In attempting to reach the genuine psychological reason for the popularity of detective stories, it is necessary to rid ourselves of many mere phrases.  It is not true, for example, that the populace prefer bad literature to good, and accept detective stories because they are bad literature.  The mere absence of artistic subtlety does not make a book popular.  Bradshaw’s Railway Guide contains few gleams of psychological comedy, yet it is not read aloud uproariously on winter evenings.  If detective stories are read with more exuberance than railway guides, it is certainly because they are more artistic.  Many good books have fortunately been popular; many bad books, still more fortunately, have been unpopular.  A good detective story would probably be even more popular than a bad one.  The trouble in this matter is that many people do not realize that there is such a thing as a good detective story; it is to them like speaking of a good devil.  To write a story about a burglary is, in their eyes, a sort of spiritual manner of committing it.  To persons of somewhat weak sensibility this is natural enough; it must be confessed that many detective stories are as full of sensational crime as one of Shakespeare’s plays.

There is, however, between a good detective story and a bad detective story as much, or, rather more, difference than there is between a good epic and a bad one.  Not only is a detective story a perfectly legitimate form of art, but it has certain definite and real advantages as an agent of the public weal.

The first essential value of the detective story lies in this, that it is the earliest and only form of popular literature in which is expressed some sense of the poetry of modern life.  Men lived among mighty mountains and eternal forests for ages before they realized that they were poetical; it may reasonably be inferred that some of our descendants may see the chimney-pots as rich a purple as the mountain-peaks, and find the lamp-posts as old and natural as the trees.  Of this realization of a great city itself as something wild and obvious the detective story is certainly the ‘Iliad.’  No one can have failed to notice that in these stories the hero or the investigator crosses London with something of the loneliness and liberty of a prince in a tale of elfland, that in the course of that incalculable journey the casual omnibus assumes the primal colours of a fairy ship.  The lights of the city begin to glow like innumerable goblin eyes, since they are the guardians of some secret, however crude, which the writer knows and the reader does not.  Every twist of the road is like a finger pointing to it; every fantastic skyline of chimney-pots seems wildly and derisively signalling the meaning of the mystery.