Maupassant's story is about pettiness and hypocrisy. None of the characters, including the protagonist Hauchecome, come off as virtuous. It’s Hauchecome’s extreme greed which makes it impossible for him to pass up the piece of string on the ground; his stooping to pick it up, while entirely consistent with his skinflint values (for which he is famous in the village), nevertheless provides the opening for his enemy Malandain to accuse him of the theft of the wallet. Hauchecome is brought before the mayor, and, despite protestations of innocence, everyone in the village believes that he is guilty, a belief that continues even after the wallet is found. It does not seem to matter if he did it or not; all that counts is his vulnerability to attack, something that everyone exploits to the best of their ability. Hauchecome becomes an outcast and a laughingstock.

On the face of it, you could say that the theme of the story is man’s inhumanity to man, or perhaps how people become like animals and will turn on companions when they become too weak to defend themselves. There does not seem to be much honor in the story, and yet Hauchecome is fixated on trying to repair his reputation—in itself a kind of hypocrisy, since he was never truer to himself than when he stooped to pick up the string. In fact, though they all behave badly, the villagers are true to their core values—it’s just that those values are ruthlessness, greed, suspicion, and hatred. So perhaps the theme is about the mutability of truth. Even though Hauchecome did not steal the wallet, he has a “sharp” reputation which makes everyone believe he did it.

The theme of "A Piece of String" has to do with the meaness, cruelty, and injustice of humanity. Maupassant often wrote stories about human selfishness, wickedness, envy, spite, greed, and other bad qualities. Here are a few pertinent quotations:

"Everyone is perfidious, a liar and a phony. Everyone wears a false face."---Guy de Maupassant

Maupassant persuades us to accept his illusion that cunning, ferocity, greed, and coarseness are more common among men than we hope they are.---Wallace Stegner

The thing that most tormented De Maupassant, to which he returns many times, is the painful state of loneliness, spiritual loneliness, of man, of that bar which stands between man and his fellows; a bar which, as he says, is the more painfully felt, the nearer the bodily connection.---Leo Tolstoy

Maupassant was deeply influenced by the pessimistic German philosopher Artur Schopenhauer, who had an even lower opinion of human nature. In "A Piece of String" an entire village makes a simple, humble man's life miserable by accusing him of theft. There is nothinig he can do to convince them that he was only picking up a piece of striing. His accusers don't want to believe him because they enjoy venting their spite on a defenseless man.

"A Piece of String" might be compared with Shirley Jackson's story "The Lottery" and with Maupassant's famous story "Boule de Suif."

What is the irony of "The Piece of String" by Guy de Maupassant?

As was mentioned in the previous post, the irony throughout the short story "The Piece of String" concerns the innocence of Maitre Hauchecorne and significance of such an insignificant object. Maitre Hauchecorne, a thrifty Norman peasant, is accused of picking up M. Houlbreque's pocketbook when he actually picked up a tiny piece of string. Hauchecorne's enemy, M. Malandain, saw him suspiciously pick up something and quickly accuses him of possessing the pocketbook. Hauchecorne spends the rest of the story trying to defend his innocence. Even after the pocketbook is returned, the villagers refuse to believe that M. Hauchecorne is innocent. It is ironic that an innocent man is considered guilty in the eyes of the villagers. It is also ironic that something as small and insignificant as a tiny piece of string made an incredible impact on the life of a man. In an attempt to defend his reputation, Maitre Hauchecorne continues to lengthen his story and swear oaths that he was innocent, yet people refuse to believe him. It is also ironic that the more he tries to defend his innocence, the more people believe that he is guilty. 

What is the irony of "The Piece of String" by Guy de Maupassant?

The supreme irony of Guy de Maupassan'ts short story, "The Piece of String," is that the protagonist, Maitre Hauchecorne, though innocent of the crime of which he is accused, is believed by all to be guilty. Due to his "crafty" nature, he has always been regarded as suspicious to the townspeople--a man not to be wholly trusted. By persistently declaring his innocence, he merely fuels speculation of his guilt. It is also ironic that such a simple act--the retrieval of a discarded piece of string--could result in such tragic circumstances. In the end, Hauchecorne realizes another irony of his situation:

Ironically, when Hauchecorne goes home after being mocked out of town, he arrives at the same conclusion that Maupassant had held for years. That is, Hauchecorne's Norman simplicity readily understands that there is considerable justice in the peasants’ disbelief of his story. The peasants’ ingrained suspiciousness has singled out this old man as a thief, even disregarding the fact that the pocketbook had been recovered a day later; this, too, is how Maupassant treats his peasant: as a man not to be trusted.