Edgar Allan Poe's "The Tell-Tale Heart"

     I've read "The Tell-Tale Heart" several times before, and what is always discussed is the obvious case of an unreliable narrator.  I am always amused by the way the narrator tries to convince us, and himself, that he is not crazy.  "And now--have I not told you that what you mistake for madness is but over acuteness of the senses?" the narrator says to explains his hatred of the old man's "vulture eye."  Earlier when describing his carefulness and planning killing the old man he says, "You fancy me mad.  Madmen know nothing."  As if premeditated murder is not something a madman/serial killer would come up with.
     But another theme I noticed after reading it this time, probably because we just covered this theme in The Scarlet Letter, is the power of confession.  "The Tell-Tale Heart" is itself a confession to the reader of the sin committed against the old man.  And although the narrator does try to explain away his madness, it seems that the narrator is aware of his madness and explaining it this way is a hidden confession of its own.  Perhaps confession is what's keeping him from losing it altogether.  The guilt after killing the old man is so much that he believes he can hear the old man's heart beating while the police are chatting with him.  He can't keep the crime to himself any longer and blurts out his confession to the policemen.  Sinning and keeping the sin to himself is driving him crazy--he hears things and he imagines himself to be pacing back and forth, "I foamed--I raved--I swore," while the police sit pleasantly chatting, not seeming to notice.  I assume this was not actually happening but a figment of his imagination--an effect of keeping sin in the dark.  "I felt like I must scream or die!" the narrator says.  But confession will do just fine.  Once the narrator confesses, the story ends--a story written by a man confessing and attempting to keep his sanity through it.