After the fall of the Western Roman Empire, the Catholic Church increasingly became the arbiter of "justice" in Western Europe, thereby assuming the role of interpreter of ancient ideas of justice for the Christian masses. Biblical understanding was overlaid on the term "nature" so that subsequent definitions of Natural Law would have to, in some way, accommodate the Christian worldview.

The Middle Ages

St. Augustine (354-430 CE) described the Garden of Eden prior to the Fall as a period during which Adam and Eve lived in harmony with natural law and enjoyed immortality and peace. The Fall obscured natural law's dictates, making man mortal and vulnerable to evil. Institutions such as government, property, and law arose; though inherently sinful (because they are human and not divine institutions), they have the potential to control man's evil impulses. The Church, as guardian of the law of God (lex aeterna), should be empowered to interfere with these human institutions, which merely enforce the worldly law (lex temporalis) in order to keep the peace on earth.

Scholasticism, whose most famous proponent was St. Thomas Aquinas (1126-1274), attempted to meld Aristotelian ethics with Catholicism. The result was a system of laws: eternal law (divine wisdom, unknowable to man); natural law (the part of eternal law accessible to man through rationality); divine law (laws given to man by God); and human law (societal laws made for common good). In this system, human laws should be disobeyed when they run counter to divine laws.

The Renaissance

The political and religious conflicts during the late Renaissance coincided with the development of raison d'état ("for reasons of state") as a criterion for justice. Raison d'état justified actions taken on behalf of the health of the state. It found its most famous advocate in the Italian Niccolo Machiavelli (1469-1527) who emphasized protecting the state from internal dissent. Jean Bodin (1530-1597) expanded the concept of raison d'état into our current notion of national sovereignty, i.e., the right of a state to protect itself from interference by outsiders.

The era of "Classical Natural Law,"** coincided with the emphasis on rationality and reason that typified the Enlightenment's reaction to medieval Catholicism. From the 16th century through the 20th, legal and political philosophers debated how to harness reason to achieve justice.

Enlightened Absolutists maintained that a rational ("enlightened") monarch would act with self-restraint and wisdom to guarantee harmony with natural law within his kingdom. Although this view was advocated throughout Europe, the idea lasted longer in the East, the home of Enlightened Despots such as Catherine II of Russia and Frederick II of Prussia.

Hugo Grotius (1583-1645), often called the father of international law, also believed that only an enlightened absolute ruler could lead a country towards reason. Grotius is better-known for his elaboration of the "law of nations," which he described as a mixture of reason-based natural law and volitional law (will of men) comprising the laws accepted by many nations. Sovereigns, though above their own domestic law, were subject to this law of nations as they were to natural law itself.

Samuel Pufendorf (1632-1694) believed that nature made people both selfish and desirous of tranquil society and that natural law expressed this duality. In his view, law should allow people to pursue their own interests but stop at the point of jeopardizing peaceful society.

Thomas Hobbes (1588-1679) gave us the famous thought that in the state of nature (before society), the life of man is "nasty, brutish, and short." Yet Hobbes also believed that people have a natural desire for peace and are therefore inclined to form societies for mutual protection. The laws of nature, which resemble our idea of the "golden rule" and the inviolability of contracts, require the presence of a strong government, preferably an absolute monarch, for their protection. Because the monarch must be strong enough to preserve the laws of nature against the inherent irrationality of the population, the monarch must be above the civil laws that he enacts to help him govern. The citizens have no recourse against a monarch who violates the laws of nature, which should serve him as a moral guide.

The Age of Reason/The Enlightenment

Macchiavelli and Hobbes wrote during times of domestic turmoil; it is not, therefore, surprising that their concepts of justice and natural law would favor an emphasis on stability. Eventually, however, the extravagances of the Western European monarchies led to disillusionment with the idea that monarchs would voluntarily act to preserve the laws of nature. John Locke (1632-1704) wrote of an idealized state of nature in which all men lived freely, equally, and in harmony with the laws of nature. However, each man was also responsible for enforcing the laws of nature, which led to instability, prompting men to form society and give government the responsibility of enforcing these laws. Unlike in Hobbes, individuals retain their natural rights in society, and indeed the purpose of society is the preservation of natural rights, which Locke calls "property." The people, through legislatures, make laws that will be enforced by the sovereign. The ultimate protector of natural law, however, is the people themselves, who can dismiss governments or positive laws that run contrary to natural laws.

Charles Louis de Montesquieu (1689-1755) further developed Locke's idea of a political system that will guarantee the preservation of natural law in his The Spirit of the Laws. Montesquieu articulated the system of separation of powers into executive, legislative, and judicial that we recognize in the U.S. system of checks and balances.

Classical Natural Law's emphasis on reason and occupation with the proper relationship between a government and its citizens in promoting the laws of nature raised many of the questions that have shaped contemporary notions of justice and the role of rule of law. This includes the current juxtaposition of Natural Law to Positivism (the laws made by legislatures), which grew from the 19th century belief that a collective (the state) would have better access to reason than an individual and would therefore only pass just laws.***

Exercises
1. How did thinkers in the Middle Ages and the Enlightenment develop different parts of the Greek and Roman ideas of natural law?

2. How did these different interpretations reflect the ideas and goals of the Middle Ages and the Enlightenment, respectively?

3. What remnants of Classical Natural Law remain in contemporary societies?

4. Where do we see conflicts between Natural Law and Positivism today? For example, when might a written law conflict with a moral law?

5. The famous utilitarian Jeremy Bentham (1748-1832) wrote that "Rights is the child of law; from real law come real rights; but from imaginary laws, from "law of nature," come imaginary rights. . ." What is Bentham's critique of the concept of law of nature?
What are some potential problems with the idea of natural law?