The Black Monk is a short story by Anton Chekhov. In it Andrey Kovrin a scholar who goes crazy seeing the hallucinations of a monk dressed in black. Kovrin is told by the hallucination that he is a genius and has been chosen by god. The hallucination talks to him and they have long discussions about many things. Tragically he is driven in to madness and then death all at the hands of the mysterious monk.
At first it seemed like the monk was perhaps a supernatural being of some sort, but the clues dropped seemed to suggest that instead he was a product of Kovrin’s head. The monk speaks to Kovrin with the same knowledge that he possesses and appeals to the vanities of Kovrin. Truly he wishes that the monk would be some divine being, but he refuses to accept the monks existence as something other than physiological in origins until his very last moments.
Strangely Kovrin seems to be aware of his madness and seems to enjoy it, for him it is an escape out of mediocrity. Without it he is just another boring scholar. This is an unusual departure from the other portrayals of insanity that treat it as an unwelcome illness. Probably Macbeth has the most poignant display of this, where each step of insanity was a step closer to death. There’s little doubt that this man had schizophrenia and being a doctor Chekhov had probably a fair bit of experience with the illness. It does not give a realistic portrayal of the mental illness but the character is close enough to reality to seem supremely pathetic, pathetic enough even by the standards of Chekhov characters.