This article concerns the conditions for the institutionalization of open academic debate. The author focuses on the changes that have occurred over time in the seminar’s place in academic practice. She describes three types of seminars, from various eras in university history. In each case, the bases for the institutionalization of academic discussion were generally-held convictions as to what knowledge is and how it should be sought. Seminars legitimized academic debate. The examples provided—of the medieval university, Humboldt’s university, and the so-called entrepreneurial university—have various sources of legitimation: religion, the authority of scholarship, or the economic ‘usefulness’ of science (devoid of other authority). The author attempts to show that the sources of legitimation are reflected in the forms of the seminar’s institutionalization: the composition of the participants, the conversational rules (its public or closed character), and the transparency of academic knowledge.