From the beginning, various narrative elements cast doubt on Hadleyburg's supposed integrity. The narrator portrays a town that "care[s] not a rap for strangers or their opinions," and some of its residents offend a stranger so profoundly that he feels compelled to seek revenge on the entire town. When the stranger delivers a sack of gold to the Richardses, Mary becomes anxious about theft, exclaiming, "Mercy on us, and the door not locked!" She only relaxes after she "listens awhile for burglars." These incidents, marked by suspicion, fear, and malice, challenge the town's claim of "unsmirched" honesty and suggest a flawed reality beneath the surface.

As the story progresses, Hadleyburg's true nature becomes clear. Behind closed doors, the townspeople slander one another, revealing the widespread animosity within the community. For instance, Goodson is the "best-hated," followed closely by Burgess. Edward's silence not only causes an unwarranted scandal for Burgess but also leads the townspeople to blame Goodson for Burgess's sudden departure. Furthermore, Edward conceals his involvement in the scandal from Mary, fearing she might reveal his secret. He confesses that he only warned Burgess once he was sure his actions wouldn't be discovered, admitting, "[A]fter a few days I saw that no one was going to suspect me [of warning Burgess], and after that I got to feeling glad I did it."

Edward's admissions to Mary reveal that even before the tempting sack of gold appeared, Hadleyburg was entangled in a complex web of self-interest and deception, contradicting its proud claims of complete integrity. Ultimately, hypocrisy, rather than honesty, defines the town's character, as the residents preach honesty but practice self-interest and deceit.

The story of Hadleyburg delivers a moral lesson to its characters and readers alike. The town's concealed truths raise several ethical dilemmas. For instance, would the Richardses have been justified in keeping the gold since it supposedly wouldn't "harm" anyone? Was it correct for Edward to conceal evidence that could have cleared Burgess's name? Mary justifies her husband's actions by claiming they couldn't risk the community's disapproval. She also believes that as long as Burgess didn't "know that [Edward] could have saved him... that makes [withholding the information] a great deal better." Edward eases his conscience by warning Burgess of upcoming danger, but only when he is sure that "no one was going to suspect me." These actions expose the self-serving nature of human tendencies, which often lead to unethical choices in difficult situations. Edward's character further demonstrates how cowardice can complicate a lack of ethical integrity. Besides Edward and Mary, other townsfolk like the Coxes, the Wilsons, and the Billsons also succumb to the lure of easy money. This narrative highlights a genuine, universal reaction of human nature to the temptation of "easy" money. Although Hadleyburg's residents are not inherently sinful, their collective response reveals the inherent weaknesses of human nature.

Critics often describe ‘‘The Man That Corrupted Hadleyburg’’ as a story of ‘‘the fortunate fall.’’ Essentially, this idea suggests that moral growth arises from learning from previous mistakes. This theme mirrors the biblical story of Adam and Eve and John Milton's "Paradise Lost." The downfall of the town leads to a deeper understanding, or as Mary comments, protected and untested virtue is as delicate as a house of cards. Although the townspeople lose their "Eden," they gain practical wisdom in how to achieve true honesty. Once their hypocrisy is exposed, Hadleyburg will actively seek out temptation to test and fortify their virtue, as symbolized by the town's new motto: ‘‘Lead us into temptation.’’ The transformed town realizes that its future depends on replacing...

Mary and Edward's dilemma in "The Man That Corrupted Hadleyburg" underscores the significant influence of societal norms on personal choices, illustrating how these values can overshadow personal judgment. The town hall scene vividly depicts the destructive allure of conforming to collective identity. Embracing a "mob" or "herd" mentality, the crowd quickly judges or praises with little provocation. For instance, when Wilson accuses Billson of plagiarism, the crowd erupts and "submerge[s Wilson] in tides of applause." However, once Wilson's deceit is exposed, they burst into a "pandemonium of delight" and the applause turns to ridicule. In "The Role of Satan in 'The Man That Corrupted Hadleyburg,'" Henry Rule compares the crowd's loud jeering to the mindless and impulsive actions of an "automatic dog" that "bark[s] itself crazy." Rule's analogy equates the crowd's reactions to those of animals, instinctively responding to external stimuli.

Despite the unflattering portrayal of Hadleyburg's community as a mob, the townspeople discourage nonconformity, as illustrated by the cases of Burgess and Goodson. In contrast, conformity brings rewards, as shown by the Richardses, who yield to public opinion and receive $38,500. Twain ironically highlights the real cost of Mary and Edward's "success" by detailing their troubled consciences and subsequent decline into physical and mental frailty. Although the narrative appears to critique adherence to societal norms, it does not advocate for individualism either. Instead, it casts a cynical eye on American society, which claims to champion individuality and freedom but, in truth, restricts personal liberties under the guise of community standards. In "The Lie that I Am I: Paradoxes of Identity in Mark Twain's 'Hadleyburg,'" Earl F. Briden and Mary Prescott argue that the story seeks "to embody a turn-of-the-century American society in which ... a personal, original, and undetermined, freely-willing selfhood could scarcely be found."

In "The Man That Corrupted Hadleyburg," Mark Twain deftly explores the discrepancy between appearance and reality, weaving together themes of pretense, habitual behavior, and the corrupting influence of vanity. Twain, along with the mysterious stranger in the story, delights in unveiling the town’s underlying hypocrisy. Hadleyburg, a town that prides itself on its steadfast honesty, is merely a facade; its residents, including Mary and Edward Richards, are quick to abandon their supposed virtues when tempted by the lure of gold.

Though the Richardses dutifully peruse the Missionary Herald, their engagement with charitable acts is purely superficial. They lack the moral fortitude to save Burgess when it truly matters, exposing the hollow nature of their supposed piety. This pattern of behavior is not isolated; the townspeople collectively demonstrate a willingness to sacrifice integrity for material gain. Ultimately, Hadleyburg's claim to virtue is nothing more than a carefully constructed illusion, underscored by the pervasive influence of vanity and self-interest.

Real virtue, as underscored by the stranger, demands rigorous testing. It is not enough to simply profess integrity; one must actively cultivate the ability to withstand temptation. Training, therefore, plays a pivotal role, shaping individuals for better or worse. In Hadleyburg, this training is misdirected, fostering cowardice, rationalization, and vanity. The townspeople are conditioned to maintain an appearance of moral superiority, yet their actions betray a lack of genuine integrity.

Edward, one of the town's notable figures, attempts to break free from these entrenched habits. In a moment of realization, he strives to uphold true virtue by resisting the pervasive norm. However, his efforts come too late. His attempt to stand against the prevailing corruption ends up causing more harm than good, particularly affecting Burgess, a character already wronged by the town's deceitful practices.

Acting virtuously often proves challenging because it demands an acknowledgment of one's own shortcomings. In "What Is Man?", Twain posits that genuine altruism is nonexistent; rather, human actions are primarily driven by self-interest. This notion is unsettling to human vanity, prompting many to deceive themselves regarding their intentions and ethical standards. It is only under significant duress, like the guilt experienced by the Richardses or the humiliation faced by Hadleyburg, that people might shatter this illusion. Such pivotal moments can lead individuals to embrace the process of confronting their weaknesses, rather than dismissing them, invoking the idea: "Lead us into temptation."