In 1841 the American sailing ship William Brown struck an iceberg. About half of the passengers and all of the crew were saved in two small, open boats. The next night, half of the passengers in the larger long-boat were thrown overboard because the boat was overfull. This was the first case of lifeboat ethics, of hard choices in the face of scarcity. Since then the question has been who should die so that others, equally needy, might live?...