Huxley's title Brave New World is an allusion to a line spoken by Miranda in Shakespeare's The Tempest. In the play, Miranda has been sheltered from the outside world and was raised on an enchanted island by her father, Prospero. When Miranda sees Ferdinand for the first time, she is in awe of him and excited about the opportunity to meet other humans. Miranda says,
How many goodly creatures are there here!
How beauteous mankind is! O brave new world,
That has such people in ’t!
Miranda's sheltered upbringing and inexperience with other cultures parallel John the Savage's circumstances in the story. Similar to Miranda, John was raised in a differing environment and naive to the outside world.
John repeats Miranda's quote several times in the story when he responds to the World State's citizens and foreign culture. Initially, John is inspired by the wonders he experiences and repeats Miranda's quote when thinking about Lenina. Later on, John ironically repeats the quote out of disgust when he witnesses a factory staffed by Gammas, Deltas, and Epsilons. He also quotes Miranda's words following his mother's death and the horrifying scene of Deltas lining up for their soma ration.
The title is also relevant to the story because the extent of John's knowledge comes from his understanding of Shakespeare. John's perspective of the outside world and human emotions are shaped by the characters in Shakespeare's plays. John sees everything through the lens of Shakespeare and is a romantic, passionate individual. Once he arrives at the World State, John recognizes that the culture is hollow, and the citizens are comfortably numb. He quickly becomes disenchanted by the World State and longs for genuine, authentic experiences.