This study examines the emergence of Lutheran casuistry in the century and a half after the Reformation, granting special attention to the compilation of Georg Dedekenn's Thesaurus consiliorum et decisionum, first published in 1623. That work was to become the premier guide for Lutheran pastors seeking to advise and console their parishioners about moral decisions over the two centuries that followed. As Mayes shows, the path to the development of handbooks like Dedekenn's was a long and circuitous one. Luther condemned the casuistic reasoning of works like the Summa angelica, a popular confessors' manual, and he included it among the books that he consigned to the flames in 1520. Although early evangelical theologians gave a prominent role to the conscience, they were not agreed on whether the conscience was a mental faculty, or a power, a habit, or an act of the mind. The Lutheran concept of the bound will, too, acted as a brake on the development of a formal casuistry. But as the evangelical reformation matured, such barriers were surmounted. The importation of much medieval canon and case law into the German territorial courts, particularly into the marriage courts, as well as the casuistic speculations that were found in the advice manuals of evangelical theologians, provided ample opportunity for the development of a case-by-case approach to moral reasoning. Before the rise of a distinctive genre of casuistic texts, much casuistry was presented in advice manuals arranged according to the loci communes method that Melanchthon had developed to bring order to the unruly contours of Luther's thought. Chief among these works was Johannes Aurifaber's edition of the Table talk, the record of Luther's refectory discussions with his students, though a number of other texts presented casuistic examinations, too. Seventeenth-century theologians, Mayes argues, demanded a more disciplined and orderly examination of the kinds of moral dilemmas once treated in the earlier, breezier compendia. Mayes grants little attention to the reasons for this surge in casuistry. Nor does he examine the specifics of the audience that consumed these texts and how the works were relied upon for moral advice. His presentation of the more complex schools of Catholic and Calvinist casuistry that flourished at the same time may offer clues as to why evangelicals came in the age of Lutheran Orthodoxy to develop a formal casuistry. These connections are not explored, though Mayes does provides a significant contribution in the detailed reading that he offers of these often overlooked seventeenth-century Lutheran texts, and in his unearthing of an important strand of casuistic examinations in which ‘aristocratic reasoning’ is consistently cited as the best moral authority. That notion – that the advice of the most prominent theologians should carry greatest weight in moral decisions – often came to undergird Orthodox Lutheran casuistic judgements.