As a complex work of literature, Death of a Salesman explores a number of themes.
One major theme of the play is delusion, which is expressed in Willy Loman's repeated drift into fantasy and his unwillingness to directly deal with the reality of his failures as a husband, father and salesman.
What appears to be true to the characters in Death of a Salesman is often a far cry from reality, and this is communicated numerous times throughout the play.
Willy believes that success can only come from innate personal qualities and not from hard work. He thinks that people must be well-liked or be bold in order to succeed. In his persistence in these beliefs, Willy chooses to ignore the hard work and success of his neighbor while continuing to weave a fantasy about his brother Ben. Beyond these somewhat practical delusions, Willy also lapses into periods where he believes his brother is in the room with him, experiencing halucinations.
Death of a Salesman also explores a theme regarding class and ambition, presenting a family that pursues the American Dream of home ownership, financial independence and entrepreneurship.
Willy's quest to realize what he views as the American Dream—the "self-made man" who rises out of poverty and becomes rich and famous...
Not only does Willy dream of riches and clear-cut success, he also pushes Biff to pursue the same dream. For some moments of the play, Biff fully participates in this vision of success. Happy, without prodding, has already taken up the notion of lavish and stereotypical success as his goal and maintains this aim throughout.
Additionally, the Lomans are making their last mortgage payment at the opening of the play, achieving some segment of their dream. This significant achievement, however, is not enough for Willy who always dreamed of being a more impressive person.