But if we attempt to examine children at an early age to eliminate many of those factors we run into a different problem.  There is a process of natural development that takes place before a child is fully rational. When one little little kid whacks another over the head it may not be an imitation of arbitra[r]y authority it might be an ...

Natural law has objective, external existence. It follows from the ESS (evolutionary stable strategy) for the use of force that is natural for humans and similar animals. The ability to make moral judgments, the capacity to know good and evil, has immediate evolutionary benefits: just as the capacity to perceive three dimensionally tells me when I am standing on the edge of a cliff, so the capacity to know good and evil tells me if my companions are liable to cut my throat. It evolved in the same way, for the same straightforward and uncomplicated reasons, as our ability to throw rocks accurately.

The historical state of nature definition: Natural law is that law which corresponds to a spontaneous order in the absence of a state and which is enforced, (in the absence of better methods), by individual unorganized violence ...

The medieval / philosophical definition: Natural law is that law, which it is proper to uphold by unorganized individual violence, whether a state is present or absent, and for which, in the absence of orderly society, it is proper to punish violators by unorganized individual violence.

The scientific/ sociobiological/ game theoretic/ evolutionary definition: Natural law is, or follows from, an ESS for the use of force: Conduct which violates natural law is conduct such that, if a man were to use individual unorganized violence to prevent such conduct, or, in the absence of orderly society, use individual unorganized violence to punish such conduct, then such violence would not indicate that the person using such violence, (violence in accord with natural law) is a danger to a reasonable man. This definition is equivalent to the definition that comes from the game theory of iterated three or more player non zero sum games, applied to evolutionary theory. The idea of law, of actions being lawful or unlawful, has the emotional significance that it does have, because this ESS for the use of force is part of our nature.

The Greeks could see that we could recognize actions as inherently lawful or unlawful, without the need of the state to tell us. (They had lived through some excellent examples of lawless states.)

Aristotle and others argued that each kind of animal has a mental nature that is appropriate to its physical nature. All animals know or can discover what they need to do in order to lead the life that they are physically fitted to live. Thus humans are naturally capable of knowing how to live together and do business with each other without killing each other. Humans are capable of knowing natural law because, in a state of nature, they need to be capable of knowing it.

This theory was demonstrated rather successfully in the “Wild West”, which history shows was not nearly as wild as many modern cities with strict gun control. Beyond the reach of state power, property rights existed, businesses functioned. (Kopel, 323 -373)

The problem of “how do we know natural law” is no different from the other problems of perception. The arguments used by those that seek to prove that we cannot know natural law, therefore natural law does not exist, are precisely the same as the arguments that we cannot know anything, therefore nothing exists, and many notable philosophers, such as Berkeley and Bertrand Russell, who started out arguing that natural law does not exist ended up concluding exactly that - that nothing exists.

Natural law derives from the nature of man and the world, just as physical law derives from the nature of space, time, and matter.

As a result most people who are not philosophers or lawyers accept natural law as the ultimate basis of all law and ethics, a view expressed most forcibly in recent times at the Nuremberg trials. Philosophers, because they often refuse to look at external facts, are unable to draw any conclusions, and therefore usually come to the false conclusion that one cannot reach objectively true conclusions about matters of morality and law, mistaking self imposed ignorance for knowledge.

Natural law was discovered (not invented, not created, discovered) by the stoic philosophers. This was the answer (not their answer, the answer) to the logical problems raised by Socrates. The doctrines of the stoics were demonstrated successfully by experiment, but political circumstances (the Alexandrine empire and then the Roman empire) prevented a clear and decisive experiment.

Not all laws are arbitrary, there must be laws universally applicable, because of the universal nature of man. Laws governing human affairs, or at least some of those laws, must derive from some objective and external reality, not subject to the arbitrary will of the ruler or the people. If this was not so, then it would be impossible to make an unlawful law. Any law duly decreed by a legitimate ruling body, such as the Athenian assembly, would necessarily be lawful, yet history shows that this was obviously false. Some laws are clearly unlawful. Proof by contradiction.

A philosopher can choose to disbelieve in Newton's laws, but this will not enable him to fly. He can disbelieve in natural law, but political and social institutions built on false law will fail, just as a bridge built on false physical law will fall, just as the deer that does not notice the tiger gets eaten, just as the Marxist philosophers who voluntarily returned to Cambodia to aid the revolution were for the most part murdered or tortured to death by the revolutionaries.

Thus the Netherlands came to be governed predominantly by natural law, rather than by men or by customary law.

Society ran itself smoothly. This showed that natural law was complete and logically consistent. Of course since natural law is external and objective it has to be complete and consistent, but our understanding of natural law is necessarily incomplete and imperfect, so our understanding of it might have been dangerously incomplete, inconsistent, or plain wrong. The experience of the Dutch strongly supports the belief that our understanding of natural law, the medieval theory of natural law as interpreted by medieval lawyers, is fairly close to the truth. If natural law was just something that somebody made up out of their heads, it would not have worked. Internal inconsistencies would have lead to conflicts that could not be resolved within natural law, requiring the man on horseback to apply fiat law or customary law to resolve them. Incompleteness would have lead to unacceptable lawless behavior. None of this happened, powerful evidence that natural law is not just something invented, but something external and objective that we are able to perceive, like the tiger, like the law of gravity.

