In Ray Bradbury's Fahrenheit 451, there are several motifs present such as "alienation and loneliness," "apathy and passivity," and "change and transformation."
The book's primary theme is found in...
...Bradbury's basic point of view, which passionately embraces the importance of books for human beings.
This theme is presented primarily in the context of Montag's job and the rules of society at large: books are burned because the knowledge they contain is dangerous—encouraging people to think, which also encourages them to question! Without books, most people (like Mildred) are easily led. They watch and listen to things that are approved by the government.
There are some people, like Faber, who fight (in secret) to preserve books and the information they hold. Montag becomes a convert, learning to hate his job burning books. He reads, he questions, and he changes. In this way, the characters support Bradbury's theme of protecting one's right to read.
In the story's plot, the reader witnesses Montag's transformation over the course of the story. In "The Hearth and the Salamander," he is questioning the norms he lives with. Clarisse promotes this with her insightful observations and questions. In "The Sieve and the Sand," Montag is reading and hiding books. He has become dissatisfied with society's manipulative rhetoric and strict laws. He comes to hate his job. In "Burning Bright," Montag has become rebellious and unpredictable. He completely turns his back on society's expectations when he kills Beatty with his torch, thereby saving himself from capture, and symbolically destroying everything Beatty stood for: the unnecessary but pleasurable destruction of books. By the story's end, the city has been bombed and Montag and others travel through the woods to join more people like themselves who are committed to protecting books and the right to freely read: Bradbury's theme.
The main conflict in the story is man vs. society, a form of external conflict. Montag, the protagonist, leaves a life of apathy—living at society dictates—to question not only the government's laws and his part in the destruction of books, but also the magic contained within the pages of outlawed books. Then man vs. self (internal conflict) is introduced. He begins to feel conflicted when Clarisse reminds him of the natural world around him; she asks honest questions that he cannot hope to address without asking himself important questions. His struggle comes to an end after his team goes to a house to burn it. Instead, the woman inside starts the fire herself while she is inside. This is a pivotal moment for Montag. Usually when they burned houses, it was just the house and the things inside. It was easy, impersonal: no one got hurt. But on this night:
Always before it had been like snuffing a candle. The police went first...so when you arrived you found an empty house...
...tonight, someone had slipped.
So the act of burning a house becomes very personal for Montag. He witnesses a woman willing to die rather than be deprived of her books. Montag's conflict grows. He finally snaps when he is called to his own house to burn it: turned in by his wife. To save himself, he kills Beatty and escapes. Montag's conflicts with society and himself also support the theme—Montag needs to decide how he wants to live his life—and becomes an advocate for saving books.