No theological topic in Early Reformation Europe was more disputed and divisive among Protestants than the nature of the sacraments. The Lord's Supper, in particular, was an issue that split theologians and emerging ecclesiastical traditions. The eucharistic controversies of the 1520s were complicated, intricate and important. Theological decisions made then still have effects today.

Now Amy Nelson Burnett helps sort out what she acknowledges to be ‘a convoluted topic’ (p. xiii). She has produced a masterful and comprehensive study of a range of theologians who contributed to this issue while setting the disputes in the context of early print culture, tracing their evolution through publications and the ways in which these writings affected a wide public. Veteran Reformation scholar, Robert Kolb, calls this book an ‘instant classic’. Kolb is right. This book does, as he writes in commending the volume, set ‘a new standard for interpreting the Protestant sacramental controversies as a whole’ (back cover).

Burnett's focus is on the period when Protestant sacramental theology became hot topics in the 1520s. Her approach is chronological as well as wide-ranging. She does not concentrate only on the ‘big names’ – Luther and Zwingli. Burnett explicates the writings and their dissemination of theologians including Karlstadt, Melanchthon, Bucer, Oecolampadius and Pirckheimer among others. This gives the book an authoritative, reference-like power that will make it the place to turn to for all future forays into this tangled topic. Her approach is also unique among other treatments of this topic since her net is wider and more nuanced than what we have had before.

At the centre is the issue of Christ's bodily presence and whether it may be said to be present in the elements of the bread and wine in the Lord's Supper. Burnett writes that ‘just as rejection of the authority of the papal see divided Roman Catholics from those who would later be called Protestants, so the rejection of Christ's bodily presence in the elements of bread and wine began the process of dividing Protestants into the Lutheran and Reformed confessional churches’ (p. 1). Later, Anabaptists emerged and divisions spread even wider.

In October 1524, when two Basel printers published Andreas Bodenstein von Karlstadt's pamphlets arguing against the presence of Christ's body in the bread and wine, the controversy was on. The spread of Karlstadt's ideas in the emerging print culture fuelled the theological controversy that was to engage the theologians.

Beneath this specific controversy, Burnett notes that the far-reaching disagreements were built on ‘the definition and purpose of the sacraments more generally and the understanding of the relationship between the visible material world and the invisible spiritual reality that underlay any discussion of the sacraments’ (p. 1). This stoked the contrasting views of Luther and Erasmus in the early 1520s. Presuppositions differed; as did their responses to questions of biblical hermeneutics and the exegesis of Scripture. The eucharistic controversy evoked a crisis of authority among the evangelicals which significantly deepened in the second half of the 1520s. The core of the controversy on the Lord's Supper was on dramatic display between 1525 and 1529.

Burnett approaches her topic through three parts. Part i provides an overview, background and discussions of the beginnings of the controversy with Karlstadt's challenge to Luther and the early debate in Switzerland. Part ii examines exchanges of between 1526 and 1529 through the writings of Bucer, Oecolampadius, Pirckheimer and contributions from Zurich and Strasbourg. These led to deepening debates from 1527 to 1529. The gradual developments detailed in part iii examine the ‘Lord's Supper in catechetical literature’, ‘Sacramentarian diversity’ and ‘Reconstituting authority’. This last chapter centres on the Marburg Colloquy (1529) which ‘brought to a head the question of religious authority within the evangelical movement and reinforced the perception of Luther and his colleagues as the ultimate arbiters of the evangelical faith’ (p. 289).

At Marburg, ‘the central question was one of exegesis, resting on the different hermeneutical assumptions of Luther and Erasmus’ (p. 291). Two key issues were ‘the ability of the sacraments to convey grace, and the presence of Christ's true body and blood in the bread and wine’ (p. 295). The contrast between Luther and Zwingli was sharp: ‘Luther taught the objective corporeal presence of Christ's body through the power of the words spoken over the bread and wine’ (p. 237). Zwingli did not believe ‘that the words brought Christ's body, but instead taught the spiritual communion of Christ's body and blood that occurred when the bread and wine were eaten by believers’ – in faith (p. 237).

Differences between Oecolampadius and Bucer with Zwingli heightened tensions. The Strassburgers could agree with the Wittenbergers that sacraments could convey grace (vs. Zwingli). But these ‘sacramentarians’ also ‘remained united on the question of whether the bread and wine could in any way contain Christ's body and blood’ (p. 295).

Marburg produced fourteen articles of agreement. But the carefully crafted and balanced Article 15 on the Lord's Supper could not hide the fact that the two sides continued to disagree on ‘whether “the true body and blood of Christ were bodily in the bread and wine”’. While the Article states that ‘each side would “show Christian love to the other insofar as their consciences would allow”, it could not be hidden that “the evangelicals could not agree regarding Christ's bodily presence”’ (pp. 294–5).

The result of Marburg was not an end to the evangelicals’ crisis of authority. But it did begin a movement toward ‘confessions’ assuming a more dominant place over the personal authority of individual reformers. For magisterial Protestant Churches, definitions of orthodoxy were to become enshrined in confessional statements, of which the Colloquy of Marburg was a precursor.

Print continued to shape and spread theological views. It helped to remove theology's isolation and embed theology in forms of communication which could disseminate its viewpoints and help shape the culture of theologians themselves. Print was indispensable to the spread of the emerging views of new theologians – such as John Calvin.