Augustine brought all intellectual interests into the closure of the Christian Faith, or discredited whatever stubbornly remained without. He did the same with ethics. For he transformed the virtues into accord with his Catholic conception of man’s chief good. That must consist in cleaving to what is most blessed to cleave to, which is God. To Him we can cleave only through _dilectio_, _amor_, and _charitas_. Virtue which leads us to the _vita beata_ is nothing but _summus amor Dei_. So he defines the four cardinal virtues anew. Temperance is love keeping itself whole and incorrupt for God; fortitude is love easily bearing all things for God’s sake; justice is love serving God only, and for that reason rightly ruling in the other matters, which are subject to man; and prudence is love well discriminating between what helps and what impedes as to God (_in deum_).[57] Conversely, the heathen virtues, as the heathen had in fact conceived them, were vices rather than virtues to Augustine. For they lacked knowledge of the true God, and therefore were affected with fundamental ignorance, and were also tainted with pride.[58] Through his unique power of religious perception, Augustine discerned the inconsistency between pagan ethics, and the Christian thoughts of divine grace moving the humbly and lovingly acceptant soul. The treatise on Christian Doctrine clearly expresses Augustine’s views as to the value of knowledge. He starts, in his usual way, from a fundamental principle, which is here the distinction between the use of something for a purpose and the enjoyment of something in and for itself. “To enjoy is to cleave fast in the love of a thing for its own sake. But to use is to employ a thing in obtaining what one loves.” For an illustration he draws upon that Christian sentiment which from the first had made the Christian feel as a sojourner on earth.[59] “It is as if we were sojourners unable to live happily away from our own country, and we wished to use the means of journeying by land and sea to end our misery and return to our fatherland, which is to be enjoyed. But the charm of the journey or the very movement of the vehicle delighting us, we are taken by a froward sweetness and become careless of reaching our own country whose sweetness would make us happy. Now if, journeying through this world, away from God, we wish to return to our own land where we may be happy, this world must be used, not enjoyed; that the invisible things of God may be apprehended through those created things before our eyes, and we may gain the eternal and spiritual from the corporeal and temporal.”