Quote 4
BIFF [crying, broken]: Will you let me go for Christ’s sake? Will you take that phony dream and burn it before something happens? (Act 2)
Biff attributes the tension and distress in his family to the irreconcilable gap between Willy's absurd dreams and reality. He longs to be released from Willy's dreams, so that he can create his own—ones that are based on the reality of his situation.
Quote 5
BIFF: He had the wrong dreams. All, all wrong.
HAPPY [almost ready to fight Biff]: Don’t say that!
BIFF: He never knew who he was. (Act 2)
Dreaming is so central an aspect of Willy's character that Happy nearly fights Biff to defend it. Unlike his brother, Happy still wants to believe in Willy.
Quote 6
BIFF [crying, broken]: Will you let me go, for Christ’s sake? Will you take that phony dream and burn it before something happens?
[. . .]
WILLY: Oh, Biff! [staring wildly] He cried! Cried to me. [He is chocking with his love, and now cries out his promise] That boy—that boy is going to be magnificent! (Act 2)
Despite Biff's admission that he is a failure, Willy convinces himself that Biff will still make it big. Willy follows this delusion to his death, killing himself in order to help his son. Does this death bring some sympathy for Willy? Does he die a hero of some sort? Or is it just the logical end to a life of deception?