Natural Law: Greek or Hebrew?

The phrase “natural law” itself is capable of so many interpretations that anyone who advocates natural law must expend a great deal of effort explaining what he means.1

In his excellent essay Perspective on Natural Law, Gordon H. Clark  argues “The Natural Law concept is more than a tool for lawyers. It is an indispensable concept for the proponent of liberty and limited government and, as liberty comes to seem more precious and popular disillusionment with political panaceas become more acute, we may expect to see increasing reliance on the Natural Law philosophy as an indispensable means for achieving a sounder society, one more in harmony with the eternal verities and the accumulated wisdom of the race.” It’s an important – an essential – topic. But it can be a rather confusing topic because the phrase is used to refer to two very related, but actually distinct ideas. The two ideas are often intertwined and the distinction is lost.

Greek Natural Law

Clark provides a nuanced history of natural law theory. He traces the predominant understanding of natural law to Greek philosophy.

Aristotle, Plato’s pupil and critic, for centuries provided the philosophical foundation for Natural Law doctrine. During the Middle Ages, Aristotle was “The Philosopher.” In the philosophy of Plato, the Forms or Ideas were manifested in individuals but their abode was elsewhere; for Aristotle, the Form or Idea was immanent in the individual as a potency to be realized in and through the individual’s life. “What each thing is when fully developed,” he wrote, “we call its nature, whether we are speaking of a man, a horse, or a family.” The ethical imperative which emerges from this position may be simply stated as follows: “Realize your nature, conceived as the ultimate end or purpose of your life, by cooperating with the Idea within you which drives toward completion.” It follows that whatever thwarts this development is repugnant to nature, and hence bad; whatever enhances this development cooperates with nature, and is good…

Theology provided a healthy setting for the Natural Law concept, and this concept reached its peak in scholastic thought. To summarize scholastic thought would require a book in itself, but a quotation from its greatest exponent, Thomas Aquinas, will give an inkling of the harmonious way the Natural Law fits into the edifice of scholasticism.

“The precepts of the natural law are to the practical reason, what the first principles of demonstrations are to the speculative reason; because both are self-evident principles… the first principles in the practical reason is one founded on the notion of good, viz., that good is that which all things seek after. Hence this is the first precept of law, that good is to be done and ensued, and evil is to be avoided. All other precepts of the natural law are based upon this: so that whatever the practical reason naturally apprehends as man’s good (or evil) belongs to the precepts of the natural law as something to be done or avoided.

“Since, however, a good has the nature of an end, and evil, the nature of a contrary hence it is that all those things to which man has a natural inclination, are naturally apprehended by reason as being good, and consequently as objects of pursuit, and their contraries as evil, and objects of avoidance. Wherefore according to the order of natural inclinations, is the order of the precepts of the natural law. Because in man there is first of all an inclination to good in accordance with the nature which he has in common with all substances: inasmuch as every substance seeks the preservation of its own being, according to its nature: and by reason of this inclination, whatever is a means of preserving human life, and of warding off its obstacles, belongs to the natural law. Secondly, there is in man an inclination to things that pertain to him more specially, according to that nature which he has in common with other animals: and in virtue of this inclination, those things are said to belong to the natural law, which nature has taught to all animals, such as sexual intercourse, education of offspring and so forth. Thirdly, there is in man an inclination to good, according to the nature of his reason, which nature is proper to him: thus man has a natural inclination to know the truth about God, and to live in society: and in this respect, whatever pertains to this inclination belongs to the natural law; for instance, to shun ignorance, to avoid offending those among whom one has to live, and other such things regarding the above inclination.…

“For it has been stated that to the natural law belongs everything to which a man is inclined according to his nature. Now each thing is inclined naturally to an operation that is suitable to it according to its form: thus fire is inclined to give heat. Wherefore, since the rational soul is the proper form of man, there is in every man a natural inclination to act according to reason: and this is to act according to virtue. Consequently, considered thus, all acts of virtue are prescribed by the natural law: since each one’s reason naturally dictates to him to act virtuously….

