The relationship between science and politics only attracts attention when something is amiss: when politics interferes excessively in science or when scientific findings have dangerous consequences for society. But when is political control ‘excessive’, and when do scientific findings pose a ‘danger’ to society? Before loudly insisting on academic freedom or invoking the responsibility of scientists, we should take a sober look at the relationship between science and politics in all its complexity. Not only are the sciences very different from one another, they also have many points of contact with political processes, which themselves are not uniform. The lecture describes these difficult relationships between science and politics in order to develop an appropriate concept of scientific freedom.