In “The Tell-Tale Heart” by Edgar Allan Poe, the narrator’s primary purpose entails convincing the reader that he is not insane. The nameless speaker provides few details to enable to reader to visualize him physically; however, he speaks to his internal purpose and finds excuses for his behavior at every turn.
The narrator is unreliable. Unreliable narrators are compelling because they represent a basic aspect of being human. All people have moments of confusion or memory loss. Sometimes it is difficult to be absolutely accurate about the events of even the most important situation. This story takes this unreliability to new heights. Because the speaker wants to justify his actions so that he is not judged as mentally unstable, the truth of the story is questionable from his point of view. Yet, his perverse view is all that the reader has.
The singular effect of this irrational narrator impacts the course of the story. Hyperbole finds the narrator convinced that his intense hearing ability enables him to hear “all things in the heaven and in the earth and many things in hell.”
This is a sick mind that has the responsibility for the care of an elderly man. Eventually, the narrator murders the old man. The reader learns everything about the murder through the narrator’s version of reality. Further, the narrator would like the reader to think that he is omniscient in his ability to see into the mind of the old man. Here is an example:
‘Presently I heard a slight groan, and I knew it was the groan of mortal terror…I knew the sound well. Many a night… it has welled up from my own bosom.’
The narrator's insight into the man's head just reflects his own experience. This narrator is paranoid, mentally ill, highly nervous, and unable to distinguish what is real or unreal. Apparently, friendless and alone, the man never sleeps. His nights are spent weirdly watching the old man laying his bed.
I could scarcely contain my feelings of triumph. To think that there I was, opening the door, little by little, and he not even to dream of my secret deeds or thoughts.
The reader must surf through the narrator’s minutiae to understand that his reasons for murder. Despite his best efforts, this insane speaker’s action cannot be justified. Without any other information provided, the reader looks at the events with the singular view of the insane narrator.