Was Nietzsche mentally ill? I am interested in Nietzsche because of his quotes, that I interpret, as being about mental illness. I just scanned his Wikipedia page, which says nothing about him suffering from mental illness. (I know that I should pick up an actual book about him. LOL) It sounds like he was unlucky in love though. From what I know, there is a link between many people's mental illness and feeling unlucky in love/life.

"Nietzsche never married. He proposed to Lou Salomé three times, but his proposal was rejected each time.^[118][ There is a theory that blamed Salomé's view on sexuality as one of the reasons for her alienation from Nietzsche. As articulated in the 1898 novella Fenitschka, she viewed the idea of sexual intercourse as prohibitive and marriage as a violation, with some suggesting that they indicated sexual repression and neurosis.^[119]

Nietzsche scholar Joachim Köhler [de] has attempted to explain Nietzsche's life history and philosophy by claiming that Nietzsche was homosexual. Köhler argues that Nietzsche's syphilis, which is "...usually considered to be the product of his encounter with a prostitute in a brothel in Cologne or Leipzig, is equally likely, it is now held, to have been contracted in a male brothel in Genoa."^[120] The acquisition of the infection from a homosexual brothel was confirmed by Sigmund Freud, who cited Otto Binswanger as his source.^[121] Köhler also suggests Nietzsche may have had a romantic relationship as well as a friendship with Paul Rée.^[122] There is the claim that Nietzsche's homosexuality is widely known in the Vienna Psychoanalytic Society, with Nietzsche's friend Paul Deussen claiming that the philosopher never "touched a woman".^[123][124]

Köhler's views have not found wide acceptance among Nietzsche scholars and commentators. Allan Megill argues that, while Köhler's claim that Nietzsche was in a confrontation with his homosexual desire cannot simply be dismissed, "the evidence is very weak," and Köhler may be projecting twentieth-century understandings of sexuality on nineteenth-century notions of friendship.^[122] It is also known that Nietzsche frequented heterosexual brothels.^[121] Some like Nigel Rodgers and Mel Thompson have argued that continuous sickness and headaches hindered Nietzsche from engaging much with women. Yet, they bring other examples in which Nietzsche expressed his affections to other women, including Wagner's wife Cosima Wagner.^[125]

Other scholars have argued that Köhler's sexuality-based interpretation is not helpful in understanding Nietzsche's philosophy.^[126][127] However, there are also those who stressed that, if Nietzsche preferred men—with this preference constituting his psycho-sexual make-up—but could not admit his desires to himself, it meant he acted in conflict with his philosophy.^[128]"