Honoré de Balzac 
Seraphita 

Séraphîta is a French novel by Honoré de Balzac with themes of androgyny. It was published in the Revue de Paris in 1834. In contrast with the realism of most of the author's best known works, the story delves into the fantastic and the supernatural to illustrate philosophical themes.

In a castle in Norway near the fjord Stromfjord, Séraphitüs, a strange and melancholic being, conceals a terrible secret. Séraphitüs loves Minna, and she returns this love, believing Séraphitüs to be a man. But Séraphitüs is also loved by Wilfrid, who considers Séraphitüs to be a woman (Séraphîta).

In reality, Séraphitüs-Séraphîta is a perfect androgyne, born to parents who by the doctrines of Emanuel Swedenborg have transcended their humanity, and Séraphitüs-Séraphîta is the perfect example of humanity.