Humans are surprisingly feeble. We are born completely defenseless, the time it takes to attain independence longer than in any other animal. And we fall victim to a stunning variety of illnesses. And yet, humans have effectively learned to cheat death. Even a few decades ago, the age of 60 was considered ripe and old; now, the average life expectancy is north of 80, and some scientists have postulated that the sky is the limit. But all this has a price, raising difficult questions – political, social, and moral.
