The notion of immortality arises out of our first awareness of death. It is impossible for us to imagine ourselves ceasing to exist. The concept of an afterlife, Ponce de Léon's fabled Fountain of Youth, enduring fame, and offspring as the torchbearers of the family name - these are all embodiments of our desire to keep some piece of our being intact post mortem – even in the absence of consciousness. 

Juan Ponce De Léon (1474 -1521) 

The field of Medicine has always been locked in a struggle with mortality, and it has won some significant victories. Life expectancy in the United States has increased by about 30 years since 1900. AIDS – once a death sentence – is now medically manageable (for those who have access to adequate health care). And now, with the help of bio- and nanotechnology, scientists are gearing up for an all out assault on Old Cloak 'n Hood. Big Think has shared the views of futurists Sonia Arrison and Ray Kurzweil and geneticist Aubrey De Grey on emerging technologies that will enable us to slow aging or end it altogether. At the forefront of this science, Cynthia Kenyon has identified and blocked a "regulator gene" in worms that tells their cells when to age, increasing their life span by up to six times. 

The Ethics of Immortality

So you want to live forever? Whoa there, Methuselah – double-check your motives, says Paul Root Wolpe, Senior Bioethicist at Nasa and Director of the Center for Ethics at Emory University. For Wolpe, the question to be asked of any new technology is 'how will we use this to improve our lives (plural)?' A 2006 NIH report on the realities and costs of longer-lifespans worldwide highlights some of the concerns we ought to keep in mind as we contemplate immortality:

• Family structures are changing. As people live longer and have fewer children, family structures are transformed, leaving older people with fewer options for care.

• Patterns of work and retirement are shifting. Shrinking ratios of workers to pensioners and people spending a larger portion of their lives in retirement increasingly strain existing health and pension systems.

• Social insurance systems are evolving. As social insurance expenditures escalate, an increasing number of countries are evaluating the sustainability of these systems.

• New economic challenges are emerging. Population aging will have dramatic effects on social entitlement programs, labor supply, trade, and savings around the globe and may demand new fiscal approaches to accommodate a changing world

Death as an Engine of Innovation, Immortality as Selfishness

To these, Wolpe adds the suggestion that there's a "natural wisdom" in death – in that it makes way for the next generation of innovators, ensuring the rapid advancement of human knowledge: