[Bioethics and rationality. Personalism at the service of expanding the horizon of reason at the foundation of bioethics].

Personalism not only provides a valuable contribution to those interested in bioethics by allowing contrasts with other schools and currents of thought, but its ethical and anthropological features can serve to widen the horizon of reason. Bioethics today needs to expand the horizon of rationality in which it is animated through: 1) An ontologically ground personalism thanks to which the personal being emerges with all its evidence as being in the most proper sense of being. 2) The overcoming of subjectivism-objectivism antinomy through the claim that human subjectivity is an objective fact. 3) The recognition of the personalistic norm of action as a fundamental precept of natural law. When bioethics is built with openness to the objective datum of subjectivity it becomes easy to appreciate the human person as a real aim that should not be used as mere means. 4) The discovery of the normative basis of the moral life, because determining the ultimate end of human action is not the same as obtaining an ultimate justification of the norms of human action. When this distinction is deeply assimilated, it can show that the precepts of natural law must be respected regardless the acceptance of God's existence.