This article focuses on debates on philosophical knowledge, mathematics, and the empirical sciences by analyzing the positions on cosmological and astronomical knowledge, around 1800, of three German authors: Herder, Schelling, and Hegel. I show the mutual interdependence of Schelling’s and Hegel’s Naturphilosophie and Herder’s Ideen, and I then demonstrate that the latter’s position during the last years of his life was a reaction to Schelling’s and Hegel’s speculative philosophy. While Herder seems to ignore the works of the Naturphilosophen in his (...) journal Adrastea, in fact he participated in a very lively debate that included Schelling’s Weltseele and Hegel’s Dissertatio de Orbitis Planetarum. (shrink)