BEFORE taking up the history of Natural Law it may be well to show how Natural Law differs from Positive Law on the one hand and from Moral Law on the other.
The Moral Law deals with such actions as tend to promote the interests of society or else to become detrimental to its welfare. Actions are morally right or wrong with reference to the individuals composing society, according as they are good or bad for society as a whole.
Positive Law includes the enactments of a particular government, enjoining certain actions upon the citizens and prohibiting others.
Laws of Nature follow from the nature of things and are not dependent upon any particular form of society or government. They are universal rules of action, discovered by natural reason. They form the ideal according to which men should fashion their actions.
Of these three classes of laws one is set down by society and forms the Right; the second is prescribed by the government and forms the Law; the third is discovered by reason as Good. While in any particular instance all three may coincide, there is the possibility of a conflict.1
The ancient Greeks were fond of speculating about the origin and meaning of Law. They first of all peoples developed the conception of Natural Law.
The germs of the conception of Natural Law are contained in the teaching of Heraclitus, whose influence reached its height about 460 B.C. The central thought of his system is the view that all things are in a state of incessant flow. Yet in this world of constant change there prevails an immutable and reasonable law to which all things are subject. This divine law or common reason illumines also the mind of man. All human wisdom is but an imitation of Nature and the Divinity.2 This divine law should guide not only the individual, but also the State. Human laws are but the efflux of the divine laws.3 Heraclitus is the first philosopher who believes in the Logos or rational world-soul—the eternal, all-comprehensive order of things. This conception of the Logos has dominated all subsequent philosophy down to the present.4 Its bearing upon the theory of Natural Law is evident. Higher and more authoritative than the positive laws of the State are the precepts of Universal Reason ; the laws which are right, not because they are commanded, but because they are founded in the nature of things.
The views of Heraclitus were attacked by Archelaus and by the Cyrenaican school, who held that right and wrong do not exist by nature, but are derived from human regulation and convention and are therefore variable.1
The Sophists, with whom a new epoch begins in Greek philosophy, return to the view of Heraclitus. While the early Greek philosophers did not question the validity of traditional morality as embodied in the positive laws of the State, the Sophists applied the critical spirit to accepted ethical and religious views. They discriminated between Natural and Positive Law. They taught that positive laws could not be obligatory because they varied so frequently. Positive laws are the arbitrary commands of those in power, framed by rulers for their own advantage. Only such laws can be considered natural or divine as are everywhere observed.2 But though the Sophists recognized the idea of Natural Law it was not with the purpose of exalting Natural Right. They emphasized rather the subjectivity and relativity of truth. Their object was primarily to prove that existing laws and institutions were conventional and variable.
Socrates, Plato, and Aristotle are not unfamiliar with the conception of Natural Right, though they make little use of it. Socrates distinguishes between written laws which are founded upon custom and unwritten laws which are observed everywhere, being given to the human race by the gods and not framed by the hand of man.3 Plato’s doctrine of ideas, which are supposed to be the essence of things, is closely related to the conception of Laws of Nature. Aristotle refers to universal law which conforms to the dictates of Nature. He speaks of a universal sense of right which, in a certain degree, all persons possess intuitively. He refers to the famous utterance of Antigone, who declared it to be right to bury Polynices, even though she violated a royal command, because the burial was by nature a deed of justice, the law enjoining it having been in force, not for this or the next day, but forever, no one knowing from whom it proceeded.1 Rhetoric I. 15 Aristotle speaks of the universal law as being more absolutely just than the written law, and as continuing in force forever, whereas written law frequently varies. Rhetoric I. 10, 3 he classifies laws as general and peculiar, the latter being those by whose written enactments men guide themselves, while the former consist of those written rules which seem to be recognized among all men. Rhetoric I. 15, 25 Aristotle again refers to universal principles of right.
