What is the theme of "Brave New World"?
I'll suggest another. Society is controlled in many ways. One is force ("1984"); BNW controls its citizens through initial "hatching" and programming, but one of the techniques it uses to reenforce their training is the control of language and literature. The (perhaps difficult to believe) example is John's experience with Shakespeare. Shakespeare provides John with a language to describe his experiences, words unavailable in the society of BNW. For example, what can "strumpet" mean in a society where "everyone belongs to everyone else." How different would their world be if the concept of "strumpt" existed? And how does making words like "mother" and "father" and "family" almost obscenities control their behavior.
Language is the way we interface with reality. If we take away the words that describe that realtionship, and if we take away the greatest examples of using language to interface/explain that reality, it is much easier to keep the people controlled. This same theme is evident in "1984" where the "Newspeak" dictionary limits their citizens view of the world.
In our world, we need to be vigilant about how words are used, because these shape reality. For example, why is something a "crisis" instead of a "problem"? Do we know when each should be used? Is "bailout" what's really going on? Would a different word change our perception of the reality.
Lots of things to think about; Huxley was aware of this a long time ago. You might want to read "Brave New World Revisited" to expand your view of the novel.
As with most novels, there are several themes. Huxley wrote a satire of a totalitarian society where the values of his day were totally reversed. Probably the most important theme is the idea of "Free Will vs. Enslavement". Although the world of "Our Ford" considers itself progressive and a utopia, there is absolutely no room for free will or self-expression. From conception, babies are made to fit into a distinct niche in society. After that, they are conditioned, not by parents, but by the state. They learn to accept all the values of a society which considers order and happiness the primary objectives in life. If they are "unhappy", they are expected to take "soma", a drug which designed to make them happy. When John arrives from the outside world and questions the values of this "Brave New World", he sees the weaknesses of the society but their values are so entrenched that he realizes there is no place for him. So, as the only exercise of real free choice in the novel, John kills himself rather than submit to the values of such a dehumanizing society.