International Law. Under this designation are included two distinct branches of jurisprudence, known respectively as Public International Law and Private International Law. Public international law regulates the relations of states to states; private international law is concerned exclusively with the legal relations of private individuals, determining by the law of what nation such relations shall be governed in each particular case. Further, it has to be noted that a variety of relations may occur wherein a state and the citizen of another state are the subjects. Here the law is public on one side and private on the other, as is the law administered in prize-courts. In practice, however, such cases are treated under public international law.
Public International Law is the name given to the aggregate of rules which govern the conduct of separate states in their relations to each other. For many years the majority of writers on international law in England and America were content to look for the origin of these rules in no higher source than the more or less general consent of nations, and to base them on no more stable foundation than the shifting sands of expediency. Jurisprudence thus became a merely arbitrary system of rules founded on tacit contracts or express conventions, and its precepts were, logically enough, considered susceptible of any degree of modification, limitation, or adaptation that temporary convenience might seem to demand. These unfortunate doctrines were introduced into English jurisprudence chiefly through the teaching of Bentham, by whom utility was put in the place of natural law. His principles were wrought out and more specifically applied by John Austin, whose works long continued to dominate English jurisprudence. This principle of utility, viewed simply as a good practical test in legislation, or as a ready guide in applying the rules of natural law to the complex facts of state life, may often prove of high value; and, according to Sir H. S. Maine, it was in this aspect, as a 'working rule of legislation,' that Bentham proposed his formula of the 'greatest happiness of the greatest number.' As a matter of fact, however, the majority of the advocates of utility claim that in itself it furnishes the rule of life, and so supplies the place of natural law, the existence of which they deny.
These doctrines have never found much currency on the Continent, and their prevalence in England and America has unfortunately had the effect of cutting off the jurisprudence of these countries from the general stream of scientific jurisprudence which in the nations of continental Europe has continued to run in the old channel. In recent years, however, both in England and America there is observable a growing tendency to abandon this arbitrary notion of positive law. This movement has been largely aided by the scientific spirit, and by the close investigation of nature. Similar researches on the ethical and social sides of human nature have been equally fruitful, with the result that the idea of the universal prevalence of law in all departments of life has been vindicated, and the faith of mankind in nature as a reasoned organism has been confirmed.
As a science, accordingly, positive international law has for its object the discovery of those laws which determine the relations of nations to each other. In all branches of municipal law, the law of the relations subsisting between citizens is defined and enunciated by a legislative authority, is applied by a judicial authority, and is enforced by an adequate executive. The positive law thus defined is accepted on all hands, and consequently a scientific investigation of natural law is only necessary on those rare occasions when alterations are being made in the enacted law. In the case of international law, in the absence of all legislative, judicial, and executive authority, there really is in the strict sense no positive law at all. There are few even of its central doctrines which are not the subject of warm dispute; the objects to be aimed at are no less undetermined; its history is in many respects fragmentary and inconsistent. The truth is, as Professor Sheldon Amos has remarked, that international law now exhibits a positive system of law in the process of making.
