In The Scarlet Letter, why can Hester be seen as a heroine?
In order to answer this question, we need only examine the qualities that make Hester heroic. One such quality is Hester's personal sense of pride. When she stands on the scaffold at the beginning of the novel, the "self-constituted judges" of Boston stand in hypocritical judgment of her, but she will not be abashed. She refuses to allow them to humiliate her. She may be subject to their laws, but she will not bow down to them.
Further, Hester takes responsibility for breaking the law, and she never attempts to shirk her punishment. She even returns to Boston years later, after she has left and made a new life for herself and her daughter, Pearl, in Old England.
Hester is also tremendously giving, especially when she protects her co-sinner by refusing to divulge his name. She could give in to a desire to share her punishment and shame, but she would rather bear all of it herself and spare him, and this generosity of spirit makes her very heroic.
Moreover, Hester is a devoted mother, even though she knows her daughter will be at a disadvantage because of her lack of earthly father. Her devotion to her daughter, to raising Pearl as best she can despite all odds, is heroic.
Hester is a heroine because she has the courage to 'own' her indiscretion. We must remember that Hester is not a Puritan, however living in a Puritan community she understands that her actions have led her present circumstance. She wears the scarlett 'A' and dresses Pearl in scarlett red not because it condemns her, but because it sets her free. Hester can be seen as a heroine to those who are willing to not only see the truth, but are wiliing to put their very soul on the truth... no matter the consequences. Truth is truth, courage is courage, and integrity has no alternative.
Hester, shunned by the Puritan community, comes to transcend it, and by the novel's end, is a source of comfort for the afflicted in that community, as one who had suffered "A mighty trouble." Hawthorne makes note of the various meanings of the letter "A" in the novel; at first it stands for "Adulterer," then at various times "Angel" and "Able." Hester was able to effect this heroic transformation by accepting the consequences of her actions, unlike Dimmesdale, and she ultimately triumphs over them.