The principle of scientific freedom is usually taken forgranted; few attempts have been made to justify it systematically. The present paper discusses three “classic” arguments, which are used to justify this principle. However, it will become clear that (a) each argument refers to a different understanding of science and therefore justifies a different type of science, and that (b) each of them is based on assumptions which are not always consistent with the social reality of scientific research; the profound changes (...) science has undergone since its inception are not sufficiently taken into account. (shrink)