Biotechnologies are generally developed to heal people from severe diseases. However, many of these technologies have the potential to be used beyond the frame of therapy as a way to improve or enhance normal human capacities. Biotechnologies can help to make people think better, to improve their memory and perception, to feel happier or to improve physical skills in sports, music or dance, or to extend the normal human lifespan. In view of the potential of biotechnologies (and other technologies like nanotechnologies and information technologies) to change our capacities, there is an ethical debate whether such an enhancement may alter our sense of self, our human nature and our relation with other life forms. Moreover, there is a concern about the impact of these technologies on our society and the position of vulnerable groups. More fundamentally there is concern over whether enhancement is a good thing in itself and whether it may expose our human nature, our personal life and our society to irreversible damage.