In Brave New World, what point is Huxley trying to make on Bernard and Lenina's different views on sex? Why may sex be at the heart of the "problem" of human nature?
Both Bernard and Lenina have been conditioned to reject monogamous relationships and "have" whomever they want, whenever they want. In fact, if a man and a woman see too much of each other, it is considered unhealthy and they must be reconditioned. Bernard, along with his friend Helmholtz, wonder what it would be like to get to know someone better, rather than simply jumping in to bed all of the time. As a result, Bernard wants to get to know Lenina better, but she is strongly conditioned towards maintaining only casual relationships with many different men. By placing these two characters together, Huxley explores what would happen if two completely different philosophies on sex intermingled. It is also a way to bring up the serious discussion about what relationships are for and what they should mean to the participants.
The lesson that is learned from Bernard and Lenina dating is that one must sacrifice his beliefs for the other in order for it to work. For example, Lenina thinks that Bernard is weird for not taking soma and wanting to be alone with her. She would rather be in a crowd socializing, dancing, or playing games. In these situations, Bernard would rather go for a walk and talk with Lenina. She asks him, "Talk about what?" (104) because she doesn't understand emotional intimacy or what he's driving at.
In the end, Bernard ends up doing what Lenina wants to do in order to make it through the night. Bernard tries to explain that he's not satisfied with being an adult during the day and acting like a child at night. She says she doesn't understand what he means and he says, "I know you don't. And that's why we went to bed together yesterday--like infants--instead of being adults and waiting" (110).
This profound statement from Bernard identifies the problem with casual sex being at the heart of human nature. It's as if Huxley is saying that intellectual adults can use their wisdom to make better choices about sex, rather than acting like kids all the time and merely following their natural impulses. Bernard knows that treating sex like a game will not result in true, emotionally intimate relationships; and consequences like pregnancy and abortions would be less of a problem.