This is a study of the philistine - or poshlyak - in Nabokov's fiction with focus on Lolita. The concept of poshlust and philistinism holds a special position in his novels and essays. The Russian tradition from which Nabokov drew for his version of the concept is outlined and then compared with other related terms, in order to define it more sharply. The aim is to analyze how Nabokov deploys the concept, not so much as a cultural concept but more as a literary device and finally what this reveals about Nabokov's aesthetics.