Natural Law Ethical Theory

“To disparage the dictate of reason is equivalent to condemning the command of God.”
~  St. Thomas Aquinas

  1. The Divine Command Theory

Let us now consider the view that morality rests upon religion. Assuming that a relationship between some God and morality exists, how do we characterize it? A classic formulation of this relationship is the divine command theory which states that “morally right” means commanded by God, and “morally wrong” means forbidden by God.

But there are multiple problems with this theory. Its defense necessitates philosophical arguments to prove a god exists, or is at least rational plausibility. Next, one needs to determine the gods commands. This would be especially difficult, since people have imagined the gods to command antithetical things like: celibacy and polygamy, the right of kings and social revolt, war and peace, humanitarian aid and witchburning. But even if we knew the gods commands, we would still have to interpret them.

This last point presents grave difficulties. Take a simple command, “thou shalt not kill!” When does it apply? In self defense? In war? Always? To whom does it apply? To animals? Intelligent aliens? Serial killers? All living things? The unborn? The braindead? Religious commands such as “do not kill,” “honor thy parents,” or “do not commit adultery” are ambiguous. For instance, where do the Christian Scriptures speak unequivocally about abortion?  For the sake of argument, let us grant that we can demonstrate some the gods existence, know that the gods commands,  know that those commands are good, and interpret the commands correctly. (This is saying a lot.) May we then suppose the divine command theory adequately accounts for morality?

The great Greek philosopher Plato suggested that it did not. In the dialogue the EuthyphroSocrates posed one of the most famous questions in the history of philosophy: Is something right because the gods command it, or do the gods command it because it is right?  It seems the relationship between the gods and morality must be characterized in one of these two ways.

If we characterized the relationship the first way, then right and wrong depend on the the gods will. Something is right because the gods say so! Two basic problems attach to this view. First, it makes the the gods will arbitrary. The gods could have commanded lying, killing, cheating, and stealing to be right! You might be tempted to say that the gods wouldn’t command us to do these things. But why not? Remember the the gods will determines right and wrong, on this view, so that if the god said, “thou shalt kill,” that would be right. The second problem is that the theory renders the notion of the the gods goodness superfluous. We ordinarily attach meaning to the notion that “The the gods commands are good.” We believe we are attributing a property goodness to the the gods commands. But on this second account good simply means “commanded by the gods” so that “The gods commands are good” just means “the gods commands are commanded by the gods,” a useless tautology.

If we characterize the relationship the second way, then we must accept some standard of morality independent of the gods will. What the religious want to say is that in the gods’ infinite wisdom, they know that truthfulness, for example, is better than untruthfulness. On this view, the gods commands things because they are right. But this is much different from making something right. On this second view, the gods recognize the moral truth, but can’t change it. The gods can’t make killing, lying, cheating, and stealing right anymore than we can. Thus, the moral law limits the gods, since they can’t change it. And if we accept this second option, we have given up the divine command theory.

Two options present themselves if the standard of morality is independent of the gods. First, the standard for morality may lie beyond our comprehension, forcing us to rely on authority, revelation, or tradition to explain morality. Going this route ends philosophical ethics. The other alternative uses human reason to understand the gods law. Let’s pursue this second alternative.

  1. The History of Natural Law Ethics

The genesis of natural law ethics is in the writings of Aristotle, who first identified the natural with the good. All things “aim at some good,” he says at the beginning of his treatise on ethics, “and for this reason the good has rightly been declared that at which all things aim.” For individuals, ethics is a study of  the goal, end or purpose of human life. Politics, on the other hand, is a study of the good, goal, end, or purpose of society.