In the works of the Stoics we find the theory of Natural Law fully developed. It was in accord with their system of metaphysics. They believed that every corporate entity is permeated by God, whom they conceived as the Logos, that is, as universal reason. They believed God to be immanent in Nature—to be the world-soul. According to their view God rules the universe by means of a universal law.2 This law they believed to be the rule of action for every being in existence. The universe is one. The law which is immanent in Nature and penetrates the being of man, is the absolute standard, above space and time, independent of human regulations—the absolute criterion of right and wrong. Every person with sound intellect can discover this law.1 The end of life, the supreme ethical law, is the life according to Nature and the agreement of the human with the divine will.2 The Stoics taught that law is derived from the common or general reason, its source being God or Nature, and not the will of man. It is Natural Law, and as such unchangeable ; the same at all times and in all places.3 The wise man will use this law as his guide in daily life and as a standard in framing other laws.4 The divine law was exclusive law in the Golden Age. The depravity of human nature, however, makes positive human laws necessary.5 Positive laws are not binding when they conflict with Natural Laws. The wise man is free from positive laws. He alone is just in the full sense of the word, since he alone obeys the divine law.6 The Stoics believed self-preservation to be the chief instinct of all living creatures, the Law of Nature impelling them to ward off that which is injurious and seek that which is beneficial. The Stoics likewise taught that all men are equal and brethren, being citizens of the world and all alike, even slaves, children of the same God.7 Stoicism anticipated many of the noblest teachings of Christianity. When Stoicism originated the Greek States were breaking up and were being merged in large empires. The distinction between Hellenes and barbarians was being obliterated. Cosmopolitanism was supplanting nationalism. Stoicism was the fruit of this process. “The place of the particular laws of individual states is taken by the general law of the world; the place of members of a nation or city by the human race; the place of native land or city by the entire world.”1
The Stoic doctrines found many adherents among the Romans, the most notable being Seneca and Cicero. The former teaches the brotherhood of mankind and the equality of all men, including the slaves, more clearly, perhaps, than any other writer of antiquity. The practical influence of these ideas made itself felt after these doctrines began to color Roman jurisprudence.2
Cicero adopts the conception of Natural Law from the Stoics, calling it jus naturale, or jus naturae.3 He does not consider it as founded upon subjective opinion, but rather as constituted by Nature. It is implanted in reason, being unknown to animals. It forms a sort of conscience, demanding obedience to its dictates.4 It is the eternal, general, and immutable standard for all lands and peoples, the expression of absolute truth, the highest wisdom of God. Its source is God, Nature, or Reason. It was law before being written. Though every person has some knowledge of it, there exist different degrees of possession. Full possession is the result of an earnest striving after the highest truth.5 Natural Law is the standard to which positive laws should conform. The latter have for their purpose the realization of the former.1 In reality positive laws are but a small and limited circle compared with Natural Law, and but a faint copy of the latter.2 Cicero does not consider the jus naturale legally binding upon all men, that is, identical with the jus gentium, but only potentially and theoretically obligatory; its only political use being to serve as a standard for positive laws and as an ethical guide for human action.3
The jus naturale is entirely different from the jus gentium of the Romans. The latter was the law according to which foreigners were judged at Rome. It was not a code applying to States, as does modern international law, but to individuals, and comprised laws that were in common usage among various tribes and States. It was, in Cicero’s time, the universal law of all free men. The jus gentium was not held in great favor, but rather regarded as a necessary evil. It had not as yet been formulated and systematized. After the introduction of Stoicism into Rome the jus naturale began to penetrate Roman jurisprudence and to influence the jus gentium. Inasmuch as the two systems had much in common, they soon coalesced and then came to be regarded as superior to political laws.4
With the adoption of the theory of Natural Law by the Roman jurists a new phase began in its development. These jurists did little in the way of broadening its speculative conception, but they applied the doctrine to positive law and made a practical application of its tenets.
The Stoic doctrine of the natural equality of all men, by coloring Roman jurisprudence, resulted in making laws more general, in weakening the force of race differences, and in improving the lot of the slaves. The latter were by Seneca and his Stoic successors regarded as human beings meriting brotherly treatment.1
There are two tendencies among the Roman jurists, the one represented by Ulpian, extending Natural Law to all living creatures, the other represented by Gaius, Paulus, and Marcian, limiting Natural Law to mankind alone.
Ulpian distinguishes two branches of Natural Law, the one including the entire animal world, the other embracing mankind only. The former rests upon instinct and applies to the union of the sexes, the procreation of kind, and the education of offspring.2 It also stipulates that what is born out of legitimate matrimony follows the mother; that it is just to repel force by force; that all living things have a common ownership of the elements.3 This is the view of Natural Law adopted by Justinian.4 Ulpian defines theft and adultery as crimes against Nature.5
Gaius and Paulus differ from Marcian in their views on the Law of Nature (lex naturae), though all three agree as regards Natural Right or Justice (jus naturale). Gaius and Paulus maintain that each thing has an essential character, which they call its nature, and that there is an objective intelligence or reason in this nature of things, the Natural Reason (ratio naturalis), whose product is Natural Law. This is Montesquieu’s view when he defines laws as necessary relations derived from the nature of things. In this sense all beings have their laws.1 Marcian, however, shares the Stoic view, regarding the Law of Nature as the Law of the entire Universe, extending its scope far beyond simple justice. According to this view, Natural Justice is only a part of Natural Law. Marcian considers God as dwelling in Nature, and as being the source of Natural Law, which is itself Reason, rather than merely a product of Natural Reason. Marcian holds, in common with Gaius and Paulus, that Natural Right is absolute justice applying to all human beings, even to slaves.2 One of the most striking deductions that were made from Natural Law by the Roman jurists was that according to it all men are from the beginning born free.
