Markus A. Mascelli
and the just war theory
in “De jure belli ac pacis”
History of International Law
Prof. Dr. Laurens Winkel
Erasmus University Rotterdam - Faculty of Law
2nd Term - 1999
to Erika for entertaining me
“By undertaking many things,
I have accomplished nothing.”*
How was the European world at the beginning of the seventeenth century equipped with international law. The ancient orient already had its rules about ambassadors, treaties, federations, warfare, neutrality; Greek and Rome and the middle ages had known and developed their international rules and institutions; even Peruvians, Mexicans, Northern Indians and Indonesians had their form of international law. Why, then, should Grotius be considered as the father of international law?
The answer seems obvious. The international law of these peoples was not an international law calculated to organize peace or to reform the world. It was just an extension of municipal law. Its main characteristic was aversion to foreigners (the goyim of the Hebrews, the barbaroi of the Greek, the hostes of the Romans). Their international law just enlarged a little the circle of law relations with some near neighbours. At its basis was not a desire to provide for disinterested co-operation with all other peoples, not a desire to submit both these and themselves to established rules of conduct.
Thus, being Grotius’ purpose to move the hearts of peoples and their rulers, he did not write a dry textbook for law students, but aimed his work to be useful to practical men of affairs. He refrained from discussion of political matters and from allusion to current controversies of his day. His examples and illustrations were taken from ancient history (classical antiquity and Biblical writers), useful, according to Grotius, to prove also the existence of the law of nature. He felt convinced that antiquity and scripture practically showed all future possibilities of human thought and human fate. Poets and orators are quoted mainly for the purpose of adornment and elegance.
- Hugo Grotius*
“Time flies like an arrow.
Fruit flies like a banana.”
- Groucho Marx**
the life and works
Hugo Grotius was born in Delft on Easter day, April 10, 1583, as Huig de Groot. His father Jan de Groot had been serving for four years as burgemeester of the city of Delft, and as curator of the University of Leiden from 1594 to 1617. He died in 1640. Hugo’s uncle, Cornelius de Groot, was professor of law at the University of Leiden.
Hugo, who had composed verses in Latin and Greek at the early age of eight, began his studies at the, then recently founded, University of Leiden on August 3, 1594, at the age of eleven, choosing for classical and oriental languages. He was invited to accompany the Dutch diplomatic mission to France in 1597. During this one year of stay in France, he obtained, on May 5, 1598, at the age of fifteen, the degree of doctor of laws from the University of Orleans. His first scholarly publication was an edition of Martianus Capella in 1599; other writings in later years included poems, dramas, histories, and many works on theology and Biblical studies, but his father wanted him to become a lawyer. On December 13, 1599, he was admitted to practice before the Hof van Holland en Zeeland, and two days later before the Hooge Raad van Holland en Zeeland.
In 1601 the government of Holland commissioned Grotius to write a history of the Dutch war of liberation; the “Annales et historiae” covered the period from 1555 to 1609, and in 1610 he published another, shorter history of his country, “De antiquitate reipublicae Batavae”. Only a conflict in the maritime trade interests between Holland and Portugal prompted Grotius, while practicing law at The Hague, to write his first legal treatise, on the law of prize “De jure praedae”, commissioned by the Dutch East India Company in 1601 as an expertise on a famous case of vessel capture on high sea undertaken by the Dutch authorities against a Portuguese merchant in 1593 in the strait of Malakka, and published only in the 19th century. Grotius himself published only its chapter XII in 1609 under the title “Mare Liberum”, and it gained remarkable attention during the controversy with England over the freedom of the sea, stimulating the Englishman John Selden to his reply “Mare Clausum”, written in 1618, and published in 1635. Another of Grotius’ works of this period, which remained unpublished until the 19th century, was the “Parallelon Rerumpublicarum” or “De Moribus ingenioque populorum Atheniensium, Romanorum, Batavorum”, a comparison of national customs and characteristics of Greek, Roman, and Dutch peoples, written in 1601 or 1602, which can be considered as Grotius’ earliest work on the subject of international law, since it emphasized the importance of good faith in dealings among nations. Only a fragment survived. He also prepared a larger treatise on the relations between the Church and the State, “De imperio summarum potestatum circa sacra”, which for political reasons was only published posthumously in 1647.
On November 12, 1607, Grotius was appointed Advocaat-Fiscaal for the court of Holland, Zeeland and West-Friesland, a kind of prosecutor in criminal cases with oversight of the state’s property interest.
On July 17, 1608, Grotius married Maria van Reigersberg, daughter of a burgemeester of the city of Vere, in the province of Zeeland, and on March 4, 1613, he accepted appointment as pensionary of the city of Rotterdam (an office formerly held by Johan van Oldenbarnevelt’s brother Elias) which carried with it a seat in the States-General of Holland and later in the States-General of the United Netherlands. In 1617 he became a member of the Committee of Councillors (College van Gecommitteerde Raden) which, with the Landsadvocaat, Johan van Oldenbarnevelt, conducted the day-to-day administration of the public business of the province of Holland. In that time the regulation of matters pertaining to religion was one of a state's most important functions.
In the political struggle between Calvinists and Arminians, which had started as a theological dispute over predestination and similar issues, Grotius, who first tried not to take sides, was considered to be aligned with the Arminians. He had been a pupil of Jacobus Arminius at Leiden, for whom he wrote a necrology in 1609, and as Advocaat-Fiscaal, he covered the second highest office in Holland under the Arminian party. The Arminians advocated religious toleration, a decentralization of national power in favor of provincial sovereignty, and efforts for promoting peace with the Spanish, whereas the Calvinists (under the leadership of Franz Gomarus, therefore also called Gomarists) wanted the “pure” Calvinist church as a state church, favored a greater degree of centralized power for the united republic, and advocated a resumption of hostilities against Spain under the leadership of the House of Oranje. Although Holland was one of the largest and most powerful of the seven provinces, Holland and Utrecht were the only two provinces controlled by the Arminians. The remaining five provinces of the United Netherlands were controlled by the Calvinists, supported by Prince Maurits of Oranje, who saw this political diversity as a chance to obtain control over the central government and to get rid of his political opponent van Oldenbarnevelt, aligned with the Arminians. Grotius’ attempt to draw up a conciliatory statement for both groups in order to restore peace (“Ordinum Hollandiae et Westfrisiae Pietas”, 1613), was looked upon by Prince Maurits and the Calvinists as too much inclined to the Arminian views, and more an apologia for van Oldenbarnevelt.
On August 29, 1618, Grotius was imprisoned while on his way to attend a meeting of the Committee of Councillors of Holland in The Hague; Rombout Hoogerbeets, pensionary of Leiden, and Johan van Oldenbarnevelt were also imprisoned. Prince Maurits tried to consolidate the gains of his military actions against the Arminian provinces by convoking a national synod in Dordrecht for November 1618, where all the Arminians were quickly branded as outlaws and guilty of corrupting religion. Disregarding the usual juridical organization, the States-General, on November 19, 1618, set up a special tribunal of twenty-four judges which, on May 13, 1619, condemned van Oldenbarnevelt to death, and sentenced, five days later, Grotius and Hoogerbeets to life imprisonment in the Castle of Loevestein (near Gorcum) with confiscation of all their property.
His confinement was, at first, stringent, but then his wife was given permission for cohabitation. She was provided with two rooms in the prison for herself and her children. Grotius himself was allowed to have books brought in in a large wooden book-chest and had enough time and leisure for intensive reading and writing. He remained in prison from June 6, 1619 till his famous escape, planned by his wife, on March 22, 1621, in his book-chest. He made his way in disguise to Antwerp, and later proceeded to Paris, where he was cordially received by the French King Louis XIII.
