Naturphilosophie is a term used in English-language philosophy to identify a current in the philosophical tradition of German idealism, as applied to the study of nature in the earlier 19th century. German speakers use the clearer term Romantische Naturphilosophie, the philosophy of nature developed at the time of the founding of German Romanticism. It is particularly associated with the philosophical work of Friedrich Wilhelm Joseph Schelling and Georg Wilhelm Friedrich Hegel—though it has some clear precursors also. More particularly it is identified with some of the initial works of Schelling during the period 1797–9, in reaction to the views of Fichte, and subsequent developments from Schelling's position. Always controversial, some of Schelling's ideas in this direction are still considered of philosophical interest, even if the subsequent development of experimental natural science had a destructive impact on the credibility of the theories of his followers in Naturphilosophie.

German idealism is a philosophical movement that emerged in Germany in the late 18th and early 19th centuries. It developed out of the work of Immanuel Kant in the 1780s and 1790s, and was closely linked both with Romanticism and the revolutionary politics of the Enlightenment. The period of German idealism after Kant is also known as post-Kantian idealism or simply post-Kantianism. One scheme divides German idealists into transcendental idealists, associated with Kant and Fichte, and absolute idealists, associated with Schelling and Hegel.