civilized states, they have been made rules of English law by the legislature. Thus no English lawyer can neglect international law, and no history of English law would be complete which did not indicate its origins, and its relations to the more purely municipal branches of English law.

International law, as understood at the present day, was unknown in the Middle Ages. The law which prevails among the independent states of modern times could not arise till these independent states had been fully developed. And, as we have seen, these independent states were the result of the new political religious and intellectual conditions of the sixteenth century.2 The division of Europe into a number of independent territorial states in constant and continuous relations with one another; the new religious ideas which finally destroyed the mediæval ideal of a single Christian Empire; the new intellectual ideas which, even in those countries which adhered to the old religion, modified men's outlook on all social, legal and political problems-all helped to create the international law of the present day. Throughout this period the material from which its rules originated was being collected by the practice of soldiers, statesmen, diplomatists, and jurists; and naturally that material was shaped by the technical conceptions of the civil law, because those concepts were known to and accepted by the courts of all the states of Western Europe-they were, as James I. said, "in a manner Lex Gentium." Their practice having thus been cast into a legal mould, it was gradually perceived in many different countries that a wholly new variety of law was arising. It was inevitable therefore that the lawyers of many different countries should attempt to make some systematic statement of the principles of this new law.

The existence of and the relations between the independent states of Europe were the immediate causes of the growth of international law as we know it to-day. But the fact that

1E.g. the Territorial Waters Jurisdiction Act; the Foreign Enlistment Acts; the Extradition Acts.

"So

2 Vol. iv 190-215; as Woolf, Bartolus of Sansferrato, says at pp. 202, 203, long as the de jure unity of Western Europe in one Roman Empire was maintained, the mediæval Italian lawyer, who lived in conditions where Roman law was actually a common law above the conflicting statutes of Italian cities, naturally went to that common law for rules to guide international relations, which were at best de facto. De jure the Emperor was universal superior. . . . When men had given up the de jure unity of Europe under a universal Empire, and moreover when they turned their attention from intercommunal to properly international problems, a wider and a higher basis than the Roman jus commune had to be found for International law."

3 Speech to Parliament 1609, Works (ed. 1616) 532, “I thinke that if it (the civil law) should be taken away it would make an entrance to barbarisme in the Kingdome and would blemish the honour of England; for it is in a manner Lex Gentium and maintaineth intercourse with all foreign nations."

many of the ideas which underlie our modern international law have their roots in the past, sometimes in a very remote past, is clearly stated by Grotius in the opening words of the Prolegomena to his famous treatise. "That law," he says, "which prevails as between different peoples or their rulers, either springs from nature itself, or is established by divine law, or has been introduced by custom or tacit agreement."1 And those were in substance its three sources when Grotius wrote. The Greek law of nature had given inspiration to the rules of the Roman jus gentium; and the Roman jus gentium thus inspired had given force and practical application to the rule of right reason, on which international law ultimately rests.2 The medieval canonists and civilians had given a new sanction to this law of nature by almost identifying it with that law of God to which all human beings and human societies ought to conform.3 In the Middle Ages, and still more in the sixteenth century, the practice of Western Europe was creating rules which depended on "custom and tacit agreement." But the technical form and much of the substance of the rules which came from these sources were determined to a large extent by the writings of the civilians and canonists of the Middle Ages; and in part by ideas derived from the Greek and Roman classics, which had either filtered through these mediæval canonists and civilians, or had come from the works of the classical scholars of the Renaissance. It follows therefore that we must know something of these mediæval ideas and speculations, as well as something of the necessities of the new territorial states, if we would understand the technical form and the substance of the rules of this new body of law which the jurists of the sixteenth and seventeenth centuries were evolving. I shall therefore consider the history of the growth of international law in England under the following heads: The medieval ideas; the necessities of the territorial state; the earliest English writers on international law.

66

1" Jus illud, quod inter populos plures aut populorum rectores intercedit, sive ab ipsa natura profectum, aut divinis constitutum legibus, sive moribus et pacto tacito introductum."

