Andreas Osiander (1498–1552) is now remembered for supervising the publication of Nicolaus Copernicus, On the Revolutions of the Heavenly Bodies (1543), and for his authorship of Whether It Is True and Believable That the Jews Secretly Murder Christian Children and Use Their Blood (1540), the first published repudiation of blood libel. As a cleric at Nuremberg's St. Lorenz Church, he was also a prolific author of Lutheran propaganda (sometimes in collaboration with local artists and writers) and a frequent advisor to the Nuremberg government as it navigated the hazardous passage to Protestantism. Nuremberg was caught in an unusually complex political situation as it implemented a strongly Lutheran reform (including secular administration of the church and seizure of church property) despite threatening opposition from the Habsburg emperors (Charles V and Ferdinand I). Although a staunch Lutheran power, the city refused to join the Protestant military alliance in 1531 (Schmalkaldic League), and after the league was crushed, it acquiesced in Charles V's religious demands in the so-called Augsburg Interim (1548), an attempt to launch the re-catholicization of Protestant territories. For the most part, Osiander advocated a hard-Lutheran line against the council's efforts to accommodate the empire. Consequently, when the city accepted the stipulations of the Augsburg Interim, Osiander emigrated for a new position in Königsberg, just outside the boundary of the Holy Roman Empire.

Andrew L. Thomas narrates this overarching history of Osiander's career expertly and in rich detail, as a background to his focus on how the theologian characterizes contemporary Jews and Turks as well as how “Jews” and “Turks” function as rhetorical tropes (“metaphorical mirrors”) for describing doctrine and practices.

Thomas opens with an overview of Osiander's engagement with Jewish scholarship (chapter 1: “Kabbalistic Encounters: Osiander's Christian Humanism”), an undertaking that probably began during his Ingolstadt studies under Johannes Reuchlin and Johann Böschenstein, and benefitted from at least some study with Jewish experts. Osiander acquired a limited grasp of Kabbalah, derived from Reuchlin and Pico della Mirandola, with perhaps some direct knowledge of the Zohar (as proposed by Anselm Schubert). He used Kabbalistic technique (e.g., gematria) and concepts (e.g., Adam Kadmon) to spin Christological or messianic meanings out of a few Hebrew texts. An important undertaking, one that deserves more analysis, was his attempt to correct the Latin Vulgate Bible to conform more closely to the Hebrew and Greek originals (1522). In chapter 2 (“Jewish Mirrors I: Osiander and Lutheran Identity”), Thomas argues that Osiander's use of Jewish examples or analogies for theological doctrines, both pejorative (“Judaizing”) and affirmative, reveals an ambivalent allosemitic mentality. In most of these cases, Osiander's perspective has little to do with actual, contemporary Jews but rather with the function of the Hebrew Bible in Christian exegesis, “admonishing Lutherans to follow the examples of faithful Jews in the Old Testament and warning them of the dangers of God's wrath to those who followed the example of faithless Jews past and present” (60). Similarly, chapter 3 (“Jewish Mirrors II: Osiander and Lutheran Resistance”) analyzes Osiander's use of Jewish biblical analogies as a source for handling the political crises of his generation (Peasants War, formation of the Schmalkaldic League, the Schmalkaldic Wars, and the Augsburg Interim). In particular, Osiander emphasizes the apocryphal books of Maccabees in his unsuccessful efforts to persuade Nuremberg to join the Lutheran revolt against Charles. Chapter 6 (“Blood Libel: Osiander's Defense of Jewish Toleration in Context”) rounds out the treatment of Judaism, a complex analysis that documents both Osiander's opposition to blood libel and his consistently anti-Jewish positions otherwise, including his endorsement of Nuremberg's 1499 expulsion of Jews. Despite the chapter's title, there is no evidence that Osiander advocated toleration of Judaism. As Osiander indicates, his defense against blood libel is not novel, for Holy Roman emperors and popes repeatedly outlawed local ritual murder prosecutions (often without success). The only exception to this was Maximilian I, who not only cited blood libel as a rationale for expulsions but also became an acolyte of the most famous blood libel “saint,” Simon of Trent.

In chapter 4 (“Turkish Mirrors I: Osiander and Imperial Dreams”), Thomas reveals the complexities and inconsistencies in Osiander's apocalyptic rhetoric. In his representations, the Ottoman Empire functions as a scourge of God, bringing retribution to Christians for their failings, whereas the principal defenders of Christian Europe, Charles V and the Habsburgs, are also a Catholic scourge that punishes Protestants. In chapter 5 (“Turkish Mirrors II: Osiander and Lutheran Reforms”), it becomes clear that Osiander does not have a coherent apocalyptic perspective – God's wrathful disfavor, as manifest in the dire threat of the Ottomans and the anti-Lutheran emperor, can only be appeased through repentance and reform. Thus, Osiander supports both Protestant aid to the Habsburgs to oppose the Ottomans and Protestant military revolt against the Habsburgs to preserve Protestantism, all the while exploiting the fear of Muslim victory as motivation for Protestant reform, on both personal and political levels.

Of the infidels, Osiander portrays the “Turks” significantly more harshly than the “Jews.” Thomas attributes this disparity to Osiander's personal contact with Jews and the complete absence of direct encounters with Muslims. This explanation seems problematic for several reasons. For one, the known contacts with Jews are slight and no benevolent descriptions of Jewish acquaintances survive in Osiander's corpus – the positive portrayals are exclusively of biblical Jews. More importantly, the circumstances of Jews and Turks are profoundly asymmetrical – the military threat from the Turks is real, whereas the Jews are a weak, largely powerless, and oppressed minority, suffering wave after wave of banishment in Western Europe.

The book includes the first English translation of Osiander's pamphlet against blood libel, which was written to undermine a 1529 ritual murder trial in Pösing (today, Pezinok, Slovakia) and was printed in 1540 to counter yet another blood libel trial in Sappenfeld (a town south of Nuremberg). The tract, which appeared anonymously and contains considerable anti-Catholic polemic, elicited a vehement defense of blood libel from the Catholic Theologian Johannes Eck, but otherwise had little impact.

Andrew Thomas's work, grounded in a thorough knowledge of Osiander's corpus, the Reformation in Nuremberg, and the political-military challenges of Charles V's Empire, offers a thought-provoking overview of the complex career of a significant early reformer.