“The force of law depends on the extent of its justice. Now in human affairs a thing is said to be just, from being right, according to the rules of reason. But the first rule of reason is the law of nature, as is clear from what has been stated above. Consequently every human law has just so much of the nature of law, as it is derived from the law of nature. But if in any point it deflects from the law of nature, it is no longer a law but a perversion of law.”

According to this Greek understanding, whatever is natural for man is prescribed by natural law. Whatever preserves life (something natural for man and all animals) is mandated by natural law. Whatever avoids obstacles to man’s potential belongs to natural law. We can find a good example of this kind of reasoning in Rutherford’s Lex Rex. Rutherford argues that

All civil power is immediately from God in its root; in that, 1st, God hath made man a social creature, and one who inclineth to be governed by man, then certainly he must have put this power in man’s nature: so are we, by good reason, taught by Aristotle. 1 2d, God and nature intendeth the policy and peace of mankind, then must God and nature have given to mankind a power to compass this end; and this must be a power of government…

No society hath liberty to be without all government, for ‘God hath given to every society,’ saith Covairuvias,’ a faculty of preserving themselves, and warding off violence and injuries; and this they could not do except they gave their power to one or many rulers.’2

Natural law is determined by the observation of nature. By looking at nature, man makes various deductions, resulting in precepts. Again, Rutherford provides us with an example.

[T]here is no law of nature agreeing to all living creatures for superiority; for by no reason in nature hath a boar dominion over a boar, a lion over a lion, a dragon over a dragon, a bull over a bull: and if all men be born equally free, as I hope to prove, there is no reason in nature why one man should be king and lord over another; therefore while I be otherwise taught by the aforesaid Prelate Maxwell, I conceive all jurisdiction of man over man to be as it were artificial and positive, and that it inferreth some servitude whereof nature from the womb hath freed us,3

Thus natural law teaches that no man is born a king because no boar is born a king over other boars.

In his influential 18th century work Commentaries on the Law, Sir William Blackstone says

But if the discovery of these first principles of the law of nature depended only upon the due exertion of right reason, and could not otherwise be obtained than by a chain of metaphysical disquisitions, mankind would have wanted some inducement to have quickened their inquiries, and the greater part of the world would have rested content in mental indolence, and ignorance it’s inseparable companion. As therefore the creator is a being, not only of infinite power, and wisdom, but also of infinite goodness, he has been pleased so to contrive the constitution and frame of humanity, that we should want no other prompter to inquire after and pursue the rule of right, but only our own self-love, that universal principle of action. For he has so intimately connected, so inseparably interwoven the laws of eternal justice with the happiness of each individual, that the latter cannot be attained but by observing the former; and, if the former be punctually obeyed, it cannot but induce the latter. In consequence of which mutual connection of justice and human felicity, he has not perplexed the law of nature with a multitude of abstracted rules and precepts, referring merely to the fitness or unfitness of things, as some have vainly surmised; but has graciously reduced the rule of obedience to this one paternal precept, “that man should pursue his own true and substantial happiness.” This is the foundation of what we call ethics, or natural law. For the several articles into which it is branched in our systems, amount to no more than demonstrating, that this or that action tends to man’s real happiness, and therefore very justly concluding that the performance of it is a part of the law of nature; or, on the other hand, that this or that action is destructive of man’s real happiness, and therefore that the law of nature forbids it.

The important point here is that the precepts of natural law are the result of a chain of reasoning performed by man, starting from the premise that “good is to be done and ensued.” Law is defined by what is good. Paul Helm helpfully explains how this applies to the 10 commandments.

For Aquinas, natural law is knowable and known by the natural reason of man as he now is. The knowledge of the content of the Decalogue is not, it would seem, innate, but it follows at once from the knowledge of first principles. Thus from the self-evident moral principle that one should do evil to no one it follows that one should not kill. Aquinas says that ‘all the precepts of the decalogue are related to them (the primary and general precepts of the law of nature) as conclusions to general principles.’ *30… It follows from this that for Aquinas the Decalogue has a supplementing function. It provides a primary set of theorems from the axioms of the natural law…

[Aquinas:] “[T]he precepts of the decalogue… are such as can be known from first general principles with but little reflection.”

