Luis Fellipe Garcia 1 Introduction: The Resurgence of Classical German Natural Philosophy An investigation into nature and natural phenomena in classical German philoso- phy may not seem to be a particularly promising enterprise. After all, this period in the history of ideas is believed to have been ushered in by Kant’s methodological innovation according to which philosophy should focus not so much on the objects of cognition as on the way in which the human mind produces concepts of objects. This approach enabled fruitful investigations into multiple areas in which the human mind manifests its rational activities, such as morality, politics, history, art, religion, and philosophy itself. At the same time, Kant’s method seems to have led to several attempts to reduce natural phenomena to the ways in which the human mind produces cognitions. Accordingly, the philosophical movement ig- nited by the early reception of Kant’s philosophy is often called German Idealism, which suggests that, for the philosophers of this period, the human mind and its ideas take priority over nature and its phenomena. This does not mean, however, that the concept of nature was neglected by the philosophers of the time. On the contrary, Kant explicitly developed a metaphysics of nature and Schelling sketched the project of a natural philosophy under the ru- bric Naturphilosophie, which turned into a sort of research program for philoso- phers and scientists of the time. Such a research program encountered a welcom- ing soil as it resonated with the investigations into natural phenomena carried out by authors such as Herder and Goethe. In little time, Naturphilosophie was taken up and further developed by philosophers as diverse as the romantics and Hegel. The conceptual problems put forward by these different works on natural philos- ophy became so widespread at the turn of the nineteenth century that a commen- tator calls the period from 1780 to 1830 a nature-philosophical epoch (Engelhardt 1976, p. 6). Now, how is it possible that a period in the history of ideas usually associated with idealism is arguably also a nature-philosophical epoch? Facing this puzzle, commentators have traditionally argued that the countless works on natural phi- losophy at the time consisted of preposterous attempts to reduce natural phenom- ena to idealistic a priori mental constructions (Adickes 1924; Lauth 1974; Pippin 1989). German natural philosophers at the turn of the nineteenth century, so the story goes, would have neglected the role of experience and focused on a priori deductions of natural phenomena, thereby taking an opposite path to that which would soon bear so much fruit for modern science (Adickes 1924, Open Access. © 2025 the author(s), published by De Gruyter. This work is licensed under the Creative Commons Attribution 4.0 International License. https://doi.org/10.1515/9783111002453-001