6 The reason is that men, created by God to His image and likeness and destined for Him Who is infinite perfection realize today more than ever amid the most exuberant material progress, the insufficiency of earthly goods to produce true happiness either for the individual or for the nations. And hence they feel more keenly in themselves the impulse towards a perfection that is higher, which impulse is implanted in their rational nature by the Creator Himself. This perfection they seek to acquire by means of education. But many of them with, it would seem, too great insistence on the etymological meaning of the word, pretend to draw education out of human nature itself and evolve it by its own unaided powers. Such easily fall into error, because, instead of fixing their gaze on God, first principle and last end of the whole universe, they fall back upon themselves, becoming attached exclusively to passing things of earth; and thus their restlessness will never cease till they direct their attention and their efforts to God, the goal of all perfection, according to the profound saying of Saint Augustine: "Thou didst create us, O Lord, for Thyself, and our heart is restless till it rest in Thee."
Source: Divini Illius Magistri (Vatican.va)