In Death of a Salesman, what is the relationship between Willy's guilt and the hallucinations and flashbacks he has?
Willy's hallucinations and flashbacks are his way of coping with the harsh realities he presently faces. They also illustrate his guilt regarding his decision to not follow his brother to Alaska and his affair with The Woman. Willy continually has hallucinations, where he has conversations with Ben and asks him for advice on how to become successful.
Willy clearly regrets not going into business with his brother, who ends up finding diamonds in Africa. He believes that his lack of success is directly related to his decision to not follow his adventurous brother overseas. Willy also has flashbacks to a time when both his sons were young and enthusiastic. Willy longs to go back in time, when Biff was a football star with a bright future and Happy respected him.
Unfortunately, Biff travels to Boston to speak with his father about his failing grade and discovers that Willy is cheating on Linda. Willy's flashback indicates that he feels guilty about cheating on his wife while on the road and he is purposely repressing the truth behind Biff's apparent lack of success. Overall, Willy's hallucinations and flashbacks reveal his guilt for passing up on business opportunities, cheating on his wife, and ruining Biff's chances of playing football in college.
This is an excellent question as it identifies the way in which Willy's flashbacks, especially those concerning The Woman, his former mistress, indicate his guilt and shame about his affair. You would do well to go through the play and note down the occurrences of The Woman, tights and the Woman's laughter, which act as symbols of Willy's infidelity.
The first time we are introduced to The Woman however, in Act One, is in the middle of rather a tender and loving scene between Linda and Willy. This clearly exposes Willy's lack of integrity. He cannot remain faithful to the one person who is completely faithful to him, and even his hallucinations seem to emphasise this. Note in this scene how it is mentioned that Willy has given stockings to his mistress, only to see his own wife mending her own stockings. This creates massive guilt in him as he has been spoiling his lover at the expense of his wife.
Of course, this is another form of "success" that Willy dreams about to bolster his sense of self-esteem, but it is also a form of "success" that increases his guilt and forces him to confront his own betrayal of Linda.