What evidence is presented in the story that proves the narrator of "The Tell-Tale Heart" is indeed a madman?
It's a good bet that when someone tries desperately to convince another that he is NOT mad, then the likelihood exists that he probably is. Such is the case with the narrator of Edgar Allan Poe's classic horror story, "The Tell-Tale Heart." In the first sentence, the narrator admits that he is "very, very dreadfully nervous," but then asks the reader if this alone makes him mad. He then claims to hear "all things in heaven and in the earth" as well as "many things in hell." Again, he questions his own sanity. The first lines solidify the likelihood that he is indeed insane.
Although he claims to have "loved the old man," the narrator's desire to kill him because of the evil eye--the "eye of a vulture"--again shows how he teeters on the edge of madness. The thoroughness with which the narrator prepares to kill the old man does not necessarily show his sanity; it instead displays his single-minded goal of murder. Once he accomplishes the act, the gruesome dismemberment only strengthens the argument. The final display of audibly detecting the dead man's still-beating heart is the clue which cements the certainty of his total derangement.