CHAPTER III.
OTHER KINDS OF LAW.
§ 14. Law in General—A Rule of Action.
Having considered in the foregoing chapter the nature of civil law exclusively, we now proceed to examine certain other kinds of law which need to be distinguished from this and from each other. In its widest and vaguest sense the term law includes any rule of action: that is to say, any standard or pattern to which actions (whether the acts of rational agents or the operations of nature) are or ought to be conformed. In the words of Hooker,[36] “we term any kind of rule or canon whereby actions are framed a law.” So Blackstone says:[37] “Law, in its most general and comprehensive sense, signifies a rule of action, and is applied indiscriminately to all kinds of action, whether animate or inanimate, rational or irrational. Thus we say, the laws of motion, of gravitation, of optics or mechanics, as well as the laws of nature and of nations.”
Of law in this sense there are many kinds, and the following are sufficiently important and distinct to deserve separate mention and examination: (1) Physical or Scientific law, (2) Natural or Moral law, (3) Imperative law, (4) Conventional law, (5) Customary law, (6) Practical law, (7) International law, (8) Civil law. Before proceeding to analyse and distinguish these, there are the following introductory observations to be made:—
(1) This list is not based on any logical scheme of division and classification, but is a mere simplex enumeratio of the chief forms of law.
(2) There is nothing to prevent the same rule from belonging to more than one of these classes.
(3) Any discussion as to the rightful claims of any of these classes of rules to be called law—any attempt to distinguish law properly so called from law improperly so called—would seem to be nothing more than a purposeless dispute about words. Our business is to recognise the fact that they are called law, and to distinguish accurately between the different classes of rules that are thus known by the same name.
§ 15. Physical or Scientific Law.
Physical laws or the laws of science are expressions of the uniformities of nature—general principles expressing the regularity and harmony observable in the activities and operations of the universe. It is in this sense that we speak of the law of gravitation, the laws of the tides, or the laws of chemical combination. Even the actions of human beings, so far as they are uniform, are the subject of law of this description: as, for example, when we speak of the laws of political economy, or of Grimm’s law of phonetics. These are rules expressing not what men ought to do, but what they do.
Physical laws are also, and more commonly, called natural laws, or the laws of nature; but these latter terms are ambiguous, for they signify also the moral law; that is to say the principles of natural right and wrong.
This use of the term law to connote nothing more than uniformity of action is derived from law in the sense of an imperative rule of action, by way of the theological conception of the universe as governed in all its operations (animate and inanimate, rational and irrational) by the will and command of God. The primary source of this conception is to be found in the Hebrew scriptures, and its secondary and immediate source in the scholasticism of the Middle Ages—a system of thought which was formed by a combination of the theology of the Hebrews with the philosophy of the Greeks. The Bible constantly speaks of the Deity as governing the universe, animate and inanimate, just as a ruler governs a society of men; and the order of the world is conceived as due to the obedience of all created things to the will and commands of their Creator. “He gave to the sea his decree, that the waters should not pass his commandment.”[38] “He made a decree for the rain, and a way for the lightning of the thunder.”[39] The schoolmen made this same conception one of the first principles of their philosophic system. The lex aeterna, according to St. Thomas Aquinas, is the ordinance of the divine wisdom, by which all things in heaven and earth are governed. “There is a certain eternal law, to wit, reason, existing in the mind of God and governing the whole universe.... For law is nothing else than the dictate of the practical reason in the ruler who governs a perfect community.”[40] “Just as the reason of the divine wisdom, inasmuch as by it all things were created, has the nature of a type or idea; so also, inasmuch as by this reason all things are directed to their proper ends, it may be said to have the nature of an eternal law.... And accordingly the law eternal is nothing else than the reason of the divine wisdom regarded as regulative and directive of all actions and motions.”[41]
This lex aeterna was divided by the schoolmen into two parts. One of these is that which governs the actions of men: this is the moral law, the law of nature, or of reason. The other is that which governs the actions of all other created things: this is that which we now term physical law, or natural law in the modern and prevalent sense of that ambiguous term.[42] This latter branch of the eternal law is perfectly and uniformly obeyed; for the irrational agents on which it is imposed can do no otherwise than obey the dictates of the divine will. But the former branch—the moral law of reason—is obeyed only partially and imperfectly; for man by reason of his prerogative of freedom may turn aside from that will to follow his own desires. Physical law, therefore, is an expression of actions as they actually are; moral law, or the law of reason, is an expression of actions as they ought to be.
