When facing a moral dilemma, Isabel Dalhousie, Edinburgh philosopher, amateur detective and title character of a series of novels by Alexander McCall Smith, often refers to the great twentieth-century poet W. H. Auden. This is no accident: McCall Smith has long been fascinated by Auden. Indeed, the novelist, best known for his No. 1 Ladies Detective Agency series, calls the poet not only the greatest literary discovery of his life but also the best...