[Nosological and aetiological conceptualisation of mental disorders and diseases: a major concern of physicians in the late Middle Age].

This article analyses the nosological and aetiological conceptualisation of mental disorders in the late Middle Ages. Medieval physicians viewed humans as composed of a body and soul that were united and closely interrelated. They located mental processes in the brain, distributed among different areas according to the faculties of the soul, in particular imagination, reason/judgement, and memory. Mental diseases, were distinguished and diagnosed on the basis of a complex and subtle symptomatology, and their causes were the subject of thorough reflection in order to situate them within the physiological theories of the time. Medieval nosology mainly distinguished three categories of mental disease: frenzy, mania, and melancholy, taking into account observed behaviors and relying on a multifactorial aetiology. Examining these medieval conceptualizations allows us to place the search for a precise classification of mental disorders and diseases, and for an etiology consistent with the physiological conceptual framework, within a long-term historical trajectory. This article thus provides insights from a historical and epistemological perspective highlighting the resonance between the concerns of medieval physicians and those of contemporary psychiatrists.