* Guilt and its torment: The narrator claims to be sane but his obsessive, detailed account of the murder reveals his deep guilt and the relentless torment it causes. He hears the beating heart even after the crime is committed, demonstrating that his conscience will not let him rest.
* The unreliability of the narrator: The story is told from the perspective of a clearly disturbed individual, who is both self-delusional and demonstrably lying. This unreliable narration makes it difficult to ascertain the truth of events, adding to the unsettling nature of the story.
* The destructive power of obsession: The narrator's obsessive hatred of the old man's eye drives him to murder. His fixation on the eye becomes a consuming force that blinds him to the consequences of his actions.
* The fragility of sanity: The narrator's descent into madness is palpable throughout the story. His actions, his language, and his increasingly erratic behavior all point to his unstable mental state. He attempts to convince the reader of his sanity, but the very act of telling the story betrays his true condition.
* The hidden darkness within humanity: Though the narrator is a fictional character, his story reflects the potential for darkness and violence that exists within all people. The story suggests that even the most seemingly ordinary person can be capable of horrific acts, driven by their own inner demons.
These themes are woven together in a compelling and chilling way, creating a powerful and enduring literary work that continues to resonate with readers today.