Pope Leo XIV in a post on X dated June 26, 2025, decried the current world situation. He tweeted:
“It is disheartening today that the strength of international law and humanitarian law no longer seem binding, replaced by the presumed right to overpower others.”
The Pope is a trained canon lawyer, and he knows how the world is ordered, and what is at stake. Leo XIV knows that international law, and humanitarian law, is Catholic. Let us begin.
Introduction
For centuries, Hugo Grotius (1583-1645), a Dutch lawyer of some renown, was considered the father of international law. All of that changed in 1934. James Brown Scott (1866-1943), an American of Canadian birth and a legal giant of the first decades of the Twentieth Century, in his epic work, The Catholic Conception of International Law published in 1934 wrote
“The modern law of nations of which Victoria was the expounder, Suarez the philosopher and [Hugo] Grotius the systematizer, is the contribution of what we may call, and indeed must call, the Spanish School of International Law. For if Grotius was not a Spaniard by blood, he was a Spaniard in his conception of international law…so far as the basic principles of his system are concerned…”1
After visiting the Vatican shortly after the publication of the book, Scott wrote to the Father General of the Jesuits on September 29, 1934 that he had given a copy of his book to go to Pope Pius XI. Scott told the Father General that his book was meant to show “that the Catholic conception of International Law should be and therefore must be, the accepted Law of Nations of the future if not of the present, if the intercourse of nations is to be, as it must be, both moral and Christian.”2
It is my position that this has occurred, made possible especially by America, and that this is now under attack. The key principles that I shall summarily address and that form the basis of this “intercourse of nations…both moral and Christian,” are the following. First, focus on the person. Second, the centrality of law (Natural Law, Law of Nations, civil law) as ordering domestic and international societies. Third, the existence of a community of nations. Fourth, peace is the natural inclination and proper goal of mankind. All four of these are currently under attack by the tyrannies,
One dynamic that becomes apparent is that Thomism figures prominently in this analysis and indeed in the way the Catholic Church looks at societies and international ethics. We are all familiar with Pope Leo XIII’s Aeterni Patris in which he directed that “you should all furnish to studious youth a generous and copious supply of those purest streams of wisdom flowing inexhaustibly from the precious fountainhead of the Angelic Doctor.”3 And there is a revival of Scholasticism thereby making this discussion all the more relevant. Thomism is based on reason and it orders relationships and societies.
A note before we go on.
Let me tell you something about James Brown Scott. A lawyer by training, he founded the USC Law School, the American Journal of International Law, assisted in the founding of the American Society of International Law, the US expert for the Second Hague Peace Conference in 1907, lectured at Johns Hopkins, Chair of International Law at Georgetown School of Foreign Service, secretary of the Carnegie Endowment for International Peace, American Commission to Negotiate Peace after World War I, served on a Committee of Experts to codify international law in March, 1925, the U.S. delegate to the International Commission of Jurists in 1927, the American Academy of International Law and on the Inter-American Bar Association, the international law section of the American Bar Association.4 Scott developed and promulgated in 1929 a Declaration of the International Rights of Man, the precursor to the 1948 Universal Declaration of Human Rights; he worked repeatedly and closely with Latin American lawyers and lawyer associations, and the Declaration of the Rights and Duties of Nations with 18 Latin American bar associations.
I make repeated references to John Eppstein, one of the most under-rated and insightful figures of the Twentieth Century. He was an Anglican who converted to Catholicism in 1919 through the aid of Fr. C.C. Martindale. He served in World War I, assisted with the League of Nations and was very involved in defining Catholic social thinking especially in the area of international ethics. Eppstein was a highly decorated veteran receiving the honor of Officer of the Order of the British Empire (OBE), and the Croix de Guerre. He was named Chevalier of the Belgian Ordre de Leopold and was made a Grand Officer of the Portuguese Order of the Infante Dom Henriques.56 Eppstein formed the Catholic Council for International Relations in Autumn, 1923.7 That organization was a part of the Catholic Union of International Studies (CUIS) which was headquartered in Fribourg, Switzerland. The CUIS was founded and approved in November, 1917 by Pope Benedict XV, and it remained active until 1942. Affiliated groups were in Switzerland, France, Germany, Belgium, Poland, Austria, Hungary, Ireland and elsewhere under the ecclesiastical patronage of Bishop Besson of Lausanne, Geneva and Fribourg.8
In 1935, Eppstein authored The Catholic Tradition of the Law of Nations published in 1935 and for which he received a papal medal. That book examined Catholic philosophy and theology for 1900 years and presented the Catholic position on the Natural Law and on the Law of Nations. Of note, Eppstein worked with the International Union of Social Studies of Malines (IUSS or Malines) begum by Belgian Cardinal Franz-Jozef Mercier and continued by Cardinal Josef Van Roey. Eppstein would later edit a work known as the Code of International Ethics which published in 1953 under the Imprimatur and nihil obstat of Francis P. Keough, the Archbishop of Baltimore and that set out in concise form the Catholic version of Natural Law and the Law of Nations.
There will be three parts. The first will concern itself with the principles rooted in Catholic thought that form the international order. The second will demonstrate American efforts in putting these principles into practice. The third will be a summary of the attack on these principles and the current world order.
