This article examines the emergence of modern psychiatric discourse under the culturally Islamic yet radically secular context of the early Turkish republic (1923-1950). To do so, it focuses on the psychiatric publications of Mazhar Osman [Uzman] (1884-1951), the widely acknowledged “father” of modern Turkish psychiatry; and aims to genealogically trace his scientific project of reconceptualizing ruh, an Arabo-Turkish concept that predominantly refers to transcendental soul, rendering it physiologically within the framework of biological-descriptive psychiatry. The article consequently addresses the elusive and multilayered psychiatric language emerged in Turkey as a result of modern psychiatry’s interventions into a field that was previously defined by religion and indigenous traditions. Attempting to contextualize republican psychiatric discourse within the cultural and socio-political circumstances that has produced it, the article sheds light on how the new psychiatric knowledge propagated by Mazhar Osman was formulated in constitutive contradistinction to religious or traditional discourses, explicitly associating them with the Ottoman past and its alleged backwardness, hence reverberating with the Kemalist project of modern Turkish state building. Furthermore, by focusing on the complexities of the Turkish psychiatric language and the contestations it has generated, the article aims to reflect on the ways in which the Turkish psychiatric language was (and presumably still is) haunted by earlier forms of Islamic knowledge and traditions, despite modern psychiatry’s as well as modern secular state’s systematic and authoritative attempts to erase them for good.