One comparison that can be made between Brave New World and Macbeth is in the treatment of fate and destiny and the characters' reactions to their fates.
Bernard Marx and Helmholtz Watson of Brave New World and Macbeth feel their fates are determined by elements outside their control. Whereas it is scientific deceit which causes the lives of Marx and Watson to become tragic, it is the accepting of fate in the mind of Macbeth that leads him to be influenced by the preternatural world which later becomes his nemesis.
In Brave New World, in one of his first dates with Lenina, Bernard shocks her when he tells her that he enjoys the sunset and likes to be alone and feel more alive and individual:
"It makes me feel as though …" he hesitated, searching for words with which to express himself, "as though I were more me, if you see what I mean. More on my own, not so completely a part of something else. Not just a cell in the social body."
Like Bernard, who feels spiritually confined in his society, Helmholtz Watson, who is an Alpha Plus and of the highest intelligence in the New World, wishes that he could do more than write snappy slogans designed to promote the values of his society. But when John the Savage reads Shakespeare to Helmholtz, he realizes that he has been limited in what he can intellectually understand because of his society's conditioning of him.
Although he has not been pre-conditioned in his world, Macbeth allows himself to become susceptible to the designs of the preternatural world with the appearance of the three witches, who make predictions of his future. Influenced by this supernatural world, Macbeth allows himself to be led down a fateful path when he confuses reality and fantasy as he is driven by his ambition.
While he is less a product of a controlled fate than Bernard Marx and Helmholtz Watson, Macbeth does become controlled by the fate predicted by the witches because in his "vaulting ambition" he accepts reality and fantasy as equal so that he can be king of Scotland. Indeed, it is his fatal confidence in the witches' predictions that later return Macbeth to the battlefield in the end, only to be finally defeated by his fate:
Accursed be that tongue that tells me so,
For it hath cowed my better part of man! (5.8.17-18)
Destiny, whether scientifically planned or one influenced by the supernatural world, affects the lives of the characters of both Brave New World and Macbeth.
The biggest comparison between the two would be the theme of knowledge vs. ignorance. In Brave New World, the citizens are denied knowledge so that they will not be tempted to rebel. The belief is that in ignorance, they are unaware of what they are missing. This applies to Macbeth because he had too much knowledge. The witches gave him so much information, he began to act in ways unusual for him and unproductive in order to speed up the events that were supposed to happen to him. In he had lived in a Brave New World, he would not have had the knowledge and so would not have become a murderer.