At worst, Dimmesdale is a symbol of hypocrisy and self-centered intellectualism; he knows what is right but has not the courage to make himself do the public act. When Hester tells him that the ship for Europe leaves in four days, he is delighted with the timing. He will be able to give his Election Sermon and "fulfill his public duties" before escaping. At best, his public piety is a disdainful act when he worries that his congregation will see his features in Pearl's face.
Dimmesdale's inner struggle is intense, and he struggles to do the right thing. He realizes the scaffold is the place to confess and also his shelter from his tormenter, Chillingworth. Yet, the very thing that makes Dimmesdale a symbol of the secret sinner is also what redeems him. Sin and its acknowledgment humanize Dimmesdale. When he leaves the forest and realizes the extent of the devil's grip on his soul, he passionately writes his sermon and makes his decision to confess. As a symbol, he represents the secret sinner who fights the good fight in his soul and eventually wins.
Pearl is the strongest of these allegorical images because she is nearly all symbol, little reality. Dimmesdale sees Pearl as the "freedom of a broken law"; Hester sees her as "the living hieroglyphic" of their sin; and the community sees her as the result of the devil's work. She is the scarlet letter in the flesh, a reminder of Hester's sin. As Hester tells the pious community leaders in Chapter 8, ". . . she is my happiness! —