What is 'truth'? The question that Pilate put to Jesus was laced with dramatic irony. But at a time when what is true and what is untrue have acquired a new currency, the question remains of crucial significance. Is truth a matter of the representation of things which lack truth in themselves? Or of mere coherence? Or is truth a convenient if redundant way of indicating how one's language refers to things outside oneself? In her ambitious new book,...