Hawthorne's views as a Dark Romantic ruled his writing and much of his personal life. Contemporaries such as Emerson liked Hawthorne but felt sorry for him because of his dark perspective of mankind.
In The Scarlet Letter, Hawthorne's belief that human nature is inherently evil drives most of the novel's characters and all of the plotline. Chillingworth is the epitome of most Dark Romantics' view of human nature. He was once an average but intelligent man, who--though Hester found it difficult to love him or show him affection in their married life--was a decent but boring man. When he discovers his wife's infidelity, Hawthorne portrays mankind's evil nature overtaking him and turning him into a fiend. Likewise, Dimmesdale who seems like a righteous, well-intentioned minister to his townspeople hides within his heart his evil nature--one that possesses a propensity to sin and then hide that sin. At the novel's end, Dimmesdale's nature "eats" its way out to his exterior. Even little Pearl who is outwardly beautiful finds it natural to scream out in church (she is called a demon because of this) and constantly points out the sins in others (her mother, Dimmesdale, Chillingworth, etc.).
Only Hester illustrates hope in Hawthorne's dark beliefs. Admittedly, she has sinned before the book's action begins (presumably in Hawthorne's view she sinned because it is her nature to do so), Hester is able to redeem herself by the novel's end. However, even her redemption is related to Dark Romanticism; she must struggle through the prime years of her life just to get by and provide for Pearl so she has very little happiness. Additionally, her "calling" at the end of her life is related to helping others who have either "given in to their sin natures" or who are tempted to.
Other Dark Romantics include Poe and Melville, and it is easy to compare characters' struggles with their "dark" natures from these authors' works.