One of the themes from the book is that when a society becomes too restrictive, trading pleasure for intellectual pursuits, it is not worth the tradeoff. Societies need art, including literature, and intellectualism.
In Montag’s society, books have been outlawed. They are so illegal, in fact, that if you are found with them your house will be burned. The firemen burn the houses, but it is only the books that burn. The houses are fireproof.
One explanation for why Montag’s society decided to do away with books is provided by Beatty, who is trying to get a woman who has been hoarding books to give herself up. He tells her that the books have no point.
"...Where's your common sense? None of those books agree with each other. You've been locked up here for years with a regular damned Tower of Babel. Snap out of it! The people in those books never lived. Come on now!” (Part I, p. 35)
Montag does not accept this explanation. He sees his society as lacking. This is reinforced for him when he comes home to a wife who is an empty shell, and when his teenage neighbor asks him if he is happy and it never occurred to him to ask himself before.
Beatty tells Montag that society is better off when no one thinks, and everyone is the same.
You always dread the unfamiliar. 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. And wasn't it this bright boy you selected for beatings and tortures after hours? Of course it was. We must all be alike. (Part I, p. 55)
Beatty easily dismisses the parts of society that Montag’s community eliminated as being unnecessary or detrimental. However, we are shown a world where people regularly commit suicide, and watch television for hours but do not talk to each other. They drive too fast in order to fill the emotional void left by their society. Clearly education, books, and literature are actually important.
Note: Page numbers are from the 60th Anniversary Edition.