Part I The Four Principles: the person, a community of nations, the rule of law, peace
–First: The Primacy of the Person
All focuses on the development and perfection of the person. In March, 2024, Pope Francis reminded us of this with his address to the Pontifical Academy of Social Sciences upon the 750th anniversary celebration of the death of St Thomas Aquinas:
“Contemporary social sciences approach human affairs and the pursuit of human flourishing through a variety of approaches and methods that should be grounded in the irreducible reality and dignity of the human person. Aquinas was able to draw upon a rich philosophical heritage which he interpreted through the lens of the Gospel in order to affirm that the person, as `the most perfect thing in all nature’ (ST I, q. 29, a. 3), is the pillar of the social order. Created in the image and likeness of the triune God, individuals are meant through personal and interpersonal relationships to live, grow and develop within communities. For this reason, `it is natural that human beings should live in society with many others in order to procure by the work of their hands and body, enlightened by the right use of their intelligence and the strength of their will, the material and spiritual goods for their well-being and good-living, for their happiness’ (De regno, B. I. c. 1)….”9
As Popes Benedict XV and Pius XI said before, Pius XII noted that international disorders are the result of domestic disorders, or disorders within countries. Pius XII in his Christmas Message from December, 1942 said
“He who would have the star of peace to shine permanently over society must do all in his power to restore to the human person the dignity which God conferred upon him from the beginning. He must resist the excessive herding together of human beings, as though they were a soulless mass. He must set his face against their disintegration in economic, social, political, intellectual and moral life; against their lack of solid principles and firm convictions; against their excessive reliance upon instinct and emotion, and against their fickleness of mood. He must favour, by all legitimate means and in every sphere of life, social forms which render possible and guarantee full personal responsibility in regard to things both temporal and spiritual.” 10
Hearkening to that theme and writing in 1946, Jacques Maritain distinguished the person from an individual and did so in the context of major social systems that had presented throughout history. He made a distinction between one who lived in a hedonistic individualistic society with one living in an ethnic corporate society with one living in a communist society and with one living in the Liberal Order or democracy as he called it:
“In the final analysis, the relation of the individual to society must not be conceived after the atomistic and mechanistic pattern of bourgeoisie individualism which destroys the organic social totality, or after the biological and animal pattern of the statist or racist totalitarian conception which swallows up the person, here reduced to a mere histological element of Behemoth or Leviathan, in the body of the state, or after the biological and industrial pattern of the Communistic conception which ordains the entire person, like a worker in the great human hive, to the proper work of the social whole. The relation of the individual to society must be conceived after an irreducibly human and specifically ethico-social pattern, that is, personalist and communalist, at the same time: the organization to be accomplished is one of liberties. But an organization of liberties is unthinkable apart from the moral realities of justice and civil amity, which, on the natural and temporal plane, correspond to what the Gospel calls brotherly love on the spiritual and supernatural plane.”11
Society and social life therefore requires a common work of its members. The “ common work of society is the freedom of expansion of the person together with all the guarantees which this freedom implies and the diffusion of good that flows from it. In short, the political common good is a common good of human persons. And thus it turns out that, in subordinating oneself to this common work, by the grace of justice and amity, each one of us is still subordinated to the good of persons, to the accomplishment of the personal life of others and, at the same time, to the interior dignity of one’s own person….In this light, the tendency towards the materialism and atheism inherent in the city of the individual appears as one of the absurdities by which it destroys itself. In the political order, the internal dialectic of this tendency, by a similar absurdity, drags it towards dictatorship which is its proper negation.”12
Pope St. John XXIII in Pacem in Terris wrote
“8. We must devote our attention first of all to that order which should prevail among men. 9. Any well-regulated and productive association of men in society demands the acceptance of one fundamental principle: that each individual man is truly a person. His is a nature that is endowed with intelligence and free will. As such he has rights and duties, which together flow as a direct consequence from his nature. These rights and duties are universal and inviolable, and therefore altogether inalienable.”
Rights give rise to duties and are set out in Part I of John XXIII’s encyclical. Rights include political rights, material rights, rights to worship God, right to chose one’s station in life, economic rights, rights of meetings and associations. The Pope wrote: “man’s personal dignity involves his right to take an active part in public life, and to make his own contribution to the common welfare of his fellow citizens. As Pope Pius XII said, `man as such, far from being an object or, as it were, an inert element in society, is rather its subject, its basis and its purpose; and so must be esteemed.’”13 He went on to write that men must “live together and consult each other’s interests” and that “each individual will make his whole-hearted contribution to the creation of a civic order in which rights and duties are ever more diligently and more effectively observed.”14 He went on explaining that “When society is formed on a basis of rights and duties, men have an immediate grasp of spiritual and intellectual values, and have no difficulty in understanding what is meant by truth, justice, charity and freedom.”15
The person is essential to the common good. While including the “various characteristics distinctive of each individual people….[the common good] can never exist fully and completely unless the human person is taken into account at all times….” The “common good is best safeguarded when personal right and duties are guaranteed….”16
The common good of the international community is based on the same principles as the common good of each individual state. John XXIII wrote:
“The common good of individual States is something that cannot be determined without reference to the human person, and the same is true of the common good of all States taken together. Hence the public authority of the world community must likewise have as its special aim the recognition, respect, safeguarding and promotion of the rights of the human person. This can be done by direct action, if need be, or by the creation throughout the world of the sort of conditions in which rulers of individual States can more easily carry out their specific functions.”17
–Second: Community of Nations and A World Government
The Catholic view is, and always has been, that there is a community of nations or an international society, and not an anarchic society as John Mearsheimer often says.
Eppstein wrote in Code of International Ethics that “mankind therefore constitutes a single family; and no difference of race, colour, language or nationality can hide the indestructible unity of that family.”18 Each person contributes to the common good and exists in a “system of relationships of ever growing complexity – families, township, profession, State – that eventually affects the human race as a whole….”19 Each State, in order to provide the “full good of human life” to each of its members can only do so if “all States mutually assist one another….” 20 Citing to St. Augustine, “the family, political society, and international society – domus, urbs, orbis….are institutions of natural law, since they correspond to certain fundamental needs of human nature….”21
A community needs a governing authority, or ethnarchy, over the community of nations to act as a political authority.22 That idea gained considerable credibility with Luigi Tapparelli, SJ (1793-1862), one of the greatest proponents of the Natural Law, and someone who was most influential on Gioacchino Pecci (1810-1903), later Pope Leo XIII. Eppstein writing in the 1930s, after reviewing Christian history to include Taparelli’s writings and those of other theologians and philosophers, explained that
“One of the most interesting conclusions of Taparelli’s treatise of Natural Law is that polyarchy, i.e., authority residing equally in a number of moral persons is the right and natural form of international society. And the ethnarchy or authority for the whole race which he sought to evolve is, by the whole context of his work, one which would be consistent with a Christian and Catholic order of society…..The obligations of obedience to an international authority established by duly constituted Governments is no other quality than the duty of obedience to the Roman magistrates for whom St. Clement prayed….”23
However, the Christian notion also was in favor of the situation in which “the necessary international institutions should be established by the secular power, their functions in relation to the Papacy being similar to those of the State in relation to the Church in civil society.” Also, since “The natural form of the society of nations being polyarchic the necessary institutions of conciliation, arbitration and justice must be established through an accord or convention between the Governments of States.” Such a “convention has a dual sanction in the moral order; it is a duty of social justice, and it is a promise on the part of each contracting party the violation of which is prohibited by the Moral Law.”24
Indeed, these same rules, these same principles of the Natural Law that apply in domestic society, call for a world government, for a community of nations that has real political power. John XXIII wrote that “Men’s common interests make it imperative that at long last a world-wide community of nations be established.”25 In support of this, John XXIII noted the “growing economic interdependence between States,” that a “kind of world economy is being born from the simultaneous integration of the economies of individual States,” and that “each country’s social progress, order, security and peace are necessarily linked with the social progress, order, security and peace of every other country.”26 He recognized the long held view that “no State can fittingly pursue its own interests in isolation from the rest, nor, under such circumstances, can it develop itself as it should” as the “prosperity and progress of any State is in part consequence, and in part cause , of the prosperity and progress of all other States.”27 This is so because there is a universal common good but modern states are incapable of ensuring it all on their own.28 Therefore, “We are thus driven to the conclusion that the shape and structure of political life in the modern world, and the influence exercised by public authority in all the nations of the world are unequal to the task of promoting the common good of all peoples.”29
Scott’s book entitled A Catholic Conception of International Law, was subtitled “Francisco de Vitoria, Founder of the Modern Law of Nations; Francisco Suarez, Founder of the Modern Philosophy of Law in General and in Particular of the Laws of Nations; A Critical Examination and a Justified Appreciation”. Scott was long involved with the countries of Latin America and their legal systems, was influenced by them, studied Francisco Vitoria, OP, (1483-1546) one of early members of the School of Salamanca, and Francisco Suarez, SJ (1548-1617).
