Journal of the History of Ideas

Belief in God is a living and animating principle within human beings, and it springs from life itself, not from dead concepts.

("Concluding Remark by the Editor," I/6, 411; IW, 179).¹

The controversy between Mendelssohn and Jacobi, which erupted publicly in 1785, impacted the development of German philosophy in the subsequent decades in almost incalculable respects. To name just two of these, the rise of German Idealism and of early German Romanticism are both inconceivable apart from the flowering of Spinozism occasioned by the earlier controversy. As Frederick C. Beiser has convincingly shown, nothing less than the authority of reason itself was at stake in the so-called "Pantheismusstreit." ² Still, it is important to keep in mind that the heart of the issue [End Page 569] was the authority of reason vis-à-vis religious belief. The debate between Mendelssohn and Jacobi, on which virtually every major figure of the period had something to say, was fundamentally a debate about religion. It brought to a head a long-standing tension in eighteenth-century thought, particularly in Germany, between the partisans of rationalist metaphysics and those (most famously in Germany, J.G. Hamann) who took religion to be fundamentally a matter of pre- or sub-rational "sentiment [Empfindung]." This tension is articulated most clearly in K. L. Reinhold's intervention into the dispute, the Briefe über die Kantische Philosophie.³ Reinhold's work presents the issue in terms of the relationship between rational reflection, on the one hand, and common sense "natural" faith, on the other. In this epochal work, Reinhold attempted to bring Kant's new "critical" perspective to bear on the larger issue of the relationship between philosophical reflection and religious belief.

Reinhold's work in turn stimulated others to take up the torch of Kantianism and to address the religious questions of the era from that point of view. In particular, the little known Leipzig philosopher K. H. Heydenreich (1764–1801) and the better known pioneer of idealism, J. G. Fichte (1764– 1814), each attempted to develop a new philosophical synthesis that responded to the "Pantheismusstreit" in the "spirit" of Kant's philosophy.⁴ Heydenreich, though virtually ignored by contemporary scholars, played a key role in shaping the larger intellectual context in which post-Kantian philosophers, including Fichte, worked out their views. The present essay has three interlocking goals: (1) to rehabilitate Heydenreich as an important figure in his own right and as an important player in the development of the philosophy of religion in Germany in the 1790s; (2) to explore the hitherto overlooked role that Heydenreich played as a stimulus to Fichte's intellectual development during the crucial "Jena phase" (1794–1800) of his career; and (3) to utilize Heydenreich's views to bring out some of the distinctive aspects of Fichte's position during this period. [End Page 570]