When the narrator declares the source of his profound dread "a mystery all insoluble" and "beyond our depth," what is Poe suggesting about the limits of human understanding in the face of certain overwhelming psychological or environmental influences?

From the book

this intolerable agitation of soul. I have, indeed, no abhorrence of danger, except in its absolute effect--in terror. In this unnerved--in this pitiable condition--I feel that the period will sooner or later arrive when I must abandon life and reason together, in some struggle with the grim phantasm, FEAR." I learned, moreover, at intervals, and through broken and equivocal hints, another singular feature of his mental condition. He was enchained by certain superstitious impressions in regard to the dwelling which he tenanted, and whence, for many years, he had never ventured…

poetic, sentiment, with which the mind usually receives even the sternest natural images of the desolate or terrible. I looked upon the scene before me--upon the mere house, and the simple landscape features of the domain--upon the bleak walls--upon the vacant eye-like windows--upon a few rank sedges--and upon a few white trunks of decayed trees--with an utter depression of soul which I can compare to no earthly sensation more properly than to the after-dream of the reveller upon opium--the bitter lapse into everyday life--the hideous dropping off of the veil. There was an iciness,…

, interested and bewildered me; although, perhaps, the terms, and the general manner of the narration had their weight. He suffered much from a morbid acuteness of the senses; the most insipid food was alone endurable; he could wear only garments of certain texture; the odours of all flowers were oppressive; his eyes were tortured by even a faint light; and there were but peculiar sounds, and these from stringed instruments, which did not inspire him with horror. To an anomalous species of terror I found him a bounden slave. "I shall perish," said he, "I must perish in…

ttention, as if listening to some imaginary sound. It was no wonder that his condition terrified--that it infected me. I felt creeping upon me, by slow yet certain degrees, the wild influences of his own fantastic yet impressive superstitions. It was, especially, upon retiring to bed late in the night of the seventh or eighth day after the placing of the lady Madeline within the donjon, that I experienced the full power of such feelings. Sleep came not near my couch--while the hours waned and waned away. I struggled to reason off the nervousness which had dominion over me. I…

remor gradually pervaded my frame; and, at length, there sat upon my very heart an incubus of utterly causeless alarm. Shaking this off with a gasp and a struggle, I uplifted myself upon the pillows, and, peering earnestly within the intense darkness of the chamber, hearkened--I know not why, except that an instinctive spirit prompted me--to certain low and indefinite sounds which came, through the pauses of the storm, at long intervals, I knew not whence. Overpowered by an intense sentiment of horror, unaccountable yet unendurable, I threw on my clothes with haste (for I felt that I…