In my view, classical utilitarianism (Bentham, Mill, Sidgwick/ Smart) shatters on the realization of what Adam Smith called the "vicarious affects" (e.g., sympathy). While the moral calculus of classical utilitarianism requires that "each is to count for one; no one for more than one," ordinary interpersonal bonds lead naturally to differential treatment. It is not only understandable but also morally right that a mother should give far greater weight to the interests of her child than the interests of a perfect stranger. But the moral calculus of Bentham only works if the parties involved are essentially interchangeable. We cannot with moral propriety ask that a person value the welfare or happiness of all fellow humans equally.