During his imprisonment at Loevestein, Grotius was a productive writer. He composed his well-known treatise “On the Jurisprudence of Holland” (published only in 1631), and “De veritate religionis christianae”, “On the Truth of the Christian Religion”, (published in 1627). Soon after his arrival in Paris, Grotius began to work on his “Apologeticus”, suggested by Pierre Jeannin, one of the French king’s ministers, and intended as a defense of his own good name and his conduct as an official at the service of the government of Holland which may be regarded as a major legal treatise on Dutch public law. The “Apologeticus” was secretly printed in 1622 in Amsterdam, and the States-General ordered the copies to be seized and banned from further printing and circulation. Another major event of his Paris years was the publication in 1625 of his famous treatise “De jure belli ac pacis”, “On the Law of War and Peace”, dedicated to Louis XIII.
Grotius remained in exile in Paris until 1631, then - due to financial problems - returned to the Netherlands where, for three month, he practiced as a consulting lawyer in Amsterdam, but - since a substantial reward was put on his head - was obliged to flee again, this time to Hamburg, on April 17, 1632. In 1634 Grotius was appointed ambassador of Sweden at the Court of France. He held this position until the middle of March 1645, but his diplomatic service was not outstanding, since shortly after his accreditation to the French court, pressure was exerted on the Swedish government to recall him. Grotius himself, finding his views incompatible with those of the leading politicians in Paris, asked for termination of his service in France, which was granted in a letter from Queen Christina, dated December 30, 1644. Grotius wished to continue his career as a diplomat, and he particularly wished to take part in the peace conference at Osnabrück. But, apparently, the Swedish government had no plans for his further service abroad, and Grotius left Sweden for an unknown destination. He might have decided to rejoin his wife in Holland or to return to Lübeck or Wismar where he had been received with the highest honours only weeks before. He sailed for Lübeck on August 13, 1645, but was obliged to land eight days later on the eastern coast of Pomerania because of a severe storm on the North Sea. He continued his journey by land and managed to reach Rostock, in Mecklenburg, but was unable to proceed farther, and died of exhaustion round about midnight of August 28, 1645 in the house of the widow Catherine Ballmann, where he had been brought by two of his six servants who had accompanied him. The vital organs were removed from his body, sealed in a copper container, and buried in the cathedral in Rostock. His mortal remains were sent to Delft, and repose there in the Nieuwe Kerk, close to those of the princes of Oranje, amongst them William the Silent and Maurits, who was responsible for Grotius fate as life-long fugitive obliged to spend the greatest part of his life outside of his beloved country, the Netherlands.
“Meanwhile, the poor Babel fish,
by effectively removing all barriers
to communication between races and cultures,
has caused more and bloodier wars
than anything else in the history of creation.”
- Douglas Adams *
The authors and thoughts by whom Grotius’ considerations on war, justification of war and warfare-related matters were mainly influenced (apart from Roman law as laid down in the Justinian Codex and Digest) - is it in accordance with or in contradiction to them - deserve a closer look.
Among those authors Francisco de Vitoria (1483-1546) has to be seen as the most influential. Although Vitoria was a Spaniard, and a Catholic, too, and Grotius a Protestant whose country was engaged in a bloody war with Spain, Vitoria’s work and thoughts were of high value for Grotius. He expressly cites Vitoria 126 times in “De jure praedae” and the “De jure belli ac pacis”. Especially Vitoria’s “Relectiones Theologicae XII”, first published posthumously in Lyon in 1557, and containing twelve lectures held by Vitoria at the University of Salamanca, were a valuable source for Grotius. Two of these Relectiones, namely the “Relectio de Indis recenter inventis” (“Relection on the Indies Recently Discovered”), sometimes referred to as the First Relection on the Indies, and the “De jure belli” (“On the Law of War”), also known as the Second Relection on the Indies, both extensively quoted by Grotius in “De jure praedae” as well as in “De jure belli ac pacis”, launch a bitter attack on certain aspects of the colonial policies pursued by the Spanish Crown in the New World. Moreover, Vitoria denies that either the Holy Roman Emperor or the Bishop of Rome qualify as “lords of the whole world”, and describes a theory of the just war which, in its nature, is broadly close to the one of Thomas Aquinas. As to the question whether a war could be seen as a just war on both sides Vitoria’s view was more “modern” than the one of his younger fellow.
A second author who deserves to be mentioned in this context is Jean Bodin (1529-1596), the well-known French jurisconsult and historian. Grotius did not hold Bodin in very high esteem, but, instead, he openly rebukes Bodin for having “mixed up politics with the body of law with which we are concerned.” Grotius, nevertheless, concedes in “De jure belli ac pacis” that Bodin’s “Six Livres de la République” (“Six Books on the Commonwealth”) were of some use to him, especially in “frequently supply[ing]” him “with material in searching out the truth.” The “Six Livres de la République”, Bodin’s most celebrated work, was written in the context of the civil wars that raged in France during the late 16th century. For his work which was originally published in French in 1576, Bodin personally prepared an enhanced Latin translation which first appeared in 1586. Translations in other main European languages followed within only a few years, including one into Italian (1588), German (1592), English (1606), and Spanish (1610). Within the framework of modern Western political thought the “Six Livres de la République” have traditionally been regarded as an epoch-making publication, for it is in this work that the key term souveraineté (sovereignty) was coined and defined. Although critics, former and present, have consistently argued that the Bodinian concept of sovereignty was most certainly not radically novel in essence, it is probably just to say that it provided a unique synthesis of politico-legal conceptions from Roman law and the medieval lawyers.
A third influential author to be mentioned is Thomas Aquinas († 1274). Grotius regarded his “Secunda secundae” as educational and something every learned man should have read in his lifetime. We also know that Grotius possessed a copy of Aquinas’ “Summa theologiae” before 1618. His edition, like so many printed in the 16th and 17th century, is very likely to have contained the influential commentary of Cardinal Thomas de Vio Cajetan († 1534). Another well-known commentary to the “Summa theologiae” is Domingo Báñez’s (1528-1604) “De fide spe et charitate” of 1584. Grotius’ references to the “Summa theologiae” of Thomas Aquinas and the corresponding commentary by Cardinal Cajetan relate to question 40 article 1 of the “Secunda secundae”. This was one of the most comprehensive and historically influential expositions of the theory of the just war. It provided the foundation not only for Cardinal Cajetan and the late Spanish scholastics such as Vitoria, Domingo de Soto (1495-1560), whose “De Justitia et Jure Libri X”, found among the books in Grotius’ library of 1618, has as well been abundantly quoted by Grotius, but also for many theorists of the just war in Protestant Europe. In the said article 1, the question whether waging “war is always sinful” stands at the center of analysis. By making use of a number of important testimonies from ancient Christian sources, notably the writings of St. Augustine, Thomas Aquinas concludes that a war may be just if it meets three basic criteria. Firstly, the war must be declared by the authority of the prince (auctoritas principis). Secondly, the war must be waged for a just cause (causa justa). And finally, the party declaring the war must hold upright intentions (intentio recta), i.e., it must seek to advance the peace and the common good, avoiding evil as far as possible.
Grotius’ interest in the exposition of Aquinas focuses on the first condition the meaning of the auctoritas principis (authority of the prince) beyond the person of the monarch or the prince, and attributes this competence, instead, to what is known as the “perfect republic” (respublica perfecta, respublica sibi sufficiens). Moreover, as Grotius argues, the notion of the “perfect republic” implies that the power of “supreme judgment” (ius iudicandi), and consequently the express right to avenge all those who seek to undermine the polity, are vested in the political community as a whole. Whereas few would have disputed the right of a “perfect republic” to convict and punish those who seek to harm the polity, and, in extreme cases, legitimately declare war upon them, there was little consensus on precisely who, or what body, was entitled to represent the “perfect republic” in this regard.