Just as Natural Law and the jus gentium were fused, though at first distinct, so Natural Law was by the later Roman jurists identified with the principles of equity.3
Such were the views of the Greeks and Romans relative to Natural Law. What were the practical consequences of these views? Did they have any appreciable influence upon the evolution of liberty among the ancients? These are questions deserving consideration.
It will be remembered that the Laws of Nature were conceived of by Heraclitus, the Stoics, and their successors, as being derived from the essence or nature of things and as being distinct from the positive laws of the State. These Laws of Nature, though not enforced by material force of any sort, are morally binding upon the individual; indeed, they form the supreme standard of action; all other laws ought to be tested as to whether or not they conform to the Laws of Natural Justice, and positive laws conflicting with them, so the Stoics held, are not to be obeyed. Natural Law thus limits the omnipotence of the State. The despotism of the State was, as we have seen in a previous connection, the chief hindrance to the growth and development of individual liberty in the ancient world. Unfortunately, Natural Law was still in too rudimentary a stage to be of much influence upon the genesis of private rights. It had not yet formulated any specific rights, like that of freedom of conscience, of speech, and other individual rights, to which the citizen should be entitled. The ideas of the natural liberty and equality of all men do, however, seem to have had considerable effect upon Roman laws in the way of rendering them more equal and just than they might otherwise have been.
It is important, nevertheless, that the conception of Natural Law was formed by the ancients, for, after subsequently receiving a wider development, it became in modern times a factor in the enfranchisement of the individual whose importance can scarcely be overestimated.
While the ancients believed in the sovereignty of the State, the German barbarians, who overthrew the Roman empire, believed in the sovereignty of the individual. Our modern liberty goes back to them primarily. Their devotion to personal liberty was so great that it was inimical to all government which was not self-imposed. They hated cities, which the ancients regarded as essential to a complete life, and lived in the forests. They chose their own chieftains. They regarded the payment of taxes as a sign of serfdom. No one can read the Germania of Tacitus and the other memorials of this people without being struck by this excess of the individualistic spirit. Thus was the Greek and Roman view of sovereignty supplanted by the German idea of liberty. It must not be supposed that the feudal system annihilated individual freedom. On the contrary, feudalism was individualism unrestrained ; feudalism was the product of the Teutonic love of liberty and hatred of control. But this almost uncontrolled liberty was for the upper classes alone. Unfortunately, the primitive economic equality had been undermined by inequalities in the possession of land, which favored the growth of an aristocracy. The depression of multitudes to serfdom went on apace. These serfs were but the property of their lords. In England the primitive liberty of Teutonic times was soon restored by abolishing serfdom and extending to the lower classes the liberty which they had lost. A like development might have resulted on the Continent but for the revival of the Roman notion of the omnipotence of the State, or rather of the ruler of the State, which was a consequence of the revival of the Roman law, from whose influence England escaped. But even on the Continent the Teutonic individualistic spirit broke out with fresh fervor during the great religious Reformation of the sixteenth century, which was essentially a product of the Germanic spirit united with the spirit of primitive Christianity.1
This brings us to the consideration of another factor of importance in the genesis and development of modern liberty; namely, Christianity.
Christianity plainly teaches the equality of all men before God, a notion which has again and again proved to be a levelling force to which no other can be compared. The words of Christ, “Render unto Cæsar the things which are Cæsar’s, and unto God the things that are God’s,”1 as well as the words of the apostles, “We ought to obey God rather than men,”2 are a declaration of war against the ancient view of the omnipotence of the State. Here is a sphere ; namely, whatever concerns conscience, within which the interference of the State will not be tolerated. The individual is thereby enfranchised. The Roman emperors did not fail to recognize the meaning of this; therefore they adopted the policy of bitter persecution. To acknowledge freedom of conscience would have meant to consent to a limitation of sovereignty.
A third factor in the evolution of individual liberty, and one of great importance, is the influence of Natural Law, which passes from Roman jurisprudence into the literature of the Middle Ages, and from thence into modern thought. From Natural Law the creed of modern liberty and democracy develops.
