Nathaniel Hawthorne uses diction and symbolism to show the negative effects of stifling conformity verses the positive empowerment found in embarrassing one's own truth. He tries to impress upon his readers that an outsider, whether from another physical location, or simply someone who thinks and acts outside that society's definition of acceptable behavior can in fact facilitate positive change within that society. The secret in this novel most likely represents an idea, privacy, or even social censure.
The Mary-like character Hester Prynne represents feminism, as the female-heroine, and truth, as she is unwavering in her stand against the wishes of the state, church, family and community with regard to her own truth. As represented by The Scarlet Letter, "Do you not think it is better for your little ones temporal and eternal welfare that she be taken out of your charge and clad soberly and disciplined strictly and instructed in the truths of heaven and earth? What can you do for the child? I can teach my little Pearl what I have learned from this, laying her finger on the red token.
Woman it is thy badge of shame. Nevertheless, this badge taught me...it teaches me daily lessons by reasons of which my child may be better and wiser." Prynne is aware of how her truth can set her free. Later in the novel it states "...people brought all their sorrows and perplexities, and besought her counsel." This shows how Prynne's stand for the truth has eventually affected the entire community in a very positive manner, changing its perspective on social norms.
Yet the character Dimmesdale, the co-adulterer, was said to be liken with "unutterable torment." Hawthorne was showing that Dimmesdale's silence about the truth and his love was worse than any judgment that would have been bestowed on him...