Academic and professional interest in international law has soared in the last several decades. The number of students now desiring to study this field has necessitated the introduction of a wide variety of courses into law school curricula. In this regard, the proliferation of many new graduate programs in international law has paralleled the growth in graduate legal education generally. Interestingly, the increased interest in international law has not been limited to the academy. Indeed, the interests of the academy only reflect a surge in the number of lawyers now confronting international legal issues at work. Lawyers in numerous practice areas, including military practice, corporate law, and labor-management relations are finding it essential to expand their knowledge of international law.
This essay will not serve as a primer in international law. Rather, it will alert the reader to the foundation of many international law principles--natural law. The natural law can be distinguished from the positive law which is defined as any source of legal authority posited by human beings. Illustrations of the positive law are as diverse as the Internal Revenue Code of the United States (1) or the Racial Purity Laws of Nazi Germany. (2) Today, many practitioners find themselves dealing with multilateral instruments, such as treaties, as their principal source of law. If the elements of these instruments come from negotiations amongst the human parties, are the instruments examples of positive law? In one sense, the answer is "yes." However, even instruments that codify the international law principles, such as modern treaties, often rely on fundamental principles stemming from the natural law. (3)
Codified international law often relies on international law principles derived from custom--the unwritten evolving law of nations. At the heart of custom is the natural law. Hugo Grotius, no stranger to the natural law and sometimes considered the father of modern international law, (4) acknowledged his debt to predecessors such as the Spanish theologians Francis di Vitoria and Francis Suarez. (5) As commentators on the political institutions of the late fifteenth and early sixteenth centuries, they relied on the Scholastic tradition (6) and the natural law principles upon which it was based. (7) These writers contributed to customary principles that had been recognized by many states that were politically and economically involved with their fellow nations.
Part I of this essay will describe the natural law and its bearing on the practice of international law and the legal relationships of the world's peoples. (8) Part II describes the concept of "the common good," a foundation of natural law. Part III introduces the term "solidarity," (9) and the collaboration required to achieve the common good. Part IV describes the concept of "subsidiarity," a form of decision-making necessary for natural law to inform international law. Part V explains the suum cuique, (10) a critical precept in natural law as it applies to international law. This essay concludes that natural law principles that rely on practical reason can make important substantive contributions to international law practice today.
THE NATURAL LAW
The definition of the natural law must be addressed at the outset. (11) In the Scholastic tradition, it is not a body of substantive law in itself. Rather, it is a means by which the human mind formulates legal principles that can then be applied to govern a specific jurisdiction. These principles include "the common good," "solidarity," "subsidiarity," and the "suum cuique." (12) Professor Charles Rice has argued that natural law is a "guide to individual conduct" and "serves as a standard for the laws enacted by the state, (13) As the celebrated canonist Gratian, who most likely compiled his collection of canon law principles during the mid-to-latter part of the twelfth century, noted in the Decretum: "Natural law is common to all nations because it exists everywhere through instinct, not because of any enactment." (14) In his commentary, Gratian explained that the natural quality of law means "an instinct of nature proceeding from reason." (15) In Summa Theologica, Thomas Aquinas identified natural law as those precepts "appointed by reason." (16) His first principle of practical reason (17) is as follows: "[G]ood is to be done and pursued, and evil is to be avoided." (18) In the present day theories of natural law, the role of reason, especially practical reason, is critical. For example, Professors Germain Grisez and John Finnis have recognized the importance of practical reason to natural law theory and have elaborated upon Aquinas's first principle. (19) Professor Robert George (20) has described the contemporary views of Professors Finnis and Grisez as the "new classical theory." (21) As George states:
According to this theory, the first principles of natural law are not themselves moral principles. They are principles that extend to and govern all intelligent practical deliberation, regardless of whether it issues in morally upright choice, by directing action toward possibilities that offer some intelligible benefit (and not merely some emotional satisfaction). Such principles refer to non-instrumental ... reasons for action. Reasons of this sort are provided by ends that can be intelligently identified and pursued, not merely as means to other ends, but as ends-in-themselves. (22) Although present day philosophers and legal theorists may disagree about the place of moral considerations in natural law theory, there is little dispute about the role of reason. Reason and cognitive function have played a crucial role in the evolution of law. As Aquinas acknowledged, law may be understood as "an ordinance of reason for the common good, made by him who has care of the community." (23) The use of reason eventually leads to the notion of the common good--principle that supports the existence of international law. (24)
THE COMMON GOOD
By way of introduction, Aquinas noted in his discussion of the natural law that "other matters of law are ordained to the moral common good." (25) Relying on Aquinas's work, Professor John Finnis has observed that "the good that is common between friends is not simply the good of successful collaboration or coordination, nor is it simply the good of two successfully achieved coinciding projects or objectives; it is the common good of mutual self-constitution, self-fulfillment, self-realization." (26) In a fundamental way, the notion of the common good entails a sense of reciprocity in which the Silver Rule (27) and the Golden Rule (28) have a role. Professor Finnis has similarly commented on the importance of community to the common good, for "the common good is the good of individuals, living together and depending upon one another in ways that favour the well-being of each." (29) The concern about the common good as a social, political, and legal subject reaches back to the classical era of ancient Greece and Rome. Aristotle noted, "[e]very state is a community of some kind, and every community is established with a view to some good." (30) In looking at the political institutions established to govern the community, he noted that just governments are those "which have a regard to the common interest." (31) In assessing what Aristotle considered to be just, one can turn to his discourse on ethics where he supplied the foundation for a vital theme: that justice is reciprocity and mutuality through relationship. (32) In placing the notion of reciprocity into the human community, Aristotle contended that the truest or best form of justice is the reciprocal display of friendship. (33) Through the use of reason, a person begins to recognize the role that mutuality and reciprocity in human relationships have in developing the common good. The ancient Roman Marcus Tullius Cicero shared the sentiments of Aristotle when he suggested that a commonwealth, or social order, emerges from the communal spirit of people who make the commonwealth their "property." This idea is based on the principles of "respect to justice" and "partnership for the common good." (34) In writing for the emerging Christian community, St. Augustine reflected some of the views of Aristotle and Cicero when he argued that the human race is not simply united "in a society by natural likeness," but it is or should be "bound together by a kind of tie of kinship to form a harmonious unity, linked together by the `bond of peace.'" (35) Later, in the Middle Ages, Thomas Aquinas, who was influenced by the ideas of Aristotle and Augustine, continued to examine the common good. According to Aquinas, the object of justice was to keep people together in a society in which they share relationships with one another. Specifically, Aquinas noted that "justice is about our dealings not only with others, but also with ourselves." (36) The notion of justice being the reciprocity shared among members of society was further refined by Aquinas when he argued "the virtue of a good citizen is general justice, whereby a man is directed to the common good." (37) Furthermore, Aquinas saw that:
[T]he good of any virtue, whether such virtue direct[s] man in relation to himself, or in relation to certain other individual persons, is referable to the common good, to which justice directs: so that all acts of virtue can pertain to justice, in so far as it directs [each person] to the common good. (38) The twentieth century Christian philosopher Jacques Maritain brought Aquinas's understanding of the common good into the present. (39) Maritain recognized the need to separate the dignity of the individual human being from the dangers of the primacy of the isolated individual and the promotion of the private good. For Maritain, the common good was "the human common good" which includes "the service of the human person." (40)...