Natural Law: An Introduction—Part 1

"Persimmon Tree," late 18th-early 19th century, Nakamura Hochu © Smithsonian Institution (The image is for ornamental purposes.)

Natural law has to do with the idea that there are some meta-laws (or principles) that transcend, supervene upon or trump positive law(s). In the Western philosophical tradition, its roots go back as far as the pre-Socratic philosophers: Anaximander (610-547 BCE), Pythagoras (570-500 BCE), and Heraclitus (540-475 BCE). There are glimmers of it in Aristotle’s notion of “right reason” and Plato appears to assume the workings of some sort of unwritten and divine natural law. It is also found in the work of the Greek dramatists, Aeschylus (525-456 BCE) and Sophocles (495-406 BCE). Natural law receives its first strong articulation among the Greek and Roman Stoics: “We find in Stoic natural law theory very general but groundbreaking concepts of divine governance, of rationality or logos embedded in nature, universal human equality and brotherhood, and the ideal of respecting and harmonizing oneself with nature” (Howard P. Kainz).

Among the Roman jurists, Gaius (130-180) identified natural law with the “law of nations,” in the sense that there is a rational element underlying and therefore common to all judicial systems. The East Roman Christian Emperor Justinian (483-565) oversaw a codification of all Roman law as the Corpus Juris Civilis (in three parts: the Digesta, Institutiones and Codex) in which natural law is distinguished from the ‘law of nations’ and is depicted as a set of immutable divine laws which can be used to judge the validity of civil laws. The twelfth century Benedictine monk and canon lawyer from Bologna, Gratian, understood natural law as contained in the Hebrew Bible’s Decalogue and in the Golden Rule of the New Testament Gospels.

After the Stoics, St. Thomas Aquinas (1225-1274) represents the most important development in the natural law tradition. Aquinas distinguishes between the “Eternal Law” that governs the universe, the “Divine Law” found in the Scriptures, “Natural Law,” which is participation in the Eternal Law by rational creatures, and civil or positive law. In this account, Eternal Law gives rise to natural law and the Divine Law reiterates aspects of the Natural Law. At its best, civil law will assume or incorporate much of the natural law that pertains to social order. In effect, natural law mediates between divine law, on the one hand, and human or positive law, on the other. As explained by Kainz, “what we experience as fundamental human inclinations are aspects of the eternal law instilled into human nature, orienting humans toward certain natural goals. Human beings have a natural inclination to accomplish the general ends congruent with their nature, and this inclination is a mark or impression of the eternal law in which they are participating. Natural law thus is the actual participation in the eternal law, facilitated by human inclinations to implement the will of the divine legislator.” The primary motivation for such participation in the eternal law is a rational apprehension of the imperative that “good is to be done and pursued, and evil is to be avoided,” which is a general principle of practical reason. This is said by Aquinas to be the “first precept” of natural law. The good for humans is eudaimonia, clarified in terms of the natural inclinations of human nature, and which entail three pivotal secondary precepts of natural law: (1) the preservation of human life, (2) sexual intercourse and education of offspring (an inclination in common with other animals), and (3) an inclination to good, according to the nature of our reason which nature has provided us, and involving an inclination to know about God, live in society, and to shun ignorance (and hence pursue knowledge). The determination of further natural law principles is not a strict logical or deductive exercise of reasoning from premises to a conclusion, but involves the derivation of conclusions from the secondary precepts, for instance: do not kill, help maintain social order and harmony, as well as the giving of “determinations” to certain generalities: for example, prison sentences or fines are a determination from the principle that evildoers should be punished.

With Francisco Suárez (1548-1617), natural law is made known to us through “natural reason” and the law of the Decalogue. The law of God is, after St. Paul, written in the hearts of all men, “But if we would look for empirical confirmation of the rational application of natural law, Suarez suggests that the ‘law of nations’ is the closest approximation to it.”—Howard P. Kainz

“For many years, natural law was thought to be the principal source of international law. Indeed, many texts of the sixteenth, seventeenth, and eighteenth centuries characterized themselves as studies of the ‘laws of nature and of nations.’ [….] A belief in the relevance of natural law to international relations may, but need not, stem from religious principles. The early sixteenth- and seventeenth-century Spanish international lawyers, Vitoria and Suárez, for example, based the law of nations on Catholic natural law foundations. However, Grotius [see below], a Protestant, later looked to more general biblical sources, as well as to classical authors and to right reason, to ground his theory of natural law. [….] When nineteenth-century legal positivists began deriding international law as being mere morality and not law at all, many international lawyers took affright and tried to sever their ties with natural law altogether. There was a suspicion that intimately linking international law to natural law debased international law.”—Mark W. Janis

