This paper argues that one of the key differences between Schelling and Hegel concerns the potential within their respective systems to conceive the history of nature as philosophically significant. The author begins by considering the late Schelling's critique of Hegel in order to elucidate the difference between an ontology of nature and a philosophical history of nature. With this distinction in mind, he turns to the early Schelling's philosophy of nature and argue that, despite his insistence on the atemporal character of nature's system of stages, the early Schelling nevertheless hints at the ontological significance of nature's history. He goes on to interpret Hegel's rejection of the idea that natural history might be of significance to an ontology of nature, and argues that this view must be understood in light of Hegel's conception of nature as "self-external reason." He concludes by suggesting that it is only in Schelling's middle period—and, in particular, in the Ages of the World—that the rationally necessary development from inorganic nature to life and spirit is presented as a historical development, making this period of Schelling's thought the high point of idealist philosophy of nature.