This chapter provides an overview of the book’s argument. It first shows how the association of Protestantism with modern freedom and German philosophy was an artifact of political and social debates in the eighteenth century, a German version of Butterfield’s famous concept of the “Whig” idea of history. It next explores the evolution of the term “Protestant” from the early days of the Reformation to the eighteenth century, concluding with the diversity of German Protestantism on the eve of the 1717 Reformation anniversary. Third, the Introduction discusses the intellectual contexts in which Protestantism and the Reformation were redefined, providing working definitions for such terms as "religion," "philosophy," "theology," and the "Protestant public sphere." Particular attention is paid to disputes over the boundaries of philosophy and religion in the context of Pietism, Wolffian philosophy, and eclecticism. Finally, the Introduction situates the book in the scholarly contexts of Enlightenment historiography, early modern European history and Church history, and the history of modern philosophy.