None can use black magic without straining the soul to the uttermost—and staining it into the bargain. None can inflict suffering without enduring the same. None can send death by spells and sorcery without walking on the brink of death’s own abyss and dripping his own blood into it. The forces black magic evokes are like two-edged poisoned swords with grips studded with scorpion stings. Only a strong man, leather-handed, in whom hate and evil are very powerful, can wield them, and he only for a space. (Fritz Leiber)
