This article provides a review of the literature on the uses of “free speech” within the school and about school. First of all, “free speech” is conceptualized from the work of Foucault on Parrhesia as “a kind of verbal activity where the speaker has a specific relation to the truth through honesty.” (Foucault, 2001, p. 19) Then a thematic analysis of the body of articles and books compiled sing the NVivo software makes it possible to distinguish four groups of work, which structure this article: a) the parrhesiasts teacher and his knowledge, b) parrhesia for a democratic project at school, c) the educational researcher as a specific intellectual and d) parrhesia and the devices for the expression of emotion. The work highlights the obstacles to be overcome so that parrhesiastic practice can be carried out within the school.