Whereas “De jure praedae” hails Ferdinando Vázquez de Menchaca († 1559) as “the pride of Spain” and “a leading authority on war”, the Prolegomena to “De jure belli ac pacis” praise him as “one of the most learned Spaniards”. Vázquez’s understanding of sovereignty and the right to declare war against is build on Aquinas’ and his follower’s view, that the right to declare war belongs only to the prince who does not recognize a superior (princeps non agnoscens superiorem). But he, substantially, modifies it based on two considerations: Firstly, although we can be left with no doubt that a prince who acknowledges no overlord must be deemed a true sovereign, the reverse must not necessarily hold true. Vázquez reminds that there may be instances where a prince recognizes someone (including his own people) as his overlord, yet at the same time he can also be considered a sovereign lord in his own right. Secondly, the right to declare war is not vested personally in the prince (whether he be sovereign or not), but in the state as such. Underlying this position are several important assumptions. One of these stems from the Lex regia (Royal Law) through which the people are thought to have transferred their individual rights to the sovereign in a historic act. The objective of this social contract is to preserve and promote the welfare of the whole of the people. For Vázquez, however, such a transfer of individual rights does not amount to their permanent alienation, but to the creation of a trust or mandate which can be revoked or cancelled if its basic conditions are infringed or left unfulfilled. For this reason, the Spaniard openly concedes that unjust orders of a prince need not to be obeyed. He also implies that a free people who have lost their liberty through usurpation of power have the right to regain their former state, if need be, by the force of arms. Moreover, the joint decision by the people’s representatives and the estates is a force which is morally binding on all good citizens and stands above any command of a prince. Vázquez expressly holds that the representatives of the people have the unconditional right to take any such action which counters evil and promotes peace within the polity, especially if it is in defence of a lost right or liberty. The Spaniard holds this to be a “case of necessity”, meaning that defensive reactions are acceptable, even though under normal circumstances, they would not be permissible. In addition, he argues that actions taken in defence oft lost rights and for the welfare of the state, can never be a rebellion, especially if they have been taken by the greater part of the people and their representatives.
Together with Francisco de Vitoria and Ferdinando Vázquez de Menchaca, Diego de Covarrubias y Leyva is one of the most frequently cited authors of Iberian origin in “De jure praedae” and “De jure belli ac pacis”. He is the author of several important juridical, economic and theological commentaries, the most significant of which is the “Relectio in Regulam Peccatum” Regarding the law of prize and booty, Covarrubias argues that both movable and immovable property may be seized in the course of a just war and need not to be returned when hostilities formally end.
Another author worth mentioning is Balthasar Ayala (1548-1584), a jurisconsult of Iberian origin who served as auditor of the Spanish troops in the Low Countries. He is the author of the “Tractatus de jure et officiis de bellicis et disciplina” (1582) in which he addresses the issues of the just war and the seizure of prize and booty. Only few of the references in “De jure praedae” and “De jure belli ac pacis” place Ayala’s work in a positive light. Grotius’ perhaps the most outspoken criticism is brought forward in the Prolegomena to “De jure belli ac pacis”. The Spaniards objective in his argumentation is to deprive the Dutch of any legitimate case for their armed insurrection against Philip II and the Spanish-Habsburg government in Brussels. It can hardly surprise that this is, in essence, diametrically opposed to the position of Grotius. Ayala, into the bargain, shares also the position advocated by the Bodinian school of political thought that sovereign monarchs - even cruel and tyrannical ones - must be obeyed at all times, and that there can never be a just cause to resist a truly sovereign monarch through the force of arms.
Who also has to be mentioned as one of Grotius’ intellectual predecessors is Alberico Gentili (1552-1608), the Italian-born jurisconsult who, in 1598, published “De Iure Belli Libri Tres”, an important work relating the law of war an the law of nations. Grotius himself openly admits in “De jure belli ac pacis” that he benefited “from Gentili’s painstaking”, and whereas he cites only from this work of Gentili in “De jure praedae”, “De jure belli ac pacis” features also citations from other works of Gentili such as “De legationibus libris tres” (1594), on the rights of diplomatic representatives, and “Hispanicae advocationis libri duo”, first published posthumously in 1613. In these books Gentili launches, for example, into a extensive discussion on waging war for the sake of preserving religious uniformity, an argument that is deliberately omitted by Grotius even though, historically, the topic of religion and religious orthodoxy played a considerable role in the Dutch Revolt. Moreover, Gentili dedicates a chapter specially to examine those cases when war is conducted by sovereigns. In contrast, Grotius empasizes that it is not just the sovereign who possesses the right to wage war on behalf of the state.
“There will never be a nuclear war;
there’s too much real estate involved.”
- Frank Zappa*
the just war theory
In the Prolegomena prefacing “De jure belli ac pacis”, Grotius explained the nature and the purpose of his book. He observed that the civil law (both Roman and that of each nation) has often been the subject of textbooks and commentaries, but that few writers have touched upon, and none has treated in a comprehensive and orderly manner, “that law which governs among several peoples or the rulers of peoples.” The international law, Grotius has in mind by saying that, however, goes beyond mere interstate relations, and is in reality to be seen as a universal law binding all mankind. But already in Grotius’ time there were people who denied the existence of international law, and considered war as something far removed from any law at all.
Controverting this common opinion, Grotius declared that war itself is an instrument of law. Far from admitting that in war all legal rights cease, Grotius asserted that war is not to be undertaken except for the enforcement of law, nor is it to be waged, when undertaken, except within the limitations prescribed by law and good faith. In warfare there were in force between enemies those unwritten laws “which nature dictates or the consensus of nations has established.” For the law of nature Grotius found a basis in human nature. This foundation would remain firm even if it should wickedly be supposed that God does not exist or takes no concern in human affairs. The law of nations, Grotius stated, was established for the utility of mankind as a whole by the consent of all (or most) nations. He traced evidence of such consent from history. Grotius considered it very important to distinguish clearly between the law of nature and the law of nations.
Grotius was, indeed, conscious of the fact that wars were fought and concluded from the perspective of superior political and military power rather than from the perspective of right and reason. His moral and legal sensitivities were disturbed, principally, at the prevalence of what he considered to be unjust wars. The justice or injustice of war, he believed, had to be determined in reference to the precepts of the law of nature.
To appreciate the role which he assigned to war in his thinking, one must understand his conception of violence. Basically, Grotius felt that a resort to violence was a trait of non-rational creatures. Since man was by nature a rational being, the brutal, insensitive behaviour of the primitive tribes and of pagan peoples was, to his mind, not natural. He saw violent practices as the inevitable result of evil which negated the sociability of men. By the law of nature men were meant to be social, he said, and thus, “it is an impious crime that one should be injured by another”. Violence in the last analysis, was destructive of human society and the great society of states. It was highly desirable, therefore, that “good faith” (just conduct) be manifested in the behaviour of nations and individuals and that peace be maintained when possible.
If violence were contrary to human nature, how then could Grotius, in the face of such conviction, validate war as a necessary part of his scheme of law? He did it by postulating war as a tool for fulfilling the natural purposes of men. War need not to be considered in the negative sense as being disruptive of order, but rather in the positive sense of promoting it. For Grotius, war was an external fact which had no inherent moral connotations. Right reason did not pronounce against it but only against force which was in conflict with the needs of society. Morality in regard to war, therefore, arose only in connection with the way in which men utilized it. Force was allowable to maintain legitimate rights.
Grotius was following here in the tradition of some classic and Christian predecessors who had reasoned that war could be either proper or improper. He made reference to Sallust, Roman historian of the first century B.C., who asserted that war should be utilized for the maintenance of social order, and Aristotle, who denounced aggressive wars predicated on self-interest, but who approved war waged in the interest of social preservation. Undoubtedly Grotius was familiar with Cicero, who had speculated upon justice or injustice of war, and he revealed his knowledge of St. Augustine’s just war theory as set forth in “The City of God”.
Though force, or just war, could be used as a means for serving justice, it was imperative, however, that a just war be waged within just limits. It had to be moral in accordance with the law of nature.
Grotius aim in writing “De jure belli ac pacis” was twofold. The first was to form a cogent theory of just war, jus ad bellum, to explain those circumstances which justify modern states to have recourse to belligerency. The second aim was to proclaim rules on the proper conduct of hostilities, jus in bello, irrespective of whether the war was just or unjust. Grotius resuscitated this critical distinction from Thomas Aquinas, St. Augustine, Cicero, and earlier writers on just war theory.