2 Pollock, Camb. Mod. Hist. xii 703-" The law of nature . . . is the Greek appeal to an ideal rule justifying itself by reason, and the law of nations, in this earlier sense, is the practical Roman recognition of a working standard in the general use of civilized mankind. Both elements were necessary; jus naturale without jus gentium would be an unbodied spirit, jus gentium without jus naturale would be a soulless body."

3 Vol. ii App. ii; vol. iv 279-282.

For the anticipations of rules of modern international law to be found in Greek and Roman law see Coleman Phillipson, the International Law and Custom of Ancient Greece and Rome; cp. also Walker, A History of the Law of Nations i 37-73.

The Medieval Ideas1

The dominant political theory of the Middle Ages, which regarded Western Europe as a single society under emperor and pope, prevented the growth of anything like the international law of modern times. But the peculiar intellectual conditions which made for the supremacy of law-divine or natural or human were favourable to the growth of rules upon particular topics, which were extensively used by the founders of international law in the sixteenth and seventeenth centuries. The application of some of these kinds of law to the war-like or peaceful relations of the several communities of which Western Europe consisted, was helped by the fact that, far back in the seventh century, Isidore of Seville, in the fifth book of his Etymologiæ, had adapted from Ulpian's institutes' certain definitions of jus naturale, jus gentium, and jus militare.® His definition of jus gentium, corresponds, as Nys has said, in some sort to our modern international law; while his definition of jus militare gives us some of the most important headings of a work upon the laws of war. These definitions, having been inserted by Gratian in the Decretum," became the starting point of a large body of doctrine. But this doctrine did not cover the whole ground marked out in these definitions. It was only the topics which interested the medieval speculator that were thus developed.

Of these topics by far the most important were the laws of war. As Professor Holland has said, "Just as the forms of litigious procedure are a more prominent topic in early legal literature than the substantive law itself, so were the rules which are applicable to the conflicts of States discussed before those which should govern their peaceful intercourse." 8 This pheno

'The best and most exhaustive account of these ideas is contained in Nys's Origines du Droit International; it is on his work that I have mainly relied; cf. also Walker, op. cit. 79-137.

2 Vol. ii 121-122, 127-128.

3 Ibid 131-132.

* Bishop of Seville 601, died 633; his Etymologiæ is "a complete encyclopedia of mediæval science in twenty books," Walker, op. cit. 205 n. 1; cf. vol. ii 135. 5 Nys, op. cit. 9.

6 The law of nature is: "Jus commune omnium nationum, et quod ubique instinctu naturæ non constitutione aliqua habeatur." "Jus gentium est sedium occupatio, ædificatio, munitio, bella, captivitates, servitutes, postliminia, fœdera, paces, induciæ, legatorum non violandorum religio, connubia inter alienigenas prohibita."

"Jus militare est belli inferendi solemnitas, fœderis faciendi nexus, signo dato egressio in hostem, vel pugnæ commissio. Item signo dato receptio; item flagitii militaris disciplina, si locus deseratur; item stipendiorum modus, dignitatum gradus ; præmiorum honor, veluti cum corona vel torques donantur. Item prædæ decisio et pro personarum qualitatibus et laboribus justa divisio; item principis portio "-cited Nys, op. cit. 9 nn. 1-3.

7 Ibid 9, 10.

8 Holland, Studies in International Law 40.

menon is due to two causes. In the first place, the turbulence of the Middle Ages made all questions relating to war matters of first-rate importance. In the second place, the desire to bring all the phenomena of the universe under some kind of law made the phenomenon of war very interesting both to canonists and civilians. Was war in any circumstances justifiable? If so, under what circumstances? What were just causes of war? What were the conditions under which it ought to be waged? What difference did it make if the enemy was an infidel? Under what conditions was private war justifiable? All these questions and many others were exhaustively discussed from that mixed legal and moral point of view which is characteristic of the speculations of both canonists and civilians. Other topics were comparatively of small importance. Indeed, at this period, and even in the sixteenth and seventeenth centuries, some of them were often only discussed in relation to war.1 We get, for instance, some discussion of methods of settling disputes other than by war, and of treaties of peace and commercial treaties, and a few hints as to the position of foreign rulers and ambassadors.2 When these topics were not discussed in relation to war, they were treated as quite separate branches of knowledge. They were not regarded as topics which belonged to one and the same department of knowledge. The only bond of union was the idea connecting all branches of knowledge in the Middle Ages-the idea that the matters with which they dealt should be regulated by some sort of law.