The natural laws governing the relations of nations must have been coeval with the existence of nations. It nevertheless remains true that international law, as a positive system, is substantially the creation of civilised Europe during the last three centuries, and its rules are now practically operative only among civilised states. In spite of the fact that the division of the Greek world into a number of separate communities would seem to us to favour the rise of such a system of law, it would appear that, beyond the recognition of certain common Hellenic customs, no effort was made to systematically enunciate any rules of international intercourse. The glory of Greece was already waning when the Stoics, tracing out in a more ethical and practical direction the principles of Socrates, arrived at the idea of the persona and, giving a definite form to the conception of the brotherhood of mankind, enunciated the doctrine of the jus naturale. In this doctrine lay the germs of a cosmopolitan system of international law. In Rome the jus feciale of the early republic—regulating the formal intercourse between Rome and other states—looks like the beginning of what under other conditions might have developed into a system of international law. Unfortunately during the whole period of the empire, while the municipal law of Rome under the influence of the Stoical conceptions was achieving its high destiny, the jurists were by their theory of a universal empire entirely shut out from applying their principles to the relations of states to states. So too, long after the Roman empire had given place to separate kingdoms, while the labours of the civilians contributed largely to the consolidation of the new societies, the imperialistic traditions still lingering among them prevented any effort being made to evolve the doctrines of a jus inter gentes. Meanwhile, the peoples of Europe, closely bound in the fetters of an omnipotent feudalism, were painfully struggling through a period of transition, out of which were to emerge the great European monarchies. During this long period the need of some definite system of international law was in some measure practically supplied by two powerful influences—the authority of the church and the institution of chivalry. The magnificent organisation of the church, besides checking violence and controlling in some degree the turbulence of princes, enabled the pope, taking advantage of the lingering notions of universal sovereignty, to act as arbitrator in a great variety of controversies ranging in importance from the disputes of private individuals to the adjustment of difficulties of serious international concern. The institution of chivalry also, by introducing declarations of war by heralds and a more humane treatment of the vanquished, and generally by inculcating the virtues of fidelity and magnanimity, tended to assuage the horrors of war. Meantime the revival of commerce and the growth of the new commercial cities gave rise to several primitive maritime codes (e.g. the laws of Oléron, the laws of Wisby), whose publication did much to regulate the relations of states in mercantile matters. At length, as the nations of Europe passed into manhood, there came the dawn of a new era and a general rekindling of intellectual life. At the same time the Reformation gave a death-blow to the old notion of a common superior whose decisions were binding upon states, and shattered the influence so long beneficially exercised by the Roman curia as a great court of international appeal. Perplexed by the terrible events of the long struggle between Spain and the revolted Netherlands, and appalled by the unbridled license of the Thirty Years' War, Europe cried aloud for deliverance from what threatened to become international anarchy. The time was ripe for the development of a system of international jurisprudence. The renewed study of Greek philosophy had revived the doctrines of the jus naturale, and in the application of these old principles in the new direction of a jus inter gentes was found the solution of the problem of international order. The first clear reference to the law of nations, as a separate branch of positive law, and as such distinguishable from the law of nature, is usually found in the work of Francisco Suarez of Granada (1548-1617), De Lege et Deo Legislatore. Here, as in the De Jure Belli of Alberic Gentilis, though there is no attempt at a detailed system, yet the true character and general objects of the law of nations are very clearly indicated. Of the workers who were thus engaged in applying the law of nature to the relations of states, the greatest and most successful was Hugo Grotius (1583-1645), who combined profound learning and keen philosophic insight with a large experience in public affairs. In his famous work De Jure Belli ac Pacis (1625), starting with the conception of a real and determinable law of nature, he wrought out his principles into a detailed and symmetrical system of rules. The success of the work was rapid and decisive, and upon the foundations thus deeply laid by its great founder international law continues securely to rest. Many of his rules indeed have undergone a process of development, and the growth of civilisation has led to the elaboration of large bodies of new rules to meet new wants and changed circumstances, but the authority of the work as a whole remains unshaken. Among the most interesting legal products of our day are the manuals of the laws of war issued by many civilised states to their officers in the field, and perhaps the most singular feature of these manuals is the number of rules adopted in them direct from Grotius.
