1 Félix Voisin and the genesis of abnormals Claude-Olivier Doron Université Paris Diderot/SPHERE-Centre Canguilhem Article to be published in History of psychiatry (2016) Keywords: ‘Abnormals’, ‘Phrenology’, ‘Idiocy’, ‘Criminals’, ‘Difficult childhood’ Abstract: This article traces the genealogy of the category of ‘abnormals’ in psychiatry. It focuses on the French alienist Felix Voisin (1794-1872) who played a decisive role in the creation of alienist knowledge and institutions for problem children, criminals, idiots and lunatics. After a presentation of the category of ‘abnormals’ as understood at the end of the nineteenth century, we identify in the works of Voisin a key moment in the concept’s evolution. We show how, based on concepts borrowed from phrenology and applied first to idiocy, Voisin allows alienism to invest medico-legal (including penitentiary) and medical- educational fields (including difficult childhood). We underline the extent to which this enterprise is related to Voisin’s humanism, which claims to refound pedagogy and the right to punish on the anthropological particularities of individuals, in order to improve them.