ECOLOGY IS AN EMINENTLY practical discipline, but the practical dilemmas of the ecological movement—and arguably of the environmental crisis itself—are the consequences of our failure to comprehend the complexity and unity of nature theoretically. The ecological crisis is first and foremost an epistemological crisis. As Thomas Kuhn has taught us, such crises are potentially revolutionary episodes out of which new paradigms can emerge. We have also learned from Kuhn that paradigm shifts are rarely sudden events; usually they unfold over decades or even centuries. So it has been with the search for a new paradigm that was inaugurated by Goethe's scientific work. As a practicing scientist and as a philosopher of science, Goethe both foresaw the crisis of mechanistic explanation and laid foundations for a new paradigm that might replace it. In doing so, he also laid foundations for a future, alternative science of ecology. Although the term “ecology” did not exist until Ernst Haeckel coined it in 1866, Goethe was a profound ecologist in principle and practice if not yet in name. This essay on four major “Goethean ecologists” seeks to add a brief chapter to the history of the reception of Goethe's scientific work and also to Donald Worster's now standard history of ecology, which barely mentions Goethe in passing.

By the middle of the nineteenth century, the mechanists seemed to have triumphed over both Naturphilosophie and the separate, more narrowly Kantian school described by Timothy Lenoir, which sought in vain to keep alive a sophisticated mode of teleological explanation. The unsophisticated teleology invoked by Darwin's critics was easily routed, and various modes of vitalism were pushed to the margins by the many patent successes of the mechanistic model. Materialism was pursued with religious fervor and supreme confidence: major biologists actually swore mutual oaths to the true faith, and talented students were counseled to avoid physics, because soon no unsolved problems would remain. But the great revolutions in early twentieth-century physics that the mechanists never saw coming doomed the project: nineteenth-century materialism was toppled because relativity and quantum mechanics undermined its deepest foundations.