Talking about Detective Fiction, by P.D. James; Faber & Faber, 2009, 159 pages, $26.99. Most real crime is sordid, intellectually uninteresting, and committed by repellent people, or at least by uninteresting people at their repellent worst. Crime fiction, on the other hand, largely by taking crime away from its real perpetrators and shaping a confection out of it, has fascinated enormous numbers of readers since the nineteenth century. Agatha Christie is reportedly the biggest-selling novelist of all time, but she is only the most popular of an ever-swelling multitude of crime novelists. The range of writing is wide, from the…