Ruling the Spirit investigates the role of the Divine Office during the fourteenth and fifteenth centuries, and its emblematic value in the religious life of Dominican cloistered women in southern Germany and neighboring regions (Alsace; Brabant; the Rhineland; such Swiss cities as Bern, Basel, and St. Gallen; and Austria). Sixty-five nuns’ monasteries were located in this territory, designated by the Dominican order as the Province of Teutonia. Of these, Saint Katherine's, in Nürnberg, was important for acquiring and composing textual resources that were made available for copying and diffusion among the monasteries. To accomplish its task, the book explores an array of sources: annals of women's religious life (known as “sisterbooks”), legislation internal to the Dominican order, liturgical books utilized by the nuns, preaching addressed to them, and literature that supported and formed their spiritual lives.

Of paramount importance for the practices and perspectives recommended to the monasteries was the Divine Office, endorsed for its efficacy in cultivating spiritual growth and its significance as a source of Dominican identity. Author Claire Taylor Jones argues as follows: soon after its founding in the thirteenth century, the Dominican order assigned a prominent place to the office in the life of the nuns, but not until the fourteenth century did a “liturgical piety” develop among German women in the order. Accordingly, the office became a locus of spiritual experience and of a community's association with the order as a whole; reports of ecstatic behavior, rather than representing a subversion of male ecclesial authority, suggested the spiritual benefits bestowed upon women's communities when under the order's jurisdiction and adopting its distinctive liturgy. In the fifteenth century, the liturgy likewise established the nuns’ identity—i.e., as participants in the order's Observant reform movement (1–3).

Addressing a scholarly audience, especially those familiar with studies of religious women in medieval Germany, the book's substantive analysis and argumentation invite the engagement of specialists in medieval women's history, the history of Christian spirituality, the history of the Dominican order, and liturgical studies. Jones begins her account with the formal encouragement given to the nuns’ liturgical practice by the order's leadership and its legislation. Later, the teachings of Henry Suso (1295–1366) and Johannes Tauler (1300–61) on gelassenheit (detachment) provided a coherent framework for integrating the practices of obedience, religious observances (such as the office), and humility. In time, the nuns’ own stories also proved influential. Recorded in the fourteenth century, the sisterbooks demonstrated an integration of obedience and religious observance that appealed to the Observant reform in the fifteenth. Begun among the friars in the late fourteenth century, the reform did not reach the German nuns until 1429 (92). In support of the reform, Johannes Nider (1380?–1438) translated the authoritative monastic resource, John Cassian's The Conferences, to foster the nuns’ integration of liturgical practice with spiritual growth. Another friar of the reform, Johannes Meyer (1422/23–85), promoted the organization of a monastery's communal life that liturgical observance enabled.

The discussion of theological matters, central to the book, occasionally lacks a needed precision. Thus, the term grace at least once seems mistakenly replaced by virtue, as if the two words were synonymous (65). Additionally, the position ascribed to Tauler, that the capacity to discern spirits is “not a divine gift, but an ability developed through trial” (46), is an unexpected departure from the received theological tradition. The latter perspective might have categorized discernment first of all as a gift (or grace) bestowed by God, and then as a capacity exercised and developed as challenges, calling for its use, arose. Fine distinctions, perhaps, but statements about grace, the capacity of the human, and the acquisition of virtue tread a fine line.

As a study of women's religious experience in late medieval Germany, Ruling the Spirit pursues a project of identifying the religious meanings that sustained two centuries of Dominican monastic life. It avoids the temptation to determine the authenticity of mystical experiences. Rather, it documents the formation of a communal religious imagination by means of shared rituals of worship, preaching, and spiritual literature available to the monasteries, as well as education shared among the nuns themselves. This is no small achievement. The book, though, has a few technical flaws. The works of Tauler are absent from the bibliography, and listed only among the abbreviations following the table of contents. Within the index, entries occasionally supply an incomplete list of page references. The names of several monasteries appear under the entry “sisterbooks” (220), rather than in their own place. Some proper names (e.g., Cristina Ebner, Dominic) are absent.

Ruling the Spirit is a notable exposition of pre-Reformation, pre-Tridentine religious life. Rigorously researched and meticulous in its presentation, it conveys the complex meanings that informed religious communities of Dominican cloistered women as they lived out an intentional and vigorous liturgical life.