Although Edgar Allan Poe claimed in his essays and reviews that he was against any didactic motive in literature, and although “The Fall of the House of Usher” is not a didactic story, Poe does communicate a definite moral message here. Importantly, however, the morality with which he is concerned is not that prescribed by any specific religion; instead, he seems to be suggesting that, despite the incestuously twisted and mentally deranged life of the Ushers, there exists an unwritten but operative universal morality that is ultimately as inescapable as the hereditary forces that determine a person’s life.
While one may argue that Roderick’s angst, as well as his acute hypochondria and seeming madness, appears to be the consequence of centuries of incest, which biologically diminishes a creature’s ability to survive, Poe is nevertheless careful to note the “repeated deeds of munificent . . . charity” offered “of late” by the Ushers (presumably by Roderick himself because the story takes place in the nineteenth century, when men, according to tradition, were in charge of financial affairs). Significant, too, is the pejorative appellation of “evil” that Roderick gives to his family, in itself an indication of his own moral sense. Indeed, it is precisely Roderick’s morality that causes the internal conflict he suffers, between his inherited traits and his moral revulsion over them, and it is his morality that prompts him to leave Madeline in the vault even after he discovers that she is still alive. Granted, knowingly allowing his sister to die, when he could save her, is immoral; yet Roderick’s sense of right and wrong has transcended concerns for what is good for the Ushers and their perpetuation, and becomes a greater, higher concern for the future of the human race. It is no wonder, then, that when the hereditary forces have succeeded in joining the brother and sister together in the house, itself an emblematic agent of those forces, a greater force prevails as it obliterates the Ushers and their house, truncating the incestuous “stem” of the family for all time.