On Natural Law by Leo Strauss

Natural law, which was for many centuries the basis of the predominant Western political thought, is rejected in our time by almost all students of society who are not Roman Catholics. It is rejected chiefly on two different grounds. Each of these grounds corresponds to one of the two schools of thought which are predominant today in the west, i.e. positivism and historicism. According to positivism, genuine knowledge is scientific knowledge and scientific knowledge can never validate value judgments; but all statements asserting natural law are value judgments. According to historicism, science (i.e. modern science) is but one historical, contingent form of man’s understanding of the world; all such forms depend on a specific Weltanschauung; in every Weltanschauung the “categories” of theoretical understanding and the basic “values” are inseparable from one another; hence the separation of factual judgments from value judgments is in principle untenable; since every notion of good and right belongs to a specific Weltanschauung, there cannot be a natural law binding man as man. Given the preponderance of positivism and historicism, natural law is today primarily not more than a historical subject.

By natural law is meant a law which determines what is right and wrong and which has power or is valid by nature, inherently, hence everywhere and always. Natural law is a “higher law” but not every higher law is natural. The famous verses in Sophocles’ Antigone (449-460) in which the heroine appeals from the man-made law to a higher law do not necessarily point to a natural law; they may point to a law established by the gods or what one may call in later parlance a positive divine law. The notion of natural law presupposes the notion of nature, and the notion of nature is not coeval with human thought; hence there is no natural law teaching, for instance, in the Old Testament. Nature was discovered by the Greeks as in contradistinction to art (the knowledge guiding the making of artifacts) and, above all, to nomos (law, custom, convention, agreement, authoritative opinion). In the light of the original meaning of “nature,” the notion of “natural law” (nomos tes physeos) is a contradiction in terms rather than a matter of course. The primary question concerns less natural law than natural right, i.e. what is by nature right or just: is all right conventional (of human origin) or is there some right which is natural (physei dikaion)? This question was raised on the assumption that there are things which are by nature good (health, strength, intelligence, courage, etc.). Conventionalism (the view that all right is conventional) derived its support in the first place from the variety of notions of justice, a variety incompatible with the supposed uniformity of a right that is natural. Yet the conventionalists could not deny that justice possesses a core which is universally recognized, so much so that injustice must have recourse to lies or to “myths” in order to become publicly defensible. The precise issue concerned then the status of that right which is universally recognized: is that right merely the condition of the living together of a particular society, i.e. of a society constituted by covenant or agreement, with that right deriving its validity from the preceding covenant, or is there a justice among men as men which does not derive from any human arrangement? In other words, is justice based only on calculation of the advantage of living together, or is it choiceworthy for its own sake and therefore “by nature”? The two possible answers were given prior to Socrates. For our knowledge of the thought of the pre-Socratic philosophers, however, we depend entirely on fragments of their writings and on reports by later thinkers.

Socrates’ disciple Plato is the first philosopher whose writings proper have come down to us. While Plato cannot be said to have set forth a teaching of natural law (cf. Gorgias 483e and Timaeus 83e), there can be no doubt that he opposed conventionalism; he asserts that there is a natural right, i.e. something which is by nature just. The naturally just or right is the “idea” of justice (Republic 501b; cf. 500c-d and 484c-d), justice itself, justice pure and simple. Justice is defined as doing one’s own business or rather doing one’s own business “in a certain manner,” i.e. “well” (433a-b; 443d). A man (or rather his soul) or a city is just if each of its parts does its work well and thus the whole is healthy; a soul or a city is just if it is healthy or in good order (cf. 444d-e). The soul is in good order if each of its three parts (reason, spiritedness, desire) has acquired its specific virtue or perfection and as a consequence of this the individual is well-ordered toward his fellow men and especially his fellow citizens. The individual is well-ordered toward his fell w citizens if he assigns to each what is intrinsically good for him and hence what is intrinsically good for the city as a whole. From this it follows that only the wise man or the philosopher can be truly just. There is a natural order of the virtues and the other good things; this natural order is the standard for legislation (Laws 631b-d). One may therefore say that the natural right in Plato’s sense is in the first place the natural order of the virtues as the natural perfections of the human soul (cf. Laws 765e-766a), as well as the natural order of the other things by nature good. But assigning to each what is good for him by nature is impossible in societies as we find them anywhere. Such assigning requires that the men who know what is by nature good for each and all, the philosophers, be the absolute rulers and that absolute communism (communism regarding property, women and children) be established among those citizens who give the commonwealth its character; it also requires equality of the sexes. This order is the political order according to nature, as distinguished from and opposed to the conventional order (Republic 456b-c; cf. 428e). Thus natural right in Plato’s sense also determines the best regime, in which those who are best by nature and training, the wise men, rule the unwise with absolute power, assigning to each of them what is by nature just, i.e. what is by nature good for him. The actualization of the best regime proves indeed to be impossible or at least extremely improbable; only a diluted version of that political order which strictly corresponds to natural right can in reason be expected. The establishment of the best regime is obstructed in the last analysis by the body, the only thing which is by nature private (Laws 739c; Republic 464d) or wholly incapable of being common. Accordingly, sheer bodily (“brachia}”) force must be recognized as having a natural title to rule-a title indeed inferior to that deriving from wisdom but not destroyed by the latter (Laws 690a-c). Political society requires the dilution of the perfect and exact right, of natural right proper: of the right in accordance with which the wise would assign to everyone what he deserves according to his virtue and therefore would assign unequal things to unequal people. The principle governing the dilution is consent, i.e. the democratic principle of simple equality according to which every citizen possesses the same title to rule as every other (Laws 756e-758a). Consent requires freedom under law. Freedom here means both the participation in political rule of those unwise men who are capable of acquiring common or political virtue, and their possessing private property; law can never be more than an approximation to the verdicts of wisdom, yet it is sufficient to delineate the requirements of common or political virtue, as well as the rules of property, marriage and the like.