But Grotius did not intend to write a textbook on international law in the modern sense understood as relations of states inter se. His theme was rather the law common to all mankind, the law of the universal human society (communis societas generis humani) which prevails on earth. He recognized that just as no national state can exist without law, also the broader international society cannot exist without law. Thus, the two principal topics treated by Grotius in his treatise are the legal obligations of human societies (including those who have sovereign power), and the procedure for enforcing such duties and punishing violations of law. War was regarded by Grotius as a type of law-enforcement procedure akin to judicial remedies. That states were subject to legal duties and to punishment for violations of law were vital features of the Grotian system. In keeping with this principle, those who were nonparticipants in a war were forbidden to hinder the party having a just cause or to aid the culprit. Civil law within a single state was excluded by Grotius from the scope of his treatise, since civil rights are enforceable by judicial procedure, not by war.
Defining two of the three terms appearing in the title of his book, Grotius states that by “war” he means “the status of those contending by force, as such.” Law (jus) is analyzed as meaning “what is just”, namely, what is not contrary to the nature of a society of rational creatures. Law also signifies a rule (lex) of moral action obliging to what is right (as distinguished from what is merely honourable or expedient). Following Aristotle, Grotius divided law into two classifications: natural law (jus naturale) and volitional law (jus voluntarium). Natural law is defined as the “dictate of right reason, indicating with respect to any act, from its conformity or non-conformity with rational nature itself, that moral turpitude or moral necessity inheres in it, and hence that such act has been prohibited or commanded by God the author of nature.”
Volitional law is divided into divine volitional law (jus divinum voluntarium) and human volitional law (jus voluntarium humanum). Divine volitional law holds that acts commanded or prohibited by it are so not because they are just or unjust, but they become just or unjust only because of God has willed so. Human volitional law contains three subclassifications: a) civil law, which is defined as that which emanates from the supreme power in the state, which is seen as a “perfect union of free men, associated for the sake of enjoying law and common utility” narrower species including paternal precepts and the like (praecepta patria, dominica, et si qua sunt similia) and c) the law of nations (jus gentium), which has received obligatory force from the will of all (or many) nations.
By this threefold criterion (natural law, the law of nations, and volitional divine law), and convinced “that there is a common law among nations, which is valid alike for war and in war”, Grotius proceedes to treat the topics of war and peace which constitute the subject matter of his treatise.
a) jus ad bellum
Grotius states that war is permitted by natural law, the law of nations and volitional divine law as contained both in the Old and New Testament. War is next distinguished into public, private and mixed, and the legitimacy of each of these species of war is demonstrated. Since public war may be waged only by authority of the holder of the sovereign power, Grotius then discusses sovereignty. Neither private nor public persons may lawfully wage a war against their superiors, according to Grotius; although unquestionably orders given in violation of natural or divine law must not be obeyed.
In Book II Grotius turns to the problem of what constitutes just cause for war and finds that nothing but an injury furnishes such cause. Hence there may be as many just causes of war as there are types of injury. Each substantive (legal) right, if violated, may give rise to a just cause of war when law enforcement by armed coercion is the only procedural remedy available to the injured party. This remedy takes three forms: defense, recovery of property, and punishment. Humanitarian intervention is fully justified, according to Grotius, under the law of nature, and, beyond that, redress could also be extracted for injuries that were in violation of the law of nations. Since there were no institutions above the state association which could adjudicate controversies and enforce decisions among nations, and the final means for obtaining or defending rights consisted of a resort to war, Grotius gives, in advocating war as a sanction to right wrongs, his universal human society a legal character.
The scheme which Grotius adopts for his discussion of the catalogue of substantive rights was taken from the Roman civil law. His treatment of persons, things, obligations, contracts, delicts, crimes, and the like, in chapters 2-17 of Book II, is reminiscent of the topics familiar since Justinian’s “Corpus Juris Civilis”. This Romanistic material is supplemented in chapters 18 and 19 by material drawn from the law of nations (jus illud gentium quod voluntarium dicimus) regarding the right of embassy and of sepulture. Following this treatment of the law of peace apart from penalties, comes chapter 20, dealing with punishment, which is the longest in the book. The topic of punitive warfare overshadows other topics of justifiable warfare such as to recover property and debts or to obtain reparation for losses and damages. It also hinders an exhaustive treatment of the importance of arbitration, and the problem of, which men and which nations are entitled to wage a non-punitive war and on what motives. All of Grotius’ real interest is centered on state crimes and on their punishment. Grotius says, it is not necessary at all that the one who punishes has jurisdiction over the one who is punished. Whosoever commits a crime, either a criminal individual or a criminal nation, “by that very act might be considered to have made himself inferior to some one else”, either individual or nation. Inferior, however, not only to the man who has been injured or the nation who has been assaulted, but to any other man or nation, who, by this act, have become his/its superior, representing, in a sense, the society of mankind. Though punitive wars, practically, will mostly be waged by those states or individuals who have been attacked either in themselves or in their associates “punishment ... is by nature permitted to any one”, exception being made only for two cases: a) a citizen or subject is never allowed to punish his own superior, because punishment presupposes non-inferiority; b) one can never be punished by a fellow-man or fellow-nation who/which is himself/itself guilty of a similar crime. The punishment itself should, as expounded in Book III, be pursued with the greatest possible strength and vigor. Grotius says, that he who punishes his children acts as a well-meaning superior (ruler) because he acts as a father, and the righteous judge or the righteous state who/which punishes a criminal offense or a criminal aggressive war or other state crime has to assume the same character of a well-meaning father. Although, according to his theorem, any individual would be entitled to punish criminal men or corporate bodies on his own responsibility, yet he urges “that it is most suitable that punishment be inflicted by one who is a superior”. Grotius, carefully, avoids any illusion to current history, but insists upon governments of his day being morally and legally obliged to take in account not only the rights and interests of their own nation, but the rights and interests of mankind. He points out how much more advisable it is to have a criminal nation punished by a nation that has no personal interest in the matter, than by a nation which, because of its personal interest or its wounds and bitter feelings, is apt to exceed the limits of justice. He also points out how much more honourable it is for nations, especially for Christian nations, to share in this form of promoting justice, than to stand alone, though he is much too prudent and reasonable to make it, for his time, a duty. Grotius insists, that the very weakness of men and nations must impel them to seek interdependence, and he summarizes his convictions by quoting, at the end of Book I, a piece of Greek poetry by Meandros (300 B.C.) reading that “crime and injustice on earth would soon disapear or become extremely rare, if only men, viewing their neighbour’s welfare as their own, joined all their strength, consistently to exact full punishment from evil-doers”.
For the sake of clearness, Grotius adds chapter 22 enumerating unjust causes of war. These include “preventive” war when the strength of a rival nation is increasing, desire for autonomy or subjugation of others, and various religious motives. Chapter 23 treats doubtful causes of war and advises that when opinions are balanced, preference should be given to peace and alternatives explored such as conference and arbitration. Chapter 24 is an admonition against going to war rashly, even for just causes. Chapter 25 treats of protection by war of the interests of others, such as allies, subjects, or friends. Grotius holds that humanity itself is a sufficient warrant for war, or the rescuing of an oppressed people from manifest wrongs by their ruler. The final chapter in Book II deals with the situation of those who are not their own masters but are subject to the authority of another. Grotius declares, it is their duty to abstain from war if they are certain that the cause of war is unjust, and he urges recognition of the rights of conscientious objectors.
One basic concept of the Grotian system is, that in a just war, no matter of what type, only one side can be in the right:
In the particular sense and with reference to the thing itself, a war cannot be just on both sides, just as a legal claim cannot; the reason is that by the very nature of the case a moral quality cannot be given to opposites as to doing and restraining.
