The narrator’s perception is unreliable.
Throughout the story, Poe makes it abundantly clear that we cannot take the narrator’s description of events as true, not because he is actively lying, but because he has a warped perception of the world. For example, his insistence that an old man’s eye is evil or has power separate from the old man is clearly irrational. However, the clearest indication that the narrator’s perception cannot be trusted comes from the police who come to inspect the report of a shout. Before this moment, the assumption that the narrator is imagining everything comes from the reader’s understanding of reality, but the police’s inability to hear the heartbeat confirms that all the supernatural malevolence comes from his own imagination. The narrator describes himself as ranting and raving, but the police do not react once, suggesting that the narrator has not actually let any of his inner distress show. Reading “The Tell-Tale Heart” is an exercise in reading between the lines, trying to pick out grains of truth through the narrator’s delusions.
People self-project their malice onto others.
It is abundantly clear that the only character who harbors any malice in this story is the narrator. Nevertheless, in his paranoia he blames external forces for his feelings, as exemplified by his reaction to the old man’s eye. The filmy appearance of the eye has no significance other than as a sign of old age or illness, but it nevertheless makes the narrator uncomfortable. Instead of understanding that this discomfort is his own emotion, he blames the discomfort on the eye, calling it evil. However, it is the narrator, not the old man, who commits an evil act. Similarly, when the narrator hears his own racing heartbeat at the end, instead of recognizing his own feelings of guilt, he blames the old man’s heart, an external force. His anger at the police for their calmness stems from his own paranoia and fear. The police’s lack of reaction to the narrator is not a taunt. They genuinely cannot hear the heartbeat, and he is not actually ranting or pacing. The narrator has no true understanding of his own inner life, blaming those around him for his darkest impulses.
Calm demeanors can mask inner turmoil.
Although the narrator constantly describes himself as calm, patient, and methodical, his paranoid, violent thoughts bely his true nature. He treats the old man with kindness despite wanting to murder him. He is hospitable to the police officers who come to investigate despite having just committed a brutal murder. This idea of superficial calmness also appears in the narrator’s definition of madness. The narrator insists that he cannot be insane because of how methodically he pursues his murder of the old man. However, no matter how patiently and carefully he sneaks into the old man’s room, the calm way he enacts his behavior belies violent intent. When the police finally enter the house, its normalcy masks the murder that had recently taken place. All appears so peaceful in the house that the narrator is able to lead them to the old man’s room and speak with them there without them suspecting a murder has just taken place. Like the floorboards that hide the old man’s corpse, calm, rational behavior in the story is a mere façade.