BRIA 22 4 c St. Thomas Aquinas Natural Law and the Common Good

Bill of Rights in Action

Fall 2006 (22:4)

Making a Just Society

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St. Thomas Aquinas, Natural Law, and the Common Good


St. Thomas Aquinas, a medieval Roman Catholic scholar, reconciled the political philosophy of Aristotle with Christian faith. In doing so, he contended that a just ruler or government must work for the "common good" of all.

Before the time of Jesus, the Greeks developed concepts about how the world worked and human beings behaved. Aristotle, who died in 322 B.C., was an Athenian philosopher who wrote about science, ethics, politics, and almost every other realm of knowledge.

Throughout his writings, Aristotle did not teach that the Greek gods or religion controlled the world and its people. Instead, his observations led him to conclude that nature was purposeful and driven by natural laws that human reason could discover. These natural laws provided a way to explain the world and the place of humans within it.

In one of Aristotle’s works called The Politics, he reasoned, "man is by nature a political animal." By this, he meant that people were naturally destined to live in groups, which required some sort of ruler or government. According to Aristotle, only by living in a community "to secure the good life" could human beings achieve such virtues as courage, honesty, and justice. In his time, this human community was a city-state like Athens.

Applying his scientific method of observation and analysis of evidence, Aristotle studied the governments of 158 city-states in the Greek world. He classified rule by a king (monarchy) and the superior few (aristocracy) as "good" governments. He judged rule by the few rich (oligarchy) and the many poor (democracy) as "bad" governments.

Aristotle concluded that the best government was one that "mixed" the features of oligarchy and democracy. For example, all the citizens would choose some government officials by lottery. But only some citizens with a certain amount of property or wealth could qualify for other offices. Aristotle thought this form of government provided the best chance for political stability.

Augustine and Christian Faith

Hundreds of years later, Christianity emerged as the dominant religion in the Roman Empire. The fathers of the early Christian Church introduced a way of explaining the world far different from that of Aristotle. Perhaps the most important of these early church fathers was St. Augustine.

Augustine was born in A.D. 354 in North Africa, then a province of Rome. As a youth, he studied the concepts of natural law and human reason from the writings of classic Greek and Roman thinkers like Aristotle and Cicero. Augustine converted to Christianity when he was 33.

He became a Christian priest and bishop of the North African city of Hippo. For a while, he believed reason and faith were compatible. By the year 400, however, he had changed his mind. "Do not therefore try to understand in order that you may believe," he wrote, "but believe in order that you may understand."

Augustine taught that when Adam and Eve put their own desires above God’s will, they committed a sin that became the source of evil among human beings. Christians often call this "original sin." Augustine believed that all human beings were born with original sin and were thus doomed to damnation. But like other Christians, he also believed that God was merciful and sent Jesus to save believers from sin and eternal suffering.

Even so, Augustine viewed humans as essentially sinful. Only some of them would escape from the fires of hell. These individuals, known only to God, would achieve heavenly bliss in what Augustine called the "City of God." Membership in the Christian (Roman Catholic) church was essential, he wrote, but even that did not guarantee salvation.

Because of Adam and Eve’s sinfulness, government was needed to control and punish sinful humans. Augustine said that government forms were not important since they were all temporary.

Augustine argued that people should obey their rulers unless they violated God’s word. In that case, believers could refuse to obey, but must expect punishment. In general, though, he advised that it was better to endure a wicked state during one’s brief existence on Earth, having faith that eternal life awaited in the City of God.

Augustine died in 430 as barbarians assaulted Hippo, heralding the end of the Roman Empire. Later, the Roman Catholic Church made him a saint. St. Augustine’s writings helped develop Catholic Church beliefs.

Thomas Aquinas Combined Reason and Faith

Nearly 2,000 years after Aristotle died, only a few of his works on logic survived in Western Europe. But Jewish and Muslim scholars had preserved much of his writing. Starting in the 1100s, scholars in the West began to translate Aristotle’s works from Hebrew and Arabic into Latin, making them available in the new universities that were forming. Along with these translations came extensive commentaries on Aristotle such as those by the Spanish Muslim scholar Averroes.

The rediscovery of Aristotle’s works with their sophisticated explanation of the world based on natural law and reason seemed to challenge the teachings of the Christian faith. At first, the Roman Catholic Church tried to ban his works.

But some church scholars such as Albert the Great at the University of Paris thought it was possible to combine human reason and Christian faith. Thomas Aquinas, an Italian Roman Catholic theologian (religious scholar), devoted his life to this task.

Aquinas was born in 1225, the son of a noble family in the kingdom of Sicily, which included part of the mainland of Italy around Naples. His family sent him at age 5 to the Benedictine monastery of Monte Casino to train as a monk.

Later, Aquinas attended the University of Naples where he first encountered the writings of Aristotle. Against his family’s wishes, he joined the Dominican order at 18, taking a vow of poverty.

In 1245, Aquinas traveled to the University of Paris where a great debate was going on about Aristotle’s ideas. The young Aquinas studied under Albert the Great who sided with those who believed Aristotle’s view of the world was compatible with that of Christianity.

Aquinas came to think that one should believe only what is self-evident (e.g., human beings use reason) or can be deduced from self-evident propositions (e.g., human reason can discover truth).

Aquinas became a Dominican teacher of religion at the University of Paris and in Italy. He continued to study the works of Aristotle and the Muslim commentaries on them.

Aquinas wrote his own commentaries on Aristotle, which included reasoned propositions based on certainties revealed by God. He also wrote summaries of Catholic doctrine that also attempted to combine reason and faith.