Grotius makes allowance for human frailty, however, and thus admits the difficulty of making an objective judgment in some situations. There are, indeed, cases where definite just causes can be established for wars; but, on the other hand, there are more uncertain cases where just causes are not easily determinable because of the fallibility of men. Grotius concedes that cases can arise where neither party have a just cause, and, here too, one has to make allowance for human fallibility:
Yet it may actually happen that neither of the warring parties does wrong. No one acts unjustly without knowing that he is doing an unjust thing, but in this respect many are ignorant. Thus either party may justly, that is in good faith, plead his case. For both in law and in fact many things out of which a right arises ordinarily escape the notice of men.
Hopefully, such instances were rare. The fact that by age-old custom the belligerents in a formal public war have been considered as being equal in the justice of their cause presented a major difficulty for Grotius. Each party has been permitted to use extremes of violence for conducting hostilities but to hold that each has a just cause is not in accordance with nature and is, by definition, impossible. Any effort, therefore, on the part of Grotius to include such customs in his legal system would threaten the entire structure he was trying to build on the foundation of the law of nature. Yet such customs existed and could not be ignored or left outside the boundaries of the law. The question, then, is how could these customs be reconciled with his legal system? To avoid the difficulty, Grotius resortes to his argument on permissibility which pushes his rationalism to the outer limits. Grotius says that the law of nature in regard to war could be supplemented with rules of positive volitional law. Such rules, ideally, should never be in opposition to the law of nature, yet, he admits, that there are provisions of the law of nations which seem to permit actions forbidden by natural law.
He, in no way, states that all conduct is permissible; he makes it quite clear that only those rules which have a the consent of nations are to be recognized. Simply because certain actions are performed frequently and by most nations does not mean that those actions are in accordance with the law. However, because of the possibility of having his permissible laws of nations misconstrued, judgments as to what is permissible and what not are often still difficult to make. In this situation, says Grotius, one should follow Cicero’s advice:
That is a good rule which they lay down who bid you not to do a thing when you are in doubt whether it is right or wrong.
But, Grotius continues:
This course, however, cannot be pursued where one really must do one of two things, and yet is in doubt whether either is right. In that case he will be allowed to choose that which appears to him to be less wrong. For always, when a choice cannot be avoided, the lesser evil assumed the aspect of the good.
Thus, wherever doubt cannot be resolved and where a choice still has to be made, Grotius recommends strongly that a decision be made against war.
In pursuing this theme, Grotius suggests three methods by which disputes can be prevented from breaking into wars: conference, arbitration (applicable amongst those who have no common judicial authority) and lot or single combat.
b) jus in bello
Book III deals with the “law of war” (jus in bello) as understood in modern international law. Grotius here continues to apply his threefold criterion of national law, the law of nations, and divine volitional law in order to determine what is lawful in war.
The primary rule of natural law is that whatever is necessary is lawful. The use of stratagems and deceit is considered, but a firm stand is taken against violation of oaths and promises.
Coming to what the law of nations permits in war, Grotius concludes that the subjects of a ruler who does an injury are liable in their person and property to reprisals. A solemn declaration of war is required by the law of nations, but not by the law of nature. Enemies may be slain anywhere except in neutral territory. Poison is prohibited, however, by the law of nations. Assassination is permissible provided it entails no breach of faith; Grotius favours the rule forbidding rape. Destruction of property, and capture, are permitted. The rule that enemy ships make enemy goods is merely a rebuttable presumption, not a settled rule of the law of nations. Contrary to the common view, Grotius asserts that when property is captured by the soldiers in their official capacity, the booty belongs to the state (if its civil law does not provide differently), and it may transfer it to whom it will. Regarding prisoners of war, slavery was introduced by the law of nations. Among Christians this rule has been changed.
Chapters 10-16 of Book III qualify the belligerent rights previously discussed by setting up admonitions (monita) and mitigations (temperamenta) in accordance with distinction between what is lawful merely because it may be done with impunity and what is lawful in the sense of right or just. This higher standard Grotius calls “internal justice”. He praises the virtues of honour, moderation, and magnanimity. The lives of women, children, the aged, and those whose way of life is remote from warfare (such as priests, scholars, farmers, tradesmen) may be properly spared. Unnecessary destruction of property is also imprudent. Charity with regard to capture and kind treatment of prisoners of war are likewise enjoined. Moderation is also urged with respect to the exercise of the right to subjugate a whole people and extinguish a state. Retention of their government by the conquered people is often a measure indicated by prudence as well as humanity.
Chapter 17 deals with nonparticipants in a war (de his qui in bello medii sunt). Grotius does not use the word “neutrals”. In his view they were not neutral in the conflict but are under a duty to do nothing to hinder the party waging a just war or to aid the culprit. Chapter 18 considers the use of privateers. The remaining seven chapters of Book III discuss the topic of good faith. The book ends with an eloquent admonition to the rulers of nations to cherish good faith and to cultivate peace.
One function of volitional laws, Grotius had says, is to bring clarity to nebulous and confusing conclusions that are drawn from the natural law. Hence, there is no obstacle to improvements that might be introduced into the rules of war by consent of nations. The laws of war are, indeed, volitional laws created by mutual consent. Grotius, no doubt, envisioned his temperamenta as potential improvements in this regard. By adopting the moderations which he recommends, the nations would be able to achieve a higher level of civilization and refinement in their relations.
“... not to know certain things
is the main part of Wisdom”*
- Hugo Grotius
Generally, it can be said that the highest hope of Grotius was to impose moderation and control upon the relations of nations and individuals by making the consciences of men sensitive to the law of nature and by expounding a system of volitional law common to them all. The common law, in turn, was not to receive its validation from mere custom as expressed in arbitrary will, but rather it would receive it from custom genuinely based on natural law, which established limitations for behaviour. Even in a situation where a just cause could not be determined objectively, the parties to a dispute were still responsible by the law of nature for any consequences emanating from their actions. Though Grotius reflected a realistic bent in his thought, he, nevertheless, made a simultaneous appeal for humanitarian sensitivity to mitigate the brutalities of war. Throughout the third book of his treatise he interjected rules of moderation, temperamenta, which the law of nature, according to his view, required of those who made use of the rights or war.
In his use of Roman civil law and the Bible as a means for giving content to what he described as the law of nature, Grotius did not depart greatly from medieval juristic theory. Yet the significance of Grotius lies in the fact that his work gave content and impetus to the nascent science of international law. That branch of jurisprudence (understood as the body of law which regulates the mutual relations of independent sovereign states) did not, and could not, come into being until the establishment of the modern state-system which after the Reformation replaced the earlier legal unity of Christendom under the Papacy and the Holy Roman Empire. The treatise of Grotius, published in 1625, furnished the intellectual foundation for the political development which achieved definitive recognition at the close of the Thirty Years’ War in 1648. As James Bryce writes:
“When by the Peace of Westphalia a crowd of petty principalities were recognized as practically independent states, the need of a body of rules to regulate their relations and intercourse became pressing. Such a code (if one may call it by that name) Grotius and his successors compiled out of the principles which they found in the Roman law, then the private law of Germanic countries, thus laying the foundation whereon the system of international jurisprudence has been built up during the last three centuries.”
The twofold nature of Grotius’ law of war (jus ad bellum and jus in bello), and the threefold basis of his system (jus naturale, jus gentium and jus divinum voluntarium) served to support the structure of rules binding upon separate national states until later thinkers perceived that these rules could be rested upon a completely positivistic jus gentium derived exclusively from one single maxim of natural law: pacta sunt servanda.
But, although Grotius had, practically, no competitors in the field of international law he had never been invited to act as an arbitrator in any international dispute, nor had his book been on the conference tables in Westphalia or been quoted in the protestations against the treaties of Münster and Osnabrück, his voice was, practically, not being heard, his book was, practically, making no change in the contemporary course of (international) history or politics. But in the world of thought we get a completely different picture: The success of the book was overwhelming. Book II became a textbook not only for law professors, but also for professors of ethics or of Greek; editions and translations multiplied in astonishing numbers.
