In this thoroughly reworked English version of her Habilitationsschrift, first published in German in 2002, Francisca Loetz explores the phenomenon of blasphemy in early modern Zurich in its theological, political, social, cultural and religious dimensions. Loetz's approach to the topic involves extensive use of linguistic models, notably the speech action theory of H. P. Grice, in combination with more established explanatory paradigms such as social disciplining, confessionalisation and acculturation. For her examination of individual blasphemy cases she is able to draw on a wealth of archival sources, including the minutes of the Zurich council, church records and a variety of legal records, especially the so-called Rats- und Richtsbücher and the supplementary investigations known as Kundschaften und Nachgänge. One of Loetz's key findings is that, contrary to expectation, the Reformation had little impact on the way in which the ecclesiastical and secular authorities defined and punished blasphemy. Of far greater significance in this regard were the closing decades of the seventeenth century, when religious offences began to disappear from the courts; it is this period that can be taken as marking the boundary between ‘religious pre-modernity’ and ‘religious modernity’. Furthermore, Loetz's analysis reveals that the prosecution of blasphemy was dependent less on ‘vertical’ than on ‘horizontal’ social control: the denunciation to the authorities of blasphemers by their fellow citizens. The study therefore poses a challenge to proponents of the confessionalisation thesis, who tend to view religious policy as an instrument of state formation during the early modern period, and suggests a much more dynamic interaction between ‘disciplining by the authorities and self-regulation in the communities’. Loetz also calls into question the popular perception of blasphemy as an offence restricted to the lower orders and marginal groups (foreigners, soldiers, beggars, criminals, prostitutes). Statistical analysis of the background of offenders, insofar as that can be determined from the records, reveals that blasphemy was, in fact, a ‘broadband phenomenon’, linked more to particular settings (especially environments involving social drinking) than to occupation or wealth. Offenders also varied greatly in their understanding of Reformed Christian teaching. Although some displayed ignorance of even the most basic doctrines, others were well versed in the tenets of Christianity and may be regarded as ‘conscious’ blasphemers. In a few celebrated instances, such as the cases of the Italian exile Antonio Mario Besozzi or the patrician Hans Rudolf Werdmüller, one finds evidence of full-blown heresy or free-thinking, but issues relating to Christology, Mariology, predestination, the sacraments and other areas of doctrine were raised even by some less educated offenders. This degree of engagement with complex theological topics appears to have been a distinctly Protestant phenomenon. When comparing the nature of blasphemy in Zurich with that in Catholic Lucerne, Loetz notes the greater theological sophistication displayed by Zurich blasphemers. This finding suggests that the biblical literacy and culture of religious debate fostered by the Reformation proved a double-edged sword for the Zurich authorities, as it frequently led people to conclusions at odds with orthodoxy. Overall, the study makes a compelling case for the ‘cultural history of religiousness’ proposed by Loetz as a way of synthesising traditional church history, focused on ideologies and institutions, with historical anthropology. In so doing, it erases the traditional distinction between elite and popular culture, reconceptualising early modern religion as a product of the interplay between the Church, the State, the community and the individual.