The same name; the same contour of person; the same day of arrival at the academy! And then his dogged and meaningless imitation of my gait, my voice, my habits, and my manner!
This quotation comes from when the narrator sneaks into Wilson’s room at Dr. Bransby’s Academy and realizes that they are identical. The exclamation points highlight the narrator’s horror and surprise in this moment. As a doppelganger, Wilson threatens the narrator doubly. The existence of someone else like him threatens his self-image as an extremely singular person, and, more importantly, suggests that a part of him is out of sync with his self-image. As a manifestation of his conscience, Wilson appears to be at war with the narrator—a part of his psyche that disapproves of his own behavior.
You have conquered, and I yield. Yet, henceforward art thou also dead—dead to the world and its hopes. In me didst thou exist—and, in my death, see by this image, which is thine, how utterly thou hast murdered thyself.
This quotation is the enigmatic warning the doppelganger delivers after the narrator defeats him in a duel and he lies dying. Here, Wilson makes the inextricable bond between himself and the narrator explicit. In killing Wilson, a physical manifestation of the narrator’s conscience, the narrator has lost all hope of redemption. Although the narrator apparently survives the encounter, we know from the beginning of the story that his life afterward has brought him no joy. In killing his alter-ego, he has trapped himself in a kind of living death.