This scholastic theory of law finds eloquent expression in the writings of Hooker in the sixteenth century. “His commanding those things to be which are, and to be in such sort as they are, to keep that tenure and course which they do, importeth the establishment of nature’s law.... Since the time that God did first proclaim the edicts of his law upon it, heaven and earth have hearkened unto his voice, and their labour hath been to do his will.... See we not plainly that the obedience of creatures unto the law of nature is the stay of the whole world.”[43] “Of law there can be no less acknowledged, than that her seat is the bosom of God, her voice the harmony of the world, all things in heaven and earth do her homage.”[44]
The modern use of the term law, in the sense of physical or natural law, to indicate the uniformities of nature, is directly derived from this scholastic theory of the lex aeterna; but the theological conception of divine legislation on which it was originally based is now eliminated or disregarded. The relation between the physical law of inanimate nature and the moral or civil laws by which men are ruled has been reduced accordingly to one of remote analogy.
§ 16. Natural or Moral Law.
By natural or moral law is meant the principles of natural right and wrong—the principles of natural justice, if we use the term justice in its widest sense to include all forms of rightful action. Right or justice is of two kinds, distinguished as natural and positive. Natural justice is justice as it is in deed and in truth—in its perfect idea. Positive justice is justice as it is conceived, recognised, and expressed, more or less incompletely and inaccurately, by the civil or some other form of human and positive law. Just as positive law, therefore, is the expression of positive justice, so philosophers have recognised a natural law, which is the expression of natural justice.
This distinction between natural and positive justice, together with the corresponding and derivative distinction between natural and positive law, comes to us from Greek philosophy. Natural justice is φυσικὸν δίκαιον; positive justice is νομικὸν δίκαιον; and the natural law which expresses the principles of natural justice is φυσικὸς νόμος. When Greek philosophy passed from Athens to Rome, φυσικὸν δίκαιον appeared there as justitia naturalis and φυσικὸς νόμος as lex naturae or jus naturale.
This natural law was conceived by the Greeks as a body of imperative rules imposed upon mankind by Nature, the personified universe. The Stoics, more particularly, thought of Nature or the Universe as a living organism, of which the material world was the body, and of which the Deity or the Universal Reason was the pervading, animating, and governing soul; and natural law was the rule of conduct laid down by this Universal Reason for the direction of mankind.
Natural law has received many other names expressive of its divers qualities and aspects. It is Divine Law (jus divinum)—the command of God imposed upon men—this aspect of it being recognised in the pantheism of the Stoics, and coming into the forefront of the conception, so soon as natural law obtained a place in the philosophical system of Christian writers. Natural law is also the Law of Reason, as being established by that Reason by which the world is governed, and also as being addressed to and perceived by the rational nature of man. It is also the Unwritten Law (jus non scriptum), as being written not on brazen tablets or on pillars of stone, but solely by the finger of nature in the hearts of men. It is also the Universal or Common Law (κοινος νόμος, jus commune, jus gentium), as being of universal validity, the same in all places and binding on all peoples, and not one thing at Athens and another at Rome, as are the civil laws of states (ἴδιος νόμος, jus civile). It is also the Eternal Law (lex aeterna), as having existed from the commencement of the world, uncreated and immutable. Lastly, in modern times we find it termed the Moral Law, as being the expression of the principles of morality.
The term natural law, in the sense with which we are here concerned, is now fallen almost wholly out of use. We speak of the principles of natural justice, or of the rules of natural morality, but seldom of the law of nature, and for this departure from the established usage of ancient and medieval speech there are at least two reasons. The first is that the term natural law has become equivocal; for it is now used to signify physical law—the expression of the uniformities of nature. The second is that the term law, as applied to the principles of natural justice, brings with it certain misleading associations—suggestions of command, imposition, external authority, legislation—which are not in harmony with the moral philosophy of the present day.
