Both of the short stories "The Minister's Black Veil," by Nathaniel Hawthorne, and "The Fall of the House of Usher," by Edgar Allan Poe, deal with the theme of the evil of human nature. However, Hawthorne presents all of human nature as naturally tending towards evil, whereas Poe only portrays certain types of evil, such as the ability for mankind to be incestuous out of prideful, arrogant desires.
In "The Minister's Black Veil," Mr. Hooper, the village minister, begins daily wearing a black veil for mysterious reasons. While a veil typically symbolizes mourning and sorrow, the villagers saw the veil as representing so much more though they were unsure of what. The veil both terrifies the villagers and makes them feel drawn to Mr. Hooper. As the story progresses, we learn that Mr. Hooper used the veil to symbolize the evil natures that all human beings try to hide.
We first see the connection between the veil and evil when we learn, while wearing the veil, Mr. Hooper became very effective in being able to convert sinners to Christianity. Sinners felt drawn to him because they felt some sort of connection between themselves and the veil. As the narrator explains, sinners said they felt that "before he brought them to celestial light, they had been with him behind the veil." In addition to being able to strongly influence Christian converts, those who were dying felt drawn to him and "cried aloud for Mr. Hooper, and would not yield their breath till he appeared."
We later learn why sinners felt drawn to the veil when we hear Mr. Hooper explain, upon his own deathbed, exactly what they saw the veil as representing. As he looks at those surrounding him on his deathbed, he asks why the veil makes them tremble since the veil only hides what every man tries to hide daily--his own sins. Mr. Hooper uses the following to explain what the veil represents:
When the friend shows his inmost heart to his friend; the lover to his best beloved; when man does not vainly shrink from the eye of his Creator, loathsomely treasuring up the secret of his sin; then deem me a monster, for the symbol beneath which I have lived, and die! I look around me, and, lo! on every visage a Black Veil!
In other words, sinners felt drawn to Mr. Hooper and his veil because they saw that Mr. Hooper was using the veil to represent sins and the sinners' attempt to hide their sinful nature. In addition, since Mr. Hooper metaphorically sees a black veil on every person, we can see that Hawthorne is presenting all of humanity as having an evil, sinful nature that each human being tries to hide.
In contrast to Hawthorne's short story, Poe presents the Ushers as being evil in "The Fall of the House of Usher" but only for specific reasons. Throughout the story, it is implied that generations of the Usher family have practiced incest to carry forth the family line.
Incest is first hinted at in the third paragraph in the following sentence:
I had learned, too, the very remarkable fact, that the stem of the Usher race, all time-honoured as it was, had put forth, at no period, any enduring branch; in other words, that the entire family lay in the direct line of descent, and had always, with very trifling and very temporary variation, so lain.
This sentence can be translated to mean that the Usher family had only one branch, not multiple branches like other families. The only branch of the Usher family was the branch that continually inherited the title and the estate. The inheritance passed directly from father to son and so forth; it never passed to the next closest male heirs, which would be sons of daughters or of cousins. The only way it would be possible for the Usher family to have only one branch and for that branch to continually be patrilineal is if no one every married outside of the one branch of the family, which would also mean that all sons are sired incestuously. Other evidence of an incestuous family practice is seen in Roderick's explanation that Madeline's death "would leave him (him the hopeless and the frail) the last of the ancient race of the Ushers." His being the last of the Ushers would only be true if he had no intention of marrying and fathering children of his own. One can conclude the reason why he has no intention of marrying is because he knows he is forced to carry on the family tradition of incest.
In the story, it is also evident that Roderick is struggling with the immorality of the tradition, and this struggle is driving him insane, just as it has apparently driven so many other male heirs of his family insane. He calls his insanity a "family evil," which also implies he is well aware of the immorality and evil his family has practiced for many generations. Hence, in Poe's story, mankind can be evil when it practices immorality, such as incestuous behavior.
However, we should also consider precisely why the Ushers felt the need to practice incest. Doing so would ensure that only the Ushers ever inherited the title and the estate, which is evidence of the family patriarch's pride and arrogance. Pride and arrogance can also be considered evil.