Andreas Zecherle has produced a detailed study of the reception of the Theologia Deutsch in the late medieval period through 1523. The book fills a significant gap in scholarship, and Zecherle situates Martin Luther's reception of the treatise within the longer history of reception. Luther's reception is also compared to that of two contemporaries: Johann von Staupitz, who likely read the Theologia Deutsch, and Andreas Bodenstein von Karlstadt, who was deeply shaped by it (pp. 258–9). Nevertheless, the chapter on Luther comprises well over half of the book (pp. 67–198). A key conclusion is that Luther, in emphasising human captivity to sin, carried forward but radicalised a strand of medieval interpretation; Luther here made a ‘qualitative break’ and ‘leap’, taken also with Karlstadt and Staupitz, in denying that human beings are responsible for their salvation (pp. 271–3).

Chapter i helpfully reconstructs what can be known about the late medieval reception of the text and the interests of those who copied and transmitted it – interests revealed by selective abbreviation, annotations and other para-texts, and the binding of the Theologia Deutsch with other writings. Composed in the fourteenth century, the Theologia Deutsch was not widely known before Luther and circulated primarily among cloisters of monks and nuns; Seelsorger of the reform movements played a key role (pp. 14–25), and they were particularly interested in promoting the Theologia Deutsch’s injunctions to humility, recognition of one's nothingness and Christ-like obedience to God's will – presumed to be manifest in the monastic rule (p. 65). Interest in ‘genuinely mystical practices’ was prevalent, although copyists were split in their assessment of ‘temporary mystical experience’; most recipients were interested in the ‘enduring deification’ of the soul and corresponding ‘ethical-practical’ instructions (pp. 52–9).

Chapter ii compiles and analyses Luther's statements on the Theologia Deutsch and his demonstrable citations of the medieval text, while also offering comparison and contrast of Luther's teachings in selected writings from 1517 to 1522 to those of the Theologia Deutsch. Luther's initial interest was connected to his reconsideration of penance, and throughout the period in question he upheld the teaching that a person must ‘humbly recognize his own nothingness, put aside self-focus, and give himself over to God's will’ (p. 74; also pp. 81, 106, 127–8, 192). From his receipt and publication of the full text in 1518, Luther used the Theologia Deutsch along with other witnesses to claim membership in a tradition of ‘German theology’ true to the Bible, in critical distinction from scholasticism and humanism (pp. 125–7, 187–91). Luther's interests also moved from penance to ethics, i.e. ‘the right relationship between the human and the divine will’ and the ‘significance of the law’. Key differences between Luther and the Theologia Deutsch included Luther's ‘more radical’ understanding of human depravity, the role he assigned to the preached word versus inward illumination in producing self-knowledge and his view that salvation happens by faith and the ‘communion of properties’ with Christ (pp. 105–6, 192–4). Still, Luther apparently did not see ‘serious differences’ between his own views and those of the Theologia Deutsch: he readily related the Theologia Deutsch's talk of illumination to the work of the outer word, he did not notice that the Theologia Deutsch ultimately requires a willing surrender to God's activity and he conceived of an incomplete union of wills with God (Willenskonformität) made possible by faith, not Willenseinheit (pp. 105–7, 129–33, 152–4, 160–1, 196–7). On the last point, he stood (along with Karlstadt and Staupitz) in continuity with most medieval interpreters, although those interpreters wanted to underline human responsibility for salvation and encourage effort (p. 58).

Zecherle's book lays substantial groundwork for future scholarship, but he does not address the most significant questions surrounding the reception of the Theologia Deutsch in the Reformation era: first, did the reception of the Theologia Deutsch contribute to Luther's theological development – that is, did Luther's evangelical theology of reform arise from a ‘transformation’ of mysticism (as Volker Leppin has argued) or does it represent itself a ‘democratisation’ of mysticism (as Berndt Hamm has argued)? Zecherle explicitly declines to enter this arena (p. 69). Second, what contours of competing reception emerged in the early Reformation to challenge Luther's? After all, while Luther introduced the Theologia Deutsch to his age, he did little to control the interpretation; his silence after 1522 spoke loudest, and he ceded the field of creative interpretation and use of the Theologia Deutsch to others like Karlstadt, Hans Denck, Valentin Weigel and Johann Arndt. Zecherle's cautious attribution of printed marginalia in the 1520 edition of the Theologia Deutsch to Luther (see pp. 137–61) strikes me as implausible, insofar as the marginalia reflect a wider interest in the medieval text than Zecherle finds elsewhere in Luther's writings of the period. In any case, it is regrettable that Zecherle's book does not discuss the influential 1528 Worms edition of the Theologia Deutsch, to which Denck's Hauptreden were appended; this discussion would not have required a major expansion of Zecherle's timeframe.

An opportunity is missed in the analysis of Karlstadt, whose two ‘mystical’ treatises of 1523 contributed to radical – and perhaps even later Pietist – approaches to the Theologia Deutsch. Zecherle notes some unique aspects of Karlstadt's reception of the Theologia Deutsch vis-à-vis Luther's: conforming more closely to the Theologia Deutsch, Karlstadt received images of the will's union with God and of human deification; he described Gelassenheit as necessary for salvation, although his concept of Gelassenheit was related to faith and the recognition of human shortcoming; and he was open to ideas about inner illumination, although he maintained the centrality of Scripture (pp. 262–3). Still, for Zecherle, Karlstadt no less than Luther ‘represented a more radical understanding [vis-à-vis the Theologia Deutsch] of the sinful depravity of human beings, interpreted Willenseinheit in the sense of Willenskonformität, and emphasized the significance of the outer word’ (p. 269). But if Karlstadt were so similar to Luther, why did he regard the Theologia Deutsch as a chief hammer in his toolbox of dissent from Wittenberg? In fact, already in the tract Von Mannigfaltigkeit, Karlstadt was deeply concerned (like Denck shortly thereafter) that the doctrine of the bondage of the will made God responsible for evil. I would argue that Karlstadt landed (by 1524) on a view of agency similar to that of Theologia Deutsch: the saved and the damned are differentiated based on whether they surrender to God's work and truth. While I cannot prove my interpretation here, I introduce it only to highlight that Zecherle might have done more to trace both the impact of the Theologia Deutsch on Karlstadt and the ‘beginning of intra-Reformation differences in the reception of the late-medieval work’ by giving more equal space to one of Luther's adversaries (p. 9).