The Finkler Question (Hardcover) by Howard Jacobson

Julian Treslove, a professionally unspectacular former BBC radio producer, & Sam Finkler, a popular Jewish philosopher, writer & television personality, are old school friends. Despite very different lives, they've never quite lost touch with each other - or with their former teacher, Libor Sevcik. Both Libor & Finkler are recently widowed, & together with Treslove they share a sweetly painful evening revisiting a time before they had loved & lost. It is that very evening, when Treslove hesitates a moment as he walks home, that he is attacked - & his whole sense of who & what he is slowly & ineluctably changes.