But what is good? Aristotle distinguished between real and apparent goods. Real goods satisfy natural needs, and they are good for us independent of our desires. Food, clothing, and shelter are examples of real goods. Apparent goods satisfy acquired wants, and are called good because we desire them. Shrimp, designer clothes, and mansions are apparent goods. A good life consists in the acquisition, over the course a lifetime, of all the real (natural) goods. These include external and bodily goods such as food, clothing, shelter, health, vitality, and vigor, and, “goods of the soul” like love, friendship, knowledge, courage, justice, honor, and skill. To obtain these real goods requires that we must act with good habits or virtues.  The person of good character exhibits moral virtues such as temperance, courage, and justice, and intellectual virtues like wisdom and prudence. A life full of  virtue is a good, happy, and fulfilling life. It is a life in accordance with our nature.

The idea that each thing has a goal or purpose in accordance with its nature, Aristotle called teleology. (From the Greek telos; meaning goal, end, or purpose.) We can understand this if we consider an artifact like a pen. A pen that writes well is a good pen; it fulfills its purpose. Aristotle also believed that teleology was also a component of the natural world. Acorns develop into oak trees, caterpillars into butterflies, and little children into mature adults; the eyes are meant to see, the hands to grasp, and the kidneys to purify. Whatever satisfies its teleology is fulfilled; whatever fails to do so is defective. To be fulfilled means to actualize the potential inherent in the thing, whereas to be defective refers to the failure to do so. Thus, actualization of natural potential is the essence of teleology and supplies the moral imperative for human beings.

The Stoics further developed the doctrine and first used the term natural law. Stoicism flourished in Athens in the third century B.C.E. and later in the Roman Empire in such great figures as Seneca, Epictetus, Marcus Aurelius, and Cicero. Unlike Aristotle, the Stoics believed that human happiness was possible without external and bodily goods. They also emphasized rationality and the control of emotions. The Stoics insisted that we have aduty to follow nature, particularly our rational nature, rather than convention. The source of natural law was Logos, the universal power or energy personified in nature’s laws.

That natural laws should prevail over cultural conventions led the Stoics to the idea of the cosmopolitan citizen. Roman jurisprudence, which needed to formulate rules to deal with various cultures, adopted the idea of a natural law for all the world’s citizens. Its basic premise was the natural law’s independence from cultural mores.

This idea had tremendous repercussions throughout human history and would inform the interaction of western Europe and much of the new world. In the sixteenth century, for instance, the Spaniards vehemently debated its applicability for the civilizations they discovered in the New World, and in the eighteenth century the idea influenced the founders of the American government. But the next great development in the idea after Stoicism occurred in the thirteenth century. 

3. St. Thomas Aquinas

St. Thomas Aquinas (12251274) synthesized  Aristotelianism, Stoicism, and Christianity to give the natural law its classic formulation. In addition to Aristotle’s natural virtues, he added the theological virtues faith, hope, and charity. And to earthly happiness he added eternal beatitude. For Thomas, action in accordance with human nature fulfills God’s eternal plan, and Scripture’s commandments. Thus, the natural law is God’s law known to human reason. Unlike the lower animals, we have the ability to understand the laws of our nature, and the free will to follow or disregard these laws. But how do we attain knowledge of the natural law? It is not innate, intuited, or easily derived from sense experience. Instead, we use reason to determine the conformity of moral conduct and nature. Since fulfilling natural needs makes us happy, the natural is the good. What then constitutes the law? While all mature individuals know its most general principles like do not kill the innocent, controversy surrounds reasoned conclusions about its specific applications.

The fundamental principle of natural law ethics is that good should be done and evil avoided. This general principle may be specified into moral axioms like: “Do not kill!” “Be faithful!” “Preserve your life!” “Care for you children!” “Do not lie or steal!” “Life is a universal human good!” All of these axioms are both natural and good. We further specify these axioms by rational analysis and by reliance on Church, scripture, or revelation. As Aristotle pointed out, natural inclinations and tendencies are good, and we fulfill them by acquiring the elements which constitute human happiness such as: life, procreation, friendship, and knowledge. Nevertheless, within the boundaries set by human nature, the specific way one satisfies natural inclinations may differ. So a range of activities might satisfy, for instance, our aesthetic or intellectual needs. However, we all need the universal human goods. Thus, morality demands that we follow the laws of our nature which are the same for all on the basis of our shared humanity.