R. A. Armstrong helpfully elaborates.

Thomas uses this term ‘self-evident’ in a strictly technical sense. What he means is not that the precepts in question are innate (in the sense that they are given to man at birth), and thus must be known to everyone; rather, he means that the truth of these precepts becomes apparent, immediately we examine the terms involved. For instance, immediately we reflect on the concept of “goodness” we see without fail that whatever the content of “good” is (and this is something we come to know, after varying degrees of reflection), it is something that ought to be done. And likewise, whatever we discover to be evil – this we immediately know, ought to be avoided.4

This is the Greek meaning of natural law.

Hebrew Natural Law

Because the focus of Clark’s essay was to demonstrate the importance of natural law for political theory, he emphasized the points of similarity between historic views of natural law. However, his comments regarding Israel do serve to highlight an important distinction.

Natural law for Israel was God’s law; Israel regarded itself as a sacred community for which God legislated. No king of Israel successfully set himself up as the source of law; there was another and higher source. There is no doubt as to what their authority was: They looked to God as the source of their law. “The Lord is our judge, the Lord is our lawgiver, the Lord is our King.” (Is. 33:22). All, or nearly all, of the basic laws of this people were written as though emanating from God Himself… But this Law was not something afar off, it was also written on the heart of man: “The word (commandment) is very near you; it is in your mouth and in your heart, so that you can do it.” (Deuteronomy 12:14) Paul, in his Epistle to Romans (2:13-16) stresses the point that this Law is natural to man as such.

In this case, natural law is not man’s process of reasoning from an axiom. Rather, natural law is a set of specific laws revealed by God in stone and innately in human hearts. Contrary to the Greek view that the law is defined by what is good, in the Israelite view what is good is defined by the law. The law is the starting point rather than the result of a process of reflection and reasoning. When Adam was created in the Garden of Eden, he instantly, instinctively, innately knew the precepts of the moral law. They were as clear in his mind as they are in yours when you read them in your Bible. He did not have to study nature or sit and think through his purpose and potential in order discover the precepts of natural law. He knew them the instant he could breathe, just as he instantly knew how to speak. Aristotle (and Aquinas following him) believed that man was born “tabula rasa” (a blank slate) without any innate ideas. Everything is learned through interaction with the world – experience. Thus they could not affirm Scripture’s teaching that God reveals his law innately within man at his creation and believed man had to discover it. Augustine, Calvin, and others affirm that man is born with innate ideas.

Thus, in this view, we do not look at the life of animals and thereby draw conclusions about what natural law demands of man concerning civil government and rulers. Instead, we look at the precepts of the moral law and draw conclusions about what it demands of man concerning civil government and rulers. Likewise, we do not start with the principle of self preservation and then conclude that whatever is conducive to self preservation is thereby demanded by natural law. Rather, we start with the precepts of the decalogue and deduce what is says about self preservation, etc.

Atheistic Aquinas vs Fideistic Augustine

Libertarian political philosopher Murray Rothbard (“Mr. Libertarian”) agreed that “natural law presents man with a set of norms which may well be radically critical of existing positive law imposed by the State.” However, being an atheist, Rothbard suppressed the truth of God’s revelation and sought an alternative foundation.5 He found it in Greek natural law. His introduction to the subject helpfully illustrates the difference between Greek and Hebrew natural law. Rothbard rejected the

extreme Augustinian position which held that faith [i.e. revelation] rather than reason was the only legitimate tool for investigating man’s nature and man’s proper end. In short, in this fideist tradition, theology had completely displaced philosophy.3 The Thomist tradition, on the contrary, was precisely the opposite: vindicating the independence of philosophy from theology, and proclaiming the ability of man’s reason to understand and arrive at the laws, physical and ethical, of the natural order, if belief in a systematic order of natural laws open to discovery by man’s reason is per se anti-religious, then anti-religious also were St. Thomas and the later Scholastics, as well as the devout Protestant jurist Hugo Grotius. The statement that there is an order of natural law, in short, leaves open the problem of whether or not God has created that order; and the assertion of the viability of man’s reason to discover the natural order leaves open the question of whether or not that reason was given to man by God. The assertion of an order of natural laws discoverable by reason is, by itself, neither pro- nor anti-religious.4


