The Fall of the House of Usher

The Fall of the House of Usher In Poe’s “The Fall of the House of Usher,” we usually identify with the narrator and view Roderick as a madman. What characteristics of the narrator seem to make him more amenable to us, and what is it about the “illness” of Roderick that makes us not identify with him? Yet at the end, it is the narrator who is called “mad” by Roderick. How is the narrator "mad" and not Roderick (and by default, we the reader)? http://www.gutenberg.org/files/932/932-h/932-h.htm  (Link to the Fall of the House of Usher)