NATURAL LAW IN POLITICAL THOUGHT

natural law has been a perennial theme for political philosophers; and even in mid-20th century, after 150 years of critical analysis, it retains an interest and vitality. The concept of natural law originated in the classical period, reached its highest development in late medieval and early modern times, and continues to be significant, especially in legal theory and in the ideology of Christian democracy and other movements of Catholic inspiration. In the course of 2,500 years, the appeal to certain fixed universal principles that can be perceived in nature and in human nature has taken a variety of forms and served a number of functions; but as long as men have sought justifications for the political order beyond those of tradition and revelation, the appeal to nature and natural law has remained an element in political thought (see state).

Classical Period. It was the breakdown of the traditional order in the period following the Persian Wars and the immediate confrontation of widely varying political systems that first gave rise to the appeal to nature in ancient Greece. In the search for an ethical and legal standard, the participants in the political discussions of 5th-century Athens made use of the concept of nature (physis ) that had been used in earlier scientific speculation to explain the ultimate constituent elements of the universe. In Thucydides's history of the Peloponnesian Wars and in the opening pages of Plato's Republic, there are images of the then current Sophist doctrine that by a natural law the strong do and should rule the weak. Surviving fragments of Sophist writings also indicate that some argued that all men were equal by nature and that social as well as moral distinctions were purely conventional. In his Republic plato attempted to respond to both these criticisms, arguing for a natural order of reason over the passions in the individual and of the more rational over the less intelligent in society. aristotle based his defense of slavery on a natural inequality among men and appealed to the nature of man as the basis for government and private property. Equally important for the history of the theory was Aristotle's teleological method, his attribution of an inherent purposiveness and intelligibility to nature. Yet neither Plato nor Aristotle developed a full-fledged natural law theory as such. For Plato law was associated with the rigid and inadequate legal rules of the contemporary Greek city-state; it appeared to be a second-best compromise when the rule of the wise could not be assured. In his Nicomachean Ethics Aristotle wrote of a natural justice invariable among gods but variable among men (1134b); in the Politics he described law as "reason free from passion" (1287a), and in the Rhetoric he alluded to a universal or common law "in accordance with nature" (1373b). Yet it is only in the writings of the Stoics that the term "law of nature" was used, and a systematic theory of a higher law based on nature developed.

Emerging in Greece after the breakdown of the Greek city-state and the triumph of the Macedonian Empire, stoicism became the dominant philosophy of the ruling classes of the Roman Empire and profoundly influenced the formulation of roman law. According to Stoic thought man participated in divine Reason, which permeated the universe; and it was in the common possession of reason, considered both as a moral and intellectual faculty, that all men were equal by nature. Stoic thought on natural law thus departed in theory from the elitism of Plato and Aristotle, although in practice cicero, whose De republica and De legibus are the principal sources for Stoic natural law theories, rejected democracy and argued for the rule of a rational elite. A similar hesitancy to apply the practical consequences of the theory characterized the attitude of Cicero and the Roman lawyers toward a possible conflict between the natural law and existing legal institutions, such as slavery, that were viewed as contrary to the natural equality of all mankind.

Christian Development. Christianity gave a different basis to the doctrine of equality—the moral responsibility of every man to God—and a different appeal as the basis of political legitimacy—the will of God. Christianity had a higher law, but it was not the law of nature; it was that of divine revelation (see revelation, theology of). The early Christian attitude toward nature was ambiguous. On the one hand, nature (and especially human nature) had been corrupted by original sin. The pagan philosophers without the guidance of revelation were steeped in sin, which would adversely affect their ability to attain moral truth. As Tertullian put it, "not Athens, but Jerusalem" (De praescriptione haereticorum, ch. 7). On the other hand, nature was created by God, who as a purposive and intelligent Being had established an ordered universe. Moreover, St. Paul, who was familiar with Stoic thought, had written, "When the Gentiles who have no law do by nature what the Law prescribes, these having no law are a law unto themselves. They show the work of the Law written in their hearts" (Rom 2.14–15).

