Why does Cosimo talk with the Abbe so much and what happens as the result?

Chapter thirteen tells the story of Cosimo's passion for reading leading him to teach Abbe Fauchelefleur. He is so full of startling ideas and stories that the Abbe listens with rapt attention, and even when his years of Jansenist training overtake him and he is swept into a bout of absolutism and legalistic ranting, he is fascinated and so changed by what the young man is telling him that word spreads to the Ecclesiastical Tribunal that an Abbe is reading all of the most forbidden books, and he is hauled off between two burly men.