Aquinas’s Ecological Vision: Natural Law and Friendship in Contemporary Environmental Political Thought

This article examines Aquinas’s thinking about law and nature to show that for Aquinas natural law is not about deriving or finding normative rules (standards) in the order of the cosmos or requirements of practical rationality. Rather, I argue that for Aquinas, natural law is a distinctive way of theorizing relationality and embodiment in the “sublunary realm”: one that aims at “friendship” across species lines (STI-1199.2-3). The word Aquinas uses to describe this ecological practice is synderesis. For Aquinas, synderesis is both the humancreaturely capacity to grasp the analogical structuring of reality and the “disposition” that allows us to work on transforming this reality into belonging-together through our participation in natural law (ST179; DV 15-17). Synderesis is thus of central importance to Aquinas’s account of natural law, yet it is largely overlooked by modern natural law theorists. The article concludes by exploring how Aquinas’s natural law thinking might contribute to an environmental politics of friendship.