Eddie Carbone changes as the play progresses. At first, the audience views Eddie as a hardworking man who has struggled to take care of his family. We learn that he took in his niece and raised her, an act which makes us appreciate him as a generous and moral man. He seems to be willing to do anything for family; for instance, he reminds Beatrice, his wife, that he slept on the floor when her father came to stay because his house had burned down. He seems to banter with Beatrice at the beginning of the play, which begins to endear him to us. He comments on her hair and says he wants to talk to her; we consider the possibility that he is a caring and loving man.

However, once his niece Catherine enters the room, he shows his possessive side, telling her to stop wearing high heels when she's walking in the streets:

Listen, you've been givin' me the willies the way you walk down the street.

Eddie's comment makes us a little uncomfortable, but at this early point in the play, we shake off any suspicions as unfounded. We want to believe in our character. Yet, it doesn't take long for our suspicions to grow, as Eddie continues to display jealousy and possessiveness toward Catherine, especially when she begins dating Rodolpho. He even visits an attorney, Alfieri, to find out if he has any recourse to stop Catherine from seeing Rodolpho. Alfieri is quite perceptive and cautions Eddie that he has too much love for Catherine. He advises that "these things have to end, Eddie . . . and the man has to learn to forget." However, Eddie is stubborn and does not take that advice. The audience recognizes Eddie's incestuous feelings toward his niece and stops thinking of him as the hardworking hero. We root for Catherine and Rodolpho to break free from Eddie's grasp, and for Eddie to break free of his obsession and return his affections to his wife. We begin to intensely dislike Eddie as he continues to thwart the young couple's romance—for instance, he suggests that Rodolpho is gay and he tells people that Catherine is merely Rodolpho's ticket to citizenship.

The last straw for the audience comes when Eddie calls Immigration to report Marco and Rodolpho. We realize he does not care at all about anyone but himself. That call hurts everyone: Marco's family will lose the money he sends to them, Marco and Rodolpho will be sent back to Italy, and Catherine will lose her fiancé and be heartbroken. Eddie does not consider any of them; all he knows is that he's losing Catherine. While he cannot admit his feelings for her, we know those feelings are driving his actions. Eddie loses everything as a result of his phone call. People lose all respect for Eddie once they realize that he turned in the two men and destroyed his family.

His ultimate refusal to make amends at the end of the play is the proverbial nail in his coffin. Beatrice pleads with him to do the right thing, but his pride will not allow him to do so. Beatrice recognizes her husband's problem:

You want somethin' else, Eddie, and you can never have her!

We hope for Eddie to have an epiphany at this point, but he still refuses to admit his feelings or deal with them. Instead, he takes out his anger on Marco, who kills him in a fight. Eddie dies as a friendless, selfish, stubborn shell of a man.

Initially, Eddie Carbone is presented to the audience in quite a sympathetic light. He's a hard-working family man, a regular blue-collar guy taking his shot at the American Dream. Yet from the start, there are one or two things about Eddie that are slightly concerning. For one thing, there's something not quite right about his behavior toward Catherine. We understand that he cares for her, but at the same time he's way too over-protective.

The unhealthy nature of Eddie's feelings for Catherine are exposed with the arrival of Rodolpho and Marco. Suddenly, he appears to take leave of his senses, acting like a controlling boyfriend, his mind crazed with jealousy. Eddie's so consumed with resentment and hate towards the two immigrants—especially Rodolpho—that he's prepared to destroy his whole life to bring them down. There's something unpleasant and sneaky about the way he calls the immigration office, hoping to get his two unwanted guests deported. Eddie claims to care for Catherine, but in making that fateful phone call, he's wrecking any chance of happiness she may have had with Rodolpho. Eddie's putting his own selfish needs first, and whatever sympathy we may have had toward him has now completely evaporated.

As the play opens, Eddie is a sympathetic character. Though he remains somewhat sympathetic to the very end, his behavior, his moral standing, and his persona all suffer a fall. Eddie becomes more a vehicle for pathos than sympathy. 

When the audience is introduced to Eddie, he is a caring man taking care of his family, willing to raise an adopted niece and to harbor two cousins who are immigrating from Italy. These generous impulses quickly degenerate into selfish impulses however, even in the opening scene as Eddie doles out heavy-handed advice to Catherine. 

Eddie's greedy and improper affections for Catherine become clear over the course of the play, yet Eddie's attempts to find an acceptable way out of his predicament suggest that he is still not a bad person.

Eddie visits Alfieri, the lawyer, seeking some legal protection for his family.

He wants to free himself of his conflict by finding a way to avoid it. 

This weakness in his character eventually comes to dominate, rendering Eddie a pathetic character in the eyes of the audience, powerless over his own passions and impulses. 

Ultimately, it is not Eddie's feelings for Catherine that will characterize the view the audience holds of him. His morally low actions regarding Rodolpho (and Marco) become the final comment.

 In desperation, Eddie places the call to the immigration office, an act he soon comes to regret.

This act effectively removes Eddie from a position allowing real or pure sympathy from the audience and places him instead in a position of pathos. The audience is sorry for him in the end, but would not imagine doing what Eddie has done.