Scott’s book examined the works of Vitoria and Suarez, both of whom relied on scripture, theology and philosophy. Scott wrote
“to Suarez, the existence of states as isolated and unrelated entities was impossible, for he also saw the world as an integrated if inorganic international community: `The rational basis of this branch of law [the law of nations], indeed, consists in the fact that the human race,, howsoever many the various peoples and kingdoms into which it may be divided, always preserves a certain unity not only as to specifics, but also, as it were, a moral and political unity called for by the natural precept of mutual love and mercy, which applies to all, even to strangers of any nation.
“ `Therefore, although a given sovereign state, commonwealth, or kingdom, may constitute a perfect community in itself, consisting of its own members, nevertheless, each one of these states is also, in a certain sense, and viewed in relation to the human race, a member of that universal society; for never are these states, when standing alone, so self-sufficient that they do not require some mutual assistance, association and intercourse, at times for their greater welfare and advantage, but at other times because also of some moral necessity or lack, as is clear from experience….’ ” 30
–Third: The Centrality of Law – the Natural Law, Law of Nations, International Law, and The Rule of Law
The natural law is certain first principles, and the law of nations is that body of right conduct that flows from first principles and supplemented in its content by secondary principles, custom and positive law. The law of nations is of a general nature. This is to be distinguished from civil law or more specific, more particularized, law. St. Thomas Aquinas in his Summa Theologica explained this. In Part I-II, question 95, Article 4:
“…Because, to the law of nations belong those things which are derived from the law of nature, as conclusions from premises, e.g. just buyings and sellings, and the like, without which men cannot live together, which is a point of the law of nature, since man is by nature a social animal, as is proved in Polit. I, 2. But those things which are derived from the law of nature by way of particular determination, belong to the civil law, according as each state decides on what is best for itself…. Reply Obj. 1: The law of nations is indeed, in some way, natural to man, in so far as he is a reasonable being, because it is derived from the natural law by way of a conclusion that is not very remote from its premises…”31
In 1935, Eppstein expounded upon and expanded these concepts especially as to the Law of Nations:
“`Law of Nations’…serves better than any other English term to indicate at once the natural and moral basis of the rules obtaining between peoples and the positive forms given to those rules. It would, however, be inaccurate to translate `Jus Gentium’ in St. Thomas as `International Law’ in the modern sense of Inter-State Law.”32
The “body of rights” to which he was referring are possessed by all peoples and come from God: “the right to conserve themselves in being; to develop according to their nature; to hold property; to bequeath it; to trade; to travel freely. To which we might add the right to speak their maternal language: to follow their own domestic and religious customs – so they be not contrary to natural law – to choose or obey their own local authorities….
“It is in part to protect these rights that, first, civil society, then international society is formed. The `Jus Gentium’ is in a sense the end to which international law is the means. For the object of conventions between States is (directly or indirectly) to promote the welfare of the families that compose them; and this welfare comprises the free exercise of all the rights contained in the `Jus Gentium’ as well as those arising from the Law of Nature itself. Such parts of the traditional `Jus Gentium’ as plainly concern public relations between States – as for instance the immunity of ambassadors….they pertain to international law in the modern sense. They can only be changed by agreement between States.”33
Suarez, recognizing the existence of a community of states, held logically that “such communities have need of some system of law whereby they may be directed and properly ordered with regard to this kind of intercourse and association; and although this law is in large measure provided by natural reason, it is not provided in sufficient measure and in a direct manner, with respect to all matters; therefore, it was possible for certain special rules of law to be introduced through the practice of these same nation.”34
Notably, both Suarez and Victoria saw that the “essence of the system of international law was equality among nations as among individuals.” They both also saw that there was a “responsibility for such imperfect communities” that “lay with more advanced peoples and they charged the latter with the task of assisting the backwards states to a position in which they would be able to look after their own welfare and interest…..” This concept would come to be known as the “mandate” or a guardian state.35
Suarez created a philosophy of law. In that regard, he determined law to be “right and virtuous rule” with the root being the eternal law followed by the natural law made known which is made known by natural reason, and through the Decalogue. Natural law consists of all “precepts written by God in the hearts of men…and all precepts which may clearly be inferred by reason from natural principles….” Natural law included things such as restitution of the property of another or the return of a deposit as well as observing good faith, telling the truth, and “observance of vows and of human promises.” The natural law also included the observance of contracts. Treaties of peace and truces are considered parts of the ius Gentium as the obligations under them pertain to the natural law. Additionally, agreements between states are part of the ius gentium and this use of the power of human agreement has the effect of law. Equality is the principle between men and women and also between countries. The rationale behind international law is that “this branch of law [the law of nations], indeed, consists in the fact that the human race, howsoever many the various peoples and kingdoms into which it may be divided, always preserves a certain unity, not only as a species, but also, as it were, a moral and political unity called for by the natural precept of mutual love and mercy….”36
With Suarez the intercourse of nations means “communities have need of some system of law whereby they may be directed and properly ordered with regard to this kind of intercourse and association; and although this law is in large measure provided by natural reason, it is not provided in sufficient measure and in a direct manner, with respect to all matters” so therefore special rules of law must be introduced. Finally, the laws of the international community must exist and are introduced by custom or habitual conduct of nations, and are ‘very closely related to the natural law, and most easily deduced therefrom in a manner so advantageous and so in harmony with nature itself that while this derivation [of the law of nations from the natural law] may not be self-evident, that is, not essentially and absolutely required for moral rectitude, it is nevertheless quite in accord with nature, and universally acceptable for its own sake.”37
