Purity is mostly an addiction of the working poor, who have nothing else to show that their efforts at controlling their lives have succeeded to some extent. They abhor the thought that others might fall into the abyss of street and trash life that they are so very close to. Held together by not much more than the mean set of their mouths, they are determined that the world will not just fall into getting its self-indulgent rocks off all around their small castles of almost-made it.

This is as true in the slums of Cairo as it is in the lower burbs of white America.