The teaching of the Catholic Church is usually divided into two broad areas, teachings on faith and on morals.
The first concerns the Divine Nature, man and his destiny, the Church and the means of grace, and so on. The second comprises teachings about human conduct. These latter teachings, while to some extent matters of revealed truth, are for the most part the teachings of the natural law, which the Church has taken over and made more clear and exact. The Church can speak with the authority of Jesus Christ on both faith and morals, giving authoritative interpretations of the natural law, and a Catholic is bound to accept what she teaches in these areas. This truth is reaffirmed in the Catechism of the Catholic Church: "The ordinary and universal Magisterium of the Pope and the bishops in communion with him teach the faithful the truth to believe, the charity to practice, the beatitude to hope for" (CCC 2034).
Now what of Catholic social doctrine? Is this a third aspect of Catholic teaching? John Paul II made it clear that the Church's social teaching "belongs to the field ... of theology and particularly of moral theology" (Sollicitudo Rei Socialis, #41). The rationale for this assertion is clear, for social doctrine concerns human behavior, and in this case primarily concerns the complex field of economic activity. But the mere fact that economic activity is complex or that it involves the interaction of people and institutions or that it is the subject of a secular discipline does not mean that it has no ethical aspects that fall within the competence of the Church's teaching authority. Many other complicated fields of human conduct likewise fall under Catholic moral doctrine and there is no reason why economic activity should not do so. The Catechism again is explicit that the Church's magisterium extends to the life of society as a whole:
To the Church belongs the right always and everywhere to announce moral principles, including those pertaining to the social order, and to make judgments on any human affairs to the extent that they are required by the fundamental rights of the human person or the salvation of souls (CCC 2032).
What can be said in reply to this? In the first place, the popes claim the right to teach about economic conduct only insofar as it has some moral bearing. They are aware that the Church does not have the mission to set forth the technical principles of economics as such. Pius XI in Quadragesimo Anno addressed this point explicitly:
We lay down the principle long since clearly established by Leo XIII that it is Our right and Our duty to deal authoritatively with social and economic problems ... not indeed in technical matters, for which she has neither the equipment nor the mission, but in all those that have a bearing on moral conduct. For the deposit of truth entrusted to Us by God, and Our weighty office of propagating, interpreting and urging in season and out of season the entire moral law, demand that both social and economic questions be brought within Our supreme jurisdiction, in so far as they refer to moral issues (#41).
For, though economic activity and moral discipline are guided each by its own principles in its own sphere, it is false that the two orders are so distinct and alien that the former in no way depends on the latter (#42).
All areas of human behavior, including politics, war and peace, medicine, or family life, have ethical aspects, and despite the fact that various secular disciplines also deal with these realities, the Church does not hesitate to teach authoritatively on moral questions that arise within those areas. Why should economists alone be permitted to fence off their subject and prevent the Church from pronouncing on moral questions that concern economic conduct?
An additional twist is that economics is said by these same critics to be a positive not a normative science; that is, it simply describes what happens, not what ought to happen. If this is correct, how is it that there is any conflict between the merely factual judgments of economics and the ethical mandates contained in the Church's teaching?
On the one hand, economists, disciples to the supposedly merely positive discipline of economics, frequently make covert normative judgments. These generally occur because most economists regard economic growth as the summum bonum of social existence, and they praise anything that they believe will further such growth and criticize anything that they hold will inhibit it. In fact, economics is sometimes understood as the science that allows us to realize as many human wants as possible, wants that are asserted to be unlimited. Thus the production of more and more stuff is seen as a sort of ethical mandate, even if it not labeled as such.
On the other hand, sometimes critics of social doctrine will assert that the means suggested or even mandated in a papal social document for achieving some end will actually be counterproductive to that end, because of papal misunderstanding of economics. At times this critique itself is simply a misunderstanding. The popes might state an ethical mandate (e.g., a just wage) and merely suggest one or more possible means toward attaining it, or such means might be suggested by others, but become widely seen as the only means of attaining the end in question (e.g., minimum wage laws). In such cases the method suggested usually does not have the same doctrinal status as the goal that is mandated.
