Please explain some of the symbolism in "The Pit and the Pendulum."

This story is full of symbolism.  One could view the entire story as one man's descent into hell (the pit functions as a symbol obviously), then his progression into purgatory (the pendulum serving as a way to pass time or work off his sins), and then finally his ascension into heaven (the French soldiers freeing him symbolic of heaven by the sudden light shining into the gloom and the sound of horns heralding his release).