"One of the salient features of the modern world is the growing interdependence of men one on the other, a development promoted chiefly by modern technical advances. Nevertheless brotherly dialogue among men does not reach its perfection on the level of technical progress, but on the deeper level of interpersonal relationships. These demand a mutual respect for the full spiritual dignity of the person. Christian revelation contributes greatly to the promotion of this communion between persons, and at the same time leads us to a deeper understanding of the laws of social life which the Creator has written into man's moral and spiritual nature."