After Grotius’ death, Hobbes published “De corpore politico” (“On the body politic”) in 1650 and “Leviathan” in 1651. In these works Hobbes made a consistent attack, not on the book of Grotius, but on the views underlying Grotius’ lifework. In flat contradiction to “De jure belli ac pacis”, he argued that law is confined to national, municipal law; that punishing innocent citizens is an awful crime, but that punishing innocent foreigners has nothing to do with justice and injustice or right and wrong; that nations (states, commonwealths) have a supreme and unlimited sovereign power; that, if we make them drop their disguises, their international relations appear to be those of perpetual hostility, not governed at all by rules of justice and injustice; that so-called peace is only a “breathing time”; that the sword of justice in municipal affairs, is directed by law, but the sword of war, in international affairs, has nothing to do with justice and injustice or right and wrong; that international duties binding states (exception to be made for those agreed to by treaty) cannot exist, and that, consequently, state crimes cannot exist.
In regard to the fact that, to Grotius, for those who were nonparticipants in a war, it was forbidden to hinder the party having a just cause or to aid a culprit, in the eighteenth century Vattel’s position that a war can be just on both sides, came more into fashion. Thus the doctrine of neutrality took shape, and the principles of Grotius were neglected until they experienced a rebirth in the twentieth century, thanks to the efforts of Woodrow Wilson and the League of Nations.
As far as Grotius’ position is to be considered in contradiction to Vattel’s view that there can be a just war on both sides, it is to say, as van Vollenhoven points out, that in his passages dealing with “formal war” (bellum sollenne), defined as a war carried out on both sides by the highest political authority, and declared in accordance with due formality, Grotius concedes that such a war may be regarded as just on both sides and that other nations should not try to decide which party is right.
About 1775 Grotius’ book was dead; about 1850 it was hale and healthy again. It is somewhat difficult to decide to which of the two countries, England or America, belongs the honour of having rediscovered the importance of this book and of having given it back to the students of international law. With full and high appreciation of England’s part in bringing Grotius to a new glory, the main incentive appears to have come from America. In 1825 nobody in Europe and in America minded the bicentenary of “De jure belli ac pacis”; in 1925, without any previous mutual understanding, the tercentenary finds cordial commemorations in the Netherlands, the United States, England, France, Belgium, Germany and Japan. And yet, his theorem on state crimes and on the right of all nations to obviate criminal wars on earth laid undiscovered, as we see, when the Hague peace conferences of 1899 and 1907 honoured Grotius as having been a fervent advocate of arbitration because of six lines in his book of eighthundred pages. But he was not. He did not even mention arbitration in the parts of the book where he speaks about interpretation of treaties and peace treaties. Arbitration was accidental and secondary in his book. Apparently because, though useful in many respects, it has no direct value as an instrument to ward off or to punish criminal war - also perhaps because arbitration was still an arbitration by chiefs of governments (a king, a president). Arbitration was not one of Grotius’ great topics, nor was disarmament, and he said not more than fifty words about peaceful settlement of international disputes. But, nevertheless, Grotius book of 1625 has been - and has to be - considered as an intellectual starting point for any discussion on a substantive interpretation of international law after the establishment of sovereign nations from 1648 on.
instead of an afterword
“... it’s WORLD WAR IX in ¾ time,
it’s WORLD WAR X again and again
and it’s WORLD WAR XI
and I’m going to heaven ...
WORLD WAR XII every man for himself,
it’s WORLD WAR XIII in the world war machine,
it’s WORLD WAR XX change the channels now honey
this just isn’t funny anymore.
But it’s on every station in the nation today,
it’s a shish-kabob shishka terra-firma flambe ...”
- World War IX. From: The Victims Family: Things I Hate to Admit.
Mordam Records, 1990
BORSCHBERG, Peter: Hugo Grotius “Commentarius in Theses XI”. An Early Treatise on Sovereignty, the Just War, and the Legitimacy of the Dutch Revolt. Berne, 1994
DUMBAULD, Edward: The Life and Legal Writings of Hugo Grotius. Oklahoma, 1969
EDWARDS, Charles S.: Hugo Grotius, The Miracle of Holland. A Study in Political and Legal Thought. Chicago, 1981
GROTIUS, Hugo: The Law of War and Peace. Translation by F.W. KELSEY, Oxford, 1925, reprint: New York, 1964
LINK, Christoph: Hugo Grotius als Staatsdenker. In: Recht und Staat in Geschichte und Gegenwart, 512. Tübingen, 1983
VAN HOLK, L.E. and C.G. ROELOFSEN (Ed.): Grotius Reader. A Reader for Students of International Law and Legal History. The Hague, 1983
VAN VOLLENHOVEN, C.: Grotius and Geneva. In: Bibliotheca Visseriana Dissertationum Ius Internationale Illustrantium. Cura Facultatis Iuridicae Lugduno-Batavae Edita. Tomus Sextus, 1926
AQUINAS, Thomas: Secunda Secundae. Vol. 2, edited by Daniel J. Sullivan, Chicago, 1952
AQUINAS, Thomas: Summa Theologiae. Edited by Daniel J. Sullivan, Chicago, 1952
ARISTOTLE: The Art of Rhetoric. Translation by John Henry FREESE, Cambridge, 1959
ARISTOTLE: The Politics. Translation by Ernest BARKER, New York, 1958
AYALA, Balthasar: Three Books on the Law of War and the Duties Concerned with War, and the Military Discipline. Translation by J.P. Bate, New York, 1964
BEDERMAN, David J.: Reception of the Classical Tradition in International Law: Grotius” De Jure Belli ac Pacis. Essay: http://www.law.emory.edu/EILR/volumes/spring96/bederman.html
BENTHAM, Jeremy: An Introduction to the Principles of Morals and Legislation
BRYCE, James: The Holy Roman Empire
CICERO: On the Commonwealth. Translation by George H. SABINE and Stanley B. SMITH, New York, 1929
COVARRUBIAS Y LEYVA, Diego de: Opera Omnia. Frankfurt a/M, 1570
FENWICK, Charles G.: The Authority of Vattel. American Political Science Review, Vol. VII, No. 3, August 1913
FRUIN, R.: An Unpublished Work of Grotius. In: Bibliotheca Visseriana Dissertationum Ius Internationale Illustrantium. Cura Facultatis Iuridicae Lugduno-Batavae Edita. Tomus Quintus, 1925
HANCKE, E.: Bodin. Eine Studie über den Begriff der Souveränität. Untersuchungen zur Deutschen Staats- und Rechtsgeschichte, Heft 47, Breslau, 1894
KNIGHT, W.S.M.: The Life and Works of Hugo Grotius, London 1925
MOLHUYSEN, P.C.: De bibliotheek van hugo de Groot in 1618. Mededelingen der Koninklijke Nederlandse Akademie van Wetenschappen, Nieuwe Reeks, Afdeling Letterkunde, 43, 1943
MOMMSEN, Th., P. KRÜGER, and A. WATSON (Ed.): The Digest of Justinian. Philadelphia, 1985
PAOLUCCI, Henry: The Political Writings of St. Augustine. Chicago, 1962
SCHRÖCK, Roman: Aurelius Augustinus and Bellum Iustum. Early Christian Pacifism and the Justification of Warfare, Rotterdam, 1999
VAZQUEZ, Ferdinando: Controversiae Illustres. 1572
VITORIA, Francisco de: Relectiones Theologicae XII. Lyon, 1557. Facsimile reproduction in: GETTING, Alonso (Ed.): Relecciones Teológicas del Maestro Fray Francisco de Vitoria. Biblioteca de Tomistas Españoles, vol. 9, Madrid-Valencia, 1933
VREELAND, Hamilton: Hugo Grotius, the Father of the Modern Science of International Law. New York, 1917
WYDUCKEL, D.: Princeps legibus solutus. Eine Untersuchung zur frühmodernen Rechts- und Staatslehre, Berlin, 1979
* Grotius’ last words according to KNIGHT, W.S.M.: The Life and Works of Hugo Grotius, London 1925, pg. 289. According to VREELAND, Hamilton: Hugo Grotius, the Father of the Modern Science of International Law. New York, 1917, pg. 233, another and perhaps more reliable account (at least referring to DUMBAULD, Edward: The Life and Legal Writings of Hugo Grotius. Oklahoma, 1969, pg. 18), his last words were: “I hear your voice well, but I understand with difficulty what you say.”