The Christian religion renders this conception more acceptable and plausible to the Middle Ages than it would otherwise have been, because it possesses a conception analogous to that of Natural Law. Thus Paul speaks of the Gentiles as doing by nature the things commanded by the law written in their hearts.1
Nor were the church fathers unfamiliar with this notion. Irenæus, in describing the divine plan of educating the human race, holds that God’s purpose is to be carried out by means of the Natural Laws implanted in man’s nature, to which he owes obedience. He believes that the patriarchs were already familiar with these laws. During the sojourn in Egypt they were forgotten. God, therefore, had them inscribed in the Decalogue. Christ did not abrogate the old law, but only expanded it, retaining all the Laws of Nature.2 Tertullian aims to show that divine law is based upon reason and that rational laws only are worthy of regard. Custom is but the interpreter of reason. In God all things are alike natural and rational. As God did not foresee, dispose, or ordain anything without reason, so He wishes that nothing should be treated or understood without reason.3 Ambrose speaks of the “true law, not engraved upon tablets or on stone, but impressed upon the mind and the senses; wherefore the wise man is not under the law, but is a law unto himself, inasmuch as the work of the law is written on his heart by a natural stylus and with a certain inscription.”4 Chrysostom says: “From the beginning of things, when God created man, He implanted within him the natural law. And what is this natural law? Conscience has revealed it to us and has given us the notion of right and wrong.”1 St. Augustine holds that law, which is supreme reason, must by every thinking person be seen to be eternal and immutable.2
The Decretum of Gratian, which appeared in 1150 and was one of the chief works on Canon Law throughout the Middle Ages, begins with a consideration of Natural Law. It declares divine law to rest upon human nature, while human laws rest upon custom.
“Natural Right is common to all nations because it rests upon the instinct of nature, not upon ordinance, as the union of male and female; the succession and education of children; the common possession of all things and the equal liberty of all men; the acquisition of whatever is taken in the sky, on land or sea ; the restitution of everything given in trust, or of money committed to charge; the repulsion of force by force. For these and similar things were never held to be unjust, but to be natural and equal.”3 Natural Right differs from custom and ordinance. While by the former all things are common to all, by the latter this is mine, that another’s. By its dignity Natural Right prevails over custom and ordinance. Whatever is contrary to it in custom or ordinance should be regarded as null and void.4
From the Decretum of Gratian the conception of Natural Law passes into the literature of scholasticism. We find this theory fully explained by Thomas Aquinas (1225–1274), the greatest teacher of the Middle Ages. Aquinas distinguishes four kinds of laws: 1. The eternal law,1 constituting the plan according to which God created the universe and governs it; 2. Natural Law,2 which is a derivation from the eternal law, being the impression of the divine light in man; 3. Human laws,3 which are deductions from the precepts of Natural Law, designed to regulate certain affairs more particularly; 4. The divine law,4 which is revealed in the Scriptures.5
Aquinas teaches that though there exists no universal earthly state, nor universal human law, there is a universal divine law, which is the highest reason, existing in God, and which is the source of all other laws. Natural Law is not in its essence different from the divine law, but is simply that part of the latter which is known to rational beings. Implanted in man at his creation, it has ever since survived in the human conscience. Man learns this Natural Law directly through the light of Natural Reason. But while man knows the divine law only in part, God knows it in its entirety. Natural Law existing in the nature of things, is not instituted by any human authority, and is unchangeable. According to this law things occur by necessity, while those actions with which human laws deal are performed because commanded. Whoever obeys the dictates of Natural Law is a virtuous man, for virtuous actions are agreeable to nature, while criminal or vicious actions are contrary to nature and reason.6 The sum and substance of Natural Law is to do right and avoid doing wrong.
Aquinas distinguishes three branches of Natural Law, according as it applies to all substances, to all animals, or to mankind only. “First,” says Aquinas, “there is in man an inclination toward that which is good by nature, which he shares with all substances, and according to which each substance strives after self-preservation. As a result of this inclination those things pertain to Natural Law by which the life of man is preserved and injuries warded off. Then there is in man an inclination toward other things more especially according to Nature, which he shares with other animals ; in accordance with which tendency those things are according to the Law of Nature, which Nature teaches to all animals, of which class are the conjunction of male and female, the education of offspring, and the like. Finally, there dwells in man an inclination toward that which is good according to the nature of reason, which tendency is confined to man; thus, man has a desire to know the truth concerning God, and a longing to live in society; wherefore those things pertain to Natural Law which apply to this inclination, to which class belong the injunction that man should shun ignorance, that he should not offend his associates, and other matters of like nature.”1
Aquinas maintains that no government can command what is contrary to Natural Law without becoming tyrannical. This amounts to an acknowledgment of the limitation of sovereignty. He regards it as the duty of the ruler to secure the common welfare.2 But there is little in his system of political philosophy that savors of individual freedom. Though he opposes the tyranny of temporal rulers, he maintains the infallibility and absolute power of the pope—a despotism which is worse, if anything, than that of temporal princes.