With its observations about the author’s dislike of spent matches and his deficient history of sexual experiment, Zona, Geoff Dyer’s recent book about a Tarkovsky film, seemed to represent an extreme case of criticism as narcissistic performance – but along comes Wayne Koestenbaum’s The Anatomy of Harpo Marx to make Dyer seem exemplary in the sobriety of his engagement, Matthew Arnold back among us.

Koestenbaum considers Harpo’s contribution to the Marx Brothers’ films in isolation, though the brothers had cultivated an appeal that was no less unitary for being carefully stratified. Groucho dressed like a shyster lawyer, Chico like an immigrant street tradesman, Harpo like a rough sleeper. Groucho undermined the authority of language from inside, Chico garbled it, and Harpo gave it the silent treatment.

Koestenbaum examines Harpo’s scenes moment by moment, consciously discounting any element of comedy, and rhapsodically likening him to more or less anybody: Gertrude Stein, Marcel Duchamp, John Cage, Dieter Roth, Thoreau and Wittgenstein (this roll-call from page 12 alone). He also recounts the dreams he had while writing the book,