It remains now to consider what may be called the secondary sources of this branch of jurisprudence, or the means by which positive international law is defined and declared in the concrete relations of states. In all departments of jurisprudence custom or usage is the earliest form in which positive law declares itself. There is, however, a constant tendency for customs to outlive the circumstances in which they arose; it is thus constantly necessary to test the customary rules by the touchstone of natural law. Further, many of the recognised rules of international law may be traced to the awards given from time to time by arbitrators, the judgments of mixed courts of prize appointed under treaty, and even to such decisions as are given in courts corresponding to our Court of Admiralty. The great body of rules comprising the maritime law of nations, together with many fundamental rules in other departments, may be found in the decisions of such international tribunals, and thus rest on authority (precedent) as trustworthily as that which commands the homage of the English lawyer. Of such precedents perhaps the most valuable are those furnished by the decisions given in matters of prize by Sir William Scott, Lord Stowell, in his capacity of judge in the Court of Admiralty. To these judgments, which must always form an important part of a course of study on the law of nations, the American Judge Kent (q.v.) has borne this remarkable testimony: 'There is scarcely a decision in the English prize-courts, on any general question of public right, that has not received the express approbation and sanction of our national courts.' A third factor in the formation of positive international law is express convention among states. While treaties during their subsistence constitute between the parties to them the most direct and authoritative declarations of law, yet it is clear that, being merely contracts, they cannot directly bind by their provisions such states as are not signatories. Nevertheless, a series of treaties between different states containing similar stipulations, or even a single treaty whose provisions have been acceded to and acted upon for a length of time by a large number of nations, may have important effects on consuetudinary law, and in this way may materially affect states which have taken no part in the matter. Thus, although the United States have steadfastly refused to adhere to the Declaration of Paris (1856), yet, if the provisions of that treaty continue to be uniformly acted on by the other powers, the obligation on the United States to conform its practice to the rules there embodied will daily become stronger. Considered as sources of international law, the most important treaties are those which profess to declare the absolute law of nations as understood by the contracting parties, such as those abolishing the slave-trade, or defining the relations of belligerents and neutrals. It is, however, in the scientific interpretation of the law as contained in the writings of the great publicists that the most important of these secondary sources of this branch of jurisprudence is to be found. To render clearer our conceptions of the objects of international law, to draw from isolated facts some general principles, to test these principles by the permanent laws of human nature as revealed by the history of events and by the moral and physical sciences, and, further, to apply admitted principles to new sets of circumstances as they arise—to do this and much more has been the work of a long line of eminent jurists, who are at once the witnesses to the law and the guides of its development. By the formation of the 'Institute of International Law' at Ghent in 1873 an attempt has been made to call into existence a new agency for the development of this branch of jurisprudence.
The subjects of international law are sovereign states. In all branches of jurisprudence life is the source of rights, and, therefore, before a community can be regarded as having the rights and being subject to the obligations of a state, it must be shown to possess the essential attributes of state-existence, or, in other words, it must receive political recognition. To the act of recognition a general character is sometimes communicated by several recognising powers simultaneously presenting to the court of the claimant identic notes of recognition, and at the same time giving to their representatives, already resident as consuls, their credentials of appointment as ministers. Of such a concerted proceeding between states the recognition of Roumania in 1880 is a recent example. Roughly, we may say that, according to modern conceptions, a state is a politically autonomous aggregate of human beings, having definite relations to territory, to social existence, to government, and to certain moral ideas, of which the ideas of a historic past and a historic future, and of national unity or common interest are the most dominant and unmistakable. During the nineteenth century the tendency has been to lay stress on nationality—a tendency to whose strength the recent unification of Italy and Germany bears eloquent testimony. Nevertheless, although a political community is composed, as Austro-Hungary now is, of very different races of men, or although it consists internally of a union or federation of smaller communities, yet it may be in the eye of international law a single state, provided the whole is subject to one supreme authority. It is, however, essential that, like every jural entity, the international state, whether great or small, be separate from every other: its moral and physical activity must be peculiarly its own. The fact that recognition thus implies separate existence at once cuts off all colonies, however important and distant from the parent state, and all communities which, though preserving the organisation of a separate nation, are in practice subject to the rule of another state. The fundamental conception of international jurisprudence is that of the interdependence of states, as opposed to their independence. The fact of the reality of such interdependence is every day becoming clearer with the increase of complexity in the social, commercial, and political ties by which the nations of the world are bound one to another. No state, for example, can administer its own criminal law or execute its own criminal judgments without the continual aid of all other states; and in declaring at its Oxford meeting in 1880 that extradition might take place at all times independently of any contractual obligations, or, in other words, that the right of extradition is a right at common law, the Institute of International Law formally accepted the doctrine of the interdependence of states as a conception fundamental in the law of nations.
Questions of the highest importance may arise when a portion of an existing state rises in rebellion, and, setting up a separate government over a considerable portion of the national territories, tenders to other powers a claim for separate recognition. Here again the question is one of fact, depending on the completeness of the new political and military organisation and the probable extent of the conflict by land and sea. The earliest stage of recognition in such cases usually takes the form of a concession of belligerent rights proceeding either from the opposite party in the war or from neutral states alone, or from both. Such belligerent recognition, while it does not confer the peaceful privileges which belong to the perfect state, yet gives all the rights of public war and binds the states which grant it to all the duties of neutrals. The insurgents thus acquire a recognised status: they may capture the goods of their enemies at sea; they can obtain loans of money, and purchase military and naval materials abroad; their flag is acknowledged; and their revenue laws are respected.
