This paper offers a novel reading of Arabic sexological publications from the 1920s. Existing studies on early Arabic sexology present a Foucauldian perspective on the subject, focusing on aspects of disciplining bodies and desires in colonial and quasi-colonial contexts of knowledge production and nation building in the MENA region. This paper looks at the emerging Arabic expert discourse on human sexuality from a new angle by focusing on its unique reception of evolutionary theory. Engaging with Bruno Latour’s concept of the modern Constitution, it analyzes the discussion of human sexuality in Arabic sexological texts, which is set between natural drive and self-refinement. The studied texts reveal an ambiguous portrayal of human sexuality as both grounded in animalistic instincts of procreation and as also transcending the bestial nature: a cultivated sexuality is presented as a fundamental part of the modern and civilized subject. While attempting to clearly distinguish the civilized from the barbarian, human from non-human and to draw a clear line between nature and culture, Arab sexologists at the same time kept blurring these supposedly clear lines. This double operation of separation and blurring, or, in Latour’s terms, of purification and translation, is particularly visible in their theorization of aesthetics. Reading Charles Darwin’s work as a theory of aesthetic feeling and judgement, Arab sexologists in the early 20th century engaged in a rich discussion on the natural predisposition to perceive beauty. Aesthetic taste, accordingly, is seen as a capacity which can be explained by natural laws. At the same time, the enjoyment of art, the refinement of taste and aesthetic judgement is discussed as a marker of culture and civilization, of transcending a purely natural state. Suggesting a post-anthropocentric reading of Arabic sexology, this paper aims at moving beyond describing the transformed sexual discourse of the late 19th and early 20th centuries as colonial adaptations of a European medicalizing sexual discourse. It presents an understanding of Arabic sexology as a discourse with a profoundly ambivalent understanding of nature that made it possible to conceive of certain bodies, practices or desires as natural and normal, and to label others as monstrosities.