"Wittgenstein's Nephew" is a semi-autobiographical novel that explores the friendship between the narrator and his friend Paul, who is the nephew of the famous philosopher Ludwig Wittgenstein. The story takes place in Vienna and is set against the backdrop of the Austrian mental health system. The novel delves into themes of sanity, insanity, and the fine line that separates the two, while also offering a critique of Austrian society. It is a meditation on the nature of illness, both physical and mental, and the impact it has on personal relationships and one's perception of the world.