This book argues that ethical judgment by individual scientific policy advisors is more important than is often acknowledged. While many scientific policy advisors routinely present themselves as neutral or value free scientists, here is demonstrated that the ideal of scientific integrity as neutrality is misguided and that an alternative understanding is demanded. The book provides an overview of the type of social and political value decisions that have to be made in all phases of research and advice. It moves on to examine proposed procedures or guidelines for scientists and critically assesses plans for the democratization of decision making in science and scientific advice. The book offers a reflection on the practice of scientific advice that will appeal to practitioners and scholars of Public Administration, Public Management and Policy Analysis.