The very existence of explicit techno-scientific controversies in the “nano” arena is often denied on behalf of a conception of science, risks, public engagement and responsibility which borders on a disembodied idealism and merits at least serious discussion. The recurrence of this view prompted us to clarify our position regarding our common field of research, in order to avoid being trapped in the seemingly clear divide between the universal and neutral pursuit of pure science, on the one hand, and on (...) the other hand the infinite variety of values and opinions that lead to the horrors throes of pure relativism. We therefore launched an internal trans-disciplinary project, in order to overhaul the premises underpinning both this idealistic standpoint and our own work, and to find a better definition of our approach to the exploration of the real policy implications of NST research initiatives. Indeed, the debates surrounding NST clearly have wider implications for the examination of issues of Science, Technology and Society as a whole. A first step in this clarification process was taken in Paris, at the conference which has now been published in this issue of Foundations of Chemistry. We further develop it in this paper, in the hope that it will contribute to the joint construction of a better nano-future. (shrink)