In the late nineteenth and early twentieth century, a number of Italian psychiatrists were convinced that medicine and education should work together to treat children with mental disabilities, then commonly defined as "feeble-minded". To this end they promoted the establishment of "Medico-Pedagogical Institutes", institutes, that is, with medical and psychological staff, reserved for disabled minors considered "amendable" or "educable". These institutions were to serve, on the one hand, to remove children from Mental Hospitals, and on the other, to enable them to be educated and to improve their psycho-physical attitudes. Nevertheless, over their long history, which lasted about a hundred years, the educational component decreased significantly and many Medico-Pedagogical Institutes ended up by resembling adult Mental Hospitals. At the end of the 1970s, several scandals erupted, revealing the inhuman conditions in which children were treated, and all the Institutes were closed. It is impossible to understand the overall sense of the value and the functions exercised by the Medico-Pedagogical Institutes over the century of their existence, unless we take a long-term perspective, which can help to create a detached and balanced history, revealing of our relationship with diversity and biopower.