Chillingworth of "The Scarlet Letter" is more pitiable than the Reverend Dimmesdale because he has not only sinned by seeking revenge, but he has totally succumbed to evil and embraced it while Dimmesdale, albeit a sinner, continues to fight to be a good man. His is still a life in the service of others, but Chillingworth's is solely a life of a "fiend" bent upon the possession of the secrets of another man's heart. In her interview with the physician, Hester accuses Chillingworth:
You search his thoughts. You burrow and rankle in his heart. Your clutch is on his life, and you cause him to die daily a living death....I [pity]thee...for the hatred that has transformed a wise and just man to a fiend! Wilt thou yet purge it out of thee, and be once more human?
Chillingworth has lost his humanity; Dimmesdale has not, and is able to stand before people and finally be redeemed through his confession of sin, while like the black flowers he picks, Chillingworth takes on a deformed shape and later fades into death with only a feeble attempt to redeem himself by leaving money for Pearl.
Although Chillingworth is a victim of sorts because his wife commits adultery, the rest of his actions are a direct result of his own free will. If there is any room for pity, it would be in the scene where he first arrives in Boston and discovers his wife has been unfaithful. After that, his descent into moral depravity is anything but pitiable. He deliberately chooses to stay in Boston only to exact revenge on Hester's lover. He freely admits "between thee and me Hester, the scale hangs fairly balanced." Still, he won't move forward; his determination to find out the identity of Hester's paramour is only exacerbated. His choices and decisions, particularly once he discovers the letter on Dimmesdale's chest and knows for certain that Dimmesdale was Hester's lover, he becomes more and more sinister and "fiend-like." There is nothing pitiable about a fiend. After Hester reveals Chillingworth's identity to Dimmesdale in the forest, he has the perfect opportunity to turn Dimmesdale into the authorities, but he doesn't; he chooses to continue exacting revenge by booking passage on the ship to Bristol with Dimmesdale and Hester. Dimmesdale finally realizes the only way to rid himself of this "fiend" is to die. Chillingworth's relentless pursuit and his steadfast refusal to forgive was his choice. He allows his bitterness and anger to fester, despite Hester's begging for him to stop.
Both characters are pitiable. However, Dimmesdale has the admiration of his congregation and the love of Hester. Chillingworth lives only for his pursuit of revenge. When the object of that revenge, Dimmesdale, dies, Chillingworth shrivels up and dies for lack of something to live for. He has evidently made no friends because he has been solely focused on latching on to Dimmesdale. He has totally alienated Hester. As she watched, she saw how Chillingworth treated Dimmesdale. She was so concerned she broke her promise to keep Chillingworth's identity a secret from the minister.He has made no attempts to get to know the daughter that is legally his and remained focused on his herbs, medicine and revenge. His body even shows the consequences of his obsession as he becomes more deformed. So when Dimmesdale mounts the scaffold for the final time, Chillingworth can only say,"thou hast escaped me." He is never able to take complete revenge because Dimmesdale takes away his ability to secretly torment his prey. Thus, Dimmesdale dies with the love of Hester and Pearl and even though his congregation is in shock at his admission, he will probably be remembered as a good pastor who made a terrible mistake.Chillingworth will be remembered as a husband whose wife cheated on him and lived with bitterness and vengeance for the rest of his life.