"Human activity, to be sure, takes its significance from its relationship to man. Just as it proceeds from man, so it is ordered toward man. For when a man works he not only alters things and society, he develops himself as well. He learns much, he cultivates his resources, he goes outside of himself and beyond himself. Rightly understood this kind of growth is of greater value than any external riches which can be garnered. A man is more precious for what he is than for what he has. Similarly, all that men do to obtain greater justice, wider brotherhood, a more humane disposition of social relationships has greater worth than technical advances. For these advances can supply the material for human progress, but of themselves alone they can never actually bring it about.

Hence, the norm of human activity is this: that in accord with the divine plan and will, it harmonize with the genuine good of the human race, and that it allow men as individuals and as members of society to pursue their total vocation and fulfill it."

These chapters and others give an overall explanation of how we can come to know God and how God reveals himself to us.