The innocence of how the very young see the world – and how it comes to be lost – is at the heart of Jim Shepard’s seventh novel. “What makes old people like that?” a child wonders. “I told her I didn’t know.”The Book of Aron is set in Warsaw between 1939 and 1942 as anti-Jewish action proliferates through the city. The story is narrated by the small, contained voice of an eight-year-old boy who sees more than he realises. Aron’s spare narrative and modest understanding create the force of the tale, which straddles fact and fiction. Aron is Jewish, living with his family in the Warsaw ghetto. He encounters the real-life figure of Janusz Korczak, a Polish-Jewish educator and paediatrician who introduced progressive orphanages into Polan