Victoria set forth some of the rules or laws from the Natural Law as well as what derived from these principles. Victoria noted freedom of travel, freedom of trade, the “bond of relationship between all men” and that “it is contrary to natural law for one man to dissociate himself from another without good reason,” rights of foreigners, nationality based on being born within the state, the right of Christian missionaries to preach and declare the gospel in barbarian lands, the presence of mandates so as to govern lands of less developed peoples for their welfare and best interests and not merely for Spanish or advanced profits, the rights of conscientious objectors who believe a war is unjust, that there is a law of nations with the natural law and derived with common consent all for the good of all, there is an international community in which “international law has not only the force of a pact and agreement among men, but also the force of a law; for the world as a whole, being in a way one single state, has the power to create laws that are just and fitting for all persons,” the “compulsory acceptance of peaceful settlement,” and arbitration by the Pope.38
Scott explained Vitoria held respecting or keeping international law was a moral obligation. “International law has not only the force of a pact and agreement among men, but also the force of a law; for the world as a whole, being in a way one single state, has the power to create laws that are just and fitting for all persons, as are the rules of international law. Consequently, it is clear that they who violate these international rules, whether in peace or in war, commit a mortal sin….it is not permissible for one country to refuse to be bound by international law, the latter having been established by the authority of the whole world.”39
–Fourth: Peace Is the Object
The Christian desire for peace goes back to the Gospels. In a letter from St Augustine to Bishop Boniface in 418, the Doctor said “peace should be the object of your desire; war should be waged only as a necessity, and waged only that God may by it deliver men from that necessity and preserve them in peace. For peace is not sought in order to the kindling of war, but war is waged in order that peace may be obtained….Our Lord says: “Blessed are the peacemakers; for they shall be called the children of God.”…..’”40
Christianity “upholds and sanctifies the true conception of the fraternity of the human race: how best to give positive form to the universal society of peoples and serve its interests: how the rights of God and His Church should be secured in the process: that is the main consideration. What peaceful methods should be evolved for the settlement of international disputes; how the aspirations of each nation and the true interests of backward peoples are to be harmonized with the good of the whole: these are examples of the practical problems whose solution must be integrated into a Christian science of international ethics.”41
A society has a common good, and there is a common good for the natural society of nations. St. Thomas Aquinas wrote “A law, properly speaking, regards first and foremost the order to the common good.”42 The legal philosopher John Austin in explaining the positive law, or law created by the actions of men, noted the importance of intelligence in the creation of law when he wrote that law is the “rule laid down for the guidance of an intelligent being by an intelligent being.”43 The great legal scholar Malcolm Shaw writes that “international law has always considered its fundamental purpose to be the maintenance of international peace.”44 Shaw explains that “International law is more limited as far as the mechanisms for the creation of new rules are concerned. Custom relies upon a measure of state practice supported by opinio juris and is usually, although not invariably, an evolving and timely process. Treaties, on the other hand, are a more direct and formal method of international law creation.”45 The “fundamental principle of treaty law is undoubtedly the proposition that treaties are binding upon the parties to them and must be performed in good faith. This rule is termed pacta sunt servanda and is arguably the oldest principle of international law.”46 Treaties take many names to include charter, and the United Nations Charter is a treaty.47 Treaties, including charters, bring a moral responsibility such that they must be honored and hence pacta sunt servanda.48 Responsibility attaches to state actors who violate international law and that in itself helps to maintain order.49
Professor Mary Ellen O’Connell from Notre Dame writes “Reigning political ideologies that ignore international law have helped to deliver a world in which armed conflicts drag on for decades and vast resources are diverted to war….Peace is not only a moral idea…Peace is pre-eminently a legal postulate. Juridically it is a metaphor for the postulate of the unity of the legal system.”50 As time would show, the Americans would base the world system on international law, thereby providing for a peaceful, prosperous world.
John XXIII wrote that the international community is to be ordered by reason to achieve peace51 two very American characteristics:
“relations between States, as between individuals, must be regulated not by armed force, but in accordance with the principles of right reason: the principles, that is, of truth, justice and vigorous and sincere co-operation….[52] Secondly, it is an objective which we Maintain is more earnestly to be desired. For who is there who does not feel the craving to be rid of the threat of war, and to see peace preserved and made daily more secure?…[53] And finally it is an objection which is rich with possibilities for good….`Nothing is lost by peace; everything may be lost by war.’” Relationships between States must be “regulated by the principle of freedom” which means that “no country has the right to take any action that would constitute an unjust oppression of other countries, or an unwarranted interference in their affairs. On the contrary, all should help to develop in others an increasing awareness of their duties, an adventurous and enterprising spirit, and the resolution to take the initiative for their own advancement in every field of endeavor.”54 However, as “all men are united by their common origin and fellowship, their redemption by Christ, and their supernatural destiny,” they are “called to form one Christian family” and so there is “the need for helping these peoples in a way which guarantees to them the preservation of their own freedom” which includes economic and social development55 and the wealthier states providing assistance while rejecting domination respecting civil institutions and honoring national characteristics so as to attain “universal prosperity.”56 The order must be founded on moral principles as that is “the surest bulwark against the violation of the freedom, integrity and security of other nations…”57
Peace is based on right order and justice. Wars are fought for that right order.