The following quotations illustrate sufficiently the ancient and medieval conceptions of the law of nature:—
Aristotle.—“Law is either universal (κοινος νόμος) or special (ἴδιος νόμος). Special law consists of the written enactments by which men are governed. The universal law consists of those unwritten rules which are recognised among all men.”[45] “Right and wrong have been defined by reference to two kinds of law.... Special law is that which is established by each people for itself.... The universal law is that which is conformable merely to Nature.”[46]
Cicero.—“There is indeed a true law (lex), right reason, agreeing with nature, diffused among all men, unchanging, everlasting.... It is not allowable to alter this law, nor to derogate from it, nor can it be repealed. We cannot be released from this law, either by the praetor or by the people, nor is any person required to explain or interpret it. Nor is it one law at Rome and another at Athens, one law to-day and another hereafter; but the same law, everlasting and unchangeable, will bind all nations at all times; and there will be one common lord and ruler of all, even God the framer and proposer of this law.”[47]
Philo Judaeus.—“The unerring law is right reason; not an ordinance made by this or that mortal, a corruptible and perishable law, a lifeless law written on lifeless parchment, or engraved on lifeless columns; but one imperishable, and impressed by immortal Nature on the immortal mind.”[48]
Gaius.—“All peoples that are ruled by laws and customs observe partly law peculiar to themselves and partly law common to all mankind. That which any people has established for itself is called jus civile, as being law peculiar to that state (jus proprium civitatis). But that law which natural reason establishes among all mankind is observed equally by all peoples, and is for that reason called jus gentium.”[49]
Justinian.—“Natural law (jura naturalia), which is observed equally in all nations, being established by divine providence, remains for ever settled and immutable; but that law which each state has established for itself is often changed, either by legislation or by the tacit consent of the people.”[50]
Hooker.—“The law of reason or human nature is that which men by discourse of natural reason have rightly found out themselves to be all for ever bound unto in their actions.”[51]
Christian Thomasius.—“Natural law is a divine law, written in the hearts of all men, obliging them to do those things which are necessarily consonant to the rational nature of mankind, and to refrain from those things which are repugnant to it.”[52]
The Jus Gentium of the Roman Lawyers.
It is a commonly received opinion, that jus gentium, although identified as early as the time of Cicero with the jus naturale of the Greeks, was in its origin and primary signification something quite distinct—a product not of Greek philosophy but of Roman law. It is alleged that jus gentium meant originally that system of civil and positive law which was administered in Rome to aliens (peregrini), as opposed to the system which was the exclusive birthright and privilege of Roman citizens (jus civile or jus quiritium); that this jus gentium, being later in date than the jus civile, was so much more reasonable and perfect that it came to be identified with the law of reason itself, the jus naturale of the Greeks, and so acquired a double meaning, (1) jus gentium, viz. jus naturale, and (2) jus gentium, viz. that part of the positive law of Rome which was applicable to aliens, and not merely to citizens. That the term jus gentium did possess this double meaning cannot be doubted; but it may be gravely doubted whether the true explanation of the fact is that which has just been set forth. It would seem more probable that jus gentium was in its very origin synonymous with jus naturale—a philosophical or ethical, and not a technical legal term—the Roman equivalent of the κοινος νόμος of Aristotle and the Greeks; and that the technical significance of the term is secondary and derivative. Jus gentium came to mean not only the law of nature—the principles of natural justice—but also a particular part of the positive law of Rome, namely, that part which was derived from and in harmony with those principles of natural justice, and which therefore was applicable in Roman law courts to all men equally, whether cives or peregrini. In the same way in England, the term equity, although originally purely ethical and the mere equivalent of natural justice or jus naturae, acquired a secondary, derivative, and technical use to signify a particular portion of the civil law of England, namely, that portion which was administered in the Court of Chancery, and which was called equity because derived from equity in the original ethical sense.
This, however, is not the place in which to enter into any detailed examination of this very interesting and difficult problem in the history of human ideas.[53]
§ 17. Imperative Law.
Imperative law means any rule of action imposed upon men by some authority which enforces obedience to it. In other words an imperative law is a command which prescribes some general course of action, and which is imposed and enforced by superior power. The instrument of such enforcement—the sanction of the law—is not necessarily physical force, but may consist in any other form of constraint or compulsion by which the actions of men may be determined. Lex, says Pufendorf,[54] est decretum quo superior sibi subjectum obligat, ut ad istius praescriptum actiones suas componat. “A law,” says Austin,[55] “is a command which obliges a person or persons to a course of conduct.”
Laws of this kind are to be classified by reference to the authority from which they proceed. They are in the first place either divine or human. Divine laws consist of the commands imposed by God upon man and enforced by threats of punishment in this world or in the next: for example, the Ten Commandments.[56] Human laws consist of imperative rules imposed by men upon men, and they are of three chief kinds, namely, civil law, the law of positive morality, and the law of nations. Civil law consists (in part at least, and in one of its aspects) of commands issued by the state to its subjects, and enforced by its physical power. Positive morality—the law of opinion or of reputation, as Locke[57] calls it—consists of the rules imposed by society upon its members and enforced by public censure or disapprobation. The law of nations or international law consists (in part at least, and in one aspect) of rules imposed upon states by the society of states, and enforced partly by international opinion and partly by the threat of war.