 VAN VOLLENHOVEN, C.: Grotius and Geneva. In: Bibliotheca Visseriana Dissertationum Ius Internationale Illustrantium. Cura Facultatis Iuridicae Lugduno-Batavae Edita. Tomus Sextus, 1926, p. 9
 GROTIUS, Hugo: The Law of War and Peace. Translation by F.W. KELSEY, Oxford, 1925, reprint: New York, 1964, Prolegomena 57, 58
 Ibid., Prolegomena 38, 46; II.1.7
* lat.: “ruit hora”, was Grotius’ lifetime motto according to VAN HOLK, L.E. and C.G. ROELOFSEN (Ed.): Grotius Reader, The Hague, 1983, pg. 43, figuring also on several contemporary copperplates representing Hugo Grotius (see title page of this paper)
** source unknown
 VAN HOLK, L.E. and C.G. ROELOFSEN (Ed.): Grotius Reader. A Reader for Students of International Law and Legal History. The Hague, 1983, p. 25
 Ibid., p. 27
 Ibid., p. 27f
 Ibid., p. 29f
 Ibid., p. 29
 EDWARDS, Charles S.: Hugo Grotius, The Miracle of Holland. A Study in Political and Legal Thought. Chicago, 1981, p. 4
 In mortem Arminii. 1609. In: Poemata collecta ... ed. 2, Leiden, 1639, p. 262ff; cf. LINK, Christoph: Hugo Grotius als Staatsdenker. In: Recht und Staat in Geschichte und Gegenwart, 512. Tübingen, 1983, p. 8
 EDWARDS, Charles S.: loc.cit., p. 3
 Cf. LINK, Christoph: loc.cit., p. 8
 EDWARDS, Charles S.: loc.cit., p. 4
 LINK, Christoph: loc.cit., p. 8
 EDWARDS, Charles S.: loc.cit., p. 4f
 Ibid., p. 5
 DUMBAULD, Edward: The Life and Legal Writings of Hugo Grotius. Oklahoma, 1969, p. 13
 EDWARDS, Charles S.: loc.cit., p. 5
 Ibid., p. 5
 VAN HOLK, L.E. and C.G. ROELOFSEN (Ed.): loc.cit., p. 39
 BORSCHBERG, Peter: Hugo Grotius “Commentarius in Theses XI”. An Early Treatise on Sovereignty, the Just War, and the Legitimacy of the Dutch Revolt. Berne, 1994, p. 27
 Ibid., p. 29
 Ibid., p.28; cf. LINK, Christoph: loc.cit., p. 9f
 EDWARDS, Charles S.: loc.cit., p. 7
 DUMBAULD, Edward: loc.cit., p. 16f
 cf. LINK, Christoph: loc.cit., p. 10; EDWARDS, Charles S.: loc.cit., p. 8; BORSCHBERG, Peter: loc.cit., p. 30
 DUMBAULD, Edward: loc.cit., p. 17
 according to a letter of Grotius to his brother Willem. In: GROTIUS, Hugo: Epistolae quotquot reperiri potuerunt. 1687, No. 1761, p. 749, dated Lübeck [erroneously printed as Paris], May 20, 1645; cf. BORSCHBERG, Peter: loc.cit., p. 30
* ADAMS, Douglas: The Hitchhiker’s Guide to the Galaxy. In: ADAMS, Douglas: The Ultimate Hitchhiker’s Guide. New York, 1996, pg. 42
 for a more detailed listing see: BORSCHBERG, Peter: loc.cit., pp. 47-101
 FRUIN, R.: An Unpublished Work of Grotius. In: Bibliotheca Visseriana Dissertationum Ius Internationale Illustrantium. Cura Facultatis Iuridicae Lugduno-Batavae Edita. Tomus Quintus, 1925, p. 61ff
 BORSCHBERG, Peter: loc.cit., p. 48
 Ibid., p. 49
 see VITORIA, Francisco de: Relectio de Indis recenter inventis. III, 6: “Nec est inconveniens quod, cum ex una parte est ius et ex altera ignorantie invincibilis, quod sit bellum iustum ex utraque parte.” [“There is no inconsistency, indeed, in holding the war to be a just war on both sides, seeing that on one side there is right and on the other side there is invincible ignorance.”]; VITORIA, Francisco de: De Jure Belli. §32: “An possit esse bellum iustum ex utraque parte: 1. Seclusa ignorantia manifestum est qoud non potest contingere quia si constat de iure et iustitia utriusque partis, non licet in contrarium bellare, nec offendendo nec defendendo. 2. Posita ignorantia probabili facit aut iuris, potest esse ex ea parte, qua vera iustitia est, bellum iustum per se, ex altera autem parte bellum iustum, i.e. excusatum a peccato bona fide, quia ignorantia invincibilis excusat a toto.” [“Whether a war can be just on both sides. 1. Apart from ignorance, the case clearly cannot occur, for if the right and justice of each side be certain, it is unlawful to fight against it, either in offence or in defence. 2. Assuming a demonstrable ignorance either of the fact or of law, it is possible that on the side where true justice exists,the war is just of itself, while on the other side the war is just in the sense of being excused from sin by reason of good faith, because invincible ignorance is a complete excuse.”]. Both in: VITORIA, Francisco de: Relectiones Theologicae XII. Lyon, 1557. Facsimile reproduction in: GETTING, Alonso (Ed.): Relecciones Teológicas del Maestro Fray Francisco de Vitoria. Biblioteca de Tomistas Españoles, vol. 9, Madrid-Valencia, 1933
 GROTIUS, Hugo: loc.cit., Prolegomena 57
 GROTIUS, Hugo: loc.cit., Prolegomena 55: “The French have tried rather to introduce history into their study of laws. Among them Bodin and Hotman have gained a great name, the former by an extensive treatise, the latter by separate questions; their statements and lines of reasoning will frequently supply us with material in searching out the truth.”
 Cf. HANCKE, E.: Bodin. Eine Studie über den Begriff der Souveränität. Untersuchungen zur Deutschen Staats- und Rechtsgeschichte, Heft 47, Breslau, 1894, pp. 1-7; WYDUCKEL, D.: Princeps legibus solutus. Eine Untersuchung zur frühmodernen Rechts- und Staatslehre, Berlin, 1979
 BORSCHBERG, Peter: loc.cit., p. 57
 MOLHUYSEN, P.C.: De bibliotheek van hugo de Groot in 1618. Mededelingen der Koninklijke Nederlandse Akademie van Wetenschappen, Nieuwe Reeks, Afdeling Letterkunde, 43, 1943, p. 60, No. 258
 BORSCHBERG, Peter: loc.cit., p. 58
 see AQUINAS, Thomas: Secunda Secundae. Vol. 2, edited by Daniel J. Sullivan, Chicago, 1952, quest. 40, art. 1, p. 578
 GROTIUS, Hugo: loc.cit., p. 249
 Ibid., p. 287
 Ibid., Prolegomena 55
 VAZQUEZ, Ferdinando: Controversiae Illustres. 1572, 1.3.3, p. 20; 1.47.9ff, pp. 120-121
 Ibid., 1.1.11, p. 16
 MOMMSEN, Th., P. KRÜGER, and A. WATSON (Ed.): The Digest of Justinian. Philadelphia, 1985, 1.4.1: “A decision given by the emperor has the force of a statute. This because the populace commits to him and into him its own entire authority and power, doing this by the Lex Regia which is passed anent his authority.”
