baum emphasizes in order to dispel the mythic narrative of sensory Reformation. The book reveals much about how that narrative developed, but leaves open questions about why sixteenth-century Protestants found it to be so powerful and why sensory religion provided such an important locus for them to articulate their differences from medieval Christians and from one another. Although Baum convincingly argues that we must put aside simple narratives of progress and embrace complexity and contradiction, his ultimate conclusion is one of ambivalence, not the advancement of a new narrative that might tell that story. Nevertheless, by making the case that such a new narrative is sorely needed, Baum makes an important contribution to Reformation historiography.