Natural and Human Law

Thomas Aquinas, much like Aristotle, wrote that nature is organized for good purposes. Unlike Aristotle, however, Aquinas went on to say that God created nature and rules the world by "divine reason."

Aquinas described four kinds of law. Eternal law was God’s perfect plan, not fully knowable to humans. It determined the way things such as animals and planets behaved and how people should behave. Divine law, primarily from the Bible, guided individuals beyond the world to "eternal happiness" in what St. Augustine had called the "City of God."

Aquinas wrote most extensively about natural law. He stated, "the light of reason is placed by nature [and thus by God] in every man to guide him in his acts." Therefore, human beings, alone among God’s creatures, use reason to lead their lives. This is natural law.

The master principle of natural law, wrote Aquinas, was that "good is to be done and pursued and evil avoided." Aquinas stated that reason reveals particular natural laws that are good for humans such as self-preservation, marriage and family, and the desire to know God. Reason, he taught, also enables humans to understand things that are evil such as adultery, suicide, and lying.

While natural law applied to all humans and was unchanging, human law could vary with time, place, and circumstance. Aquinas defined this last type of law as "an ordinance of reason for the common good" made and enforced by a ruler or government. He warned, however, that people were not bound to obey laws made by humans that conflicted with natural law.

Government and the "Common Good"

In 1267, Thomas Aquinas completed a work on government inspired by Aristotle’s Politics. Aquinas asserted, "Yet it is natural for man, more than any other animal, to be a social and political animal, to live in a group." He presented logical proofs of this such as the self-evident fact of human speech to allow individuals to reason with one another.

Aquinas further observed that people tend to look only after their own self-interest. "Therefore," he concluded, "in every multitude there must be some governing power" to direct people toward the "common good."

Thus, Aquinas did not agree with St. Augustine that the main purpose of government was simply to keep the sinful in line. Aquinas saw government as also helping to work for the "common good" that benefits all. The common good included such things as protecting life, preserving the state, and promoting the peace. Aristotle would have called this "the good life."

Aquinas addressed the problem of unjust rulers who might be a king, the few rich, or the many poor. Aquinas noted that when rulers make laws that violate natural law, they become "tyrants." Aquinas went on to conclude, "A tyrannical government is not just, because it is directed not to the common good, but to the private good of the ruler, as the Philosopher [Aristotle] says."

What should the people do about a tyranny? Aquinas agreed with St. Augustine that the subjects of unjust rule are not obliged to obey the laws since they are not legitimate. But Aquinas went far beyond St. Augustine and virtually all other medieval thinkers on this matter.

Aquinas argued that the subjects of a tyranny, acting as a "public authority," might rebel and depose it. Aquinas cautioned that the people should not do this hastily, but only when the damage done by the tyranny exceeds what may occur in a rebellion. This was one of the first justifications for revolution in Western thought.

Aquinas further developed the meaning of "just war" that had been discussed by the Roman statesman Cicero and by St. Augustine. For a war to be just, there must be these three conditions:

1. A declaration by the ruler to defend the "common good" against enemies.

2. A "just cause" for an attack on an enemy "because they deserve it on account of some fault" such as avenging wrongs they have committed.

3. A "rightful intention" to advance good or avoid evil such as punishing evil-doers and not simply grabbing land or goods.

These conditions for a "just war" later influenced the development of international laws of war.

Aquinas wrote thoughtfully about the best form of government. He, like Aristotle, preferred a mixture of government forms. Aquinas recognized the value of a king, "a shepherd seeking the common good of the multitude." But he opposed an absolute monarch.

The nobility, Aquinas argued, should advise the king and limit his power. Furthermore, the king’s laws must result from the "deliberation of reason" and have the consent of both the nobility and the common people. These were radical ideas for a time when kings claimed no one but God could hold them accountable.

The Legacy of St. Thomas Aquinas

Aquinas spent his last years teaching and writing in Italy. He died in 1274 at age 49 from an illness he developed while walking to France to attend a church conference.

At first, the Roman Catholic Church rejected Aquinas’s massive effort to reconcile human reason with Christian faith. In 1277, the church condemned some of his writings based on Aristotle’s ideas. About 50 years after his death, however, the church revived his works and made him a saint.

The writings of St. Thomas Aquinas combining reason and faith became the basis for official Roman Catholic doctrine (known as "Thomism"). In addition, his forward-looking political ideas regarding natural law, unjust rulers, and rebellion influenced European Enlightenment philosophers such as John Locke and even Americans such as Thomas Jefferson and Martin Luther King.

For Discussion and Writing

1. How did Aristotle and St. Augustine differ in their views about the natural world and government?

2. Do you agree with St. Thomas Aquinas’ three conditions for a "just war"? Explain.

3. How do you think the writings of St. Thomas Aquinas may have influenced Thomas Jefferson and Martin Luther King?

For Further Reading

Klosko, George. History of Political Theory, An Introduction. Vol. I. Fort Worth, Tex.: Harcourt Brace College Publishers, 1994.

Kretzmann, Norman and Stump, Eleanor, eds. The Cambridge Companion to Aquinas. Cambridge: Cambridge University Press, 1993.


The "Common Good"

1. Form small groups to discuss and list five laws, policies, or programs the U.S. government should enact for the "common good" of all Americans.

2. The groups should then rank their five government acts from most to least important.

3. Each group then should read its ranked list to the rest of the class and defend its first choice for the "common good."




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