Part II America As the Executor of These Ideals
On July 4, 1776, the United States of America came into being. The Declaration of Independence, written largely by Thomas Jefferson with assistance from Ben Franklin and John Adams, was adopted and promulgated by the Second Continental Congress The declaration of independence and Constitution set forth not only the principles governing domestic organization, but also America’s acceptance of the principles of the Law of Nations and cognizance of a society or community of nations. It demonstrates the connection between the domestic and the foreign, the necessity of right ordering of each with the person as the object of development, and the existence of a community of nations.
–The Provenance of Ideas: Grotius to Vattel
Robert R. Reilly in America on Trial: A Defense of the Founding, writes that America derived its ideas about domestic organization from the Christian, or Catholic tradition. He proceeds from the position that the
“ideas of democratic constitutional government have only one set of roots in human history. Christendom (strongly influenced by its antecedents in Jerusalem and in Athens), and only Christendom, has ever indigenously produced modern constitutional government….
“From Athens: the existence of universal truth, a rational universe ordered by a divine intellect, the primacy of reason in man’s moral life, the existence and immutability of human nature, and the existence and immortality of the human soul. From Jerusalem: monotheism, creation ex nihilo, the fundamental goodness and reliability of creation, man made in the imago Dei…and salvation history. Finally, from Rome (Christianity): the universalization of the truths of Judaism stated above, the Incarnation and the culmination of salvation history in Christ, the dedivinizaiton of the world (the final end of pantheism), the separation of the sacred from the secular, and the recognition of the inviolability of the individual person.”58
According to Reilly, one, if not perhaps the most important channel of conveyance of these ideas was through the English philosopher, Algernon Sidney (1623-1683) who was executed for treason by King Charles II. According to Reilly, “Sidney’s work conveyed influences from the Middle Ages through Hooker, Bellarmine, and Suarez on the subjects of equality, popular sovereignty, the requirement of consent, the rule of law, and the right to revolution directly to the American colonies.”59
However, America received ideas about the Law of Nations, or international society, from Emmerich de Vattel (1714-1767) who wrote The Law of Nations; or Principles of the Law of Nature, Applied to the Conduct and Affairs of nations and Sovereigns and published in 1758. It was one of the most widely read books by the Founders60, and it contained ideas on the international order that originated with Suarez and the School of Salamanca and by implication St. Thomas Aquinas as well as Holy Scripture. The American Founders also repeatedly referred to it in making various arguments before the Revolution, during the Revolution, after the Revolution and into the Constitutional Convention, and after the United States Constitution took effect.61
Vattel was of the school of Grotius. Grotius, as we have seen, was influenced by Suarez and Victoria who were in turn influenced by Aquinas and the Gospels.62 Grotius and Vattel were of the naturalist period as he sought to find in “a prior conception of natural law…standards of just conduct in addition to prescribing rules to govern the relations of independent agents (individuals or nations) in a mutually beneficial fashion.”63 As one scholar wrote,
“The tradition in which Vattel worked was founded by Grotius and was continued by other writers whom Vattel acknowledges: Hobbes, `whose work, in spite of its paradoxes and its detestable principles, shows us the hand of the master’; Pufendorf; Barbeyrac; and Wolff64. The law of nations (in conjunction with natural law) had become established as an academic subject in Germany with the creation of a chair for Pufendorf at Heidelberg in 1660…The trend was resisted in France….Vattel belongs to the (by then) century old tradition of political philosophy that combined natural law with the concepts of an original state of nature inhabited by individuals and of a social contract as a procedure by which legitimate political authority may be constituted. His presentation of these ideas carries, on the whole, the fundamentally liberal implications that were becoming increasingly common in the eighteenth century. Natural law is understood as a body of obligatory moral principles, prescribing basic duties and rights for individuals (and, suitably adapted, for states) in their relations with one another. Unlike some of his predecessors (such as Pufendorf, Burlamaqui or Wolff), Vattel does not present his law of nations in conjunction with an elaborate natural law philosophy, in which questions regarding the epistemological status, justification and obligatoriness of the natural law are treated in detail. The ethical structure of Vattel’s doctrine (for example, the distinctions between `internal’ and `external’ obligation, or between `perfect’ and `imperfect’ rights and duties) appears to be its most derivative (Wolffian) part, and his claims about natural law appear to be assumptions, or perhaps a kind of `shorthand’ for moral premises that he simply finds plausible or attractive…… Rather, Vattel is more concerned (following Wolff and Pufendorf, and remotely Hobbes) to assert that independent states or nations, which may be thought of as similarly free and independent `persons,’ may also usefully be considered as existing together in a state of nature (e.g., Preface, p. 7a; II.201; III.188).”65
Despite the sovereignty of nations and their logical desire to enrich themselves at the expense of others, oppress and dominate, Vattel understood there was “natural society of mankind” at the international level.66 “War is that state in which we prosecute our right by force,”67 wrote Vattel, but “nature has given men no right to employ force, unless when it becomes necessary for self-defence and the preservation of their rights….”68
Vattel wrote:
“The universal society of the human race being an institution of nature herself, that is to say, a necessary consequence of the nature of man,–all men, in whatever stations they are placed, are bound to cultivate it, and to discharge its duties. They cannot liberate themselves from the obligation by any conventions, by any private association. When, therefore, they unite in civil society for the purpose of forming a separate state or nation, they may indeed enter into particular engagements towards those with whom they associate themselves; but they remain still bound to the performance of their duties toward the rest of mankind.”69
A general maxim, or duty, was set out by Cicero as being a fulfillment of the law of nature or the fulfillment of justice: “`Nothing,’ says he, `is more agreeable to nature, more capable of affording true satisfaction, than, in imitation of Hercules, to undertake even the most arduous and painful labours for the benefit and preservation of all nations.’”70
Therefore, “Nations, being obliged by nature reciprocally to cultivate human society….are bound to observe towards each other all the duties which the safety and advantage of that society require….The offices of humanity are those succours, those duties, which men owe to each other, as men, –that is, as social beings formed to live in society, and standing in need of mutual assistance for their preservation and happiness, and to enable them to live in a manner conformable to their nature. Now, the laws of nature being no less obligatory on nations than on individuals (Prelim. § 5), whatever duties each man owes to other men, the same does each nation, in its way, owe to other nations (Prelim. § 10,…) Such is the foundation of those common duties – of those offices of humanity – to which nations are reciprocally bound towards each other. They consist, generally, in doing everything in our power for the preservation and happiness of others, as far as such conduct is reconcilable with our duties toward ourselves….”71
