I can’t see the stanza, but generally, alliteration can help add mood and sometimes tone to the writing. The repetitiveness can add a cadence to the poem.
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 decent into madness. This madness is manifested not only in the breakdown of Usher's mind but in his decrepit body. The diseased rotting corps of his sister also illustrates this motif.
The role of philosophy in medieval thoughts is to propagate religious doctrine especially christian doctrine. It also a means to address or solve theological problems and learnings. Early philosophers contemplates in the field of religion and theology. Also it is times of rediscovery of ancient philosophies that was once lost after the fall of the western roman empire which chaos and destruction ravage due to barbarian invasions. Early church leaders affect the philosophical ideas of this age due to the fact that in this age most educated are from the church. They depose and excommunicate philosophers who opposed their views and philosophy of the world. Also most philosophy of this age is religious oriented and people seek refuge in God for hope and salvation in chaotic times. Early philosophers tend to be more God-oriented and mystical rather than to be logic and rational in thinking. Also in this age everything are explained through religion and the church doctrine rather than math and science which in the future will play a vital role of Renaissance.