In their confrontation with classical culture, the Fathers of the Church ultimately adopted the latter attitude and incorporated the natural-law doctrine as part of the Christian tradition. St. augustine himself, despite his emphasis on the opposition of nature and grace, often referred to the natural law in his writings. However, the Stoic teaching about the original equality of all men received a different formulation in Christian teaching. The Fathers saw equality as the condition in the Garden of Eden and attributed all forms of domination and government, property, and slavery to man's fall from grace. As this instance demonstrates, the relation of natural law to revelation was not clear in early Christian writings; and as late as the writings of the canon lawyers of the 12th and 13th centuries, the natural and the divine law tended to be equated.

It was the genius of St. thomas aquinas in the 13th century to distinguish divine law, in the sense of revelation, from natural law, in the sense of those moral imperatives that man can perceive with his reason in an ordered universe created by God. Aquinas drew on Aristotle to affirm the natural character of government and to relate Aristotelian teleology to the natural law in a hierarchy of ends and inclinations in human nature corresponding to the principal precepts of the natural law. In a famous passage (Summa theologiae 1a2ae, 94.2) he described these as existence; self-preservation; the family; and education, society, and (natural) religion.

The appeal to the natural law had more force in the Middle Ages when it was associated directly with God's will than in Roman times when it was simply a philosophic theory. Yet despite Aquinas's argument that human laws contrary to natural law are null and void (ST 1a2ae, 95.2.), it was not widely used for the purpose of invalidating existing laws or practices. Laws were sometimes opposed by referring to natural and divine law (retaining the canonist confusion of the two), but the most common appeals were to the positive law of the Church or to traditional feudal rights. The natural law decreed human equality, but there was no demand for the abolition of slavery; and the belief in a hierarchical universe, derived ultimately from Neoplatonist sources, tended to justify a hierarchical social order as a part of the nature of things. Yet in the late Middle Ages the doctrine of the original natural equality of all mankind was also cited to reinforce the development of representative institutions in both Church and State, and appeals were made in both canon and civil law to the principle that all those affected by governmental decisions have a natural-law right to give their consent, either through representatives or (more often) tacitly.

Modern Period. Aquinas had asserted the limits of human reason and the importance of the divine law as a guide and a supplement to the natural law; but at the same time, in emphasizing the rational character of the moral law and the powers of the human reason to attain truth, he had helped to lay open the possibility of the assertion of a naturalist and rationalist morality without recourse to revelation, or for that matter, to God. The late scholastics had asked whether the natural law was so firmly based in reason that even God himself could not change it, and grotius (1583–1645), the first of the modern theorists of international law, argued in 1625 that the natural law would still exist "even if we should concede that which cannot be conceded without the utmost wickedness, that there is no God" (De Jure Belli ac Pacis, prolegomena). Although one can exaggerate the secularism of early modern theories of natural law, there is no doubt that the medieval link between the natural and the divine law was broken once there was disagreement after the Reformation as to the content of revelation. In fact, it appeared for a time that the reformers' suspicion of reason and the natural man would end all reference to the natural law by Christian writers. However, the need for a common standard in a religiously divided Christendom compelled those who wrote works of political theory to appeal to it and to develop theories as to its origin and content that were less specifically religious than those of the Middle Ages.

In the works of Thomas hobbes (1588–1679) the term natural law was used to describe a set of maxims for self-preservation, and a hypothetical state of nature replaced the Judeo-Christian Garden of Eden. God entered only as the enforcing sovereign of revealed law, not as the eternal reason of Thomism. John locke (1632–1704) borrowed the state of nature from Hobbes, but combined it with a theory of natural law that was derived from St. Thomas by way of the Anglican divine Thomas hooker (1553–1600). Although there are problems in relating Locke's theory of natural law to the empiricism of his Essay Concerning Human Understanding, the recent discovery of a manuscript copy of his Essays on the Law of Nature makes it clear that his theory of natural law was more traditional than Hobbesian. A novel element, however, was his strong emphasis on the right of private property as decreed by the natural law.

In the 17th-century theories, the natural law served the important function of providing a ground for legitimacy in a political theory. For Grotius the requirements of the social nature of man were the source of the binding force of international law. For Hobbes, man's drive to preserve himself made obedience to the sovereign a moral obligation. For Locke, the natural rights of man provided the basis for consent to government and the limits upon the exercise of power. In all three cases, too, the natural law was seen as prescribing a fundamental equality among men that was not simply a characteristic of some earlier lost state—although in Hobbes's theory, this equality was more physical than moral. In the same century, new scientific advances undermined whatever arguments for hierarchy could be drawn from analogy to the structure of the universe. Natural law arguments were drawn from human nature, not from nature in general.

