" You have great power inborn in you, and you used that power wrongly, to work a spell over which you had no control, not knowing how that spell affects the balance of light and dark, life and death, good and evil. And you were moved to do this by pride and by hate. Is it any wonder the result was ruin? You summoned a spirit from the dead, but with it came one of the Powers of unlife. Uncalled it came from a place where there are no names. Evil, it wills to work evil through you. The power you had to call it gives it power over you: you are connected. It is the shadow of your arrogance, the shadow of your ignorance, the shadow you cast. Has a shadow a name? "
― Ursula K. Le Guin , A Wizard of Earthsea (Earthsea Cycle, #1)