This most basic and useful ethical theory, sometimes called the “Rule of Reciprocity,” has a long history: Confucius (500 B.C.): “What you do not want done to yourself, do not do to others.” Aristotle (325 B.C.): “We should behave to others as we wish them to behave to us.” From the Mahabharata (200 B.C.): “Do nothing to thy neighbor which …