“One of the wonders of the human heart,” wrote twelfth-century poet Usama ibn Munqidh, “is that a man may face certain death and embark on every danger without his heart quailing from it, and yet he may take fright from something that even boys and women do not fear.” He relates the story of a battle hero his father knew who “would run out fleeing” if he saw a snake, “saying to his wife, ‘The snake’s all yours!’ And she would have to get up to kill it.”