There is a trick in Huxley's argument that makes it difficult to refute. Unlike the people in the Gulag Archipelago, the masses in Huxley's world do not know they are not free. They have been drugged and brainwashed into thinking that they are doing exactly what they want, not what some dictator wants them to do. So, if we say that we are free, how can we prove that we have not been programmed to say that by a Master who is manipulating us into thinking that? Perhaps he put soma into our drinking water.
There is, however, an answer to that. The masters of the Brave New World would not allow a movie version of Brave New World to be shown on television. The movie reveals what such a society could be like and what a horror it would be. The heroes of the movie are a man and woman who escape the system with their baby and are going to live like a traditional family. As long as Brave New World is shown on television we will know we are not in it.
I describe the Brave New World as a horror, and Huxley thought of it as that also. He was writing a warning, not a prescription. There may be people who do not look upon it as horrible. It is a society in which every want is fulfilled. But, as Professor Frank H. Knight used to say, what people want is not only to have their wants fulfilled but also to have better wants. People in the Brave New World satisfy the wants they have but are prevented from having some good wants, like want for love and family, and deprived of the opportunity to reach for new and better wants.