Making reference to the well-known proposal of T.H. Marshall on the development of citizenship in the West - according to which each century had a specific issue to face (the XVIII century was concerned with "civil" citizenship; the XIX century with "political" citizenship; the XX century with "social" citizenship) -, the author holds that bioethics is the latest stage of such a development, and that it sets the foundations for a new sort of "bio-medical" citizenship. In the late '60s and early '70s of the XX century, people in the West experienced a new capacity to control biological life, and this favoured the fading away of the traditional principle of the sanctity of (human) life, which prescribes the absolute respect of basic biological finalisms of human bodies. The ethics of the quality of life is replacing the traditional ethics; it requires new hierarchies of values and principles as well as new ways of looking at the world. Basic objections to the new ethics of quality of life are considered, and major changes at the conceptual level are presented in order to clarify the nature of bioethics and current bioethical debates.