It becomes clear to Julien that the de La Moles and their friends suffer from deep boredom. One of the reasons might be that they never tolerate any serious subjects in their conversation. Everything has to be about superficial amusement. It's no wonder they're bored.
The only reason that people come to the de La Moles' house is because they want something from the marquis. Everyone seems to know this and it makes everything in the house seem hollow.
One day, Julien asks Father Pirard whether he'd be allowed to stop eating dinner with the de La Moles, since it's so boring. Then he realizes that the marquis' daughter has been listening. He feels like he's really put his foot in it, but he doesn't realize that Mathilde feels the same way.
It turns out that Mathilde has a little social group that makes fun of how boring her parents' friends are.
Julien soon finds his way into this company. He's shocked, though, because he doesn't think it's appropriate to sit around insulting people behind their backs.
Julien hears his rival Tanbeau talking about how a poet named Béranger should be thrown into a dungeon for ten years because he writes obscene political things. Julien thinks Tanbeau is a monster.
Father Pirard beckons Julien over and tells him not to write anything political in the French language or the marquis will dislike him forever.
Julien goes upstairs and burns a few things he's been writing.