Because this position is startling to most people today, let us investigate this Thomistic position a little further. The statement of absolute independence of natural law from the question of the existence of God was implicit rather than flatly asserted in St. Thomas himself; but like so many implications of Thomism, it was brought forth by Suarez and the other brilliant Spanish Scholastics of the late sixteenth century. The Jesuit Suarez pointed out that many Scholastics had taken the position that the natural law of ethics, the law of what is good and bad for man, does not depend upon God’s will. Indeed, some of the Scholastics had gone so far as to say that:

even though God did not exist, or did not make use of His reason, or did not judge rightly of things, if there is in man such a dictate of right reason to guide him, it would have had the same nature of law as it now has.[5]

Or, as a modern Thomist philosopher declares:

If the word “natural’ means anything at all, it refers to the nature of a man, and when used with “law,” “natural” must refer to an ordering that is manifested in the inclinations of a man’s nature and to nothing else. Hence, taken in itself, there is nothing religious or theological in the “Natural Law” of Aquinas.[6]

Dutch Protestant jurist Hugo Grotius declared, in his De Iure Belli ac Pacis (1625):

What we have been saying would have a degree of validity even if we should concede that which cannot be conceded without the utmost wickedness, that there is no God.

And again:

Measureless as is the power of God, nevertheless it can be said that there are certain things over which that power does not extend … Just as even God cannot cause that two times two should not make four, so He cannot cause that which is intrinsically evil be not evil.[7]

D’Entrèves concludes that:

[Grotius’s] definition of natural law has nothing revolutionary. When he maintains that natural law is that body of rules which Man is able to discover by the use of his reason, he does nothing but restate the Scholastic notion of a rational foundation of ethics. Indeed, his aim is rather to restore that notion which had been shaken by the extreme Augustinianism of certain Protestant currents of thought. When he declares that these rules are valid in themselves, independently of the fact that God willed them, he repeats an assertion which had already been made by some of the schoolmen.[8]

 …Thus, let there be no mistake: in the Thomistic tradition, natural law is ethical as well as physical law; and the instrument by which man apprehends such law is his reason — not faith, or intuition, or grace, revelation, or anything else.[11]

Note D’Entrèves’ recognition of the “extreme Augustinianism of certain Protestant currents of thought.” It is precisely that current of thought that I am seeking to highlight and distinguish here. Here is Augustine

For hence it is that even the ungodly think of eternity, and rightly blame and rightly praise many things in the morals of men. And by what rules do they thus judge, except by those wherein they see how men ought to live, even though they themselves do not so live? And where do they see these rules? For they do not see them in their own [moral] nature; since no doubt these things are to be seen by the mind, and their minds are confessedly changeable, but these rules are seen as unchangeable by him who can see them at all; nor yet in the character of their own mind, since these rules are rules of righteousness, and their minds are confessedly unrighteous. Where indeed are these rules written, wherein even the unrighteous recognizes what is righteous, wherein he discerns that he ought to have what he himself has not? Where, then, are they written, unless in the book of that Light which is called Truth? Whence every righteous law is copied and transferred (not by migrating to it, but by being as it were impressed upon it) to the heart of the man that works righteousness; as the impression from a ring passes into the wax, yet does not leave the ring.6


The concept of natural law is important because it transcends positive laws made by man.  As Aquinas said, representing natural law theory as a whole, “if in any point it [a man-made law] deflects from the law of nature, it is no longer a law but a perversion of law.” This is why we and Gordon Clark both appeal to it favorably – as a check against legislation. However, as has been shown, there is disagreement over the content and source of natural law. Greek natural law and Isralite natural law are seeking to answer two different questions. Greek natural law asks “What is man’s good?” Hebrew natural law asks “What does God require of man?” The Christian is going to answer “What is man’s good?” with “Doing what God requires,” so there will be a great deal of overlap. But the two questions are distinct. Recognizing these two different meanings of natural law can help untangle some of the confusion involved in discussions of natural law. When we talk about the importance of natural law for a biblical political philosophy on this site, we are not at all endorsing the use of fallen man’s reasoning from the general principle of “seek what is good” to specific conclusions about civil government. Rather, we are simply referring to the fact that the precepts of the moral law are binding on all men from all time. There can be no appeal to natural law in distinction from revealed law in Scripture because the two are the same. Nothing can be deduced from natural law that cannot also be deduced from Scripture.