A nation has as the chief object of all of its duties to itself being “preservation and perfection, together with that of its state” and the nation “ought, on occasion, to labour for the preservation of others, and for securing them from ruin and destruction, as far as it can do this without exposing itself too much. This included helping a nation “afflicted with famine or any other calamities” and “contribute to the perfection of other states” but not to use force.72
Nations have the right to ask for help when in necessity. The “offices of humanity” provides the love to help other nations in their time of necessity, and so “Every nation is obliged to cultivate the friendship of other nations, and carefully to avoid whatever might kindle their enmity against her.”73 There is a general “prohibition of doing any harm to others, of causing them any prejudice,–in a word, of injuring them….”74
Vattel proceeded with the rest of the book to set out the rules which translated as rights and obligations with the argument proceeding from the point of view of an individual as a nation is itself like an individual. One obligation was to conduct “mutual commerce between nations”.75 Titles belonging to the different sovereigns are to be respected.76 Each nation has a “right to security” which is the “right to preserve herself from all injury” and in that regard it must be aware of a number of threats to that security. Each nation as “an evident consequence of the liberty and independence of nations…all have a right to be governed as they think proper, and…no state has the smallest right to interfere in the government of another” as “sovereignty is, doubtless, the most precious” of the rights that belong to a nation and should be respected. The exception to this was “if the prince, by violating the fundamental laws, gives his subjects a legal right to resist him,–if tyranny, becoming insupportable, obliges the nation to rise in their own defence–every foreign power has a right to succor an oppressed people who implore their assistance.” There is no right to “interfere in the government of an independent state” and such may be opposed. Similarly, there is no right to interfere in the religion of another nation especially force of arms may not be used to “oblige her to receive a doctrine and a worship which” concerns religion. However, when a “religion is persecuted in one country, foreign nations who profess it may intercede for their brethren” but if persecution is carried to the extreme of tyranny then it “becomes a case of manifest tyranny, in opposition to which all nations are allowed to assist an unhappy people.”77
As “justice is the basis of all society, the sure bond of all commerce” then all “nations are therefore under a strict obligation to cultivate justice towards each other” and the right to justice is “a perfect one,–that is to say, it is accompanied with the right of using force in order to assert it.” Justice may be obtained by force and “right defence,” and an “intentional act of injustice is undoubtedly an injury” which can then be punished. This is an aspect of the “right to security.”78
–American Commitment to the Law of Nations
According to Chancellor James Kent in Lecture I of his Commentaries on American Law (1826-1830), entitled “Of the Foundation and History of the Law of Nations,” the Second Continental Congress by Ordinance of December 4, 1781, “Relative to Maritime Captures,” held that “Congress claimed cognizance of all matters arising upon the law of nations, and they professed obedience to that law, `according to the general usages of Europe.’” 79 However, according to the Articles of Confederation, each of the states were sovereign thereby leaving open the possibility of separate and inconsistent treatment of the Law of Nations.
The Law of Nations was discussed by the American Founders during the Constitutional Convention during the hot summer of 1787. The question was whether the new United States of America would accept all of the Law of Nations in its dealings in the area of foreign policy and relations, or whether it would accept only a portion of the same. The wording of Article I, Section 8, Clause 1080 shows that Americans would be bound by the Law of Nations, though Congress, or more generally, the national government, would reserve the right to determine which actions were worthy of sanctions for having been a violation of the Law of Nations.
“The founders expected the United States to comply with international law and for Congress to check a president’s lawless rush to war,” said Mary Ellen O’Connell, a University of Notre Dame law professor and an expert on international law. “Without a discussion and vote in Congress, this restraining mechanism is lost.”81
Following the Convention, America’s lawyers and leadership were informed by the likes of the afore-mentioned Chancellor James Kent (1763-1847) who has been called the American Blackstone. He recognized the impact of Vattel on American thinking and he also recognized that of Grotius who informed Vattel through a line of jurists. Kent taught the Law of Nations was part of American jurisprudence in his Commentaries on American Law
“Thus stood the law of nations at the age of Grotius. It had been rescued, to a very considerable extent from the cruel usages and practices of the northern barbarians. It had been restored to some degree of science and civility by the influence of Christianity, the study of the Roman law, and the spirit of commerce…It consisted of a series of undigested precedents, without order or authority….”82
After Grotius came Pufendorf who “always held the first rank. His work went more at large into the principles of natural law and combined the science of ethics with what may be more strictly called the law of nations…It is rather a treatise on moral philosophy than on international law; and the same thing may be said of the works of Wolfius….”83
The legal scholar Samuel Pufendorf writing in 1672 saw the connection between human rights and human dignity, and with it the need for something called sociability, or friendship. Pufendorf
“argued that human beings have perfect natural rights (rights owed to one another) in virtue of a certain moral “standing” that we assign to each other as a constitutive part of being sociable. Whenever we address another person directly—e.g., with a claim like “You must allow me to speak”—we implicitly treat them as an accountable, responsible being. Otherwise, why address them at all? And the same is true when they address us. In other words, according to Pufendorf, being sociable implicitly involves a reciprocal assumption of basic moral status—us of them, them of us—whenever we interact, and even if the address is one that offends the equal standing of the other. Indeed, this is precisely when “dignity” becomes most urgent. Thus, Pufendorf writes: `There seems to him to be somewhat of Dignity [dignatio] in the appellation of Man: so that the last and most efficacious Argument to curb the Arrogance of insulting Men, is usually, I am not a Dog but a Man as well as yourself. (1672: I.VII.I [2003]: 100)…’”84
In Kent’s Second Lecture entitled “Of the Rights and Duties of Nations in a State of Peace,” in his Commentaries on American Law (1826-1830), he said:
“As the end of the law of nations is the happiness and perfection of the general society of mankind, it enjoins upon every nation the punctual observance of benevolence and good will, as well as of justice, towards its neighbors. This is equally the policy and the duty of nations. They ought to promote a free intercourse for commercial purposes….The numerous wants of civilized life can only be supplied by mutual exchange between nations of the peculiar productions of each….as every nation has the right, and is disposed to exercise it, of judging for itself, in respect to the policy and extent of its commercial arrangements, the general freedom of trade, however reasonably and strongly it may be inculcated in the modern school of political economy, is but an imperfect right….”85
These ideas, these concepts, these values, informed generations of Americans who were dedicated to law to right order our society. We pick matters up later in the Nineteenth Century as the American elites, and society at large, moved forward with these ideas of right order thereby providing a light unto the world.