It is in accordance with the general character of Aristotle’s philosophy that his teaching regarding natural right is much closer to the ordinary understanding of justice than in Plato’s. In his Rhetoric he speaks of “the law according to nature” as the unchangeable law common to all men, but it is not entirely certain that he takes that law to be more than something generally admitted and hence useful for forensic rhetoric. At least two of his three examples of natural law do not agree with what he himself regarded as naturally right (Rhetoric 1373b4-18). In the Nicomachean Ethics (1134b18- 1135a5) he speaks, not indeed of natural law, but of natural right. Natural right is that right which has everywhere the same power and does not owe its validity to human enactment. Aristotle does not give a single explicit example but he seems to imply that such things as helping fellow citizens in misfortune into which they have fallen in consequence of performing a civic duty, and worshipping the gods by sacrifices belong to natural right. If this interpretation is correct, natural right is that right which must be recognized by any political society if it is to last and which for this reason is everywhere in force. Natural right thus understood delineates the minimum conditions of political life, so much so that sound positive right occupies a higher rank than natural right. Natural right in this sense is indifferent to the difference of regimes whereas positive right is relative to the regime: positive right is democratic, oligarchic, etc. (cf. Politics 1280a8-22). “Yet,” Aristotle concludes his laconic statement on natural right, “one regime alone is by nature the best everywhere.” This regime, “the most divine regime,” is a certain kind of kingship, the only regime which does not require any positive right (Politics 1284a4-15, 1288a15-29). The flooring and the ceiling, the mini­ mum condition and the maximum possibility of political society, are natural and do not in any way depend on (positive) law. Aristotle does not explicitly link up his teaching regarding natural right with his teaching regarding commutative and distributive justice, but the principles of commutative and distributive justice cannot possibly belong to merely positive right. Com­ mutative justice is the kind of justice which obtains in all kinds of exchange of goods and services (it therefore includes such principles as the just price and the fair wage) as well as in punishment; distributive justice has its place above all in the assignment of political honors or offices. Natural right understood in terms of commutative and distributive justice is not identical with natural right as delineating the minimum conditions of political life: the bad regimes habitually counteract the principles of distributive justice and last nevertheless. Aristotle is no longer under a compulsion to demand the dilution of natural right. He teaches that all natural right is changeable; he does not make the distinction made by Thomas Aquinas between the unchangeable principles and the changeable conclusions. This would seem to mean that sometimes (in extreme or emergency situations) it is just to deviate even from the most general principles of natural right.

