This work serves several purposes. On one hand, it is a clear and original bioethics that tries to explain why this young discipline has emerged and what problems it faces are introduced. Problems arousing both fascination and fear. On the other hand, bioethics is confronted with religions; and, especially, to the Catholic religion. Hence the title of Principles of secular bioethics, where the space of bioethics against intrusions that do not correspond to a secular society claimed. In this connection, cloning and euthanasia are studied in the light of that claim.  A universal bioethics, attentive to the data of science and the rights of citizens, is the key to the whole book. Overcoming ethical dilemmas, Sádaba observed only be achieved by building a responsible and respectful secular bioethics, that does not deny the different cultures but integrates them into a common universality.  Finally the question of life after death arises. And takes stock both the most bizarre postures (cryopreservation or some new parareligiosos movements) as new technologies immortality.  Bioethics, in short, is a sign of our times; an era that opens to dramatic improvements in our lives and avoided, while evils of manipulation and a well only for the privileged