Many writers are content to classify the civil law as being, essentially and throughout its whole compass, nothing more than a particular form of imperative law. They consider that it is a sufficient analysis and definition of civil law, to say that it consists of the commands issued by the state to its subjects, and enforced, if necessary, by the physical power of the state. This may be termed the imperative or more accurately the purely imperative theory of the civil law. “The civil laws,” says Hobbes,[58] “are the command of him, who is endued with supreme power in the city” (that is, the state, civitas) “concerning the future actions of his subjects.” Similar opinions are expressed by Bentham[59] and Austin,[60] and have in consequence been widely, though by no means universally, accepted by English writers.
This imperative theory, though it falls short of an adequate analysis, does undoubtedly express a very important aspect of the truth. It rightly emphasises the central fact that law is based on physical force. For law exists only as an incident of the administration of justice by the state, and this consists essentially in the imperative and coercive action of the state in imposing its will, by force if need be, upon the members of the body politic. “It is men and arms,” says Hobbes,[61] “that make the force and power of the laws.” Law has its sole source, not in custom, not in consent, not in the spirit of the people, as some would have us believe, but in the will and the power of him, who in a commonwealth beareth not the sword in vain.
This, then, may be accepted as the central truth contained in the imperative theory of law, and if this is so there is no weight to be attributed to that which may be termed the historical argument against this theory. It is objected by some, that though the definition of law as the command of the state is plausible, and at first sight sufficient, as applied to the developed political societies of modern times, it is quite inapplicable to more primitive communities. Early law, it is said, is not the command of the state; it has its source in custom, religion, opinion, not in any authority vested in a political superior; it is not till a comparatively late stage of social evolution that law assumes its modern form, and is recognised as a product of supreme power; law, therefore, is prior to, and independent of political authority and enforcement; it is enforced by the state, because it is already law, not vice versa.[62]
To this argument the advocates of the imperative theory can give a valid reply. If there are any rules prior to, and independent of the state, they may greatly resemble law; they may be the primeval substitutes for law; they may be the historical source from which law is developed and proceeds; but they are not themselves law. There may have been a time in the far past, when a man was not distinguishable from an anthropoid ape, but that is no reason for now defining a man in such wise as to include an ape. To trace two different things to a common origin in the beginnings of their historical evolution is not to disprove the existence or the importance of an essential difference between them as they now stand. This is to confuse all boundary lines, to substitute the history of the past for the logic of the present, and to render all distinction and definition vain. The historical point of view is valuable as a supplement to the logical and analytical, but not as a substitute for it. It must be borne in mind that in the beginning the whole earth was without form and void, and that science is concerned not with chaos but with cosmos.
The plausibility of the historical argument proceeds from the failure adequately to comprehend the distinction, hereafter to be noticed by us, between the formal and the material sources of law. Its formal source is that from which it obtains the nature and force of law. This is essentially and exclusively the power and will of the state. Its material sources, on the other hand, are those from which it derives its material contents. Custom and religion may be the material sources of a legal system no less than that express declaration of new legal principles by the state, which we term legislation. In early times, indeed, legislation may be unknown. No rule of law may as yet have been formulated in any declaration of the state. It may not yet have occurred to any man, that such a process as legislation is possible, and no ruler may ever yet have made a law. Custom and religion may be all-powerful and exclusive. Nevertheless if any rule of conduct has already put on the true nature, form, and essence of the civil law, it is because it has already at its back the power of the organised commonwealth for the maintenance and enforcement of it.
Yet although the imperative theory contains this element of the truth, it is not the whole truth. It is one-sided and inadequate—the product of an incomplete analysis of juridical conceptions. In the first place it is defective inasmuch as it disregards that ethical element which is an essential constituent of the complete conception. As to any special relation between law and justice, this theory is silent and ignorant. It eliminates from the implication of the term law all elements save that of force. This is an illegitimate simplification, for the complete idea contains at least one other element which is equally essential and permanent. This is right or justice. If rules of law are from one point of view commands issued by the state to its subjects, from another standpoint they appear as the principles of right and wrong so far as recognised and enforced by the state in the exercise of its essential function of administering justice. Law is not right alone, or might alone, but the perfect union of the two. It is justice speaking to men by the voice of the state. The established law, indeed, may be far from corresponding accurately with the true rule of right, nor is its legal validity in any way affected by any such imperfection. Nevertheless in idea law and justice are coincident. It is for the expression and realisation of justice that the law has been created, and like every other work of men’s hands, it must be defined by reference to its end and purpose. A purely imperative theory, therefore, is as one-sided as a purely ethical or non-imperative theory would be. It mistakes a part of the connotation of the term defined for the whole of it.