In the eye of international law mankind may be said to fall into three spheres, to each of which belong, of right, at the hands of civilised nations, three distinct stages of recognition—plenary political recognition, partial political recognition, and natural or mere human recognition. The sphere of plenary political recognition extends to all the Christian states of Europe and to those states of North and South America originally colonised by them which have vindicated their independence. By the treaty of Paris in 1856 Turkey was formally 'admitted to a participation in the advantages of the public law of Europe and the system of concert attached thereto.' In spite, however, of this technical recognition the position of the Ottoman empire is still properly only one of partial recognition, in which sphere are also included Persia, China, Japan, and Siam. In the case of Turkey and these other countries, even when diplomatic relations have been established between them and civilised states, the recognition does not extend to their municipal law, either public or private, except as regards their own citizens within their own frontiers. Within the borders of all these states separate courts are maintained, and to these courts is entrusted the decision of questions between the citizens of the western states resident in these eastern countries. The constitution of these consular courts or mixed tribunals varies considerably in different oriental states, and is in most cases regulated by convention. The practice of Great Britain in this respect is still mainly regulated by the Foreign Jurisdiction Act (6 and 7 Vict. chap. 94). The third sphere, that of mere human recognition, extends to the residue of mankind.
All the subsidiary principles which regulate international relations, so long at least as they continue to be normal, are directly deducible as corollaries from the central doctrine of recognition. Thus, since recognition implies capacity for self-support and self-government, each state has the right to choose whatever form of government best suits the people and to exercise without interference all the powers which it possesses. It may establish, alter, or abolish its own municipal constitution, discover and settle new countries, extend its navigation and fisheries, improve its revenues, arts, agriculture, and commerce, increase its military and naval forces, and develop its national resources by all innocent and lawful means. This fundamental rule that the jural attitude of states is normally one of mutual confidence, and that the highest political wisdom consists in allowing to each nation entire freedom to manage its own internal affairs and to develop spontaneously its natural resources, negatives the principle of the Balance of Power, now practically obsolete.
As regards proprietary rights, each state is owner of the whole area included within definite boundaries, ascertained by occupation, prescription, or treaty. All ports, bays, mouths of rivers, and a strip of sea three miles in width bordering on the coast-line are included within the territory of the state. In this way each state is enabled more perfectly to carry into effect its maritime laws and customs regulations, to provide for an adequate system of coast defence, and to secure, as long as it remains neutral, immunity from all acts of belligerency between the ships of the enemy. Where, however, part of the territorial waters, so defined, consists of a channel of communication between two portions of the open sea, all vessels of friendly states have the right of free passage. The position of interoceanic canals in international law is not yet quite settled, but the tendency seems to be in favour of the neutralisation of such canals under an international guarantee, so that they may be at all times open to the ships of every nation for the purposes of peaceful passage.
Within its territorial limits each state is entitled to the exclusive power of legislation in respect to the personal rights and civil status of its citizens, and in respect to all real and personal property, whether belonging to citizens or aliens. In recognising the state, other nations recognise its legislative capacity, and consequently are bound, not only to allow it to administer its own municipal law without interference within its own limits, but also to accept as valid and give effect to the definitions of private rights contained in that municipal law. That part of the municipal legislation of a state which deals with the public relations of citizens is in a different position, and is not recognised as valid within the jurisdiction of other states. Thus, for example, a peer of the United Kingdom carries with him, when he goes abroad, none of the privileges peculiar to his peerage; but as to his private relations—whether he is married or single, a debtor or a creditor, a major or a minor—the continental states in which he is sojourning accept and give effect to what English law says regarding them. So the judgments of the judicial tribunals of a recognised state ought to be, and in practice generally are, accepted without question by foreign states, provided only their validity in the country in which they were pronounced is established. Such foreign judgments are, however, executed within the territory of the recognising state only under the authority and by the order of the native tribunals, and thus the form and manner of execution are exclusively governed by the law of the executing state. With regard to crimes, each state administers