Gothic literature is always concerned with the duality of society and reflects the anxieties simmering beneath the surface. Never is this more true than in the fin de siecle Gothic classics: Stoker's Dracula, Wilde's Picture of Dorian Gray, and Stephenson's Dr Jekyll and Mr Hyde, all of which are concerned with the idea that the politeness of late Victorian society is only a veneer, beneath which society is dark and ugly. Dorian Gray, like Jekyll and Hyde, is set in London, a city which serves to represent a whole sprawling empire. London, in this novel, is a microcosm of society as a whole: Dorian moves between the respectable London of the upper class, and the back-alley London that is, perhaps, more the "real" London, representing the fact that the image society portrays of itself is not necessarily the truth. Wilde debated this concern of illusion and reality repeatedly: "Man is least himself when he talks in his own person. Give him a mask, and he will tell you the truth." In the darkness, and with his evil deeds confined to the portrait hidden in the attic, Dorian feels free to do whatever he likes—and that way lies only evil.
Note as well that this novel was published in 1890, a mere two years after the height of the Jack the Ripper murders in London. The imagery of dark alleys and "black-shadowed archways" recalls the lurid details published in newspapers and magazines the world over of prostitutes killed gruesomely in London's underworld—but, indeed, in Whitehall, only a stone's throw from some of the city's most respectable districts. The importance of the setting in this novel, then, is that it reminds us that the best and worst of society often go side by side and, indeed, are frequently contained within the same person.