Recent work in the social studies of science has emphasized the importance of studying both the social and cognitive aspects of the evolution of scientific specialties and disciplines. This has implications for science policies that aim at the direction of scientific fields toward external goals: the cognitive state and dynamics of the field have to be taken into acount. Such a cognitive approach to science policy has been elaborated by a number of German science scholars. The three-phase model of scientific developments and the finalization thesis of the Starnberg group is discussed, and the policy implications are critically reviewed. A group based in the University of Bielefeld has published case studies designed to trace the role of cognitive factors in explaining the impact of science policy programmes on scientific fields. It turns out that mutual adaptation processes occur in the course of formulating the programmes which reduce conflict and resistance. In conclusion, some perspectives for further work are noted.