Here's an option: John the Savage is freer than people in the World State because he is not controlled by drugs (soma), psychological conditioning, or promiscuity. With each of these three options, you can discuss three major themes that surface in the novel. You'll have to find examples in the novel, though, to prove how this statement is true. There are also many examples to argue the other side of the issue, though; so, be aware of that, too. The best essays are written when the author understands both sides of the issue. You can read the discussion behind the other side at the end of the book where the controller, Mustapha Mond, explains these things to John the Savage.