Mortality
The plot of Poe's tale essentially involves a woman who dies, is buried, and rises from the grave. But did she ever die? Near the horrific finale of the tale, Usher screams: "We have put her living in the tomb!" Premature burial was something of an obsession for Poe, who featured it in many of his stories. In "The Fall of the House of Usher," however, it is not clear to what extent the supernatural can be said to account for the strangeness of the events in the tale. Madeline may actually have died and risen like a vampire--much as Usher seems to possess vampiric qualities, arising "from a sofa on which he had been lying at full length" when the Narrator first sees him, avoiding all daylight and most food, and roaming through his crypt-like abode. But a more realistic version of events suggests that she may have been mistaken for dead--and luckily managed to escape her tomb. Either way, the line between life and death is a fine one in Poe's fiction, and Usher's study of the "sentience of all vegetable things" fits aptly with Poe's own preoccupations.
Madness
Poe writes that Usher "entered, at some length, into what he conceived to be the nature of his malady." What exactly is his "malady" we never learn. Even Usher seems uncertain, contradictory in his description: "It was, he said, a constitutional and a family evil, and one for which he despaired to find a remedy--a mere nervous affection, he immediately added, which would undoubtedly soon pass off." The Narrator notes an "incoherence" and "inconsistency" in his old friend, but he offers little by way of scientific explanation of the condition. As a result, the line between sanity and insanity becomes blurred, which paves the way for the Narrator's own descent into madness.
Fear
If we were to try to define Roderick Usher's illness precisely, we might diagnose him with acute anxiety. What seems to terrify Usher is fear itself. "To an anomalous species of terror," Poe writes, "I found him a bounden slave." Usher tries to explain to the Narrator that he dreads "the events of the future, not in themselves but in their results." He dreads the intangible and the unknowable; he fears precisely what cannot be rationally feared. Fear for no apparent reason except ambiguity itself is an important motif in Poe's tale, which after all begins with the Narrator's description of his own irrational dread: "I know not how it was--but, with the first glimpse of the building, a sense of insufferable gloom pervaded my spirit." Later, Usher identifies fear itself as the thing that will kill him, suggesting that his own anxiety is what conjures up the blood-stained Madeline--or that she is simply a manifestation of his own deepest neuroses.
Incest
What binds Usher to Madeline, and what renders him terrified of her? If he conjures up her specter, arisen from the grave to bring him to his own, why does he do so? There is a clear incestuous undertone to the relationship between the brother and sister. Without spouses they live together in the great family home, each of them wasting away within the building's dark rooms. The Narrator describes the strange qualities of the Usher family--that it never has put forth "any enduring branch," that "the entire family lay in the direct line of descent." The implication is that incest is the norm for the Ushers, and that Roderick's and Madeline's strange illnesses may stem from their inbred genes.
Friendship
The Narrator arrives at the House of Usher in order to visit a friend. While the relationship between him and Roderick is never fully explained, the reader does learn that they were boyhood friends. That Usher writes to the Narrator, urging him to give him company in his time of distress, suggests the close rapport between the two men. But Poe's story is a chronicle of both distancing and identification. In other words, the Narrator seems to remove himself spiritually from Usher, terrified of his house, his illness, his appearance, but as the narrative progresses he cannot help but be drawn into Usher's twisted world. Alas, family (if not incest) trumps friendship at the end, when Usher and Madeline are reunited and the Narrator is cast off on his own into the raging storm.
Burial
There are three images of would-be "tombs" or "crypts" in "The Fall of the House of Usher." The house itself is shut off from the daylight, its cavernous rooms turned into spacious vaults, in which characters who never seem entirely alive--Madeline and Usher--waste away. Second, Usher's painting is of "an immensely long and rectangular vault or tunnel," foreshadowing the third image of a tomb, the real one of Madeline's temporary burial. What Poe has constructed therefore is a kind of mise-en-abime (story-within-a-story)--tombs being represented within tombs. The implication, especially once the entire House of Usher sinks into a new grave below the tarn, is that the world itself is a kind of crypt.
The Arts
Despite (or because) of his madness, Usher is skilled at music and apparently is quite a painter. The Narrator compares Roderick's "phantasmagoric conceptions" to those of a real artist, Fuseli, and the Narrator seems both entranced and terrified by them. "If ever mortal painted an idea," he proposes, "that mortal was Roderick Usher." Insofar as art might be deemed a stab at immortality, the death-obsessed Usher, so certain of his own demise, strives to cling to time itself by producing works which can last beyond him. And insofar as art is a fleeting good in itself, Usher might at least claim a bit of beauty in the midst of his anxieties. Ironically, though, the one painting of his that the Narrator describes portrays a tomb, and everything is finally destroyed by the House's collapse. It would seem that his art fails Roderick Usher.
