Nanotechnology is a swiftly developing field of technology that is believed to have the potential of great upsides and excessive downsides. In the ethical debate there has been a strong tendency to strongly focus on either the first or the latter. As a consequence ethical assessments of nanotechnology tend to radically diverge. Optimistic visionaries predict truly utopian states of affairs. Pessimistic thinkers present all manner of apocalyptic visions. Whereas the utopian views follow from one-sidedly focusing on the potential benefits of (...) nanotechnology, the apocalyptic perspectives result from giving exclusive attention to possible worst-case scenarios. These radically opposing evaluations hold the risk of conflicts and unwanted backlashes. Furthermore, many of these drastic views are based on simplified and outdated visions of a nanotechnology dominated by self-replicating assemblers and nanomachines. Hence, the present state of the ethical debate on nanotechnology calls for the development of more balanced and better-informed assessments. As a first step in this direction this contribution presents a new method of framing the ethical debate on nanotechnology. Thus, the focus of this paper is on methodology, not on normative analysis. (shrink)