Natural law becomes a philosophic theme for the first time in Stoicism. It there becomes the theme primarily not of moral or political philosophy but of physics (the science of the universe). The natural or divine or eternal law is identified with God or the highest god (fire, aether, or air) or his reason, i.e. with the ordering principle which pervades and thus governs the whole by molding eternal matter. Rational beings can know that law and knowingly comply with it in so far as it applies to their conduct. In this application natural law directs man toward his perfection, the perfection of a rational and social animal; it is “the guide of life and the teacher of the duties” (Cicero, On the Nature of the Gods I 40); it is the dictate of reason regarding human life. Thus the virtuous life as choiceworthy for its own sake comes to be understood as compliance with natural law-with a law, and hence as a life of obedience. Inversely, the content of natural law is the whole of virtue. ‘ The virtuous life as the Stoics understood it is however not identical with the life of moral virtue as distinguished from the life of contemplation, for one of the four cardinal virtues is wisdom which is above all theoretical wisdom; the virtuous man is the wise man or the philosopher. One is tempted to say that the Stoics treat the study of philosophy as if it were a moral virtue, i.e. as something which could be demanded from most men. Justice, another of the four virtues, consists primarily in doing what is by nature right. The foundation of right is man’s natural inclination to love his fellow men, i.e. not merely his follow citizens: there is a natural society comprising all men (as well as all gods). The inclination toward the universal society is perfectly compatible with the equally natural inclination towards political society which is of necessity a particular society. The unchangeable and universally valid natural law-a part of which determines natural right, i.e. that with which justice in contradistinction to wisdom, courage, and temperance is concerned-is the ground of all positive law; positive laws contradicting natural law are not valid. It is sometimes asserted that the Stoics differ from Plato and Aristotle by being egalitarians. Differing from Aristotle (but not from Plato) they denied that there are slaves by nature; but this does not prove that according to them all men are by nature equal in the decisive respect, i.e. as regards the possibility of becoming wise or virtuous (Cicero, On the Ends of the Good and Bad Things IV 56). The peculiarity of the Stoics in contradistinction to Plato and Aristotle which explains why the Stoics were the first philosophers to assert unambiguously the existence of natural law would seem to be the fact that they teach in a much less ambiguous way than Plato, to say nothing of Aristotle, the existence of a divine providence which supplies divine sanctions for the compliance or non-compliance with the requirements of virtue. (Cf. Cicero, Laws II 15-17 and Republic III 33-34.).

The Stoic natural law teaching is the basic stratum of the natural law tradition. It affected Roman law to some extent. With important modifications it became an ingredient of the Christian doctrine. The Christian natural law teaching reached its theoretical perfection in the work of Thomas Aquinas. It goes without saying that in the Christian version, Stoic corporealism (“materialism”) is abandoned. While natural law retains its status as rational, it is treated within the context of Christian (revealed) theology. The precise context within which Thomas treats natural law is that of the principles of human action; these principles are intrinsic (the virtues or vices) or extrinsic; the extrinsic principle moving men toward the good is God who instructs men by law and assists them by His grace. Natural law is clearly distinguished from the eternal law – God Himself or the principle of His governance of all creatures-on the one hand, and the divine law, i.e. the positive law contained in the Bible, on the other. The eternal law is the ground of the natural law, and natural law must be supplemented by the divine law if man is to reach eternal felicity and if no evil is to remain unpunished. All creatures participate in the divine law in so far as they possess, by virtue of divine providence, inclinations toward their proper acts and ends. Rational beings participate in divine providence in a more excellent manner since they can exercise some providence for themselves; they can know the ends toward which they are by nature inclined as good and direct themselves toward them. Man is by nature inclined toward a variety of ends which possess a natural order; they ascend from self-preservation and procreation via life in society toward knowledge of God. Natural law directs men’s action toward those ends by commands and prohibitions. Differently stated, as a rational being man is by nature inclined toward acting according to reason; acting according to reason is acting virtuously; natural law pre­ scribes therefore the acts of virtue. Man possesses by nature knowledge of the first principles of natural law which are universally valid or unchangeable. Owing to the contingent character of human actions, however, those conclusions from the principles which are somewhat remote possess neither the evidence nor the universality of the principles themselves; this fact alone would require that natural law be supplemented by human law. A human law which disagrees with natural law does not have the force of law (Summa theologica 1 2 q.90ff.). All moral precepts of the Old Testament (as distinguished from its ceremonial and judicial precepts) can be reduced to the Decalogue; they belong to the natural law. This is true in the strictest sense of the precepts of the Second Table of the Decalogue, i.e. the seven commandments which order men’s relations among themselves (Exodus 20: 12-17). The precepts in question are intelligible as self-evident even to the people and are at the same time valid without exception; compliance with them does not require the habit of virtue (S.th. 1 2 q. 100). A sufficient sanction is supplied by divine punishment for transgressions of the natural law but it is not entirely clear whether human reason can establish the fact of such punishment; Thomas surely rejects the gnostic assertion that God does not punish and the assertion of certain Islamic Aristotelians that the only divine punishment is the loss of eternal felicity. He does say that sin is considered by the theologians chiefly in so far as it is an offense against God, whereas the moral philosophers consider sin chiefly in so far as it is opposed to reason. These thoughts could lead to the view of some later writers, according to which natural law strictly understood is natural reason itself, i.e. natural law does not command and forbid but only “indicates”; natural law thus understood would be possible even if there were no God (cf. Suarez, Tractatus de Legibus ac de Deo Legislatore II 6 sect. 3; Grotius, De jure belli ac pacis, Prolegomena sect. 11; Hobbes, Leviathan ch. 15 end; Locke, Treatises of Civil Government II sect. 6; Leibniz, Theodicee sect. 183). Thomas treats natural right (as distinguished from natural law) in his discussion of justice as a special virtue (S. th. 2 2 qu. 57). Therein he is confronted with the task of reconciling with the Aristotelian teaching the Roman law distinction between ius naturale and ius gentium according to which natural right deals only with things common to all animals (like procreation and the raising of offspring) whereas the ius gentium is particularly human. The Roman law distinction might seem to reflect early conventionalist teaching (cf. Democritus fr. 278). Thomas’ reconciliation apparently paved the way for the conception of “the state of nature” as a status antedating human society. (Cf. Suarez, foe. cit. II 8 sect. 9.).

