IN THE summer of 1968, while youth was redefining itself in Paris, San Francisco and elsewhere, a committee at the Harvard Medical School was busy redefining the end of life.

• 1968年之夏，当年轻人们在巴黎、旧金山和其他的地方重新定义自我的时候，哈佛医学院的一个委员会则正忙于为生命的终结重新定义。