 Ibid., 1.1.8; 1.5.10; 1.8.11; 1.8.19; 1.18.10; 1.20.24; 1.47.5
 Ibid., 1.2.12
 VAZQUEZ, Ferdinando: loc.cit., 2.82.3, p. 201; cf. GROTIUS, Hugo: loc.cit., II.4.13
 Ibid., 1.28.7, p. 49
 Ibid., 1.41.20ff, pp. 170ff; 2.82.9, pp. 202-203
 the work is contained in: COVARRUBIAS Y LEYVA, Diego de: Opera Omnia. Frankfurt a/M, 1570; highlights of the Relectio in Regulam Peccatum have been published in a Spanish translation: COVARRUBIAS Y LEYVA, Diego de: Textos Jurídico-Políticos. edited by M. FRAGA IRIBARNE, Madrid, 1957
 COVARRUBIAS Y LEYVA, Diego de: Opera Omnia. Frankfurt a/M, 1570, Regula Peccatum, 2 §10, p. 548
 a translation of this work into English appeared as: AYALA, Balthasar: Three Books on the Law of War and the Duties Concerned with War, and the Military Discipline. Translation by J.P. Bate, New York, 1964
 GROTIUS, Hugo: loc.cit., Prolegomena 38: “What all these writers especially lacked, the illumination of history. (...) The causes which determine the characterization of a war as lawful or unlawful Ayala did not touch upon.”
 AYALA, Balthasar: Three Books on the Law of War and the Duties Concerned with War, and the Military Discipline. Translation by J.P. Bate, New York, 1964, 2.20, p. 15; 2.25-26, p. 18f
 Ibid., 2.12, p. 11
 GROTIUS, Hugo: loc.cit., Prolegomena 38: “Knowing that others can derive profit from Gentili’s painstaking, as I acknowledge that I have, I leave it to his readers, to pass judgment on the shortcomings of his work as regards method of exposition, arrangement of matter, delimitation of enquiries, and distinctions between the various kinds of law. This only I shall say, that in treating controversial questions it is his frequent practice to base his conclusions on a few examples, which are not in all cases worthy of approval, or even to follow the opinions of modern jurists, formulated in arguments of which not a few were accommodated to the special interests of clients, not to the nature of that which is equitable and upright.”
 BORSCHBERG, Peter: loc.cit., p. 97
* Frank ZAPPA on the “Tonight Show”, C.A. 1988
 GROTIUS, Hugo: loc.cit., Prolegomena 1
 DUMBAULD, Edward: loc.cit., p. 72
 GROTIUS, Hugo: loc.cit., Prolegomena 25: “Least of all should that be admitted which some people imagine, that in war all laws are in abeyance. On the contrary war ought not to be undertaken except for the enforcement of rights; when once undertaken, it should be carried on only with the bounds of law and good faith.”
 Ibid., Prolegomena 26
 Ibid., Prolegomena 11
 Ibid., Prolegomena 17: “But just as the laws of each state have in view the advantage of that state, so by mutual consent it has become possible that certain laws should originate as between all states, or a great many states; and it is apparent that the laws thus originating had in view the advantage, not of particular states, but of the great society of states. And this is what is called the law of nations, whenever we distinguish that term from the law of nature.”
 Ibid., Prolegomena 30
 EDWARDS, Charles S.: loc.cit., p. 116f
 GROTIUS, Hugo: loc.cit., II.15.5.1
 EDWARDS, Charles S.: loc.cit., p. 117
 GROTIUS, Hugo: loc.cit., I.2.1.4
 EDWARDS, Charles S.: loc.cit., p. 118
 see ARISTOTLE: The Art of Rhetoric. Translation by John Henry FREESE, Cambridge, 1959, book I, ch. 4; ARISTOTLE: The Politics. Translation by Ernest BARKER, New York, 1958, book VII, ch. 14, no. 1333a
 see CICERO: On the Commonwealth. Translation by George H. SABINE and Stanley B. SMITH, New York, 1929, book III, ch. 23, p. 216f
 see PAOLUCCI, Henry: The Political Writings of St. Augustine. Chicago, 1962, pp. 162-183
 GROTIUS, Hugo: loc.cit., III.1.1.1ff
 see AQUINAS, Thomas: Summa Theologiae. Edited by Daniel J. Sullivan, Chicago, 1952
 see SCHRÖCK, Roman: Aurelius Augustinus and Bellum Iustum. Early Christian Pacifism and the Justification of Warfare, Rotterdam, 1999
 BEDERMAN, David J.: Reception of the Classical Tradition in International Law: Grotius” De Jure Belli ac Pacis. Essay: http://www.law.emory.edu/EILR/volumes/spring96/bederman.html
 GROTIUS, Hugo: loc.cit., I.1.2.1; the definition includes private war, and excludes “justness” as an element in the definition; I.1.2.3; in both respects Grotius departs from the definition given by Gentili.
 Ibid., I.1.3.1; I.1.4
 Ibid., I.1.10.1
 Ibid., II.7.1; civil law is defined as that which emanates from the supreme power in the state; I.1.14.1; the state is definedas a “perfect union of free men, associated for the sake of enjoying law and common utility
 Ibid., I.1.14.1
 Ibid., Prolegomena 28
 Ibid., I.3.1.1
 for a more detailed discussion on the subject of resistence to authority see: EDWARDS, Charles S.: loc.cit, p. 129ff
 Ibid., II.20.40.1
 EDWARDS, Charles S.: loc.cit, p. 121
 VAN VOLLENHOVEN, C.: loc.cit., 22
 GROTIUS, Hugo: loc.cit., II.20.3.1
 Ibid., II.20.8.2; II.20.14; II25.5ff
 Ibid., II.20.40.1; there seems to be inconsistency when Grotius says elsewhere (I.3.8.14) that the sins of governments are not punished on earrth because they have no judges superior to them
 Ibid., II.25.1; II.25.4
 Ibid., II.20.7.1; II.20.9.2
 Ibid., II.14.6.2
 Ibid., II.20.3; II.20.7.1; II.21.3
 Ibid., III.1.2.3; III.20.43.3
 Ibid., II.24.2.1f
 Ibid., II.20.3.1
 Ibid., Prolegomena 24; II.15.12
 Ibid., II.20.40.1
 Ibid., II.25.7; II.15.12
 Ibid., I.5.2.2
 Ibid., II.23.13.2
 Ibid., II.23.13.2
 EDWARDS, Charles S.: loc.cit., p. 123
 Ibid., p. 125
 GROTIUS, Hugo: loc.cit., II.23.2.2
 EDWARDS, Charles S.: loc.cit., p. 125f
 DUMBAULD, Edward: loc.cit., p. 69
 EDWARDS, Charles S.: loc.cit., p. 129
 Ibid., p. 129
* conclusion of a poem titled “erudita ignorantia” (learned ignorance), written by Hugo Grotius in 1605 for a friend, saying that nature orders us to know only a few things, but to admire many. The poem is contained in: Anthologia Grotiana. The Hague, 1955, pg. 38-39. (see: VAN HOLK, L.E. and C.G. ROELOFSEN (Ed.): Grotius Reader. The Hague, 1983, pg. 44)
 the term “international law” seems to have been coined by Jeremy Bentham; cf. BENTHAM, Jeremy: An Introduction to the Principles of Morals and Legislation, p.326
 BRYCE, James: The Holy Roman Empire, p. 436
 the fundamental basis of the whole Grotian system is the claim that men in a society are bound together by a natural law which makes promises binding
 VAN VOLLENHOVEN, C.: loc.cit., p. 17ff
 Ibid., p. 19
 GROTIUS, Hugo: loc.cit., II.17.3.1
 see FENWICK, Charles G.: The Authority of Vattel. American Political Science Review, Vol. VII, No. 3, August 1913, p. 395
 DUMBAULD, Edward: loc.cit., p. 61
 see FENWICK, Charles G.: loc.cit., p. 395
 GROTIUS, Hugo: loc.cit., II.23.8.4
 Ibid., II.23.8.3f