What does mediation mean/do for/in visual and culture studies? This is the question that we asked ourselves throughout the 4Cs, more particularly over the mediation labs and the workshops. In this handbook, we have gathered essays from curators and thinkers as well as the materials produced during the mediation activities of the 4Cs. Composed as much of theories as of practical examples, the handbook aims to provide a critical reflection on the transforming potential of mediation.This exhibition takes a look at the avant-garde practices that the psychiatrist Francesc Tosquelles carried out in the therapeutic, political and cultural field. Tosquelles transformed psychiatric institutions during the Republic and in fascist Europe. Today, he is an inspiration when addressing mental health policies in times of extreme crisis. This exhibition has the support of the 4Cs Project.