its own criminal laws within its territories to foreigners and natives alike. Further than this, each state is bound by the principle of recognition, and consequently by the common law of nations, to aid other states in administering their criminal laws and executing their criminal judgments. Thus the right of each state to demand from other states the surrender of an individual accused of having committed a crime within its territory is a right at common law. To this rule political offences form an exception, inasmuch as they do not partake of the universal character attaching to other crimes. The matter is generally regulated by extradition treaties, in which are usually contained stipulations to the effect that no one will be surrendered unless prima facie evidence of his guilt is furnished, and unless adequate assurances are given that the accused will not on that occasion be tried for any offence other than the crime for which he is surrendered. The civil and criminal jurisdiction of a state extends to all its ships on the high-seas or within its territorial waters, and to its public vessels everywhere. When a private ship enters a foreign port, it becomes subject to the 'concurrent jurisdiction' of its own state and of the country in whose territorial waters it lies for the time. Considerable light was thrown upon the exact character and extent of the jurisdiction of a state over that portion of the sea within the three-mile limit by the case of the Franconia (Regina v. Keyn, 2 Exch. Div. pp. 202-205). In that case the majority of the court held that, as the law of England stood at that time, the English courts had no jurisdiction over a criminal offence committed by a foreigner on board a foreign ship which was on the open sea but within three miles of the English coasts. In consequence of this decision the Territorial Waters Jurisdiction Act (40 and 41 Vict. chap. 73) was passed, conferring jurisdiction in such cases upon the Courts of Admiralty. To the rule that the jurisdiction of a state extends over all persons and things within its territory the following exceptions are taken—foreign sovereigns and their suites, when visiting a country in their official capacity, diplomatic agents of other states, and public armed forces of a foreign nation passing peacefully through the state territory. The exemption of the citizens of the western European states from the local jurisdiction in eastern countries cannot be considered an exception, inasmuch as these latter countries are only partially recognised, and consequently the principles deduced from plenary recognition are in their case inapplicable.
Private International Law is that department of national law which arises from the fact that there are in the world different territorial jurisdictions possessing different laws. The subjects of this branch of jurisprudence are private individuals, and its rules are administered by municipal courts. The majority of the relations in which human beings stand to each other are in their nature universal, and entirely independent of the states to which the parties belong. Thus an individual may possess real property in a state other than that of his domicile, or he may enter into a contract or execute a testament in a country different from either. As, in general, each of these countries is governed by a distinct system of laws, it is frequently a question under which system the particular relations fall. In the event of an action becoming necessary, is he to appeal to the municipal laws of his native country or domicile, or to that of the place in which the property is situated, or to that in which the contract was entered into, or in which the testament was executed? The whole of the doctrines of private international law accordingly resolve themselves into the single doctrine of the localisation of such legal relations. This branch of law determines no legal relations whatever; it simply says by what system they shall be determined. It is a doctrine of jurisdiction, and nothing more. The collection of rules for thus determining by what system of municipal law each legal relation is governed was usually, till recently, known as the 'conflict of laws'—a title justly censured as expressing a limited and unsound view of this branch of jurisprudence.
According to the famous rules of Foelix and Huber, which were long accepted as the fundamental propositions on which private international law was founded, all the effects which foreign laws can produce within the territory of any nation depend absolutely on the consent of that nation, either express or tacit. The sole foundation for the whole system was found in the voluntary and reciprocal good-will of nations (comitas gentium). After being abandoned by the majority of continental jurists, this view was formally repudiated by the Institute of International Law at Geneva in 1874. The whole principle of this branch of law is nothing more than a direct corollary from the doctrine of recognition. The right and duty of mutual confidence involved in the doctrine of recognition imply, as we have seen, the acceptance and enforcement by the recognising state of the definitions which the recognised state may have imposed on legal relations—and this, as a rule, even when the definitions so imposed differ from those which are applied to the same legal relations when existing among its own citizens. In this aspect private international law rests not upon the right of the state which concedes it, but on that of the state to which it is conceded.
