Edgar Allen Poe's "The Tell Tale Heart" is a short story about how a murderer's conscience overtakes him and whether the narrator is insane or if he suffers from over acuteness of the senses. Poe suggests the narrator is insane by the narrator's claims of sanity, the narrator's actions bring out the narrative irony of the story, and the narrator is insane according to the definition of insanity as it applies to "The Tell Tale Heart".
             First, Poe suggests the narrator is insane by his assertions of sanity. For example, the narrator declares because he planned the murder so expertly he could not be insane. He says, "Now this is the point. You fancy me mad. Madmen know nothing. But you should have seen how wisely I proceeded-with what caution-with what foresight-with what dissimulation I went to work!" (74). In addition, every night at midnight the narrator slowly went into the room of the old man. He claims this was done so wisely that he could not be insane. The narrator thinks that if a murder is carefully planned then the murderer is not insane. Also, the narrator claims he suffers from over acuteness of the senses. Regarding the sound of the old man's beating heart, the narrator says, "And now have I not told you that what you mistake for madness is but over-acuteness of the senses?--now, I say, there came to my ears a low dull, quick sound, such as a watch makes when enveloped in cotton"(76). !
             The narrator claims he is not imagining the sound but he is hearing it because his senses are so sharp. The narrator believes he is justified in killing the old man because the man has an Evil Eye. The narrator claims the old man's eye made his blood run cold and the eye looked as if it belonged to a vulture (74).
             Poe shows the narrator is insane because the narrators' actions bring out the narrative irony used in "The Tell Tale Heart". Through the use of narrative irony Poe shows reason not to trust what the narrat...