The biomedicine threat could become real

Biomedical advances in recent decades have been hugely beneficial - particularly for the world's poor, whose life expectancy has increased dramatically. But the future looks dangerous. Although continued innovation will further improve people's lives, it will also give rise to new threats, and sharpen some ethical dilemmas concerning human life itself.

For starters, some scientists are looking into extreme ways of enabling people to live longer. Although we would almost certainly welcome an extended, healthy lifespan, many of us would not want to prolong matters once our quality of life or prognosis dips below a certain threshold. Some people dread to live in the grip of, say, dementia, or being a drain on resources.

Medical progress is also blurring the transition between life and death. Today, death is normally taken to mean "brain death", when all measurable signs of brain activity cease. But now there are proposals to restart the heart artificially after "brain death", in order to keep transplantable organs "fresh" for a longer time. Which would add to the moral ambiguity of transplant surgery.