This volume explores the development of Luther's principle of sola scriptura by considering the authorities to which he appealed in the early years of his theological career: Scripture, the Fathers, and the papal canons and decretals. Its intention is to explore how Luther moved to sola scriptura from the ways in which his theological training had originally taught him to think. This is an important question. However, this volume, comprising eight essays with lengths ranging from nine to 109 pages, is strangely uneven in its shape and depth of treatment,.

Augustine is key to this discussion. The volume opens with one of the shorter papers, in which Volker Gummelt compares the use of Augustine by Luther and Bugenhagen in their lectures on the Psalms, Luther in 1513–14/15 and 1520–1, Bugenhagen in 1521–3, arguing that both concur with Augustine's approach to the Psalms: ‘seeing Christ here, understanding Christ here’ (p. 17). This question is deserving of a much more detailed treatment, exploring not only the frequency of Augustine citations, but their content. In another brief contribution, Hannegreth Grundmann shows how Luther and Jacobus Latomus disagreed on the correct interpretation of Augustine in seeking to understand gratia Christi. The volume's final essay, Stefano Leoni's very substantial ‘Der Augustinkomplex’, argues that in 1515–16 Luther experienced a conversion to anti-Pelagian Augustinian thought which laid the foundations for his theologia crucis (as opposed to a theologia gloriae), and which necessarily preceded the so-called Reformation breakthrough; Gummelt's contribution, which spans this same period, could usefully have engaged with Leoni's thesis.

Pelagianism and the proper understanding of the relationship between grace and the human will were also central in Matthias Mikoteit's discussion of the disputation theses presented by Bartholomäus Bernhardi in September 1516: Quaestio de viribus hominis sine gratia (‘On the question of human capacity without grace’). Mikoteit rejects the idea that these theses show the influence of Gregory of Rimini, holding that Gabriel Biel was more influential. Neither Gummelt nor Leoni explores the interesting question of how and in what form Augustine's works were known to Luther; Mikoteit makes a strong case that Bernhardi was not citing Augustine according to Gregory of Rimini's commentary; he also records that Luther presented Nikolaus von Amsdorf with an edition of Augustine but does not say which, a question which has been shown by Arnoud S. Visser (Reading Augustine in the Reformation, Oxford 2011) not to be trivial. Ingo Klitzsch argues that Gabriel Biel, and specifically Biel's Sentence Commentary, the Collectorium, was also Luther's interlocutor in his Disputatio contra scholasticam theologiam [‘Disputation against scholastic theology’], along with Aristotle. Here too Luther draws on the Bible and Augustine, reading them as a unit, but also on the insights of Johannes Tauler; in addition he engages critically with the positions of his own teachers in Erfurt and with the work of Erasmus.

In the controversy which followed the promulgation of the Ninety-Five Theses against indulgences, Johannes Eck became one of Luther's most significant opponents. In another very brief essay, Christopher Voigt-Goy considers Luther's use of canon law in these debates. Here Luther is responding to the citation by Eck and others of papal decretals against his position; the result, suggests Voigt-Goy, is that Luther presents canon law – against medieval tradition – as ‘a monolithic block of letters of the law’ (p. 95) with no room for interpretation. Volker Leppin explores how Luther's understanding of authority developed during his disputes with Eck in the period leading up to the Leipzig Disputation in 1519, suggesting that Luther moved from a ‘harmony model’ which assumed that the will of Christ was ‘represented equally in Scripture, the Fathers, and the canones’ to a questioning of papal and ecclesiastical authority (p. 138). Leppin suggests that it was Melanchthon in his baccalaureate theses in September 1519 who was the first to formulate a clear principle of sola scriptura. Jun Matsuura traces Luther's growing conviction that the pronouncements of a ‘holy Father’ must be confirmed by Holy Scripture, noting that Luther was here drawing on a statement by Richard of St Victor: ‘All truth is suspect to me if it is not confirmed by Holy Scripture’ (p. 151). This leads Luther to two convictions: Scripture is clear, and Scripture interprets itself.

This volume makes clear that Luther's development of the Schriftprinzip was precisely that: a development. The principle of sola scriptura did not simply arise but had to be worked out, with a consequent articulation of the relationship between Scripture and other possible authorities including the Church Fathers and the canons of the Church. This volume outlines the issues and offers some insights, but, as the introduction says, it can only make an initial contribution to an important and potentially much larger debate.