The professed purpose of the culture is to keep people happy and content, while the actual purpose is to keep people ignorant and controlled. Chief Beatty explains that the government banned books in order to make people more secure and comfortable in their lives; having too much knowledge made people concerned and worried, and informed illegal or hostile actions. By eliminating information and keeping people docile with meaningless emotional stimulus (television programs with no plot), the government was able to create a world in which they could control almost every facet of human life, including personal opinions. Clarisse points out that people don't have any actual opinions in their conversation:
"They name a lot of cars or clothes or swimming-pools mostly and say how swell! But they all say the same things and nobody says anything different from anyone else."
(Bradbury, Fahrenheit 451, Google Books)
Because nobody questions society or the government, people are not aware that they have been culturally programmed. Montag only becomes uneasy because of his exposure to the unconventional thinking of Clarisse, and because he becomes aware that Mildred, his wife, is unconsciously not as happy as she seems.
I agree with everything belarafon said. However in a very telling speech, Beatty also notes that the purpose of censoring books and tv program content was to ensure equality among people. Bradbury wrote this novel in the 50s, a time when there was extreme sensitivity regarding equality. What did equality mean and what should it look like? Beatty says that they had to ban books due to peoples' objections over the content of books. They couldn't offend any minority group.
Bigger the population, the more minorities. Don't step on the toes of the doglovers, the catlovers, doctors, lawyers, merchants, chiefs, Mormons, Baptists, Unitarians, second generation Chinese, Swedes, Italians, Germans, Texans, Brooklynites, Irishmen, people from Oregon or Mexico. The people in this book, this play, this TV serial are not meant to represent any actual painters, cartographers, mechanics anywhere. The bigger your market, Montag, the less you handle controversy, remember that! All the minor minor minorities with their navels to be kept clean. Authors, full of evil thoughts, lock up your typewriters.
He also notes that books were being shortened and shortened so that they were accessible to everyone. There was a need to ensure that everyone could access and be able to talk about the classics, so what did it truly mean to be able to say that you had read the famous classics.
Beatty argues that equality was achieved by eliminating books. It took away the need for people to compete over intellect, and it served to erase any offensive literature from the country.