The theme of "The Minister's Black Veil" is that secret sin exists in people, and they are hypocritical about their sins, pretending that they are guileless. This condition is especially true in Mr. Hooper's Puritan congregation since revealing one's sins makes one vulnerable to public punishment or ostracism by the community. Because of the fear of punishment or ostracism, the congregation, therefore, becomes very uneasy when the minister dons the black veil for his sermon, but does not discard it afterwards:
Each member of the congregation, the most innocent girl, and the man of hardened breast, felt as if the preacher had crept upon them, behind his awful veil.
So uncomfortable are the congregation that those who normally invite him to dinner on Sunday, do not. Even his fiancee breaks off their marriage plans after Mr. Hooper refuses to remove his veil. Adamant to the end, on his deathbed, the minister retains his veil. He speaks to the "circle of pale spectators":
'Why do you tremble at me alone?....Tremble also at each other! Have men avoided me, and women shown no pity, and children screamed and fled, only for my black veil? What, but the mystery which it obscurely typifies, has made this piece of crape so awful? 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!'
The moral of Hawthorne's story is much the same as that of his novel, "The Scarlet Letter": "Be true! Be true!" Do not hide sin; reveal your innermost heart to your friends so that you will not be separated from the world by your sin.