What is the narrator's "other self"?
The onset of the narrator’s psychological “ill temper” and deterioration is described in paragraphs 6-7, which is climaxed by his violence against his wife and the atrocity he commits on his cat. The narrator attributes his deterioration to alcoholism. He also uses the term “fiendish malevolence” as explanation, but points out that the malevolence was “gin-nurtured.” Those who have witnessed the effects of alcoholism and drug dependence in real life will likely assert that such addiction convincingly explains the alteration of the narrator’s character. Others that see it cannot deny that the person has lost control and is truly taken over by his "other self."