The similarities and differences between Hester Prynne and Arthur Dimmesdale of Hawthorne's The Scarlet Letter revolve around the effects of their mutual sins. For, while they are both guilty of adultery, the effects of their sins upon them greatly differ; Hester's is an open sin, and Dimmesdale's is a concealed sin. And, it is in the examination of the psychological effects of Dimmesdales's secret sin in contrast to Hester's declared sin that Hawthorne explores in his novel.
Because hers is an openly acknowledged sin, Hester initially suffers horribly from the scorn of the Puritan community; however, she maintains her pride and boldly displays her scarlet letter with golden embroidery and elaborateness. Likewise, she dresses Pearl, her living conscience, in scarlet. For Hester, her salvation lies in truth. In Chapter XVII, "The Pastor and His Parishioner," after Hester confesses that Chillingworth is her husband, she tells Dimmesdale,
In all things else, I have striven to be true! Truth was the one virtue which I might have held fast, and did hold fast, through all extremity; save when they good,--thy life,--thy fame,--were put in question! Then I consented to a deception. But a lie is never good, even though death threaten on the other side!
But, unlike Hester, Dimmesdale is weak, and is unable to confess his sin for seven years. During their forest conversation, he tells Hester,
"...thou little, little knowest all the horror of this thing! And the shame!--the indelicacy!--the horrible ugliness of this exposure of a sick and guilty heart..."
And, so, Dimmesdale suffers the torment of his conscience in the cowardice of his nature as he attempts to rationalize that he is serving God by keeping his secret in order to continue to preach and serve the community. But, his fight is really against his own conscience--a fight to which he loses his life, while Hester who is open about her sin mainains her strength and finds redemption for her sin. Thus Hawthorne's underlying meaning in exploring the psychological effects of secret sin are given meaning in Dimmesdale's death and Hester's survival. When Dimmesdale finally has his victory of soul after the Election Day sermon, Chillingworth's reaction demonstrates the significance of Dimmesdale's confession and truthfulness. He tells Dimmesdale, "Hadst thou sought the whole earth over, there was no place so secret,--...where thou couldst have escaped me,--save on this very scaffold! In fact, Hawthorne himself underscores the importance of confession, a principle contrary to that of Puritanism that forbade sin of any kind. In Chapter XXIV, "The Conclusion," Hawthorne specifically points out his meaning suggested by the differences in Hester's open sin and Dimmesdale's secret sin:
Among many morals which press upon us from the poor minister's miserable experience, we put only this into a sentence:--"Be true! Be true! Be true! Show freely to the world, if not your worst, yet some trait wherby the worst may be inferred!"