 The aim of this entry is to outline the impact of Martin Luther (1483–1546) on the philosophical tradition which came after him. The Protestant Reformation as a whole undoubtedly had considerable influence in philosophy and not just theology, not least because many key philosophical figures were themselves part of this religious heritage in its various forms, as well as being caught up in the major social and political changes and conflicts that the Reformation unleashed. However, to trace the influence of Luther himself specifically is a more complex exercise, in part because other central Reformation figures such as Philip Melanchthon (1497–1560) and John Calvin (1509–64) had their own impact;[1] at the same time, the Reformation itself took on a range of different forms even in Luther’s own lifetime and more strongly afterwards, many of which departed from Luther himself on key issues, despite various attempts to arrive at some uniformity of doctrine. This complexity, combined with the feeling that Luther was in some sense an “anti-philosopher” because of his hostile remarks concerning the discipline, Aristotle, and reason, have led Luther’s influence within philosophy to be rather neglected.[2] Nonetheless, the impact of his thinking on “modernity” more generally has been much discussed (see §6), while recent scholarship has suggested it is a mistake to neglect Luther’s influence on philosophy more narrowly conceived, and that the discussion of his ideas (both positively and critically) can be seen to mark the philosophical tradition from the early modern period onwards in a distinctive way (see §§1–5). Naturally enough, this impact takes place most obviously in the countries of northern Europe, where the Reformation generally was spread most effectively.[3]