§ 24.

2. Comity.

Comity is another duty of nations. To this source may be referred in part the privileges conceded to ambassadors, and the preference given in certain cases to foreign over domestic law by the courts of Christendom. Comity, as generally understood, is national politeness and kindness. But the term seems to embrace not only that kindness which emanates from friendly feeling, but also those tokens of respect which are due between nations on the ground of right.

A much wider sense is given to the term comity by those who embrace in it all those praiseworthy acts of one nation towards another, which are not stricti juris, that is, all that, the refusing or withholding of which, although dictated by malevolence, is not an injury, and so not a ground for war. But usages originating in comity may become rights by lapse of time. (Comp. Phillimore, I., 161, and §§ 26, 28, infra.)

3. Intercourse.

§ 25.

Some have contended that there is a positive obligation on nations to enter into relations at least of commerce, so that the refusal thus to act would be an injury, and possibly a cause of war. It might be said that differences of climate, soil, productions, and acquired skill, enable all parts of the world to aid one another, and that this clearly points out a divine destination and intention that they shall so act. But the better opinion is, that, except in exas when one nation cannot do without the productions of another, or must cross its borders to get at the rest of the world, this is only a duty, an exercise of a spirit of good-will, to be judged of by each state according to the light which it possesses. In all intercourse the two parties concerned must settle the terms; how then can one force the other into a treaty of commerce, any more than one man force another into a contract.

treme cases,

But although writers are believed to agree substantially in

this, there is a disposition on the part of nations to act as if they had a right to require others to exchange products with them. This has been seen in the dealings of later years with certain Oriental and other states. But might not one Christian state with greater reason force another to give up its protective tariff?

It thus appears that intercourse, which is a preliminary to all international law, and the condition, without which rights and obligations would be mere abstract conceptions, is itself referable to the class of duties, and that the refusal to allow it is no injury. There is nothing more strange in this than in the voluntariness of all private contracts, as of the marriage union, which must be presupposed before any family rights can exist. All that rights serve for is, when intercourse is given, to make it jural. Thus we see again the voluntary quality of international law.

§ 26.

interna

Vattel divides the law of nations into the natural or necessary, so called because nations are absolutely obliged Vattel's dito observe it; and the positive, proceeding from the visions of volition of nations. This latter, again, is subdi- tional law. vided into voluntary, conventional, and customary law, which are respectively derived from presumed, expressed, and tacit consent. Of voluntary law Vattel says, that it embraces the rules drawn from the principle that nations, being equal and independent, are obliged to suffer each other to do many blamable things, presuming or acting as if they were right. Thus capture in war is valid, whether made by the aggressor or the injured. But there seems to be no reason for setting off this as a distinct branch, and it is by no means clearly defined. Such cases as Vattel contemplates are to be referred to the obligation under which nations lie of not interfering with each other's sovereignty, and thus run back to the necessary law of nations.

Dr. Wheaton, justly discarding this subordinate division of voluntary law, makes natural law one genus, and voluntary,

another, under which latter conventional and customary are included. The division of international law into

Wheaton's. primitive and secondary law, is altogether similar to this, primitive being the law of nature and secondary that of treaty and usage. But these divisions, although avoiding Vattel's error, are of no great value. For, (1.) A requirement of natural law may be confirmed by voluntary, as by a treaty; to which, then, of the two does it belong? (2.) Conventional law hitherto includes no treaties between all the Christian states of the world, and thus is rather to be taken as evidence of what international law is, than as a part of it. Nay, treaties are often made to except the parties from the operation of a real or supposed international rule. (3.) In reality all international law is voluntary, not in the sense that it derives its sole obligation from the will of the parties, but in the sense that all nations in a certain circle agree to abide by it. (4.) And again, all voluntary law is natural, being built on the foundation of the sacredness of agreements.

ions.

§ 27.

Perhaps a division like the following may have something Other divis to commend it, which separates the rights and obligations known to this science into, (1.) those which are deducible from natural jus, which no action of a sovereignty began or can terminate; (2.) those deducible from the idea of a state; (3.) those which are begun and can be ended by compact, express or tacit. Another division still which we have made already (§ 2), follows the division of the three grounds or reasons for international rules, namely, jus, morality, and convenience. The first class comprehends natural rights and obligations, which can be defined and enforced. The second, duties and moral claims which cannot be easily defined, and need compact to establish them; and the third, arrangements of a purely voluntary nature. A A very considerable part of international law is included under the second and third of these heads; a fact which serves to show the highly positive or voluntary nature of much of the science.

Thus exterritoriality, private international law, the rules of respect, some, at least, of the regulations touching ambassadors, the laws of war to a great extent, are of this description. These parts of the science cannot be deduced from a theory, nor could they have arisen prior to a long experience.

§ 28.

Custom and

alike sources

Whether the free assent of nations take the form of express agreement or of usage, it places them alike under the obligation of contract. Customs within free consent each country existed before statutes, and so obsery- of law. ances come in imperceptibly and control the conduct of a circle of nations. A nation which grants privileges to another by tacit consent, and then revokes them without cause, may commit an injury just as if it had broken a treaty. For example, intercourse may become a right by becoming a fact, and to end it without an express cause, would be a proof of a hostile mind.

It is to be remarked, also, that not only obligations of natural justice are recognized in this tacit way, but duties become obligations, and claims or conveniences, allowed, become rights, just as by formal contract. A nation may grant the privilege of transit to the troops of another by treaty; it has now become a right. The same thing may come about by custom or tacit consent. It might seem as if nations could alter their conduct at pleasure, within the spheres of moral claims and convenience. But if they have sanctioned a usage by long permission without protest, they have laid an obligation on themselves, and cannot alter it. It may, however, be difficult to say when such obligations begin, for instance, when transit, silently suffered, becomes a kind of servitude on the soil. There is a difference, also, in usages. Mere forms of intercourse may have little binding force, but principles admitted in common in a silent way, and giving birth to common habits, as well as mutual privileges conceded without treaty, appeal to the moral sense of nations.

§ 29.

International law

adopted by

As soon as a nation has assumed the obligations of international law, they become a portion of the law of the land to govern the decisions of courts, the conduct municipal. of the rulers and that of the people. A nation is bound to protect this part of law by statute and penalty as much as that part which controls the jural relations or in other ways affects the actions of individuals. Otherwise it is a dead letter; there is a want of faith towards foreign powers, and there is danger of quarrel ending in war. All Christian states have, it is believed, in this way sanctioned international law, so far as it seemed to them necessary. It is, says Blackstone, “adopted in its full extent by the laws of England; and whenever any question arises which is properly subject to its jurisdiction, it is held to be a part of the law of the land." "As being a part of the common law of England, the law of nations is adopted by our own law also, for it is well settled, that the common law of England, so far as it may be consistent with the Constitution of this country, and remains unaltered by statute, is an essential part of American jurispru dence." 1 Parts of it, moreover, have received an express sanction from the Constitution and Statutes of the United States.

§ 30.

The helps for ascertaining what international law is, or has been, may be derived principally from the following documents:

Aids for

knowing

what inter

is.

national law 1. The sea laws of various ports or districts, which had a commercial importance in medieval Europe. 2. The treaties in which a large number of important nations have had a part, as the treaty of Westphalia, the Congress of Vienna, and the recent treaty of Paris, in 1856. Other political treaties are evidences of an opinion entertained by the parties in regard to certain provisions of the law of nations; and that, whether they sanction these provisions or 11 Kent, Lect. 1.