The Thomistic natural law teaching, which is the classic form of the natural law teaching, was already contested in the Middle Ages on various grounds. According to Duns Scotus, only the commandment to love God or rather the prohibition against hating God belongs to natural law in the strictest sense. According to Marsilius of Padua, natural right as Aristotle meant it is that part of positive right which is recognized and observed everywhere (divine worship, honoring of parents, raising of offspring, etc.); it can only metaphorically be called natural right; the dictates of right reason regarding the things to be done (i.e. natural law in the Thomistic sense) on the other hand are not as such universally valid because they are not universally known and observed.

Natural law acquired its greatest visible power in modern times: in both the American and the French revolutions, solemn state papers appealed to natural law. The change in effectiveness was connected with a substantive change; modern natural law differs essentially from pre-modern natural law. Pre-modern natural law continued to be powerful but it was adapted more or less incisively to modern natural law. The most striking characteristics of modern natural law are these: 1) Natural law is treated independently, i.e. no longer in the context of theology or of positive law; special chairs for natural law were established in some protestant countries; treatises on natural law took on the form of codes of natural law; the independent treatment of natural law was made possible by the belief that natural law can be treated “geometrically,” i.e. that the conclusions possess the same certainty as the principles. 2) Natural law became more and more natural public law; Hobbes’ doctrine of sovereignty, Locke’s doctrine “no taxation without representation,” or Rousseau’s doctrine of the general will, are not simply political but legal doctrines; they belong to natural public law; they do not declare what the best political order is which by its nature is not realizable except under very favorable conditions, but they state the conditions of legitimacy which obtain regardless of place and time. 3) Natural law by itself is supposed to be at home in the state of nature i.e. a state antedating civil society. 4) In the modern development, “natural law” is as it were replaced by “the rights of man,” or in other words the emphasis shifts from man’s duties to his rights. 5) Whereas pre-modern natural law was on the whole “conservative,” modern natural law is essentially “revolutionary.” The radical difference between modern and pre-modern natural law appears most clearly if one studies the still-remembered great modern natural law teachers rather than the university professors who as a rule rest satisfied with compromises.

The principles informing modern natural law were established by two thinkers who were not themselves natural law teachers, Machiavelli and Descartes. According to Machiavelli, the traditional political doctrines take their bearings by how men should live and thus they culminate in the description of imaginary commonwealths (“utopias”), which is useless for practice; one ought to start from how men do live. Descartes begins his revolution with the universal doubt which leads to the discovery of the Ego and its “ideas” as the absolute basis of knowledge and to a mathematical­ mechanical account of the universe as of a mere object of man’s knowledge and exploitation.