Relying on the polyvalent meaning of jus in early medieval philosophy as law, right or justice, “the Spanish Dominicans, Francisco de Vitoria (1492-1546) and Bartolemé de las Casas (1474-1566), reflecting critically on the Spanish conquest of the New World, insisted that natural rights inhered in humans and were being subverted by European colonizers. Vitoria applied jus gentium [the ‘law of nations’ or international law] in condemning the actions of the Conquistadores in America, arguing that jus gentium forbids the taking of property of the Indians, or trying to bring them under the domination of the Spanish Empire, since they have a right to their own government. Native Americans may not be enslaved since they have dominion over themselves and over things, and their state of freedom is indicated by their political systems, magistrates, and system of exchange and religion; and it is unjust to force the Christian religion on them, since faith has to be voluntary.”—Howard P. Kainz

The Dutch jurist Hugo Grotius (1588-1645), made explicit a point found earlier in the tradition (e.g. with Robert Bellarmine): natural law can be valid and binding even if God does not exist (i.e., we need not presume a divine legislator). The “father of international law” grounded natural law in what he took to be our intrinsically social, altruistic nature as rational beings. In her recent book, Frontiers of Justice: Disability, Nationality, Species Membership (2006), Martha C. Nussbaum states that she is attempting to “revive” the natural law philosophy of Grotius. Although Grotius applies natural law principles specifically to international relations, Nussbaum contends such principles suggest a broader or more “general template for thinking about domestic issues as well, although he does not so apply it: In On the Law of War and Peace (1625), Grotius gives an account of the basic principles of international relations, tracing it to the Greek and Roman Stoics (Seneca and Cicero above all). Put very simply, this approach holds that the way to begin, when we think about fundamental principles, is to think of the human being as a creature characterized both by dignity or moral worth and by sociability: by ‘an impelling desire for fellowship, that is for common life, not just of any kind, but a peaceful life, and organized according to the measure of his intelligence, with those who are of his kind.’ Grotius thinks of these features as deeply natural. We may, however, (with Cicero, who was agnostic in metaphysics), view these claims as freestanding ethical claims out of which one might build political conceptions of the person that can be accepted by people who hold different views in metaphysics and in religion. The general idea of Grotius’ natural law theory is that these two features of the human being, and their ethical value, suggest a good deal about the treatment to which every human being is entitled. Thus political theory begins from an abstract idea of basic entitlements, grounded in the twin ideas of dignity (the human being as an end) and sociability. It is then argued that certain specific entitlements from those ideas, as necessary conditions of a life with human dignity. [….] What I want to bring out about Grotius’ theory is that it begins with the content of an outcome, in the sense of an account of basic entitlements of human beings whose fulfillment is required by justice; if these entitlements are fulfilled, then a society (in this case, ‘international society’) is minimally just. The justification of the entitlement set is not procedural, but involves the intuitive idea [what for Aquinas would be a ‘self-evident’ idea] of human dignity and arguments to the effect that a certain entitlement is implicit in the idea of human dignity. Grotius explicitly argues that we must not attempt to derive our fundamental principles from an idea of mutual advantage alone; human sociability indicates that advantage is not the only reason for which humans act justly. Grotius evidently believes that a society based upon sociability and respect rather than upon mutual advantage can remain stable over time. [….] Notice that for Grotius the important kind of equality among persons is moral equality, which entails equality of respect and entitlement. Equality of powers plays no significant role in his argument. [….] Thus there is no analogue in his theory to Hume’s Circumstances of Justice or to the similar assumptions in the theories of Hobbes, Locke, and Kant. Wherever human beings are alive, there are already Circumstances of Justice between them, just because they are human and sociable.”—Martha C. Nussbaum

“Thomas Hobbes’s Leviathan (1651) might be treated as the antitype to everything Grotius stands for, but such a presumption would clearly be mistaken. Indeed, what is most striking to someone who examines the social contract tradition beginning from the natural law tradition is how much these thinkers agree with Grotius and his fellow natural law thinkers. That is to say, Hobbes holds that there are natural moral laws that enjoin ‘Justice, Equity, Modesty, Mercy, and (in summe) doing to others, as wee would be done to’ (XVII). But he believes that these moral laws can never give rise to a stable political order, because they are ‘contrary to our naturall Passions, that carry us to Partiality, Pride, Revenge, and the like’ (ibid). Natural sociability can be observed among bees and ants, but in human beings there is no reliable sociability without coercion. Because our natural passions are fundamentally competitive and egoistic, with fear playing a central motivating role, the state of nature—the state of human relations in the absence of a strong coercive sovereign—is a state of war. Hobbes famously describes this state as a very miserable one indeed. In this state of war, there is a rough equality of power and resources. Where bodily strength is concerned, the weakest can kill the strongest by stealth; where mental capacity is concerned, this rough equality will be doubted only by those who have a ‘vain conceipt’ of their own wisdom. [….] Although Hobbes appears to think humans are moral equals as well (the natural law part of his theory suggests this strongly, at any rate), it is equality of power and ability that plays the salient role in his argument. Equality of ability plays a large role in making the state of nature as bad as it is: for it generates an equality of hope, which in turn spurns people on to further competition. Given this natural equality of power, our passions incline us to make peace with one another, so that we can get on with our lives in tolerable security. ‘The Passions that encline men to Peace, are Feare of Death; Desire of such things as are necessary to commodious living; and a Hope by their Industry to attain them. And Reason suggesteth convenient Articles of Peace, upon which men may be drawn to agreement’ (XIII). Hobbes does not portray his social contract as generating principles of justice. He speaks of justice in ways that are hard to reconcile, sometimes arguing that there is no justice where there is no coercive power (XV), and sometimes arguing that there are natural principles of justice, albeit ineffectual ones, given our natural passions. But the social contract does generate the fundamental principles of political society. The contract is a reciprocal agreement to transfer natural rights (XIV). Its object is for every man a ‘good to himselfe,’ for the group of human beings a mutual advantage, ‘that Is to say, of getting themselves out from that miserable condition of Warre’ (XVII).”—Martha C. Nussbaum

