When Herman Melville, author of "Moby Dick," read Hawthorne's works, he was exposed for the first time to what he called the "power of blackness." Hawthorne writes of this power in "The Scarlet Letter," as he portrays the dark side to human existence in its secret sin. This dark side of is portrayed in the opening setting of a prison door, gray-garbed Puritans, and the scaffold upon which Hester Prynne stands alone; alone before the condemning matrons who enjoy maligning her.The red letter upon her breast alienates her in the "prison" of being outside the circle of accepted society. She and her imp-like Pearl must live on the outskirts of the village. Even when she is later accepted into homes for her charitable deeds, she is yet isolated, being identified by the A that acts as a label to identify her whether it be as "angel" or another label. Always her sin isolates Hester; after she goes to England with her grown daughter, Hester returns to her Puritan colony and takes up her A, for her identity has become one with this isolation.
The Rev. Dimmesdale's secret sin is cause for his spiritual isolation because he cannot reveal the sin torturing him with guilt. Only with Hester can he be himself; when he tries to tell the townspeople of his sin, they refuse to accept his claims of lowliness in his sermons as anything but piety and humility. Symbolically, he stands on the scaffold alone.
Profoundly isolated by "the power of blackness" is Roger Chillingworth who seeks revenge upon the minister. In this evil act, Chillingworth loses his own soul as he becomes "a fiend" by his own admission. When Hester and Dimmesdale and Pearl finally stand together on the scaffold, united in the past sin of passion and bonded by love, Chillingworth is isolated from them because of his evil secret sin--"He will be mine"==against God.