This chapter takes the philosopher Karl Leonhard Reinhold as a starting point to look at the ways in which critical philosophers sought to cast Kantianism as the heir to Protestantism. In his highly influential Letters on the Kantian Philosophy, Reinhold argues that the “first” Reformation of the sixteenth century was only a “preparation” for the current attempts to purify morality through philosophy. Situated in the context of Friedrich Heinrich Jacobi’s accusation that contemporary philosophy led to atheism (the so-called pantheism controversy or Spinozastreit) it traces Reinhold’s evolution from a proponent of the Catholic Enlightenment to an energetic advocate for Kantian philosophy at the University of Jena. Concluding briefly with Johann Gottlieb Fichte, the chapter shows how the new language of Protestantism discussed in the previous chapters proved fruitful for advocates of the new philosophy.

This chapter sets out the origins of the traditional historiography of early modern philosophy based on the dichotomy of empiricism and rationalism. After reconstructing the spread of the notions of empiricism and rationalism in Germany during the 1780s, we argue that the first outline of a history of metaphysics that displays the Kantian, epistemological, and classificatory biases can be found in Karl Leonhard Reinhold’s works from the early 1790s. Two early Kantian historians, Wilhelm Gottlieb Tennemann and Johann Gottlieb Buhle, turned Reinhold’s outline into fully fledged histories of early modern thought. Tennemann, who became a Kantian after reading Reinhold’s works, developed Reinhold’s historical sketches into a detailed, nuanced, and comprehensive account of seventeenth- and eighteenth-century philosophy that revolves around the empiricism/rationalism distinction and displays the biases of the traditional historiography. Thus, in Germany, the decline of experimental philosophy and the eclipse of the experimental/speculative distinction went hand in hand with the rise of Kantianism and the development of a historiography based on the empiricism/rationalism distinction.