My comments regarding the importance of basing our civil society upon bedrock natural law principles, rather than positivist/originalist theories, drew some fire. I respond here with a fresh entry with relevant quotes from the Compendium of the Social Doctrine of the Church regarding the natural law’s role in building up our legal system.
When I emailed Archbishop Chaput the question as to whether the Compendium was “Authoritative”, he emailed back that it was indeed, and he did not know why it was not utilized very much by all the various politically active Catholics. When I asked my own Bishop to come to the high school where I teach, to speak to our senior class on the responsibility of the laity for the temporal order, Bishop Wenski of Orlando, brought a copy of the Compendium and based his talk around the teachings found in it. The Compendium is a concise rendering of the entire corpus of Catholic social doctrinal teachings. I would argue that if this is not the basis for your worldview as relating to the political and social aspects of the temporal order- then you are not going to be able to represent well the thinking of the Church, on the array of issues commonly found on socio-political blogs like American Catholic, or any other.
Here are the relevant quotes taken straight from the Magisterial Compendium:
142. The natural law, which is the law of God, cannot be annulled by human sinfulness. It lays the indispensable moral foundation for building the human community and for establishing the civil law that draws its consequences of a concrete and contingent nature from the principles of the natural law. If the perception of the universality of the moral law is dimmed, people cannot build a true and lasting communion with others, because when a correspondence between truth and good is lacking, “whether culpably or not, our acts damage the communion of persons, to the detriment of each”. Only freedom rooted in a common nature, in fact, can make all men responsible and enable them to justify public morality. Those who proclaim themselves to be the sole measure of realities and of truth cannot live peacefully in society with their fellow men and cooperate with them.
397. Authority must recognize, respect and promote essential human and moral values. These are innate and “flow from the very truth of the human being and express and safeguard the dignity of the person; values which no individual, no majority and no State can ever create, modify or destroy”. These values do not have their foundation in provisional and changeable “majority” opinions, but must simply be recognized, respected and promoted as elements of an objective moral law, the natural law written in the human heart (cf. Rom 2:15), and as the normative point of reference for civil law itself. If, as a result of the tragic clouding of the collective conscience, scepticism were to succeed in casting doubt on the basic principles of the moral law, the legal structure of the State itself would be shaken to its very foundations, being reduced to nothing more than a mechanism for the pragmatic regulation of different and opposing interests.
437. Universal respect of the principles underlying “a legal structure in conformity with the moral order”  is a necessary condition for the stability of international life. The quest for such stability has led to the gradual elaboration of a “right of nations”  (“ius gentium”), which can be considered as “the ancestor of international law”. Juridical and theological reflection, firmly based on natural law, has formulated “universal principles which are prior to and superior to the internal law of States”, such as the unity of the human race, the equal dignity of every people, the rejection of war as a means for resolving disputes, the obligation to cooperate for attaining the common good and the need to be faithful to agreements undertaken (pacta sunt servanda). This last principle should be especially emphasized in order to avoid “temptation to appeal to the law of force rather than to the force of law”.