From the start, the relationship between humans and douen bears strong overtones of real-life race relations. Characteristic of both white-black and European-Native American relations are played out, although in each case the analogy is imperfect. Both are represented by the quick judgment by humans that the douen are inferior.
Sam Yeager's blog
I thought that the most interestig part of Snow Crash was Stephenson's ideas about what would take the place of government in a lawless society. The Mafia is the most obvious example of this. An organization that has always had to hide to some extent in our society is right out in the open in this futuristic America, and what is more, it seems to be one of the most enlightened ruling groups around. For example, when Jason mistakenly hand-delivers his package to Uncle Enzo, the contrast between the Mafia-controlled block and the ones held by Narcolombians are emphasized.
The theme of dependence is dominant from the start in Lore's relationship with Spanner. She arrives "naked and nameless in the city." (5) When she first encounters Spanner, she is lying on the gorund, utterly helpless. Spanner nearly leaves her, but finally decides to help. Then, as Lore goes back to Spanner's home, she realizes that she "needed this woman, Spanner; depended on her, in a way that was shocking." (11) For Lore, a child of privelege, confident in her education and her ability, this is a very difficult situation to accept.
The mental status of the rats seems a little unclear. Clearly, they are seen as possessing far less than normal human intelligence. They are treated as animals (rats!) and have to be carefully instructed to perform even simple tasks. For example, the trainer in Muct says "You tell a rat to take a shit, you gotta remember to tell 'er to pull her pants down first and pull 'em up afterwards." (14) Yet the man at the RAT institute says the procedure to become a rat will not change the narrator in the prologue, (5) and indeed it does not seem to other than the obvious effect on his will.
This is kind of a peripheral point in the novel, but wouldn't something like mindspeech completely change a society? I can't think of more than a couple of scientific advancements in human history that have been anywhere close to as important to the nature of human interaction than that would be. The telepathy itself is cool, but not all that important. The part that matters is that it is impossible to lie. Of course, people could still speak lies, but how could they ever get away with it in anything important?