This book shows how the German Protestant Enlightenment forged a succession narrative from the Protestant Reformation to modern life and thought. Organized around the discursive redefinition of Protestantism as a public process, the book shows how two key cultural and intellectual achievements, the sixteenth-century Reformation and birth of “German” philosophy in the late eighteenth century became fused in public debate and discussion over the course of the long eighteenth century. The book argues first that Protestant theologians and intellectuals­­­ recast the meaning of Protestantism as part of a wide-ranging cultural apology aimed at the twin threats of unbelief and deism on the one hand, and against Pietism and a nascent evangelical awakening on the other. It then shows how the new conceptualization and language of Protestantism forged by this apologetical and reforming impulse proved exceptionally fertile for the rise of a new philosophical and social world view that began its ascent in the 1780s and became part of mainstream German intellectual culture in the early decades of the nineteenth century. The result was a rich if unstable idea linking Protestantism and modern freedom that would dominate German intellectual culture until the First World War.