(To Be Continued)
1 James Brown Scott, The Catholic Conception of International Law (The Lawbook Exchange, Clarke, New Jersey, 2014), 127-128.
2 James Brown Scott Papers, Box 52, Folder 2, Georgetown University Library, Special Collections Division, Washington D.C.
3 Leo XIII, Aeterni Patris, para. 26
4 George A. Finch, Adventures in Internationalism: A Biography of James Brown Scott (The Lawbook Exchange, Ltd., Clarke, NJ, 2012), 168-174, 199-206.
5 John Eppstein, Has The Catholic Church Gone Mad? (Arlington House, New Rochelle, New York, 1971), dustjacket.
6 Mark Bosco, “Kindred Spirits: Catholic Writers Inspired by Jesuit Friendships,” November 10, 2015, America Magazine, retrieved December 20, 2023; “Cyrus Charles Martindale,” Encyclopedia.com retrieved December 20, 2023.
7“Founded in 1924 under the presidency of Cardinal Bourne and composed of representatives of 19 Catholic societies of England , Scotland, and Wales. Its aim is to assist the sovereign pontiff in his efforts to establish “the Peace of Christ in the Reign of Christ.” It endeavors to give Catholics in Great Britain a greater and more sympathetic knowledge of their fellow Catholics in other countries; to create a Catholic public opinion, informed by the tradition of the Church , which shall be a real power for international justice and peace; to enable Catholics to understand, appreciate, and when necessary, criticize from the standpoint of religion, the international organizations and movements of the day. The Cattholic [sic] Council for International Relations supplies to Catholic schools and societies, lecturers on the various aspects of Catholic life abroad, the pacific function of the Holy See, the League of Nations, and such international topics. It has held conferences at Reading, Oxford, Southend, London, and Birmingham , and arranged for British representation at Catholic international congresses on many subjects, in Europe. By means of pamphlets and the quarterly publication of “A Catholic Survey,” it establishes Catholic principles of international morality and justice. It is affiliated to the “Union Catholique d’Etudes Internationales,” and is in touch with Catholic peace-societies all over the world. (E.V.W.)” Encyclopedic Dictionary of Bible and Theology, https://www.biblia.work/dictionaries/catholic-council-for-international-relations/ accessed January 1, 2024.
8 John Eppstein, The Catholic Tradition of the Law of Nations, pp. 371-372, n. 1.; Catholic Hierarchy, https://www.catholic-hierarchy.org/bishop/bbess.html accessed December 24, 2023; “Catholic Union of International Studies,” uia.org/s/or/en/1100010566 as accessed December 26, 2023. On April 5, 1927, the Conference of Presidents later known as the Conference of Presidents of International Catholic Organizations, met at the invitation of the CUIS. Later, the entity became known as the Conference of International Catholic Organizations (CICO) and it became a formal institution approved by the Holy See in 1951 with the adoption of the current name of CICO in 1953. The purpose of this organization or its aims are to act “Under the inspiration of Christian principles, participate in the life of the universal Church and collaborate constructively in the development of international life; for Christian values worldwide.” Conference of Catholic International Organizations, UIA Global Civil Society Database, https://uia.org/s/or/en/1100044386 accessed December 26, 2023.
9 Pope Francis, ”Messagge of His Holiness Pope Francis to the Participants in the Workshop `Aquinas’ Social Ontology and Natural Law in Perspective,” March, 2024, Vatican.
10 Pope Pius XII, December, 1942 Christmas message, entitled “The Internal Order of States and People” expounded on the “Dignity and Rights of the Human Person” found in Eppstein, Code of International Ethics, 194-195.
11 Jacques Maritain, The Person and the Common Good (University of Notre Dame Press, Notre Dame, Indiana, 1966), 101-102.
12 Maritain, 102-105.
13 Pope St John XXIII, Pacem In Terris, paragraph 26.
14 Ibid., paragraph 31.
15 Ibid., paragraph 45.
16 Ibid., paragraphs 55, 60, 61.
17 Ibid., paragraph 139.
18 Eppstein, Code of International Ethics, para. 5: Men are descended from a single couple, their first parents; they are children of the same Father, who is in heaven; they have been redeemed by the blood of the God-Man and are invited to incorporate themselves in His Mystical Body. Mankind therefore constitutes a single family; and no differences of race, colour, language or nationality can hide the indestructible unity of that family.
“Natural morality, confirmed and reinforced by the law of the gospel, creates reciprocal duties of justice and charity for all human beings in their relations with one another. Among other things, it puts them under an obligation to contribute, each according to his means, to the establishment and maintenance of material and spiritual conditions favourable to the full development of the human race and conducive to the common good of mankind.
19 Pope St. John XXIII, Pacem in Terris., para. 6.
20 Ibid., para. 9.
21 Ibid., para. 10
22 Thomas C. Behr “Social Justice and Subsidiarity: Luigi Taparelli and the Origins of Modern Catholic Social Thought,” (The Catholic University of America Press, Washington, DC 2019), 94, 113,128, 135, 198.
23 John Eppstein, The Catholic Tradition of the Law of Nations (The Lawbook Exchange, Ltd., Clark, New Jersey, 2012), 160-161.
24 Ibid., 182.
25 Pope St John XXIII, Pacem In Terris, paragraph 7.
26 Ibid., paragraph 130.
27 Ibid., paragraph 131.
28 Ibid., paragraph 132.
29 Ibid., paragraph 135.
30 Scott, A Catholic Conception of International Law, 483.
31 St Thomas Aquinas, Summa Theologica, Part I-II, q. 95, pp. 458-459.
32 John Eppstein, The Catholic Tradition of the Law of Nations, (The Lawbook Exchange, LTD., Clark, New Jersey, 2012), 259; Jus Cogens is a term that has come to refer to the “norms laying down international obligations `so essential for the protection of fundamental interests of the international community that their breach was recognized as a crime by that community as a whole.’” Jus Cogens has come to take the place of Jus Gentium in the minds of many as the former expands. See, Antonio Cassese, International Law (2nd Edition) (Oxford University Press, 2005), 202.
