The fixed idea of sex and the dawn of theoretical gender medicine.

Cross-gender behaviour gradually entered the spheres of aetiology and diagnosis during the eighteenth century with reference to scattered instances of male cross-dressing. But well into the nineteenth century, "gender identity" (a mid-twentieth-century term) remained a poorly theorised instance of medicalisation. Late eighteenth-century concepts of "dynamic hermaphroditism" accounted for gender-nonconforming behaviours and aspirations, but could not account for the observed heterogeneity in disparities between sexed body and mind. Increasingly substantive contributions to aetiology were seen during the late 1870s and 1880s, particularly in response to Carl Westphal's convoluted, 1869 concept of "contrary sexual feeling" (conträre Sexualempfindung). Richard von Krafft-Ebing's notion of metamorphosis sexualis paranoica provided one of the most authoritative approaches to the question of gender identification in "sexual inversion". The notion, which took the first seven German editions of his Psychopathis sexualis to achieve a definitive formulation, needs to be seen in light of Krafft-Ebing's earlier conceptions of sexual delusion, which straddled the realms of the experienced sexual body and sense of self. Moreover, Krafft-Ebing was not the first to outline a theory of non-cisgender identity, as demonstrated by the mid-1880s work of Théodule-Armand Ribot and Rudolph Arndt, as well as various significantly earlier approaches to what had been considered the "monomania of sexual transformation".