Act 2 Scene 13 begins with Willy sorting through the seeds he has bought in confusion. Biff tries to reason with him. Biff wants Willy to let him go and stop shoving his version of the American Dream on him. This scene is climatic as it ends with Biff tearing away the façade of the family and exposing them to the harsh truth of what they really are.
In the first few lines of this scene Biff tries to tel Willy that he doesn't have a critical appointment with Oliver, but Willy's mind has either deteriorated so badly or he just blatantly refuses to accept Biff's decision to leave.
Willy thinks Biff is spiting him by rejecting the American Dream that he has always wanted his family to live by
Willy: Spite, spite is the word of your undoing! And when you're down and out, remember what did it. When you're rotting somewhere beside the railway tracks, remember and don't blame it on me!
Willy's insistence that Biff blames him for his failures, stems from his own guilt at having an affair with the Woman and not pushing Biff to do well in school.
Biff: I'm not blaming it on you
Willy: I won't take the rap for this you hear.
Willy's guilt at having the affair and not having pushed Biff to do well in school leads him to believe this is the cause of Biff's lack of material success.
Biff, gets angry ay Willy and pulls out the rubber hose. Willy claims not to know what it is. Biff tells him he knows exactly what it is and tells him he doesn't pity him. He also informs the family that they will all hear the truth and thus proceeds to rip the family fabric of lies to shreds. Biff claims they never told the truth in the house, Happy coming downstairs hears this and counters saying that they always told the truth. Happy Loman has always believed in Willy and Willy's idyllic American Dream where attractiveness, personality, and likeability will get you to the top as opposed to honesty and hard work.
It is ironic that Happy continues to believe in Willy's dream, having been the neglected son all his life and forever living in Biff's shadow. Even now, as an adult, Happy is still trying to get his father's attention. When Happy claims they always told the truth, Biff rounds on him and says
Biff: You big blow, are you the assistant buyer? You're one of two assistants to the assistant aren't you?
Happy: Well, I'm practically-
Biff: You're practically full of it.
Happy has no doubt developed his father's disturbing habit of making himself out to be bigger than he really is. Biff proceeds to tell his family that he stole at evry job he ever had, because Willy 'filled him with so much hot air' he 'could never stand taking orders from anyone'. This he states, is the real reason he hasn't become successful. Willy simply did not instill the right values into him. He makes a short speech in which he basically says that he doesn't want to become a businessman or at least he doesn't want to work in an office because that doesn't bring him happiness. Working and being in the great outdoors brings him happiness. The scene ends with Willy Biff telling him that he's a dime a dozen and so is Willy but Willy hotly rejects this.
Scene 14 opens with Biff telling Willy that they aren't leaders of men, both are a dime a dozen and there are millions of men out there just like them. Biff is the only member of the Loman family that demands that the lies of the family be dragged out and weighed and tested. Biff knows that his family has come up short and ahs been found wanting.
The family Is indeed a dime a dozen. Willy's sons are not Greek Gods or Adonises. The harsh reality is that they are really nothing special, Biff realizes this and he wants Willy to see that as well. They are simple young men who have been unwittingly fooled by their father and a harsh and cruel system. They are not uncommon.
Biff actually begins to cry and the salesman in Willy, not the 'father' kicks in and says 'he likes me'. All of Willy's life he has placed great emphasis on people liking him, not necessarily loving him. Even when his family is now broken and dejected, he cannot accept their love, but instead is delighted that Biff actually 'likes him'. Ironically, Biff's tears now seal Willy's intention to kill himself so Biff might get a chance to experience the American Dream, which Biff has already rejected.
The infamous Ben, now appears visible to only Willy and proof that Willy's mental health is rapidly deteriorating. The imaginary Ben now prods Willy to kill himself so his family might benefit from the insurance money and he uses such phrases as
'The jungle is dark but full of diamonds' and 'One must go in to fetch a diamond out'
Willy believes that his death will actually be the biggest sale of his life. He has given years of service to a harsh and cruel system to have nothing in return. His death at least, will mean something tangible to his family. It is ironic that he feels this way, after years of service, he must give up his life, so his family can live the American Dream he always wanted. Willy is excited again. He believes when Biff gets the cheque he'll be ahead of Bernard again. When they were children, Willy always believed that Biff would be more successful than Bernard because of his likeability as opposed to Bernard's anaemic personality. Even as Willy sees that he is worth more to his sons dead than alive, he fails to grasp any semblance of self realization and failing to realize that killing himself to put Biff ahead of Bernard is utterly pathetic.
In the last lines, Willy makes sure his family is all safely in bed. He is by himself when he starts having delusions and he goes out into the night and kills himself. The scene ends with his family at his graveside.