Any well-regulated and productive association of men in society demands the acceptance of one fundamental principle: that each individual man is truly a person. His is a nature, that is, endowed with intelligence and free will. As such he has rights and duties, which together flow as a direct consequence from his nature. These rights and duties are universal and inviolable, and therefore altogether inalienable.
When, furthermore, we consider man’s personal dignity from the standpoint of divine revelation, inevitably our estimate of it is incomparably increased. Men have been ransomed by the blood of Jesus Christ. Grace has made them sons and friends of God, and heirs to eternal glory.
–St. John XXII