Once this is admitted, it follows that in human society one man's natural right gives rise to a corresponding duty in other men; the duty, that is, of recognizing and respecting that right. Every basic human right draws its authoritative force from the natural law, which confers it and attaches to it its respective duty. Hence, to claim one's rights and ignore one's duties, or only half fulfill them, is like building a house with one hand and tearing it down with the other.
Since men are social by nature, they must live together and consult each other's interests. That men should recognize and perform their respective rights and duties is imperative to a well ordered society. But the result will be that each individual will make his whole-hearted contribution to the creation of a civic order in which rights and duties are ever more diligently and more effectively observed.
For example, it is useless to admit that a man has a right to the necessities of life, unless we also do all in our power to supply him with means sufficient for his livelihood.