We should be sufficiently reminded of this ethical element by the usages of popular speech. The terms law and justice are familiar associates. Courts of law are also courts of justice, and the administration of justice is also the enforcement of law. Right, wrong, and duty are leading terms of law, as well as of morals. If we turn from our own to foreign languages, we find that law and right are usually called by the very same name. Jus, droit, recht, diritto, have all a double meaning; they are all ethical, as well as juridical; they all include the rules of justice, as well as those of law. Are these facts, then, of no significance? Are we to look on them as nothing more than accidental and meaningless coincidences of speech? It is this that the advocates of the theory in question would have us believe. We may, on the contrary, assume with confidence that these relations between the names of things are but the outward manifestation of very real and intimate relations between the things named. A theory which regards the law as the command of the state and nothing more, and which entirely ignores the aspect of law as a public declaration of the principles of justice, would lose all its plausibility, if expressed in a language in which the term for law signifies justice also.
Even if we incorporate the missing ethical element in the definition—even if we define the law as the sum of the principles of justice recognised and enforced by the state—even if we say with Blackstone[63] that law is “a rule of civil conduct, prescribed by the supreme power in a state, commanding what is right and prohibiting what is wrong”—we shall not reach the whole truth. For although the idea of command or enforcement is an essential implication of the law, in the sense that there can be no law where there is no coercive administration of justice by the state, it is not true that every legal principle assumes, or can be made to assume, the form of a command. Although the imperative rules of right and wrong, as recognised by the state, constitute a part, and indeed the most important part of the law, they do not constitute the whole of it. The law includes the whole of the principles accepted and applied in the administration of justice, whether they are imperative principles or not. The only legal rules which conform to the imperative definition are those which create legal obligations, and no legal system consists exclusively of rules of this description. All well-developed bodies of law contain innumerable principles which have some other purpose and content than this, and so fall outside the scope of the imperative definition. These non-imperative legal principles are of various kinds. There are, for example, permissive rules of law, namely those which declare certain acts not to be obligatory, or not to be wrongful; a rule, for instance, declaring that witchcraft or heresy is no crime, or that damage done by competition in trade is no cause of action. It cannot be denied that these are rules of law, as that term is ordinarily used, and it is plain that they fall within the definition of the law as the principles acted on by courts of justice. But in what sense are they enforced by the state? They are not commands, but permissions; they create liberties, not obligations. So also the innumerable rules of judicial procedure are largely non-imperative. They are in no proper sense rules of conduct enforced by the state. Let us take for example the principles that hearsay is no evidence, that written evidence is superior to verbal, that a contract for the sale of land cannot be proved except by writing, that judicial notice will be taken of such and such facts, that matters once decided are decided once for all as between the same parties, that the interpretation of written documents is the office of the judge and not of the jury, that witnesses must be examined on oath or affirmation, that the verdict of a jury must be unanimous. Is it not plain that all these are in their true nature rules in accordance with which judges administer justice to the exclusion of their personal judgment, and not rules of action appointed by the state for observance by its subjects, and enforced by legal sanctions?
There are various other forms of non-imperative law, notably those which relate to the existence, application, and interpretation of other rules. The illustrations already given, however, should be sufficient to render evident the fact that the purely imperative theory not merely neglects an essential element in the idea of law, but also falls far short of the full application or denotation of the term. All legal principles are not commands of the state, and those which are such commands, are at the same time and in their essential nature something more, of which the imperative theory takes no account.
Some writers have endeavoured to evade the foregoing objection by regarding rules of procedure and all other non-imperative principles as being in reality commands addressed, not to the ordinary subjects of the state, but to the judges. The rule, they say, that murder is a crime, is a command addressed to all persons not to commit murder; and the rule that the punishment of murder is hanging, is a command to the judges to inflict that punishment.[64] With respect to this contention, it is to be observed in the first place, that no delegation of its judicial functions by the supreme authority of the state is essential. There is no reason of necessity, why a despotic monarch or even a supreme legislature should not personally exercise judicial functions. In such a case the rules of procedure could not be enforced upon the judicature, yet it could scarcely be contended that they would for that reason cease to be true rules of law. And in the second place, even when the judicial functions of the state are delegated to subordinate judges, it is in no way necessary that they should be amenable to the law for the due performance of their duties. Are the rules of evidence, for example, entitled to the name of law, only because of the fact, if fact it be, that the judges who administer them may be legally punished for their disregard of them? It is surely sufficiently obvious that the legal character of all such rules is a consequence of the fact that they are actually observed in the administration of justice, not of the fact, if it is a fact, that the judicature is bound by legal sanctions to observe them.
