Angry debate about assisted suicide is raging in Europe after a British conductor and his wife drank a lethal barbiturate at a clinic in Switzerland. At 85, Sir Edward Downes was almost deaf and blind, but otherwise healthy. His 74-year-old wife Joan was suffering from terminal cancer. This month, they traveled to Zurich and checked in at the Dignitas clinic, where with two of their children holding their hands, they each took a single does of barbiturate and died. John Burns is London Bureau chief for the New York Times.