In many cases there is an urgent need to revamp economic and social structures. But one must guard against proposals of technical solutions that are untimely. This is particularly true of those solutions providing man with material conveniences, but nevertheless contrary to man's spiritual nature and advancement. For "not by bread alone does man live, but by every word which proceeds from the mouth of God" (Matt. 4:4). Every sector of the family of man carries within itself and in its best traditions some portion of the spiritual treasure entrusted by God to humanity, even though many may not be aware of the source from which it comes. (Second Vatican Council. Gaudium et Spes, 1965).