§ 18. Conventional Law.
By conventional law is meant any rule or system of rules agreed upon by persons for the regulation of their conduct towards each other. Agreement is a law for the parties to it. Examples are the rules and regulations of a club or other society, and the laws of whist, cricket, or any other game. What are the laws of whist, except the rules which the players expressly or tacitly agree to observe in their conduct of the game?
In many cases conventional law is also civil law; for the rules which persons by mutual agreement lay down for themselves are often enforced by the state. But whether or not these conventional rules thus receive recognition and enforcement as part of the law of the land, they constitute law in the wide sense of a rule of human action.[65]
The most important branch of conventional law is the law of nations, which, as we shall see later, consists essentially of the rules which have been agreed upon by states, as governing their conduct and relations to each other.
§ 19. Customary Law.
By customary law is here meant any rule of action which is actually observed by men—any rule which is the expression of some actual uniformity of voluntary action. Custom is a law for those who observe it—a law or rule which they have set for themselves, and to which they voluntarily conform their actions. It is true that custom is very often obligatory; that is to say, it is very often enforced by some form of imperative law, whether the civil law or the law of positive morality; but, irrespective of any such enforcement, and by reason solely of its de facto observance, it is itself a law in that wide sense in which law means a rule of action.[66]
Some writers regard international law as a form of customary law. They define it as consisting of the rules actually observed by states in their conduct towards each other. We shall consider this opinion in a later section of the present chapter. Civil law, as we have defined it, is a form of customary law, inasmuch as it consists of the rules actually observed by the state in the administration of justice. It is the custom of the judicature. The relation between popular custom and the civil law is an important matter which will be considered in a later chapter. It is sufficient here to make the following remarks with regard to it:—
(1) Popular custom has not in itself the nature of civil law; for the essence of civil law lies in its recognition by the state in the administration of justice.
(2) Popular custom is one of the primitive substitutes for civil law, men being governed by custom before the state has been established or has undertaken the function of making and administering law.
(3) Popular custom is one of the sources of the civil law; for that law, when it comes into existence, is largely modelled on the pre-existing customs of the community. Civil law, which is the custom of the state, is based to a large extent on that precedent customary law which is merely the custom of the society.
§ 20. Practical Law.
Yet another kind of law is that which consists of rules for the attainment of some practical end, and which, for want of a better name, we may term practical law. These laws are the rules which guide us to the fulfilment of our purposes; which inform us as to what we ought to do, or must do, in order to attain a certain end.[67] Examples of such are the laws of health, the laws of musical and poetical composition, the laws of style, the laws of architecture, the rules for the efficient conduct of any art or business. The laws of a game, such as whist, are of two kinds: some are conventional, being the rules agreed upon by the players; others are practical, being the rules for the successful playing of the game.
§ 21. International Law.
International law or the law of nations consists of those rules which govern sovereign states in their relations and conduct towards each other. All men agree that such a body of law exists, and that states do in fact act in obedience to it; but when we come to inquire what is the essential nature and source of this law, we find in the writings of those who deal with it a very curious absence of definiteness and unanimity. The opinion which we shall here adopt as correct is that the law of nations is essentially a species of conventional law—that it has its source in international agreement—that it consists of the rules which sovereign states have agreed to observe in their dealings with each other.
This law has been defined by Lord Russell of Killowen[68] as “the aggregate of the rules to which nations have agreed to conform in their conduct towards one another.” “The law of nations,” says Lord Chief Justice Coleridge,[69] “is that collection of usages which civilised states have agreed to observe in their dealings with each other.” “The authorities seem to me,” says Lord Esher,[70] “to make it clear that the consent of nations is requisite to make any proposition part of the law of nations.” “To be binding,” says Lord Cockburn,[71] “the law must have received the assent of the nations who are to be bound by it. This assent may be express, as by treaty or the acknowledged concurrence of governments, or may be implied from established usage.”
