In writing her new biography of W.B.Yeats, George's Ghosts, Brenda Maddox found Yeat's belief that he and his young wife spent five years of communication with spirits an initial obstacle. She talks with psychotherapist Susie Orbach author of The Impossibility of Sex about how this supposed magic worked - to save the Yeats's marriage and give Yeats the metaphors for his late great poetry. But do biographers, or therapists, need to like the people they are analysing?