After a quarter of a century in which the history of Catholicism in the Dutch Republic was a field with very, very few players, recent years have seen a sudden flourishing of interest. Like other recent students of Dutch Catholicism, Christine Kooi started her career working on the history of Dutch Reformed Protestantism, only to discover the gaps in our knowledge about the many adherents of ‘popish insolence’ who so angered the consistories of the public Reformed Church. Using Reformed consistory records as her principal source, and limiting herself to the period from 1580 to 1700, in this new book she examines the interaction between Calvinists and Catholics in the confessional, civic and personal ‘spaces’ of the republic's richest province, Holland. The conceptual device of space works well to explain the odd contrast between the hostility towards Catholicism as expressed in Reformed sermons, pamphlets and consistory complaints, and the day-to-day experience of peaceful coexistence between people of different faiths; she argues that coexistence hinged on both sides accepting the boundaries in public space. Intriguingly, she argues that Catholics were perhaps better at understanding the realities of Dutch governance than their Reformed counterparts. Although the first two chapters give a useful overview of the broader political and ecclesiastical context, to the specialist this is familiar fare. Yet chapters iii–v contain a wealth of new evidence and ideas, also on the period after 1650, which remains surprisingly understudied by religious historians. Thus Kooi offers a new take on the phases in the levels of religious polarisation, arguing that this was less significant in the years before 1609 than in the second quarter of the seventeenth century. As yet, I am not fully convinced by her claim that it fell off after 1648; after all, the wars with the French and the plight of Calvinists abroad triggered much anti-Catholic rhetoric, as well as some anti-Catholic legislation, but Holland differed in this respect from the other provinces of the Republic. Her excellent chapter on conversion discusses a range of examples of clerical and lay apostasy in which clerics especially referred to their ‘conscience’ – freedom of conscience had been enshrined in the Union of Utrecht. Lay people did not speak much of inner struggles, but nevertheless freely and for a variety of religious and non-religious motives exercised their right to choose and change religious affiliation. The final chapter examines how this right played itself out among religiously mixed couples, and between parents and children, and examines the conflicts which this did cause at times. Although there is some repetition between the chapters, sections of which have been published before, this is a lively and well-written book that will find a place on reading lists for all students of the Golden Age. Kooi is not very assertive about the points where she differs from other recent scholarship, and perhaps this book would not have been the best place to spell this out. Still, having read this study, I would be interested in a concluding assessment of where we currently stand in understanding the workings of Dutch coexistence, and where there still is work to be done. It is to be hoped that she will produce that for us on another occasion.