But another question can arise with regard to the relationship between Catholic social teaching and the discipline of economics. This question concerns the papal statements that assume or assert various facts. For example, in his teaching that "[f]ree competition ... cannot be an adequate controlling principle in economic affairs [because of] the consequences that have followed from the free rein given to these dangerous individualistic ideas" (Quadragesimo Anno, #88), Pius XI was enunciating an ethical principle as well as making a judgment about empirical economic facts: "the consequences that have followed from the free rein given to these dangerous individualistic ideas." Is he justified in doing so? Does his authority extend to empirical evaluations of historical facts?
Two things should be said here. In the first place, when the pope spoke negatively about "the consequences that have followed from the free rein given to these dangerous individualistic ideas," he was evaluating these consequences according to Catholic moral teaching, not according to whatever standards economists might employ. Thus if many economists claim that free competition will generally have beneficial results, they are judging according to their own standards, which are seldom those of the Church. What is beneficial in the minds of an economist might not be beneficial according to the mind of the Church.
Second, how could the popes not sometimes mention historical facts or the perceived results of certain kinds of conduct? In many instances in their teaching the popes assume or assert such facts, assess the effects of various actions, and make judgments based on those assessments. Usually no one objects to this, except when it is done in the field of economic activity. Thus when in Casti Connubii #90 Pius XI remarks "what an amount of good is involved in the absolute indissolubility of wedlock and what a train of evils follows upon divorce," are we to accuse him of straying into the realm of contingent facts? Many would dispute that indissolubility of marriage brings great goods or prevents great evils, and some of those who dispute this assertion undoubtedly claim to base their opinion on the findings of psychology or sociology. How are they different from economists who assert that their expertise allows them to dispute facts claimed by popes? In order to operate in the real world the popes must necessarily make statements and judgments that concern contingent situations. Otherwise the Church's moral doctrine would exist in some realm separate from the real world, with little or no relevance to actual human life, and the Church would indeed stand condemned as having nothing important to say about the realities of human behavior, individual or social.
But additionally one more matter must be considered with regard to the binding nature of Catholic social teaching. As I mention above, the encyclicals and other documents of the social magisterium contain statements that enjoy various levels of teaching authority. Both Leo XIII and Pius XI, besides authoritatively teaching on aspects of economic morality, make recommendations and suggestions at times, and generally they clearly denote when they do so. These recommendations and suggestions are usually not a matter of Catholic magisterial teaching as such. How do we distinguish those levels of authority?
The rules for doing so are no different from any other area of Catholic teaching. The Church's social teaching, like the rest of her moral doctrine, is for the most part an example of the ordinary magisterial teaching. But the teaching of the ordinary magisterium can be binding and infallibly taught when it is both ordinary and universal. The First Vatican Council, in its Dogmatic Constitution, De Fide, chap. 3, taught,
Further, all those things are to be believed with divine and Catholic faith which are contained in the Word of God, written or handed down, and which the Church, either by a solemn judgment or by her ordinary and universal teaching, proposes for belief as having been divinely revealed.
This loyal submission of the will and intellect [in matters of faith and morals] must be given, in a special way, to the authentic teaching authority of the Roman Pontiff, even when he does not speak ex cathedra in such wise, indeed, that his supreme teaching authority be acknowledged with respect, and sincere assent be given to decisions made by him, conformably with his manifest mind and intention, which is made known principally either by the character of the documents in question, or by the frequency with which a certain doctrine is proposed, or by the manner in which the doctrine is formulated (#25).
Human beings are by nature social animals. If our lives are to be led within society, then it surely would be odd if the Church, whose precepts we must follow if we hope to reach eternal life, could have nothing to say about one of the central aspects of human social life, our economic conduct. Those who endeavor to restrict the Church's teaching are trying to erect an arbitrary and artificial limitation on her authority. This is not compatible with Catholic orthodoxy. As Pius XI wrote in his first encyclical, Ubi Arcano (1922), concerning those who do not conform their thinking and writing to the social teachings of the popes: "In all this we recognize a kind of moral, judicial, and social Modernism, and We condemn it as strongly as We do dogmatic Modernism" (#61).