Some of the major themes in Arthur Miller's play, "Death of a Salesman," are denial and betrayal. Others include reality versus illusion, abandonment and the American dream.
The theme of denial in "Death of a Salesman" is explored primarily through the Willy Loman character and his refusal to see reality for what it is. Reality versus illusion can be seen as a major theme, intrinsically connected to Willy's propensity to live in denial. His delusional thoughts wreak havoc on his personal life and drive him deeper into denial.
Betrayal also runs through the plot. For example, Willy feels betrayed by Biff's desire to stray from the life path Willy would have him take. Betrayal is also explored through the relationship between Willy and Linda.
Abandonment comes up throughout "Death of a Salesman," starting early in Willy's life when his father leaves the family. The effects of his feelings of abandonment seem to propel much of his unhealthy behaviors later in life.
The idea of the American dream is also an overarching theme, interwoven with the other themes in the work.
"Death of a Salesman" was written in 1949. It won the Pulitzer Prize for Best Drama as well as a Tony Award for Best Play.