This excellent and thought-provoking volume takes aim at the most basic organising principle in the historiography of the Protestant Reformation: the distinction between ‘radical’ and ‘magisterial’ reformations. As co-editor Bridget Heal explains in her introduction, ‘If there is one key, unifying theme to this volume, it is that the division between the radical and the magisterial, the marginal and the mainstream, the wild and the housetrained is artificial and unsustainable’ (p. 10). The volume's fifteen essays – the bulk of which focus on German, English and Dutch reformers – address this theme in a variety of ways.

Several stress the difficulty of defining Luther and other ‘magisterial’ reformers as somehow non-radical. Thomas Kaufmann discusses the radicalism of the reform programme in Luther's famous 1520 tract To the Christian nobility, which empowered all baptised Christians to undertake reform, asking ‘Was it less radical when Luther propagated these ideas than when the peasants or the community of Orlamünde practised them?’ (p. 29). Luther would vehemently oppose the peasants’ attempted reformation in the mid-1520s, of course, but Gerd Schwerhoff notes that radical rhetoric – invective and ‘hate speech’ – was a persistent feature of Luther's career as a reformer, playing a central role in his attack on Rome and remaining part of his repertoire as he defended his theology and attacked the Schwärmer. As a result, ‘radicalism and conservatism consequently stood in an ambivalent and unclear relationship: in one case his “invectivity” served to renew radicalism, in another it protected the existing order from further changes’ (p. 52). Turning to England, Ethan Shagan's essay on ‘radical charity’ outlines the sweeping economic transformation that leading figures in the Protestant establishment of Edward vi’s reign envisioned as an inherent element of reform. This economic radicalism ‘was not a critique of the Protestant Reformation in England, but rather was that Reformation for at least a brief moment’ (pp. 72–3). While Shagan argues that these radical economic ideas have gone unnoticed because they were unlike the Anabaptist or proto-Marxist ideas that historians equate with ‘radicalism’, Susan Royal finds radical attitudes about oaths and obligatory tithes among early English Protestants that were uncomfortably close to well-known Anabaptist ideas. These similarities, Royal argues, may well help to explain the extraordinary volume of distancing anti-Anabaptist polemic in a kingdom where there were very few actual Anabaptists.

Other essays approach the radical/magisterial divide from the other direction. Alec Ryrie considers radical views of Scripture and the Holy Spirit during the English Revolution, stressing that the radicals’ ‘fundamental appeal to the witness of the Holy Spirit was in itself entirely normal Protestantism’, but taken in radical directions in response to developments within seventeenth-century Protestant orthodoxy. Here and throughout the volume, attending carefully to context is crucial for understanding radicalism. In an essay on ‘Dutch Anabaptist and Reformed historiographers on Servetus’ death’, for instance, Mirjam van Veen shows how changing circumstances from the sixteenth through nineteenth centuries led Anabaptist writers to ‘distance themselves from Servetus’, while Reformed authors started to excuse and even criticise Calvin's role in his execution (p. 164). Viewed through this lens and on this time scale, van Veen notes that ‘on the one hand the Radical Reformation ceased to be radical; on the other hand, the mainstream Reformation became radical’ (p. 171). More broadly, as Hartmut Lehmann notes in the volume's first essay on ‘Martin Luther's unruly offspring’, it has not been the magisterial Churches that have come to dominate global Protestantism in the modern era, but rather Baptists, Pentecostals and non-denominational Protestants.

If the distinctions between radical and magisterial were so blurry, is it still useful to think about ‘radicalism’ in the Reformation? Several authors have their doubts. In a provocative essay on the production of anti-Anabaptist literature in what he strikingly dubs the early modern ‘republic of hateful letters’ (p. 141), Michael Driedger argues that ‘“the Radical Reformation” and similar categories are not a historical reality but a framework borrowed from the early modern heresy-making literature – that is, they are a discursive choice characteristic of a long-past cultural moment’ (p. 161). Even shorn of negative stereotypes, this category ‘cages’ historians, and Driedger declares himself ‘against “the Radical Reformation” and related frameworks for organizing our research about groups that heresy-makers defined as “heretics”’ (p. 161). Dmitri Levitin likewise characterises the term radical as ‘a concept of limited usefulness in explaining early modern religious, political, and intellectual history’, offering the volume's most minimalist definition as ‘something like “very unusual by contemporary standards”’ (p. 173). Gerd Schwerhoff ends his analysis of Luther's rhetorical radicalism with the deflationary conclusion that ‘The relative character of the term radicalism is particularly clear here – a trait which makes it, in my opinion, rather problematic and unsuitable for higher level of analysis’ (p. 52). The volume's contributors do not speak with one voice on this subject, though, and John Coffey uses the categories of George Williams's (in)famously magisterial The Radical Reformation in his essay assessing the relationship between the Radical Reformation of the sixteenth century and the radical religion of the English Revolution. Rather than distorting our understanding, Coffey argues that an ‘etymologically precise (and contemporary) definition of the term’ – ‘radical’ as a return to roots – ‘points us towards the historical and eschatological vision that defined the Radical Reformation’ (p. 203). Jon Sensbach is likewise content to employ ‘the Radical Reformation’ as an analytic category in his essay on radical Protestants and slavery, concluding that ‘the Radical Reformation was intimately bound up with, and left an indelible imprint on, the black Atlantic’ (p. 270). Whichever side of this debate readers take, this volume abundantly illustrates that critical investigations of ‘radicalism’ continue to deepen our understanding of the long Reformation, in all of its kaleidoscopic variety.