Still, we need not satisfy all of our natural tendencies. For instance, we must curb aggression and dishonesty, so that friendship and society thrive. In this way, we see how reason makes value judgments and imposes moral obligations upon us. The moral law demands that we develop our reason, and act in accordance with reason’s imperatives. As we have seen, nature directs us to live well, flourish in human communities, and, finally, to experience the beatific vision. Therefore, beginning with human nature and using reason to determine the goals nature sets for us, we determine what we ought to do.

Perhaps a simple illustration may help. If we want to become nurses, then we ought to go to college and study nursing. Employing our rational faculties, we impose a non-moral obligation upon ourselves, given an antecedent goal or purpose. Analogously, reason imposes moral obligations upon us. If we want friends and friendship demands justice, then we ought to be just. Of course, the examples are very different. Moral obligations may not depend upon self-interest in the same way that non-moral obligations do. But the basic idea is the same, without goals nothing is obligatory. If we don’t want to be nurses or don’t want friends, then we probably have no obligation to study nursing or be just. And if there are no ultimate purposes in human life, then there probably are no moral obligations either. On the other hand, according to the natural law, the complete actualization of human potential demands that we develop our talents and be just. If we fail to do this, we violate the natural law.

4. Some Philosophical Difficulties

Natural law theory derives values about what we ought to do from facts about our human nature. This is a major philosophical difficulty. When we derive what we ought to do from what is the case, we commit what philosophers call the naturalistic fallacy. This fallacy involves the derivation of ethical conclusions from nonethical facts. Isn’t there a logical gap between what is the case and what ought to be the case? Even if it is true, for instance, that humans are naturally aggressive, does that mean they should be? Though a conception of human nature is relevant to morality, it seems unlikely that one could explain morality by appealing to human nature. Yet, if values don’t come from facts, where do they come from?

A second difficulty with the theory is that modern science rejects teleology. Explanations in science don’t refer to goals, values, or purposes. Rocks don’t fall because they desire the earth’s center, as Aristotle thought, nor does it rain in order to make plants grow. Rather, physical reality operates according to impersonal laws of cause and effect. Evolutionary theory rejects teleology and all of cosmic evolution results from a series of fortuitous occurrences. This brings to light another difficulty. Natural law theory traditionally maintains the immutability of human nature, which contradicts modern biology. Furthermore, technology transforms human human nature. What happens when gene splicing, recombinant DNA, and genetic engineering become normal? For various reasons then, natural law as traditionally conceived and modern science are at odds.

5. Final thoughts

Of course the fact that, with the exception of the Catholic Church, the theory of natural law has fallen into disfavor doesn’t mean it is mistaken. If we believe that we can philosophically demonstrate the existence of a source of values and purposes for human beingsand believe also that knowledge of this source is accessible to human reasonthen one may rationally defend the theory. Furthermore, without such presuppositions, moral thinking is likely futile. A number of contemporary philosophers suggest that without some ultimate, objective source for morality, notions like obligation, duty, right, and good make no sense.

Nevertheless, natural law theory does rest upon a number of dubious philosophical propositions. We should not forget that, at least in the formulation of the Catholic Church, the natural law ultimately comes from God. Like the divine command theory, natural law ethics is open to all of the objections of philosophical theology. Is there a God? Are there any significant proofs for God’s existence? Why is God so “hidden?” How do we know our reason is sufficient to understand God’s natural moral laws? Moreover, a nontheistic natural law ethics must answer the challenge of the naturalistic fallacy. Why is the natural, good?

Whatever the conclusion, the gap between a nonteleological, factual, and scientific account of human nature and a teleological, ethical, and religious conception constitutes the central dispute in contemporary culture. We do not know how to reconcile the two poles, or if one or the other is bankrupt. But, as the historian of philosophy W.T. Jones asserts: “The whole history of philosophy since the seventeenth century is in fact hardly more than a series of variations on this central theme.”