The present paper builds on the Rawlsian critique of utilitarianism in order to identify the moral implications of Niklas Luhmann’s social systems theory. While Luhmann aptly discerned the pervasive problems of the precarious system–environment relations throughout the modern society, he took moral communication to be person-centered and thus ill-equipped to deal with these problems. At the same time, the Rawlsian possibility of sacrificing fundamental liberties for the sake of economic gains not only exemplifies the Luhmannian precariousness of the relations of (...) the economic system to its societal environment, but also shows this precariousness to be a moral problem. Thus, from the systems-theoretic perspective, the Rawlsian idea of justice denotes the moral dimension of the capacity of the societal environment to carry the economic system. More generally, the proposed complementarity between Rawls and Luhmann allows to see the precariousness of system–environment relations, for any type of social system, as a moral problem. Two implications follow. First, the morally problematic manifestations of the precarious system–environment relations are not limited to the Rawlsian case of the discrimination of the least advantaged groups but rather include a broad range of social costs and damaging effects of business on society and nature. Second, and related, the proposed systems-theoretic perspective explicates the moral value of sustainability of the economic as well as other social systems in their environment, societal and ecological alike. (shrink)