The notion of sustainability is interdisciplinary, requiring more than multidisciplinary research, and normative, requiring ongoing discussion about ethical priorities. Hence, the authors of this anthology recommend improved interdisciplinary collaboration and intensified public discussion about sustainability. By such admittedly fallible procedures we should try, again and again, to avoid or rectify instances of unsustainability. Further, the authors argue in favour of reduced material consumption, an ideal of 'good life', and gradualistic obligations toward non-human beings.