The coevolution of descriptive and evaluative beliefs in Aldo Leopold’s thinking

Abstract The founder of conservation biology, Michael Soulé, set out a vision for conservation biology that was explicitly value-laden, analogous to cancer-biology. In so doing, he drew on the writings of Aldo Leopold, known among philosophers primarily for his land ethic. Employing and extending the work of Anderson (2004) and Clough (2020), I argue that the Leopoldian views that Soulé was drawing on were the product of the coevolution of descriptive and evaluative beliefs over the course of Leopold’s life, grounded in his experiences, resulting in tested and reliable – albeit defeasible – values underlying conservation biology.