In today’s moral climate where issues such as abortion, embryonic stem cell research and euthanasia are legalized, any opposition to the legality of these issues is viewed as an inherently religious position. The culture then concludes that since all religious views are to be seen as personal, they should be dismissed as having no place in the public square. How then do we decide if something is morally right or not? We could consult the civil law, but that is not always a reliable guide as Martin Luther King pointed out in his Letter from a Birmingham Jail. We could consult the Church, but certainly not all her teachings are binding on everyone’s consciences (like observing Holy Days of Obligation for example). However, if we take what is common to man, namely his nature and what is good for him, then we can form a foundation for all laws. This is the basis for the natural law and this is precisely why the natural law must play a key role in Catholic morality. Since the demands of the natural law can be known by reason and by all, the Church is able to use it as common ground in discussing the moral demands of the law with the rest of the culture.
Before discussing how natural law can be used as common ground for disseminating Catholic moral teaching, it is important that we lay out precisely what the natural law is.
The Catechism of the Catholic Church tells us that there are different expressions of the moral law, all of which are interrelated. It mentions that there is the eternal law which has its source in God, the natural law, revealed law and finally civil and ecclesiastical law. If the eternal law and the natural law then are interrelated, we must begin by defining what is meant by the eternal law. Eternal law is the intelligence of God as it is manifested in everything which He has created.
How are the eternal law and natural law related? The natural law, according to Aquinas, is “nothing other than the rational creature’s participation in the eternal law.” In other words, the natural law is simply the eternal law applied to human moral actions. Not only is it addressed to rational creatures but it must be viewed as being addressed to creatures who are also free. In this way it is different from physical laws. In a certain sense, physical laws are mechanical in that they are always “obeyed” while one can choose to obey the natural law or not.
It was mentioned above that the natural law is an extrinsic principle in which man actively participates in the eternal law. Despite being an intrinsic part of human nature that man can discover the natural law, it still remains the task of practical reason to do so. The “something” that it discovers are the foundational precepts of the natural law.
As we begin to uncover these precepts, we find that they follow from a set of inclinations that flow directly from human nature. With the precepts of the natural law then being grounded in these inclinations we can see how the natural law can be used to teach Catholic moral thought to non-Catholics. It is not without coincidence that each of these precepts also is closely related to the commandments given in the Decalogue. This is why you will (or at least would have at one point) find the Ten Commandments in many court buildings in the US. This was not just because the US was a Christian country but because the Decalogue summarizes the just demands of the natural law as well.
The first of the fundamental inclinations is the natural inclination to the good. Man by his very nature seeks the good. This attraction of the good is universally expressed then in the first precept of the natural law: Good is to be done and evil avoided. This primary precept of the natural law sums up the entire Ten Commandments and is succinctly summarized by Jesus when He says that we are to love God and neighbor.
The second inclination is to preserve one’s being. What this means practically is that life, and all that promotes life (like food, clothing, shelter, etc.), is to be preserved. This inclination is expressed in the fifth commandment which says “Thou shall not kill”.
Thirdly, there is the inclination to propagation and education of children. Man has not only the power to transmit life through the exercise of their sexuality but an inclination as well. This seems to be the inclination that our generation has the most trouble regulating. But like all inclinations, it must be regulated if it is to develop properly. So important is this precept that three of the Ten Commandments address it; the fourth which is ordered toward respect for one’s parents; the sixth which links sexuality with marriage; the ninth which forbids lust.
Because man is not only a material being, but a spiritual one as well, the inclination to know the truth also forms a the fourth foundation for the precepts of the natural law. The Decalogue again protects this inclination so that it might flourish in the eighth commandment “Thou shall not bear false witness”.
Finally the fifth inclination is the inclination to life in society. This inclination forms the foundation for the seemingly innate demands of justice. Anyone who has spent time with young children recognizes immediately that this inclination is present because they often say that something is not fair.
Despite inevitable difference in opinions as to precisely what constitutes a good, nevertheless the natural law can be used to form a common foundation and basic criteria for moral action. For this reason, Catholics must continue to address human actions in light of natural law in order to share common ground with non-Catholics.
Let’s look at a few so-called “Catholic teachings.” First there is contraception. While it has been labeled as a “Catholic belief” it is really a teaching based on the Natural Law. There is a more detailed argument about this in this article, but all one needs to do is look at the five inclinations that I mentioned above. Because contraception harms the good of marriage and procreation it is contrary to the natural law.
In fact, once we establish the four human goods connected to the five inclinations (namely life, marriage and procreation, society and truth) we can evaluate every law as either good or bad in relation to whether it harms one or more of these goods or not. A second example will help further clarify a little further. What about something like euthanasia? Again, we check the inclinations and we find that it harms both the good of life (voluntary) and society (involuntary). Involuntary euthanasia harms society because the most vulnerable are wiped out, destroying the trust that is absolutely necessary for any society to remain intact. This is why St. John Paul II addressed euthanasia very specifically in Evangelium Vitae as belonging to the natural law saying, “I confirm that euthanasia is a grave violation of the law of God, since it is the deliberate and morally unacceptable killing of a human person. This doctrine is based upon the natural law and upon the written word of God, is transmitted by the Church’s Tradition and taught by the ordinary and universal Magisterium” (EV, 65).
As a very important aside, I should mention this also addresses the question as to whether something like the Church’s teaching against contraception is an infallible teaching. The argument goes something like this, “well the Pope has never declared ex-cathedra that contraception is wrong so I am free to follow my own conscience.” Not only does this represent a misunderstanding about when the charism of infallibility is exercised, but no Pope will ever make an ex-Cathedra statement about something that can be known by human reason. Ex-Cathedra doctrines are reserved for what is considered divinely revealed only. This seems to be a great source of confusion for many Catholics and mostly ends up being a red herring for following the Church’s moral teachings. When he was Prefect for the Congregation of Divine Faith, then-Cardinal Ratzinger addressed this—a commentary very much worth reading.
The point is that we need to stop labeling our positions against abortion, euthanasia and contraception as beliefs. We should not be saying “I believe contraception is wrong” but instead “I know contraception is wrong.” We can know certain moral precepts infallibly without the Church declaring it so (even if she does as a service to us in many instances).
There is also the evangelical aspects that come with this. Because the Church alone has preserved the natural law tradition, she can provide a great service to mankind by proclaiming once again these teachings with confidence as binding upon all men as the only path to true freedom.