It''''s hard to think of a word more charged with meaning—or meanings—than "
life." Some of the most passionate debates of
our day, over stem cells or the right to die, genetically modified food, or wartime conduct, revolve around it. Whether we''''re talking about when
life begins or when it ends, the sanctity of life, or the danger of playing God, we all have an idea of what we mean when we talk about life. Yet, it often turns out, we actually mean different things. Scientists, despite their intimacy with the subject, aren''''t exempt from this confusion.