Symbolism, Imagery, Allegory
When White's explaining how the cultural things he used to have faith in have now lost their meaning, he uses an example from the Holocaust:
"The things I believed in dont exist any more. It's foolish to pretend that they do. Western Civilization finally went up in smoke in the chimneys of Dachau but I was too infatuated to see it. I see it now." (27)
Dachau was a concentration camp in Germany where the Nazis murdered tens of thousands of people, mainly Jews. White's stating that, in light of the horrors of history, it's impossible to believe that these high-minded cultural productions—like the symphonies of Beethoven, or Rembrandt's paintings, or Shakespeare's plays—have the ability to redeem humanity. People can do all the pretty and interesting stuff they want, but so long as they're capable of the Holocaust, it doesn't really matter.
Interestingly, White uses genocide as a reason for his own loss of faith in life. There's a sort of circular nature to this logic—it's death rationalizing death. But this also syncs up with the Sunset Limited's symbolic work (which we explore elsewhere in this section): White sees life as a way station, and from where he's sitting, whatever limited good we do with it doesn't counteract the bad.