The primary themes in the second chapter of Fahrenheit 451 are learning to read the content and understand the meanings in books, the importance of resisting the social norms that enforce conformity, and forming bonds of solidarity with the community of readers. Ray Bradbury encourages the novel's readers to realize the importance of taking a stand when their conscience compels them to do so. He also suggests a broad interpretation of learning to read: the most important lessons are not the knowledge gleaned from books. Rather, people who read are entering into a community, forming bonds of solidarity with other people who value intellectual curiosity. They do not fear challenging the status quo or established authority.
As the first chapter ended, Guy Montag had made the decision to start reading the books he had stashed away. As the second chapter, "The Sieve and the Sand," begins, Montag is diving in to many books. His tentative steps in learning to read are shown in the passage that explains the chapter title.
He compares the tiny bit of knowledge that sticks to his brain when he reads difficult content to the grains of sand that do not pass through a sieve. He thinks that maybe if he reads everything fast, "some of the sand will stay in the sieve."
Montag is not only trying to read by himself but also encouraging his wife, Mildred, to join him. When he (Montag) reads to her friends, the emotions stirred up by "Dover Beach" frighten and anger them. Montag realizes that by learning the content in the books, he must distance him from the norms that society relentlessly imposes. This is shown in the train, when he tries to block the dental detergent ad. "The people were pounded into submission; they did not run, there was no place to run."
When he connects with Professor Faber, Faber tells him, "'It's not books at all you're looking for!...Books are only one type of receptacle." When he reveals his plan that "we" might sabotage the firemen, Montag shows he understands that he is not alone. To Faber's question, "We?" Montag responds, "You and I."