In the next two or three decades, people may have the option to change themselves and their children in ways that, up to now, have existed largely in the minds of science fiction writers and creators of comic book superheroes.Both advocates for and opponents of human enhancement spin a number of possible scenarios.Some talk about what might be called “humanity plus” – people who are still recognizably human, but much smarter, stronger and healthier.Others speak of “post-humanity,” and predict that dramatic advances in genetic engineering and machine technology may ultimately allow people to become conscious machines – not recognizably human, at least on the outside.This enhancement revolution, if and when it comes, may well be prompted by ongoing efforts to aid people with disabilities and heal the sick.Indeed, science is already making rapid progress in new restorative and therapeutic technologies that could, in theory, have implications for human enhancement.It seems that each week or so, the headlines herald a new medical or scientific breakthrough.