The increasing intercourse between individuals of different nations gives a growing importance to the interests affected by this branch of law—the rules being accepted and enforced by the various states as part and parcel of their local law. The rights and obligations which result to persons from the possession of immovables are entirely regulated by the law of the country where the immovable subjects are situated. This lex loci rei sitæ, as it is called, determines, even in the case of an alien proprietor, all questions relating to the acquisition of immovables, whether by sale or prescription, to feu-duties, to letting, hiring, and mortgaging, working of mines and minerals, servitudes, and to all taxes and public burdens. The law of the place where real property is situated in short governs exclusively as to the tenure, the title, and the descent of such property. In England and America the lex loci rei sitæ is also applied to determine the jural capacity of the alien proprietor, in so far as depends on his personal status, for example, the age at which he can acquire, alienate, or succeed to immovables. In Scotland and in most continental countries the capacity to acquire or alienate immovable property is regulated by the law of the domicile of the owner, by which all matters relating to status are exclusively governed. In nearly all European countries the rule long obtained that the tenure of immovable property was only possible to a foreigner on the condition of political naturalisation. In almost all states this rule has now been relaxed; and in Britain it has been entirely departed from under the Naturalisation Act of 1870 (33, 34 Vict. chap. 14, sect. 2), which provides: 'Real and personal property of every description may be taken, acquired, held, and disposed of by an alien in the same manner in all respects as by a natural-born British subject; and a title to real and personal property of every description may be derived through, from, or in succession to an alien, in the same manner in all respects as through, from, or in succession to a natural-born British subject.' On the other hand, all movable and personal property is governed by the law of the domicile (lex domicilii). Domicile is defined by Westlake to be the 'legal conception of residence,' and is made up of various elements of birth, citizenship, &c. This law of the domicile also regulates all questions regarding personal status, legitimacy, and succession to movable property. If a question arises about a contract, its validity and interpretation are determined by the law of the country in which the contract was entered into (lex loci contractus). Thus, if a marriage is valid by the law of the place where it was made, it is, generally speaking, valid everywhere else. Wherever, from the nature of the contract itself, or the law of the place where it is made, or the expressed intention of the parties, the contract is to be executed in another country, everything which concerns its execution is to be determined by the law of that country. Again, all questions as to the admissibility and value of evidence or as to procedure or remedy are determined by the laws in force at the forum in which an action is raised (lex fori). If a contract made in one country is attempted to be enforced in the judicial tribunals of another, all questions of prescription are to be determined by the law of the state where the suit is pending. Such at least was the view taken in the famous case Don v. Lippmann, though Savigny, Westlake, Bar, and others argue strongly that this is a matter which ought to be decided by the law of the place where the contract was made.
Reference may also be made to the following articles as bearing on international law:
| Alien. | Enemy. | Naturalisation. |
| Ambassador. | Extradition. | Neutrality. |
| Arbitration. | Foreign Enlistment. | Paris (Treaty of). |
| Balance of Power. | Foreign Law. | Piracy. |
| Blockade. | Geneva Convention. | Political Offences. |
| Capitulation. | Grotius. | Prisoners of War. |
| Conflict of Laws. | Immigration. | Privateer. |
| Cousul. | Jurisdiction. | Prize. |
| Contraband. | Jurisprudence. | Siege (State of). |
| Diplomacy. | Law. | Treaty. |
| Domicile. | Marriage. | War. |
BIBLIOGRAPHY.—Public International Law: Hugo Grotius, De Jure Belli ac Pacis (Paris, 1625; Whewell's Eng. ed. 1853); Vattel, The Law of Nations (Chitty's Eng. ed. 1797); Bluntschli, Das moderne Völkerrecht (Leip. 1877) and Le Droit International Codifié (Paris, 1874); Kent's Commentaries (Abdy's ed. Lond. 1878); Wheaton's Elements of International Law (Dana's ed. Boston, 1866; Boyd's ed. Lond. 1878) and History of the Law of Nations (New York, 1868); Phillimore, International Law (4 vols. 2d ed. 1871); W. Oke Manning, Commentaries on Law of Nations (Sheldon Amos's ed. Lond. 1875); W. E. Hall, International Law (Oxford,
1880); Lormer, Institutes of the Law of Nations (1884); and the works by Westlake (1895) and Lawrence (1896).
Private International Law: Savigny's System, &c. vol. viii. (Eng. trans. by William Guthrie, with notes and appendixes); Story's Conflict of Laws (new ed. Boston, 1883); Westlake's International Law (new ed. 1880); Bar's International Law (Eng. trans. by G. R. Gillespie, 1883); Horace Nelson, Selected Cases, Statutes, and Orders (1889); A. V. Dicey, Law of Domicile (1879); Pitt Cobbett, Leading Cases and Opinions on International Law (1885).