The dilemmas bioethics faces in the 21st century are marked by a special situation: it can be said that this century started with the emergence of bioethics, during the decade of the sixties, in the past one. If, as it can be understood, a century really starts when the thinking paradigms and the scope of the socially significant practices have a twist that implies deep and irreversible transformations with effects in all of the life aspects, the 21st century started, actually, more than 40 years ago.