Most readers think an authorized biography, written with the help of the subject’s family, gives the writer an advantage. But Jonathan Bate’s unauthorized life of Ted Hughes (1930–98) has turned out better without such help. He’s free from obligation and pressure, censorship and constraint. No longer tempted to pad his book with quotations that he doesn’t have to pay for, he now quotes with “fair use” and is more selective and concise. A biographer frequently encounters a family who refuses to cooperate and then criticizes the author for making errors it could easily have corrected. Hughes’s widow, Carol, first gave and then withdrew permission to quote his literary work. Before reading Bate’s book, she publicly contradicted his statement that friends accompanying Hughes’s body from London to his home in Devon...