Biodiversity, conservation biology, and rational choice

This paper critically discusses two areas of Sahotra Sarkar's recent work in environmental philosophy: biodiversity and conservation biology and roles for decision theory in incorporating values explicitly in the environmental policy process. I argue that Sarkar's emphasis on the practices of conservation biologists, and especially the role of social and cultural values in the choice of biodiversity constituents, restricts his conception of biodiversity to particular practical conservation contexts. I argue that life scientists have many reasons to measure many types of diversity, and that biodiversity metrics could be value-free. I argue that Sarkar's emphasis on the limitations of normative decision theory is in tension with his statement that decision theory can “put science and ethics together.” I also challenge his claim that multi-criteria decision tools lacking axiomatic foundations in preference and utility theory are “without a rational basis,” by presenting a case of a simple “outranking” multi-criteria decision rule that can violate a basic normative requirement of preferences (transitivity) and ask whether there may nevertheless be contexts in which such a procedure might assist decision makers.