What is the main conflict in the novel Fahrenheit 451?
The main conflict in the novel is Man versus Society. Montag slowly comes to the realization that the oppressive government system is doing far more harm than good, and he sees that the destruction of the human mind is causing society to stagnate rather than innovate. He is almost entirely alone in his developing thoughts, and clashes with his superior, Chief Beatty, who represents the Society:
"Surely you remember the boy in your own school class who was exceptionally 'bright,' did most of the reciting and answering while the others sat like so many leaden idols, hating him... We must all be alike. Not everyone born free and equal, as the Constitution says, but everyone made equal."
(Bradbury, Fahrenheit 451, Google Books)
Montag's fight against society is not successful except in that it gives him his freedom. He escapes the city and watches as it is destroyed in the war. Montag understands, finally, that he can only free himself, not others; other people must come to their own epiphanies and free themselves in turn, but he can do little to force them out of their apathy. The society that rejected Montag and Clarisse's individualistic ideals is destroyed by its own failures, leaving only a few individuals alive to rebuild society from the ashes.