Back in the 19th century Edgar Allan Poe had presented us with the detective story as an analogue of poetic composition. Already in the age of the telegraph, it had occurred to him that when information is simultaneous (electric speed) the beginning and end of any situation are interchangeable. He therefore proposed that we should write poetry backwards. starting with the effect we wish to obtain before proceeding to discover the causes necessary for producing that effect. This is also the pattern of detective fiction in which the writer necessarily begins with the solution to the crime, writing the story backward in order to fit the crime mysteriously.