33 Eppstein, 259; Eppstein notes that Francisco Suarez, SJ (1548-1617) viewed Jus Gentium as different from the agreements or conventions between states which is better known as international law, whereas Francisco de Vittoria, OP (1483-1546) tended to include international law, which consists of agreements or conventions or customs, in the concept of Jus Gentium.
34 Scott, A Catholic Conception of International Law, 483.
35 Ibid., 486.
36 Ibid., 491-493.
37 Ibid.
38 Ibid., 488-490.
39 Ibid., 482-483.
40 Eppstein, The Catholic Tradition in the Law of Nations, 78.
41 Ibid., 128.
42 St. Thomas Aquinas, from Summa Theologica, the Basic Writings of Saint Thomas Aquinas, ed., Anton C. Pegis (New York: Random House, Inc., 1945), Vol. II as contained in Philosophy of Law ed. Joel Feinberg and Hyman Gross (Dickinson Publishing Company, Encino, California, 1975), 10.
43 John Austin, from The Province of Jurisprudence Determined, as contained in Philosophy of Law, 16.
44 Malcolm Shaw, International Law (9th Ed., Cambridge University Press, 2021), 879.
45 Ibid., 787.
46 Ibid., 788.
47 Ibid., 789; “UN Charter,” Academic Impact, United Nations, found at https://www.un.org/en/academic-impact/un-charter#:~:text=The%20Charter%20is%20an%20international,purposes%20of%20the%20United%20Nations as of December 27, 2024.
48 John Eppstein, Code of International Ethics (Sands & Company, Glasgow, Scotland, 1953), 16.
49 Nolkaemper, André (2009) “Constitutionalization and the Unity of the Law of International Responsibility,” Indiana Journal of Global Legal Studies: Vol. 16: Iss. 2, Article 7.
50 O’Connell, The Art of Law In The International Community, 296, 304.
51 John XXIII, Pacem In Terris, paragraph 114.
52 Ibid., paragraph 115.
53 Ibid., paragraph 116.
54 Ibid., paragraph 120.
55 Ibid., paragraphs 121, 123.
56 Ibid., paragraph 125.
57 Ibid., paragraph 124.
58 Robert R. Reilly, America on Trial: A Defense of the Founding, (Ignatius Press, San Francisco, 2020), 10.
59 Ibid., 223
60 See, Founders Online for instance “List of livres, December 1782-January 1783 of Franklin Papers,” https://founders.archives.gov/documents/Franklin/01-36-02-0234, “Vote of Thanks from Harvard College [for books from Ben Franklin],” September 30, 1776, referring to William C. Lane, “Harvard College and Franklin,” Publications of the Colonial Society of Massachusetts, x (1907), 238–9, https://founders.archives.gov/documents/Franklin/01-22-02-0376; and January 23, 1783 “The Committee instructed on the motion of Col. Bland to report a list of books proper for the use of Congress, recommend that Superitendt. of Finance & the Secy. of Congress be empowered to take order for procuring the books enumerated below; the same when procured to be under the care of the said Secy.” https://founders.archives.gov/documents/Madison/01-06-02-0031.
61 Ibid.
62 Also, see Notre Dame Professor Mary Ellen O’Connell who wrote: “Grotius avoided theological disputes in winning adherents in the short term. He followed Aquinas and Suarez in applying a body of positive law, the jus gentium, to inter-state relations, explaining that this law incorporated concepts beyond positive law in only limited ways. Grotius taught that the jus gentium was needed for its detail and it should be interpreted in the light of natural law. In other words, the positive law contains the principles and rules that guide daily life. Natural law remains for its explanation of why positive law has authority to bind and what the moral limits of positive law are. Grotius’s efforts led to the first `detailed body of specific rules’ in international law.” Mary Ellen O’Connell, The Art of Law in the International Community (Cambridge University Press, 2019), 21.
63 Emer de Vattel, The Law of Nations: or, Principles of the Law of Nature, Applied to the Conduct and Affairs of Nations and Sovereigns, (T& J W Johnson, Law Booksellers, Philadelphia 1854) as reprinted by The Lawbook Exchange, LTD. (Clark, New Jersey, 2020), Book I, Chapter II, Sections 24-25.
64 Christian Wolff (1679-1754) and then Samuel von Pufendorf (1632-1694), and then Hugo Grotius (1583-1645)
65 Whelan, 407-408.
66 Frederick G. Whelan, “Vattel’s Doctrine of the State,”(from 1988, History of Political Thoughts, Volume IX, no. 1) found inKnud Haakonssen, ed. Grotius, Pufendorf and Modern Natural Law (Ashgate Publishing Company, Brookfield, Vermont, 1999), 403-434, pp. 405-407, 430-432.
67 Emer de Vattel, The Law of Nations, (The Lawbook Exchange, Ltd., Clark, New Jersey, 2020), Book III, Chapter I, Section 1, 392.
68 Vattel, Book III, Chapter 1, Section 4, 393.
69 Ibid., lx.
70 Vattel, Book II, Chapter I, Section 1, 212.
71 Vattel, Book II, Chapter I, Sections 1-2, 213.
72 Vattel, Book II, Chapter I, Sections 4-6, 214-216.
73 Vattel, Book II, Chaper I, Sections 8-14, 217-219.
74 Vattel, Book II, Chapter I, Section 18, 221.
75 Vattel, Book II, Chapter II, Sections 21-34, 225-231.
76 Vattel, Book II, Chapter III, Sections 35-48, 231-237.
77 Vattel, Book II, Chapter IV, Sections 49-62, 237-243.
78 Vattel, Book II, Chapter V, Sections 63-70, 244-245.
79 Journals of Congress, Vol. VII, p. 125.
80 “The Congress shall have Power….To define Piracies and Felonies committed on the high Seas, and Offenses against the Law of Nations.” Article I, Section 8, Clause 10, Constitution of the United States
81 WJ Hennigan, “Trump Is Threatening War Against Iran. Here’s Who Can Stop Him,” June 18, 2025, The New York Times.
82 Chancellor James Kent, Commentaries on American Law, Lecture I
83 Ibid.
84 Dignity, Stanford Encyclopedia of Philosophy Febraury 18, 2023.
85 Chancellor James Kent, Commentaries on American Law, Lecture II.