(late post) As mentioned in class, I believe the overcoat to be symbolic of one man's overemphasis on artificial items. By routing the cause of the protagonist's death to his obsession over his overcoat, Gogol is portraying (in an extreme fashion) consequences of relying on superficial possessions rather than more concrete characteristics of ourselves. The overcoat itself could be observed as a protective item, which may also serve to display the protagonists obsession over his coat (HAHA) as a device to shelter himself from reality.