Aldo Leopold's approach to environmental management changed drastically between the early 1920s, when he advocated predator eradication, and 1944, when he drafted “Thinking Like a Mountain.” How are we to understand these changes?
It is shown that, early in his career, Leopold developed the basic elements of a conservation ethic, borrowing key elements from the Russian organicist P. D. Ouspensky and from A. T. Hadley, an American pragmatist who was president of Yale University when Leopold was a student there. Hadley's pragmatism counseled that we act on the wisdom embodied in the intuitive perceptions of our forefathers. While Leopold changed the presentation of his conservation ethic over the years, he never gave up these key ideas, traces of which remain in the final version of “The Land Ethic.”
The changes in Leopold's management strategies were not due to a change in metaphysical or moral views, but to his evolving experience as a forester and game manager. Leopold learned that “violent” strategies, such as monocultural planting of trees, pervasive agricultural management of fragile ecosystems and, above all predator eradication, led to unforeseen and unwelcome results. Leopold recognized that we may never have adequate information to manipulate natural systems for maximal human utility without diminishing their vitality. He therefore lost faith in “economic biology” as a guide to environmental management.
Leopold's changing views on management resulted from his experience as an environmental manager, not from a conversion from utilitarian anthropocentrism to biocentric nonanthropocentrism. While Leopold was drawn to Ouspensky's organicism, and he hoped Americans would through a profound change in their perceptions of nature adopt such a view eventually, he believed throughout his career that longsighted anthropocentrism provides an adequate basis for conservation practices.