In this slim volume about the life and work of François de Sales (1567−1622), Thomas A. Donlan tackles a very large theme. Indeed the central point of the book – to explore François de Sales's contributions to non-violent religious cultures in Counter-Reformation French Catholicism – is so intimately tied to major historiographic debates about violence and emotions that one hopes Donlan will build upon his research findings in a further monograph. The ideas developed in The reform of zeal are of considerable relevance to current interdisciplinary work on ‘contentious politics’, to borrow a phrase from Charles Tilly and Sidney Tarrow. Violence, in all its various manifestations and in different historical contexts, is currently occupying a space to the fore of historians’ interests, not least as a result of scholarly reactions to Steven Pinker's thesis on the subject. Donlan's focus on François de Sales permits the reader a point of entry to the theological writings and social world of one Catholic priest, deeply immersed in spiritual reflections and active ministry during the French Wars of Religion (1562−1629). The sermons, correspondence and religious pamphlets (Méditations) produced by François de Sales are the main documentary sources analysed by Donlan, who skilfully situates his argument about Salesian non-violent religious messages within the extensive secondary literature on confessional struggles of the sixteenth and seventeenth centuries. Chapters i to iii show the evolution in François de Sales's thinking, from his exposure (and initial attraction) to Catholic militancy in Paris during the decade 1578–88 to the elaboration of his Christocentric critique of war and conflict, informed by the Scriptures, after entering the priesthood in 1593. Donlan effectively argues for the consistency and longevity of influences stemming from François de Sales's education by Jesuits at the Collège de Clermont, where as a student he developed a piety based on Marian devotion, spiritual friendships and pastoral care. Chapters iv and v of the book deal with the practical efforts of François de Sales to implement his compassionate theology via preaching and pastoral outreach during the 1590s and early 1600s when he was based in the Chablais (north Savoy) and then in Geneva. Here Donlan's fine attention to the letters of spiritual direction written by François de Sales allow the reader glimpses of the personality and charisma of the Catholic priest, urging the faithful toward a closer relationship with God as loving and merciful Creator. A key element in the Salesian approach was the concept of Christ-like douceur (gentleness) conveyed in New Testament accounts of the teachings of Jesus. Truly Christian behaviour, according to François de Sales, should be modelled on Jesus’ example of tenderness, patience and humility. In his own personal encounters with Huguenots, and the respectful dialogue that he maintained with them on matters of Scripture and liturgy, this Catholic priest championed peace and fraternity. He thereby radically departed from the confrontational rhetoric of Catholic militancy in which the Protestant was cast as monstrous heretic. The sensitivity, tact and assertiveness evident in the language of François de Sales won him the confidence of his followers as he sought to challenge the vision of an angry punishing God that underpinned combative religious culture. In the establishment of the Order of the Visitation of Holy Mary, with his spiritual friend and collaborator Jeanne de Chantal, François de Sales found a wonderful terrain for healing. He addressed his theological teachings and pastoral care to worshippers accustomed to exerting spiritual and psychological violence upon themselves through bodily mortification. The Salesian emphasis on gentleness was in direct contradiction to contemporary beliefs about rigorous penitence for sin, upheld by members of religious orders such as the nuns in Ursuline, Carmelite and Capucine convents who practised harsh austerities and strict asceticism. The most powerful aspect of François de Sales's end-of-career work lay precisely in this interpersonal effort at transforming self-hatred and self-punishment among religious women and men into physical health, emotional peace and mental well-being.