The message in the play is developed through the lives of numerous characters. Some (like Howard and Charley) succeed financially, while others fail. Willy enjoyed success as a salesman so long as he had the physical stamina to compete in the marketplace. When he grows old and tires, he finds that he no longer has a place in the economic system. When he can no longer stand up to the competition, after thirty-four years, Howard fires him. Losing his job finally pushes Willy over the edge, psychologically, because he always defined himself in terms of how much money he could make. It was his only yardstick in determining a man's personal worth.
Biff and Happy grew up accepting their father's principles, but they did not inherit his work ethic. As a result, neither works while chasing "success," and neither achieves anything of value. Bernard, however, works hard, gets an education, and becomes a successful lawyer, arguing a case before the Supreme Court. Unlike Biff and Happy, Bernard did not cut corners in the pursuit of success. He desired more than turning a quick profit.
Arthur Miller's "Death of a Salesman" statement on capitalism and free enterprise is clearly a naturalistic one. in which environment and heredity dominate, even determine human endeavor or success. Willy's deepening failure parallels that of his environment and the play's setting: His home in Brooklyn is constricted by the city whose chocking growth has killed the elms, crushed hope, and blotted out growth.
Heredity also works against Willy and his sons. Each generation repeats patterns of behavior established by their parents. Both Willy and Biff have been less successful than their brothers. Presumably, both Willy and his "wild-hearted" father were unfaithful, both fathers failed their sons and left them insecure. Willy explains, "Dad left when I was such a baby...I still feel temporary about myself."
The character of Ben is not so much a revealed character as he is a representation of the ideas of success in Willy's mind. Bernard on the other hand, ends up successful, according to Willy, but not in an economic sense. He has a job with prestige.