The international agreement which thus makes international law is of two kinds, being either express or implied. Express agreement is contained in treaties and international conventions, such as the Declaration of Paris or the Convention of the Hague. Implied agreement is evidenced chiefly by the custom or practice of states. By observing certain rules of conduct in the past, states have impliedly agreed to abide by them in the future; by claiming the observance of such customs from other states, they have impliedly agreed to be bound by them themselves. International law derived from express agreement is called in a narrow sense the conventional law of nations, although in a wider sense the whole of that law is conventional; that part which is based on implied agreement is called the customary law of nations. The tendency of historical development is for the whole body of the law to be reduced to the first of these two forms—to be codified and expressed in the form of an international convention, to which all civilised states have given their express consent. Just as customary civil law tends to be absorbed in enacted law, so customary international law tends to be merged in treaty law.
International law is further divisible into two kinds, which may be distinguished as the common law of nations and the particular law of nations. The common law is that which prevails universally or at least generally among all civilised states, being based on their unanimous or general agreement, express or implied. The particular law is that which is in force solely between two or more states, by virtue of an agreement made between them alone, and derogating from the common law.
International law exists only between those states which have expressly or impliedly agreed to observe it. Those states (which now include all civilised communities and some which are as yet only imperfectly civilised) are said to constitute the family or society of nations—an international society governed by the law of nations, just as each national society is governed by its own civil law. New states are received into this society by mutual agreement, and thereby obtain the rights and become subject to the duties created and imposed by international law.
Writers are, however, as we have already indicated, far from being unanimous in their analysis of the essential nature of the law of nations, and the various competing theories may be classified as follows:—
(1) That the law of nations is, or at least includes, a branch of natural law, namely, the rules of natural justice as applicable to the relations of states inter se.
(2) That it is a kind of customary law, namely the rules actually observed by states in their relations to each other.
(3) That it is a kind of imperative law, namely the rules enforced upon states by international opinion or by the threat or fear of war.
(4) That it is a kind of conventional law, as already explained. Having accepted the last of these theories as correct, let us shortly consider the nature and claims of the three others.
§ 22. The Law of Nations as Natural Law.
All writers on international law may be divided into three classes by reference to their opinions as to the relation between this law and the principles of natural justice. The first class consists of those who hold that the law of nations is wholly included within the law of nature—that it consists merely of the principles of natural justice so far as applicable to sovereign states in their relations and conduct towards each other—that the study of international law is simply a branch of moral philosophy—and that there is no such thing as a positive law of nations, consisting of a body of artificial rules established by states themselves. Thus Hobbes says:[72] “As for the law of nations, it is the same with the law of nature. For that which is the law of nature between man and man, before the constitution of commonwealth, is the law of nations between sovereign and sovereign after.” The same opinion is expressed by Christian Thomasius,[73] Pufendorf,[74] Burlamaqui,[75] and others, but is now generally discredited, though it is not destitute of support even yet.
A second opinion is that international law is both natural and positive—that it is divisible into two parts, distinguished as the natural law of nations, which consists of the rules of natural justice as between states, and the positive law of nations, consisting of rules established by states by agreement, custom, or in some other manner, for the government of their conduct towards each other. The natural law of nations is supplementary or subsidiary to the positive law, being applicable only when no positive rule has been established on the point. Representatives of this opinion are Grotius, Wolf, Vattel, Blackstone, Halleck, Wheaton, Phillimore, Fiore, Twiss, and others. The third opinion is that international law is wholly positive—that it consists exclusively of a set of rules actually established in some way by the action of sovereign states themselves—and that the rules of natural justice are not in themselves rules of international law at all, but pertain to that law only if, and only so far as, they have been actually incorporated into the established system of positive law. This is now the prevalent opinion, and we have here accepted it as the correct one.[76] By those who maintain it the rules of natural justice as between states are called international morality, and are distinguished by this name from international law. These two bodies of rules are partly coincident and partly discordant. The conduct of a state may be a breach of international morality but not of international law, or a breach of law though in accordance with morality, or it may be both immoral and illegal.
The question whether rules of natural justice are to be included as a part of international law is, indeed, in one aspect, a mere question of words. For these rules exist, and states are in honour bound by them, and the question is merely as to the name to be given to them. Nevertheless, questions of words are often questions of practical importance, and it is of undoubted importance to emphasise by a difference of nomenclature the difference between rules of international morality, by which, indeed, states are bound whether they have agreed to them or not, but which are uncertain and subject to endless dispute, and those rules of international law, which by means of international agreement have been defined and established and removed from the sphere of the discussions and insoluble doubts of moral casuistry.
§ 23. The Law of Nations as Customary Law.
