[fantasyfan]

The theme of the book is socially "taboo". Further, It explores the psychological processes of a person who delights in violating this forbidden area and portrays him as superficially cultivated. In addition to this there is--as Caleb72 has pointed out--a condemnation of the social processes which should protect the vulnerable who are victimised.

Nabokov subverts so many social structures so effectively that that this kind of exploration is simply too difficult for many people to engage with. I would find Chinatown a cinematic equivalent. It brilliantly subverts and expands the world of film noir. But the sheer horror is just too ugly for many. Still such works remain necessary to cast light on the dark.