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.
— The Defendant (1901).