In The Pervert’s Guide to Cinema, Slavoj Žižek’s rambling psychoanalytic diagnosis of classic Hollywood films, the Slovenian philosopher claims that the three Marx Brothers—Groucho, Chico and Harpo—each represent a single element of the Freudian psyche: superego, ego and id, respectively. A similar scheme is at play in E.L. Doctorow’s twelfth novel, Andrew’s Brain (Random House; $26), which is structured as an ongoing conversation in an undisclosed location in the early 2000s between a middle-aged cognitive scientist named Andrew and someone he calls “Doc,” presumably his psychotherapist, though Doc’s identity is never made explicit. The novel features two speaking characters at most, but many more personalities. Throughout, Andrew refers to himself alternately as the Holy Fool (spontaneous, gregarious, smoking a cigar), Sir Andrew the Pretender (happy, rational, ephemeral) and “the brain,”…