Be sure to the read the story before you read this essay.
Rejection in Rome:
Masons and Freemasons in Poe's "The Cask of Amontillado"
In Poe's "The Cask of Amontillado," the main character Montresor is a mason (with a lower case "m") because he uses bricks and mortar to wall up his enemy alive. Montresor's victim, Fortunato, is a Mason (with an upper case "M") because he indentifies himself by gesture and word as member of the Brotherhood of Freemasons:
He. . .threw the bottle upward with a gesticulation I did not understand.
I looked at him in surprise. He repeated the movement -- a grotesque one.
"You do not comprehend?" he said.
"Not I," I replied.
"Then you are not of the brotherhood."
There are only a few vague clues to tell us why Montresor pursues such a horrible vengeance for "the thousand injuries" of Fortunato, but this business about masons and Masons hints that Montresor may resent Fortunato's status as an important man deserving of respect and fear and that Montresor is in some ways a rejected outsider.
Collecting all those vague clues together, however, does suggest that Montresor is an outsider who suffers from the envy, resentment, and self-pity that most outsiders feel. For example, his name is French, but he lives in Italy, and yet he does not really like Italians. As he says early in the story, "few Italians have the true virtuoso spirit." He even calls the Italians "quacks" in most cultural and artistic matters. Also, a little while later, we hear Montresor whining in self-pity as he speaks with Fortunato:
"Come," I said, with decision, "we will go back; your health is precious. You are rich, respected, admired, beloved; you are happy, as once I was. You are a man to be missed. For me, it is no matter."
Of course, this is only a little bit of evidence; but what evidence there is suggests that Montresor was an envious and self-pitying outsider who felt rejected.
The business about the Brotherhood of Freemasons seems to point in the same direction as the evidence cited above. Since Poe's story was published in 1846 and the narrator claims the murder of Fortunato took place 50 years earlier, we can assume the main action of the story took place in the 1790's. At that period of history, the Brotherhood of Freemasons was the world's largest and most exclusive secret society. It was a fraternity which only the most elite members of society were allowed to join. To mention just a few examples, President George Washington, Colonel William Travis of Alamo fame, Sylvanus Thayer who founded West Point, Jonathan Swift of Gulliver's Travels fame, Joseph Smith who founded the Mormon religion, the novelist and poet Sir Walter Scott, both Lewis and Clark of the Lewis and Clark expedition, Paul Revere, the Marquis de Lafayette, and hundreds of members of European noble families -- these were the kind of prominent people who were members of the Masons in those days. For a man as wealthy as Montresor to not only be excluded from membership but to be ignorant of even the existence of the Masons clearly means that he was not accepted into the elite upper crust who were selected as members of "the brotherhood." The case for Montresor as a rejected "outsider" is clearly strengthened by all this Mason business.
Montresor, as it turns out, is not an upper-case Mason like the "fortunate" Fortunato. It seems at least possible that what turned him into the lower-case mason who walled up Fortunato was his rejection by the cream of Roman society. As the Montresor family coat of arms put it: Nemo me impune lacessit, or "Nobody injures me and gets away with it!"