4 ideas
Hermine, a young woman he meets in a bar, teaches him the foxtrot, arranges an affair with the courtesan Maria, and introduces him to the saxophonist Pablo, who takes him into a drug-fuelled Magic Theatre. There Harry sees his self broken into countless figures, stabs a mirror-image of Hermine, and is sentenced not to death but to laughter, with the understanding that he must play the game of life again and do it better.
The Treatise on the Steppenwolf argues that Harry's man-versus-wolf story is a false simplification: every person holds hundreds or thousands of selves, and the belief in a single unified 'I' comes from the body being one. Squeezing that plurality into a neat two-part conflict is a coping story that keeps the person stuck. Relief comes from treating the self as a chessboard of pieces that can be rearranged, not from settling which of two sides wins.
Harry despises middle-class respectability yet chooses to live among clean staircases, polished furniture and potted plants, because order and comfort soothe him. The outsider's revolt feeds on the thing it rejects: his identity as a lone wolf only means something against the bourgeois world he stays close to. Rebellion that depends on its target for definition and comfort cannot carry a person out of it.
The Immortals, figured as Mozart and Goethe, laugh because they see life's clashes of high and low, eternal and trivial, from a distance that turns them into play rather than tragedy. Harry's seriousness is the disease: he treats each contradiction in himself as a wound to agonise over. The cure prescribed to him is to learn to laugh, accepting even the cheap radio broadcast of Handel as containing the eternal.