The Heart of Darkness

An artifact that according to the elves dates back to the creation of the Universe. It is seen as a physical manifestation of the merciless power of pure reason. To humans the association with the dark seems strange, since light is allegorically equal to reason, as in enlightenment. But the elves consider this another sign of human lack of insight. Light affects the senses, not reason, and the sensory impressions create feelings. Feelings are wonderful, but only muddles logic. The Heart of Darkness does exist in a real sense, but is more often thought of as a symbol. The underlying thought is that a being by shutting off all sensory input can change reality by force of will. This artifact holds only indirect importance to humans, as they cannot use it themselves, and believe only the gods can change reality (with or without the Heart). For the elves the Heart is a minute, but constant, temptation. Elves regard it as sinful (for an elf) to change the world for one's own sake. The fact that elves deep down believe themselves capable of shaping  the world by willpower alone partly explains the somewhat measured respect they show the gods. 
The Heart is supposedly kept by Remenesh Turvalmor at his fortress in the Ragged Mountains