Natural Law and Constitutionalism

by Joan Arnsteen-Neumann
(an excerpt from my forthcoming book)

Lord, we pray, graft onto our hearts the love of your Word and Your Holy Name, and impress onto our souls the Natural Law so that we may bear witness to Your love and be fruitful for Your Glory.

It is a humbling experience to read Plato, Aristotle, and St. Thomas Aquinas and to understand natural law. We are blessed that God has designed us so that we may understand natural law and morality in order to live a virtuous and happy life. Natural law is the foundation of our morality, where we can argue to valid conclusions based upon our practical experiences.

A general definition of natural law is a universal pattern of laws that are innate in our human nature, known through reason and applicable to everyone as a foundation for our moral actions.

We can trace the philosophy of natural law to the ancient Greeks beginning with Socrates, Plato, Aristotle, and the Stoics. These philosophers grounded natural law in nature and then law. We learn about Socrates through the pen of Plato and the Platonic Dialogues. Socrates walked the streets of Athens and asked questions about beauty, justice, goodness, and virtue. Socrates taught us how to use our reasoning power to dialectically examine our natures, the nature of justice, goodness, and virtue. The Stoics ideal life was a life of reason undisturbed by passions. Hellas bequeathed to us philosophy, a belief in reason and the gods (in a pagan age before the birth of Christ), the language of politics, and a political regime where reason, and participation with dialogue and debate were the customs and habits of the citizens. Plato and Aristotle expressed natural law as a teleological (telos: the end or purpose) goal where human activity is good when it is purposeful and aims at fulfillment of the human good that was called happiness or eudaimonia. Plato and Aristotle taught us that reason or intellect is developed in order to discover the moral commands and virtues. The city-state (polis) exits to help men to achieve an ethical life.

In the thirteenth century, natural law ethics can be identified with a theological theory where the sacred foundation is issued by a command of God. St. Thomas Aquinas (1225-1274) developed a moral science that was influenced by the classical Greek moralists. St. Thomas Aquinas was a devoted and faithful follower of Christ, a Dominican Friar of the Order of Friar Preachers, a theologian, philosopher, professor, scholar, teacher, and saint. His prolific output of writings enrich our Christian thinking, philosophical reasoning, and understanding of God’s laws and natural law. Two books are widely considered to be his masterpieces — Summa contra Gentiles and Summa Theologica (1266-1273).

Aquinas’s examination of natural law is an important source of knowledge for our modern consideration of natural law. St. Thomas teaches us that, “good is to be done and pursued, and evil is to be avoided. All other precepts of the natural law are based upon this.” (Summa Theologica I-II. 94.2) It is self-evident that whenever we act in accord with reason we do so because we take the action to be good in some way, and avoid that which we take to be evil. (Summa Theologica I-II. 21.1; I-II. 90.1). Aquinas defines law as, “Law of its very nature is an ordinance of reason for the common good, which is made by the person who has care of the community, and this rule is promulgated.” (Summa Theologica I-II, 90.4). Aquinas distinguishes four kind of law: eternal law, natural law, positive or human law, and divine law. Eternal law is the mind of God. God governs the universe through physical, moral and revealed laws and eternal law includes all of these. Thomas teaches us that natural law is our participation in the eternal law, and is known by reason. Human laws are the civil laws that we create in order to apply the natural law to our behavior and society. Divine law is taught to us in Scripture where God reveals to us laws to guide us to our end of eternal happiness. Divine law is given to us directly by God and is infallible as a moral imperative that is justified by divine authority: for example, the Ten Commandments.

The rational creature comes to know the natural order and freely chooses to act in accordance with this natural order, and this is called natural law. St. Thomas writes, “The natural law is nothing else than the rational creature’s participation of the eternal law.” (Summa Theologica I-II. 91.2) There is a relationship that we have as creatures created by God and this relationship is one of participation. God gives us His principles of governance and the human mind grasps this divinely given law, and we participate in this divine law through our practical activity. This practical activity includes individual, social, and political judgments. The natural law provides us with the general principles whereby individuals and societies ought to be governed. Natural law is inscribed in our nature; and we know natural law through our nature. We obey natural law because of our love for God (and God’s love for us!).

The spirit of our modern American democratic age is a republican spirit that has been influenced by natural law since our Nation’s foundation. Our human laws are conventional and contingent principles that are made by those governing; however, human laws are based upon the universal and unchanging requirements of natural law, whereby natural law serves as the pattern for the formulation of human laws. The United States Constitution was founded on the belief in a law that was superior to the will of human governors. The Constitution is the supreme law of the land that provides a guide for actions that are good for the nation, community, and the individual. Natural law theory is reflected in The Declaration of Independence with the words, “That all men are created equal.” (Thomas Jefferson) Two natural law principles that are protected in the Constitution are due process and equal protection for all individual citizens under the laws. (See The Constitution of the United States, Article 5, and the Fourteenth Amendment, Ratified in 1868).

Natural law theory is important for us to understand so that our modern ethical and political ideas will evolve to a moral reliance upon God’s governance and natural law. This is the vision of individuals that will animate and improve our representative government, and protect our Constitution. God is the source of natural law and His creatures are endowed with a rational discernment to understand His moral law that is inscribed in our nature. For Christians, we are rational beings and our reason is a reflection of God’s laws for us. God’s universally valid principles guide us as we work toward the perfection of what it means to be God’s creature. As rational creatures, we have the innate ability to discern right from wrong but it is only with Christ’s guidance that we have the ability to develop as human beings, maintain moral laws, and live a life of virtue in preparation for an eternal life.

Aquinas, St. Thomas. Summa Theologica, translated by Fathers of the English Dominican Province, Five Volumes. Notre Dame, Indiana: Christian Classics, 1981.