“…Hobbes is normally portrayed as the great defender of the position that moral laws are not laws properly so called, and ‘states could be bound by no higher law.’ This view is based on Hobbes’s claim that the relationship among States in international affairs is like the relationship of people in the state of nature, where the natural human condition can be described as the ‘war of very man against every man.’ As Hobbes says at the end of Chapter 30 of the Leviathan: ‘The Law of Nations and the Law of Nature, is the same thing. And every Sovereign hath the same Right, in procuring the safety of his People, that any particular man can have, in procuring his own safety.’ It is thus contended that Hobbes is the great defender of the use of violence, especially in situations where there is no sovereign, and most especially in the relations between States. It is often forgotten, though, that in the very paragraph where Hobbes speaks of the war that exists in any state of nature, he also declares that the first branch of the ‘first, and fundamental law of nature’ is ‘to seek peace and follow it.’ The more Hobbesian-sounding law of nature, ‘by all means we can, defend ourselves,’ is said to be only the second branch of the first law of nature. Hobbes has been often unfairly characterized as the defender of the right of States to use any means, including violence, in the relations with one another and with their own subjects. This is because in the state of nature, while individual persons have the right to do everything, this is not a reasonable position in which to remain.”—Larry May

“[W]hile it is always unreasonable to be first performer of the social covenant, it is also unreasonable not to want to join cooperative associations that could protect us. It seems reasonable to argue that if Hobbes rejects the desirability of first performance to the social contract, he should also be opposed to the attitudes of cooperation and trust that are essential to an international rule of law. Yet, in Chapter 14 of Leviathan, Hobbes indicates that the first performance of contracts is only conditionally irrational in the state of nature—that is, only when cooperation jeopardizes self-defense. But Hobbes also counsels that we should always pursue peace over war and that it is reasonable to go to great lengths to create a situation in which people feel bound to keep their promises and contracts. Indeed, Hobbes defines the law of nature as a dictate of right reason that counsels against the use of force and violence. Civil society, along with the domestic rule of law, is created so as to provide just the sort of mutual enforcement of agreements that will make the first performance reasonable. [….] A Hobbesian position on international law would support a systematic set of laws of nature that can be derived from the two-pronged principle: Seek peace where you can, and otherwise be ready to resort to war. What is lacking in Hobbes’s account, from a contemporary perspective, is a strong defense of human rights.”—Larry May

“Hobbes argues that the laws of nature are mere theorems for what ‘conduceth to the conservation and defense of themselves.’ For this reason, natural laws are not laws properly so-called: they are binding ‘in foro interno,’ not ‘in foro externo.’ Nonetheless, for Hobbesians, natural laws are no less binding in terms of their reasonable restraint on violent action because of their ‘in foro interno’ status. These secular laws bind in the conscience, and this is a true bindingness. But they do not bind as laws often do—that is, they do not bind because of the fear of punishment at the hands of the law-givers. Fear of the person who could punish creates a bindingness that is externally motivated . Yet the internally motivated bindingness of conscience, while weaker than such things as fear, is still a motivation for most people. And a Hobbesian can follow Hobbes in arguing that it is reasonable for humans to place restraints on what they can bargain away: ‘[T]here be some rights that no man can be understood by any words, or other signes, to have abandoned or transferred….’ Because Hobbes did not clearly recognize a category of moral rights that could be used to ground fundamental legal norms, and because he did not think that the laws of nature were laws properly so-called, he is normally seen as the first strict legal positivist rather than a defender of natural law theory. But it seems to me that the Hobbesian, although non-standard Hobbesian, position on international relations…blurs the distinction between positive and natural law theories in significant ways and sets the stage for a moral minimalism that lets in a minimal conception of natural law. For while the law of nature only bind in the conscience, they do still bind, and can form the basis for restraint of violence, even in the international arena. A secularized and minimalist natural-law theory is one that derives constraints on the use of violence from principles of human psychology and morality.”—Larry May

Please Note: A list of "References and Further Reading" will be appended to the third and final post in this series.