With the elimination of history and books as well as genetic engineering and hypnopaedia and soma, the New World has, for the most part, achieved its goal of manufacturing happiness in servitude, better known in Brave New World as "stability." For, as Huxley has also written,
the really revolutionary revolution is to be achieved, not in the external world, but in the souls and flesh of human beings.
After the artificial creation of people in the Hatchery, the New World accomplishes its goal of servitude by infant conditioning such as is exhibited in Chapter 3 in which the children run around naked and are taught that "everyone belongs to everyone else." With this conditioning, sexual relations as adults will be meaningless and have no connection with love. Also, the sexual freedom of people as adults compensates for the lack of polititcal and economic freedom that they have. Then, with the caste system and their consequent sleep conditioning, no one in the New World wants to be more that what he/she already is. ( That is, except for a few aberrations, such as Bernard Marx and Helmholtz.) With these created differences in people, the government of the New World assigns the castes to their appropriate places in the social and economic hierarchy. The various castes do not like each other, either, so there is no envy to disrupt order. For instance, Lenina sees the Gammas and tells her date, Henry Foster, she is so glad that she is not one of them.
Even though the people of the New World have been created to be content with their lives through eugenics, the New World recognizes that reality may be a burden even to them, or they may yet have some misgivings about their society. So, in place of alcohol and other narcotics, soma has been created and is dispersed at Solidarity Meetings or anytime people become collectively agitated. For instance, when the multitudes of Deltas become upset after John the Savage becomes so angered by their presence near his dying mother, the police spray soma to subdue them. Thus, along with the freedom to escape and daydream that soma provides, it reconciles the people of the New World to their servitude.