I shall therefore consider briefly the medieval treatment of (i) various topics connected with war, and (ii) other topics which in modern times have become important branches of international law.

(i) Topics connected with war.

3

The legality of war was a subject of discussion all through the Middle Ages. The early fathers of the church had pronounced against war. But Augustine had admitted that it might be just; his opinion was followed by Gratian; and it prevailed, even though the war was waged between Christians. 5 Wycliffe, on the other hand, maintained the illegality of war between Christians in the broadest terms." In the sixteenth

1 Below 57.

2 Below 36-39.

Nys, op. cit. 44, 45; Walker, op. cit. 204; Holland, Studies in International Law 42.

4 Walker, op. cit. 205; Nys, op. cit. 45, 46.

Ibid 98; Holland, op. cit. 43-44.

"Quod homicidium per bellum vel prætensam legem justicia pro temporali causa, sive spirituali revelatione est expresse contraria Novo Testamento quod quidem est lex gratiæ et plena misericordiæ,” Fasc. Ziz. (R.S.) 366, cited Nys, op. cit. 48.

century his views found an echo in the writings of such men as Colet, Erasmus, and More;1 and they were deemed worthy of refutation by Suarez. But they were opposed to the weight of mediæval authority, and still more to the weight both of mediæval and modern practice.3 They still remain an ideal which from century to century has attracted the finer spirits of successive ages.

It was impossible, therefore, to maintain that all war was unjust. But it was equally impossible to maintain that all wars were just; nor was it possible to say that any atrocity might be permitted even in a just war. This obviously gives rise to two classes of questions-When will a war be considered just? and, to what laws ought the combatants in a just war to conform ? To the solution of these questions the mixed moral and legal criteria of medieval thinkers were applied. This gave rise to a large literature which influenced profoundly the earliest writers on modern international law, and, through them, the law of our own times.

When will a war be considered to be just?

The starting-point of the discussion was found in some words which Isidore of Seville borrowed from Cicero as to the just war, the unjust war, the civil war, and the more than civil war. Gratian used these words in the parts of the Decretum in which he dealt with war, and enlarged upon them.5 From him they I passed into those numerous Summa which medieval canonists composed for the use of those who heard confessions. Just as these Summa are one of the roots from which sprang the idea of equitable rules superior to the rules of merely human law, so they are one of the chief sources of the rules as to when war may be justly waged. The Summa of the great Hostiensis distinguished seven species of war, four of which were just and three unjust.8 Aquinas said that the just war must comply with three requisites. It must have the authority of a prince in obedience to whose orders one is bound to wage war. It must

1 Nys, op. cit. 48, 388-399.

2 Ibid 138.

3 Even among those who admitted that war might be just, "Deux courants se produisent; tandis qu'une partie des auteurs est sinon trés favorable à la guerie, du moins portée a l'excuser, une autre partie s'en montre l'adversaire irréconciliable"; the former party prevailed in the sixteenth century, ibid 100, 101.

4 For this literature see ibid c. 6.

5 Ibid 99, 100; cf. Walker, op. cit. 206-207.
Nys, op. cit. 101, 102.

7 Vol. iv 276 n. 5, 280 n. 5.

8 Bellum Romanum, between believers and infidels-just; bellum judiciale, between believers under the authority of a judge-just; bellum præsumptuosum, waged by rebels in contempt of authority-unjust; bellum licitum, authorized by a prince-just; bellum temerarium, waged by believers against legal authority-unjust; bellum voluntarium, waged by believers on their own authority-unjust; bellum necessarium, waged by believers in self-defence-just: see Nys, op. cit. 102; Walker, op. cit. 211.