Modern natural law as originated by Hobbes did not start as traditional natural law did from the hierarchic order of man’s natural ends but from the lowest of those ends (self-preservation) which could be thought to be more effective than the higher ends: a civil society ultimately based on nothing but the right of self-preservation would not be utopian. Man is still asserted to be the rational animal but his natural sociality is denied; man is not by nature ordered toward society but he orders himself toward it prompted by mere calculation. This view in itself is very old but now it is animated by the concern for a natural-right basis of civil society. The desire for self­ preservation has the character of a passion rather than of a natural inclination; the fact that it is the most powerful passion makes it the sufficient basis of all rights and duties. Natural law which dictates men’s duties is derivative from the natural right of self-preservation; the right is absolute while all duties are conditional. Men being equal regarding the desire for self-preservation as well as regarding the power of killing others, all men are by nature equal; there is no natural hierarchy of men, so much so that the sovereign to whom all must submit for the sake of peace and ultimately of the self-preservation of each is understood as a “person,” as the “person,” i.e. as the representative or agent, of each; the primacy of the individual-of any individual-and his natural right remains intact (cf. Leviathan ch. 21).-The doctrine of Locke may be described as the peak of modern natural law. At first glance it appears to be a compromise between the traditional and the Hobbean doctrines. Agreeing with Hobbes, Locke denies that the natural law is imprinted in the minds of men, that it can be known from the consent of mankind and that it can be known from men’s natural inclination. His deduction of natural law is generally admitted to be confusing, not to say confused, which does not prove however that Locke himself was confused. It seems to be safest to understand his doctrine as a profound modification of the Hobbean doctrine. Certain it is that, differing from Hobbes, he sees the crucially important consequence of the natural right of self-preservation in the natural right of property, i.e. of acquiring property, a natural right which within civil society becomes the natural right of unlimited acquisition. Property is rightfully acquired primarily only by labor; in civil society however labor ceases to be the title to property while remaining the source of all value. Locke’s natural law doctrine is the original form of capitalist theory. Rousseau too starts from the Hobbean premise. Hobbes asserted that the natural right to judge of the means of self-preservation is the necessary consequence of the right of self-preservation itself, and belongs, as does the fundamental right, equally to all men, wise or foolish. But Rousseau, differing from Hobbes, demands that the natural right to judge of the means of self-preservation be preserved within civil society as an institution agreeing with natural right: every one subject to the laws must have a say in the making of the laws by being a member of the sovereign, i.e. of the legislative assembly. The corrective to folly was to be found above all in the character of the laws as general both in origin and in content: all subject to the laws determine what all must or may not do. The justice or rationality of the laws is, by that generality, guaranteed in the only way compatible with the freedom and equality of all. In the society established in accordance with natural right there is no longer a need or a possibility of appealing from positive law to natural right although or because the members or rulers of that society are not supposed to be just men. Rousseau further differed from Hobbes by realizing that if man is by nature asocial, he is by nature arational; questioning the traditional view that man is the rational animal, he found the peculiarity of man in his perfectibility or, more generally stated, his malleability. This led to the conclusions that the human race is what we wish to make it and that human nature cannot supply us with guidance as to how man and human society ought to be.-Not Rousseau but Kant drew the decisive conclusion from Rousseau’s epoch­ making innovations: the Ought cannot be derived from the Is, from human nature; the moral law is not a natural law or derivative from a natural law; the criterion of the moral law is its form alone, the form of rationality, i.e. of universality; just as according to Rousseau the particular will becomes the unblameable positive law by being generalized, according to Kant the maxims of action prove to be moral if they pass the test of being universalized, i.e. of being possible principles of universal legislation. At about the same time that Kant, sympathizing with the French Revolution, radicalized the most radical form of modern natural right and thus transformed natural right and natural law into a law and a right which is rational but no longer natural, Burke, opposing the French Revolution and its theoretical basis, which is a certain version of modern natural right, returned to pre-modern natural law. In doing so, he made thematic the conservatism which was implicit to some extent in pre-modern natural law. Therewith he profoundly modified the pre-modern teaching and prepared decisively the transition from the natural “rights of man” to the prescriptive “rights of Englishmen,” from natural law to “the historical school.”

Bibliography

1. Carlyle, R. W., and Carlyle, A. J., A History of Medieval Political Theory in the West (Edinburgh and London 1903-36: 6 vols.).
2. Gierke, 0. von, Political Theories of the Middle Ages (Cambridge 1900) tr. by F. Maitland.
3. Gierke, 0. von, Natural Law and the Theory of Society, 1500 to 1800 (Cambridge 1934) tr. by E. Barker.
4. Gierke, 0. von, The Development of Political Theory (New York 1939) tr. by B. Freyd.
5. Kelsen, Hans, “Natural Law Doctrine and Legal Positivism, in General Theory of Law and State (New York 1961) tr. by A. Wedberg.
6. Mcilwain, C.H., The Growth of Political Thought in the West (New York 1932).
7. Nussbaum, A., A Concise History of the Law of Nations (New York 1947).
8. Rommen, H. A., The Natural Law (St. Louis 1947) tr. by T. Hanley.
9. Strauss, L., Natural Right and History (Chicago 1953).