Chapters 16-20 in The Scarlet Letter reveal the nature of the encounter in the forest between Hester, Arthur, and Pearl. What are 2 or 3 imagery quotes from these chapters, and how do the images help to reveal certain complex themes and issues?
The most obvious complex themes and issues that spring to mind regarding The Scarlet Letter are the issues of identity, sin, and the nature of evil.
Images regarding the nature of evil from these chapters include the fact that the sun itself, indicative of light and goodness, does not seem to shine on Hester. Pearl notices this and says, "The sunshine does not love you. It runs away and hides itself, because it is afraid of something on your bosom." With the optimism of youth, Pearl offers to catch it, which she does, but when Hester draws near and reaches out her hand to "grasp some of it," the sunshine vanishes. "Or," adds Hawthorne, "to judge from the bright expression that was dancing on Pearl's features, her mother could have fancied that the child had absorbed it into herself, and would give it forth again, with a gleam about her path, as they should plunge into some gloomier shade." Hester thinks of the darkness of the forest as representative of her own "moral wilderness"--presumably fitting considering her moral shortcomings.
The child, being the product of sin, is shunned with her mother, but is shown through this imagery to be innocent. Moreover, the light imagery suggests she herself is a source of goodness and joy, since she is presumably capable of absorbing the light and using it again later should they enter "some gloomier shade."
Sin is, of course, a major theme of this Puritan-themed novel, as well. The "Black Man," who Pearl believes is ugly, "haunts this forest, and carries with him a big, heavy book, with iron clasps." He forces people he meets to write their names in blood in his book after which he "sets his mark upon their bosoms," a superstitious embodiment of this evil. This is an interesting image as evil itself is an idea, formed and maintained in the mind, but is not embodied in any concrete form. When Pearl asks her mother if she'd ever seen the Black Man, Hester (surprisingly) says yes. She declares that the scarlet letter she wears is his mark; she speaks not literally, but Pearl is too young to understand this.
Another major theme is identity and the most obvious image of this is Hester's scarlet embroidered "A," which plays a curious part in these chapters. After deciding to leave for Europe with Dimmesdale and leave the past behind, starting anew, Hester unpins her scarlet letter and flings it away (in Chapter 18). She immediately feels "the burden of shame and anguish [depart] from her spirit," and releases her hair. Her transformation from the imprisoned, shamed woman to vital beauty is remarkable, and immediately, the sun "[pours] a very flood" of light into the forest, "gladdening each green leaf, transmuting the yellow fallen ones to gold" and "the objects that had made a shadow hitherto, embodied"--like Pearl, earlier--"the brightness now." The scarlet letter had determined Hester's identity as a shamed woman who had accepted her punishment; discarding it demonstrates her emergence from her own shame, like a butterfly emerging from a cocoon.
However, when Pearl returns in Chapter 19, she refuses to cross the stream and come to her mother because her notion of her mother's identity--of a woman with hair tied under a bonnet wearing a scarlet A--is too different from the woman she sees before her. Even the presence of Dimmesdale, the minister, cannot entice her to come to her mother until her mother has retrieved her brand and assumed her former appearance. Hester's identity is marked by this letter, but over the years, she has, by force of will, transformed herself into an admirable woman who is humble and helps the sick, thus transforming the meaning of the symbol itself. This doesn't change her joy upon discarding the letter, but it speaks to Pearl's reverence for it (Pearl even kisses it after she has kissed her mother, as though the letter is a good part of her that Pearl does not wish to lose).