This essay on classroom mediation is dedicated to Professor Maria Irma Coudry who, since the foundation of the area of Discursive Neurolinguistics, has greatly contributed to reflect on pathologization, medicalization and mediation, themes that permeate the discussions about pedagogical practice in our days. The text is based on one of the concepts present in her work, Diario de Narciso: discurso e afasia - the "shared construction of meanings", introduced to question the standardized assesssement and therapeutic practices with aphasic subjects. Coudry's (1986) reflections about building up sense through language aiming to turn interlocutions meaningful and to allow subjects to assume their historical positions open a very fertile field for understanding what "mediation" means in the school context. By recognizing the student as a subject of language, and therefore dependent on the relationships established in his/her environment, this concept acts as a counter-apparatus to the standard methodologies, implemented by public policies and current in the school. The reflection presented are based on several authors of the Discursive Neurolinguistics, especially Coudry (1986, 1996, 2010), Freud (1891, 1895), Vygotsky (1926, 1934) and Luria (1977, 1979), relating cerebral functioning to symbolic and historical shared sense construction.