This work develops an analysis of teaching philosophy at school, commonly associated to the idea of critic. It takes Adornos philosophy as the ground for an analysis of this idea in its most pressing senses. It deals with the scope and limits of several conceptions of teaching philosophy in a scene that is resolutely plural. The work asks for the meaning we could still find in the concept of Bildung in our country, and the role we would be willing to assign to teaching philosophy within this debate. The issue brings up questions concerning the tensions, similarities and differences bewteen the philosophical and the pedagogical discourse about teaching philosophy. While comparing these two discourses, I have tried both to dismiss any attempt to take philosophy as a global and unifying discourse about human education and to rely on the so called educational sciences for its ability to enlighten important aspects of educational practices due to its closeness to empirical problems. As part of a larger analysis on the relationship between knowledge and society, these issues are considered under the light of some ideas of Theodor W. Adorno, a philosopher who considered that relationship making use of philosophy`s social mediation, as well as its history and educational power. I believe Adorno also offers the proper methodological investigation of a philosophical analysis which somehow functions as a social theory, as much as a proper investigation of theoretical and methodological questions for a research lying between philosophical reflection and educational science. As an additional path, the thesis explores the virtues of a pedagogical discourse which is at least partially inspired by Critical Theory: Henry Giroux`s radical pedagogy. Finally, there is an empirical incursion on the practice of teachers of philosophy on the field, at secondary level. The main result of this research is to point out the power, the scope and limits of Adorno`s characterization of philosophical discourse for a contemporary analysis of the capacity to criticize usually attributed to teaching philosophy at school. This thesis recognizes concepts as dialectics, totality, negation, and mediation as tools of width and significance to deal with problems of a conception of teaching philosophy that see itself as critical, which means teaching philosophy in a way that is able to conceptualize the obstacles that constrain teachers and students when facing the challenge of reason as a promise of a happier life and a better society.