Benedict has appealed often in his pontificate to natural law, but it is a natural law that has recuperated its finality and center in God. He affirms and develops Aquinas‘s understanding of the natural moral precept to seek to know the truth about God and to live in community with others. Note that Benedict emphasizes the nature of law as a matter of desire and thus love, in contrast to the modern tendency, following Kant, to conceive law more basically as duty. As emphasized in his first encyclical, Deus Caritas Est, what the human being desires (eros) is most basically to love God above all things and others for their own sake (agape). The point is thus that this desire to love God and others generously arises naturally. It is not merely a function of grace, although the desire is fully realized only in grace.Seriously, check out the whole thing. Its very well done, and gives a great degree of insight into what to expect from Benedict this visit.
The task of Christians, then, is to awaken this desire and give witness to it: to show that the restlessness driving every act of human consciousness in its depths is–even in America–a restlessness for God and for love. This is what is meant by the pursuit of happiness, rightly conceived.