What does total darkness symbolize in "The Pit and the Pendulum?"

In 's
horror story "," the narrator, after being sentenced and swooning, wakes up in a cell
that is pitch black, which he feels is "the blackness of the eternal night." This deep
blackness represents the depths of fear that the narrator
experiences--the exact fear that is a key tool the inquisitors use as part of
their torture. This fear has three aspects: fear of the unknown, fear of the future, and fear of
death and the afterlife. 

The first thing the narrator wonders when he
experiences the darkness is whether he may have been buried alive. Not knowing whether he may be
in a...