In a 1998 journal article, R. Scott Clark clarifies the difference between these views.

The discontinuity between Calvin and Thomas lay in their varying estimates of our ability to capitalize on this natural awareness and on the exact content of this law… the most notable difference between Thomas and Calvin is that the latter defined natural law primarily in terms of the Decalogue and Thomas did not… Natural law was promulgated by God at creation and implanted in the human consciousness… Far from being a conduit of the Classical or Thomistic view of the lex naturalis Calvin made a very sophisticated revision of the concept of natural law by removing it from the Stoic and Thomistic corpus of “self-evident” truths and identifying it with the content of the Law revealed in the Garden and at Sinai and in the Sermon on the Mount… Calvin did not follow Thomas’ doctrine of natural law, though he did make significant use of natural law.

Thus it now becomes much clearer why David VanDrunen has created such a sharp divide between natural law and Scripture, arguing that the former is for the common kingdom under Noah while the latter is only for the church. He states

I treat natural law as in the sense of being a normative moral order communicated through nature, though this moral order can be helpfully summarized through general rules (such as “have dominion” and “be fruitful and multiply,” or the principles of the Decalogue). This does not mean that the natural moral order is itself a complete ethical system, for it requires individuals and societies to put it into concrete application through their divinely bestowed creative freedom, and this can happen potentially in many different cultural forms… Thomas understood the natural law more in terms of a moral order than a series of discrete rules. Natural law, for Thomas, is encapsulated in one rule – pursue good and shun evil – but this is so general that it is of little concrete usefulness. More specific rules (such as those of the Decalogue) can also be understood through practical reason, but even these do not capture the natural law comprehensively, for natural law pertains to all things to which human beings are inclined by nature. Though again I develop these matters differently, the idea of natural law in terms of moral order rather than discrete rules is also important to the theology of natural law for which I argue in subsequent chapters… I believe that my project, in many significant ways, stands in continuity with the perennially important natural law theory of Thomas Aquinas7

Thus VanDrunen is working from a Greek (Thomistic) definition of natural law while we are working from a Hebrew (Augustinian) definition of natural law.


Further Reformed Libertarian Reading

Examples of Greek Natural Law as appropriated by Christians

  1. John W. Robbins. Freedom and Capitalism (Kindle Locations 690-691). The Trinity Foundation. 

  2. Question I; Buchanan, George; Rutherford, Samuel (2013-04-22). Lex, rex, or, The law and the prince : a dispute for the just prerogative of king and people, containing the reasons and causes of the most necessary defensive wars of the kingdom of Scotland (1843) . . Kindle Edition. 

  3. Question 2; Buchanan, George; Rutherford, Samuel (2013-04-22). Lex, rex, or, The law and the prince : a dispute for the just prerogative of king and people, containing the reasons and causes of the most necessary defensive wars of the kingdom of Scotland (1843) (p. 2). . Kindle Edition. 

  4. Armstrong, R.A. Primary and Secondary Precepts in Thomistic Natural Law Teaching. P. 56 

  5. Rothbard does not even acknowledge the possibility of political law being rooted in revelation. “In fact, the legal principles of any society can be established in three alternate ways: (a) by following the traditional custom of the tribe or community; (b) by obeying the arbitrary, ad hoc will of those who rule the State apparatus; or (c) by the use of man’s reason in discovering the natural law — in short, by slavish conformity to custom, by arbitrary whim, or by use of man’s reason. These are essentially the only possible ways for establishing positive law.” 


  7. p. 15-25 Divine Covenants and Moral Order 

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