Scientists employed by agencies of the US government (and by extension, those working at universities who are recipients of federal grants) have distinctive responsibilities to the community that supports their work. Traditionally, such public scientists retreated behind a veil of objectivity thought to define scientific knowledge. But this approach today fails on both epistemological and political grounds. Most striking is the fact that the very stance of principled distance from societal debates has opened the scientist to charges of irrelevance. What is the distinctive role of federal science agencies in society? Is there a way out of the dilemma in which government scientists are seen as irrelevant, or if relevant, biased? It is argued here that the notion of a public self offers a means out of this dilemma. (C) 2000 Published by Elsevier Science Ltd.