Even those writers who agree in the opinion that international law is or at least includes a system of positive law, differ among themselves as to the essential nature and source of these rules; and we proceed to consider the various answers that have been given to this question. Some writers consider that international law has its source in international custom—that it consists essentially and exclusively of the rules which are actually observed by sovereign states in their dealings with one another.[77] This view, however, is not prevalent, and is, it is believed, unsound. International custom is not in itself international law; it is nothing more than one kind of evidence of the international agreement in which all such law has its source. There are many customs which, because they are based on no such underlying agreement, have not the force of law, states being at liberty to depart from them when they please. Conversely there is much law which is not based on custom at all, but on express international conventions. These conventions, if observed, will of course create a custom in conformity with the law; but they constitute law themselves from the time of their first making, and do not wait to become law until they have been embodied in actual practice. New rules of warfare established by convention in time of peace are law already in time of peace.
§ 24. The Law of Nations as Imperative Law.
By some writers international law is regarded as a form of imperative law; it consists, they say, of rules enforced upon states by the general opinion of the society of states, and also in extreme cases by war waged against the offender by the state injured or by its allies. Thus Austin says:[78] “Laws or rules of this species, which are imposed upon nations or sovereigns by opinions current among nations, are usually styled the law of nations or international law.” In considering this view it is to be admitted that in many cases the rules of the law of nations are thus sanctioned and enforced by international opinion and force. But the question to be answered is whether this sanction is of the essence of the matter; because, if it is so, all rules so sanctioned must be, and no others can be, rules of international law. It is clear, however, that the sanction of war cannot be the essential test; for in the first place this sanction is but seldom applied even to undoubted violations of international law, and in the second place it is at least as often resorted to when there is no violation of such law at all. What then shall be said of the alternative sanction of international opinion? Is this the test and essence of a rule of international law? For the following reasons it is submitted that it is not:—
(1) Many forms of state action are censured by public opinion, which are admittedly no violation of the law of nations. A state may act within its legal rights, and yet so oppressively or unjustly as to excite the adverse opinion of other nations.
(2) There may be violations of international law which are in the particular circumstances regarded as excusable, and approved by international opinion.
(3) Public opinion is variable from day to day—dependent on the special circumstances of the individual case—not uniform as we pass from state to state—not uniform even throughout the population of the same state. International law, on the other hand, is a permanent, uniform system of settled rules, independent of the fickle breath of public approbation or censure—made and unmade by the express or implied agreements of sovereign governments, and not by the mere opinions and prejudices which for the moment are in public favour. International law is one thing, international positive morality is another thing; but the doctrine here criticised identifies and confounds them as one. International law is made, as has been said, by the acts and contracts of governments; international opinion is made chiefly by journalists and the writers of books. Opinion, if sufficiently uniform and sufficiently permanent, will doubtless in time constrain the law into conformity with it; but it is not the same thing.
(4) Public opinion cannot be made the basis of any rational or scientific body of rules or legal doctrines. For such opinion is simply the belief of the public that certain forms of conduct are in conformity with natural justice. So far as this belief is well founded, the law based upon it is simply the law of nature; so far as it is erroneous, the law based on it is simply a mistake which disappears ipso facto on being recognised as such. It is impossible to recognise as a subject of scientific interpretation and investigation any international law based on erroneous public opinion; and if based on true opinion, it is nothing save the principles of natural justice.
Certain writers seek to avoid the first of these objections by so defining international law as to include only one portion of the body of rules approved and sanctioned by international opinion, the remaining portion constituting international positive morality. According to this opinion international law consists of those rules which international opinion not merely approves, but also regards as rightly enforceable by way of war. International positive morality, on the other hand, consists of those rules of which opinion approves, but of the enforcement of which by way of war it would not approve. That is to say, international law is distinguished from international morality by an application of the distinction familiar to the older moralists between duties of perfect and duties of imperfect obligation.[79]
This view would seem to be exposed to all the objections already made to the cruder theory which we have just considered, with the exception of the first; and it is also exposed to this further criticism, that it is impossible thus to divide public opinion sharply into two parts by reference to the justification of war or any other kind of forcible compulsion. Whether such compulsion is right is a matter to be determined not by the application of any fixed or predetermined rules, but by a consideration of all the circumstances of the individual instance; and even then opinion will in most cases be hopelessly discordant. Moreover, there are forms of state action which are not the violation of any established rule of international law, and which nevertheless are so contrary to the rightful interests of another state that they would be held to be rightly prevented or redressed by way of war. Conversely there are rules of undoubted law which are of such minor importance, that a war for the vindication of them would be viewed by international opinion as a folly and a crime.