Following Foucault's analysis of expanding psychiatric power, this article addresses the shift from psychiatry into pedagogy in interventions concerning children with mental problems in the nineteenth century. The aims of this article are twofold. First, to answer the question of how the notion of "idiocy" developed in the context of an increasing interest in sensorial experiences in childhood, in relation to both psychopathology and "normalcy". New research into the early nineteenth-century case of the "wild boy of Aveyron" reveals the importance of care in the first observations of the boy and the connection that was subsequently made with sensorial experiences in childhood and child development. In the wake of the work of Enlightenment alienists such as Pinel and Itard, Edouard Séguin constructed an educational trajectory for children with mental impairments in which, through strict pedagogical guidance, the lack of "will" would be restored by stimulating the senses. The second aim is to examine the case of the first autonomous school for "idiotic" children in The Netherlands. Following the "praxeography" approach, I focus on the interventions by the Reverend Cornelis van Koetsveld, who shaped his "cure by education" through training the senses in children with problems.