It was as a theory of consent and equality that natural law, as transformed by Locke into natural rights, achieved its most widespread acceptance in the 18th century. In the Declaration of Independence (1776) and the Declaration of the Rights of Man (1789), it became a central feature of the ideologies of the American and French Revolutions; and subsequently it provided the intellectual background for the early court decisions that established the American doctrine of judicial review.

Yet at the very time that it attained its greatest influence the theory of the law of nature was subjected to a series of attacks that led to a rapid decline in its influence. In England David hume (1711–76) in his Treatise of Human Nature (1740) took issue with the notion that any values could be derived from the facts of nature or human nature, while the utilitarians such as Jeremy bentham (1748–1832) argued that moral and legal principles were better derived from their effects on society than from anything inherent in nature. On the Continent, Immanuel kant (1724–1804) posited a sharp dichotomy between the facts of nature and the realm of moral obligation, and attempted to draw conclusions about law and morality from the nature of legal and moral obligation rather than from the nature of man. In the 19th century, the positivists attempted to separate legality and morality to the detriment of natural-law theory, which had considered them as closely related (see positivism in jurisprudence). The theory of evolution and new anthropological research also revealed that the nature of man was not as fixed and unchanging as the defenders of natural law had assumed. By the end of the 19th century, the only political theory that made use of natural law was that contained in the papal social and political encyclicals, which continued to speak in terms of Thomistic natural-law theory (see social thought, papal).

Natural Law Revival. In the 20th century, particularly since the 1930s, there has been a marked revival of interest in natural law as it relates to political theory. A variety of different factors account for this. The excesses of the Nazi regime suggested the need for a higher standard beyond that of the positive law, and after World War II the UN Declaration of Human Rights was justified by some as an attempt to set down natural law obligations binding on governments. The neo-Thomist revival, and especially the writings of Jacques maritain (1882–1973), modernized the theory of Aquinas and placed greater emphasis on the development in history of new insights into the implications of the natural law, thus partially coming to terms with the evolutionist critique. In terms of practical effect, the most important development was the organization of Christian Democratic parties in Europe and more recently in Latin America, whose programs are couched in natural-law terms borrowed from the papal encyclicals and the writings of Maritain. Proposals such as family allowances, worker participation in management, guarantees of the right to organize trade unions, and, more recently, religious freedom and a nuclear test ban treaty have been advocated as conclusions from the natural law. In the area of personal morality with implications for public policy, artificial birth control, sterilization, and divorce have been opposed as prohibited by the same law. Among the areas currently in dispute among natural-law theorists of Thomist inspiration are the extent of the limits on property rights that may be imposed by the state, and the morality of nuclear warfare.

Aside from legal theorists, there are few non-Thomist political philosophers who use the vocabulary of natural law. Yet much of the writing about politics and morals is based on an implicit or explicit conception of the nature of man and the prerequisites for the full expression of human potentialities. To speak about the dignity of man or the necessity of human freedom is to assert a goal for society and the political order that is related to certain universal and constant values inherent in the nature of man. That these moral and legal conceptions vary in different societies proves only that the perception and application of these goals and the choice among them in the common situation of conflict of one with another remains difficult. Ultimately the problem remains the one that puzzled the Greeks: how to find the one in the many, a constant principle in a world of change, a measure that is neither too rigid nor too vague to provide a standard for positive law and government and a basis for political obligation. The answer that the Greeks first conceived—a law of nature—continues to appeal to political theorists, among them many who are not aware of the type of argument they are using.

Bibliography: a. passerin d'entrÈves, Natural Law: An Introduction to Legal Philosophy (New York 1951), the best general survey of the topic with an excellent bibliog. Center for the Study of Democratic Institutions, Natural Law and Modern Society (Cleveland 1963). e. s. corwin, The "Higher Law" Background of American Constitutional Law (Ithaca, NY 1955). j. maritain, Man and the State (Chicago 1951); The Rights of Man and Natural Law, tr. d. c. anson (New York 1943). h. a. rommen, The Natural Law, tr. t. p. hanley (St. Louis 1947). l. strauss, Natural Right and History (Chicago 1953).

[p. e. sigmund]