John Locke made a major advance to our understanding of natural law, by emphasizing the nature of man as a maker of things, and a property owning animal. This leads to a more extensive concept of natural rights than the previous discussions of natural law. From the right to self defense comes the right to the rule of law, but from the right to property comes a multitude of like rights, such as the right to privacy “An Englishman's home is his castle.” Further, Locke repeatedly, in ringing words, reminded us that a ruler is legitimate so far as he upholds the law.

A ruler that violates natural law is illegitimate. He has no right to be obeyed, his commands are mere force and coercion. Rulers who act lawlessly, whose laws are unlawful, are mere criminals, and should be dealt with in accordance with natural law, as applied in a state of nature, in other words they and their servants should be killed as the opportunity presents, like the dangerous animals that they are, the common enemies of all mankind.

John Locke's writings were a call to arms, an assertion of the right and duty to forcibly and violently remove illegitimate rulers and their servants.

Natural law is a method, not a code. One does not reason from words but from facts. The nearest thing to a written code of natural law is the vast body of natural law precedent. But a precedent only applies to similar cases, and is thus rooted in the particular time and circumstances of the particular case, whereas natural law is universal, applying to all free men at all times and all places.

As Hugo Grotius pointed out in the early seventeenth century, even if there was no God, or if God was unreasonable or evil, natural law would still have moral force, and men would still spontaneously back it with physical force.

Throughout most of our evolution, men have been in a state of nature, that is to say. without government, hierarchically organized religion, or an orderly and widely accepted means of resolving disputes. For the past four or five million years the capacity to discern evil lurking in the hearts of men has been an even more crucial survival capability than the capacity to discern tigers lurking in shadows.

The primary purpose of this capability was to guide us in who we should associate with, (so as to avoid having our throats cut in our sleep), who we should make alliance with (to avoid betrayal), who we should trade with, (to avoid being cheated), who we should avoid, who we should drive away, and who, to make ourselves safe, we should kill.

It would frequently happen that one man would, for some reason good or bad, use violence against another. When this happened those knowing of this event needed to decide whether it indicated that the person using force was brave and honorable, hence a potentially valuable ally, or foolish and eager for trouble, hence someone to be avoided, or a dangerous criminal, hence someone to be driven out or eliminated at the first safe opportunity to do so. Such decisions had to be made from time to time, and making them wrongly could be fatal, and often was fatal.

A secondary purpose of this capability was to guide us in our own conduct, to so conduct ourselves that others would be willing to associate with us, ally with us, do deals with us, and would refrain from driving us away or killing us.
Not all things that are evil, or contrary to nature, are violations of natural law. Violations of natural law are those evils that may rightly be opposed by force, by individual unorganized violence.

The Medievals took for granted that natural law was morally and legally binding on freeholder, Emperor and Pope alike, and during the dark ages and for a little time after, men often attempted to enforce natural law against the Holy Roman Emperor, and these attempts were sometimes successful. On one occasion the Holy Roman Emperor was briefly imprisoned for debt by an ordinary butcher, locked up with the beef and mutton, and held by the butcher until the bill was paid, and this action was mostly accepted as lawful and proper, though such actions were safer against some emperors than others.

The definition of natural law that I have just given is similar to that used in the middle ages, but this definition is not obviously scientific. It fails to show that natural law is legitimately part of science. To show that the study of natural law is part of science - part of sociobiology, it is necessary to restate the definition in the same value free, game theoretic, terminology that Reeve & Nonacs would use to describe the social contract in wasps.

Here follows a definition of natural law in properly scientific terms, value free terms:

An act is a violation of natural law if, were a man to commit such an act in a state of nature, (that is to say, in the absence of an orderly and widely accepted method of resolving disputes), a second man, knowing the facts and being a reasonable man, would reasonably conclude that the first man constituted a threat or danger to the second man, his family, or his property, and if a third man, knowing the facts and being a reasonable man, were to observe the second man getting rid of the first man, the third man would not reasonably conclude that the second man constituted a threat or danger to third man, his family, or his property.

Note that in order to define natural law in a value neutral fashion we require three people, not two.

When we apply the value free theory of iterated non zero sum two player games to the value free theory of evolution we get such value loaded concepts as trust, honor, and vengeance (Barkow, Cosmides and Tooby). In the same way, when we apply the value free theory of iterated three player non zero sum games we get such value loaded concepts as natural law.

Natural law theory is a valid part of science, because any n person natural law statement about values can be expressed as an explicitly scientific, value free statement about rational self interest, evolution, and n + 1 player game theory. It is also a valid part of the study of law and economics

Small children -- who are without an explicitly-defined moral code -- already impose the trader principle on each other. Takers are shunned. Taking can't "take hold" among a young one (unless parents -- read: ARBITRARY POWER -- always pick up the slack for the lost values that Takers will always perpetuate on themselves because of the kind of creatures that we are).

An act is a violation of natural law if, were a man to commit such an act in a state of nature, (that is to say, in the absence of an orderly and widely accepted method of resolving disputes...

...being a reasonable man, would reasonably conclude that the first man constituted a threat or danger to the second man, his family, or his property...

The bully takes away someone else's toy -- forcefully. The other kids watch this. How do you think the other kids will treat the bully thereafter?

Do you think that they'll as readily engage him in games (as they would with the ones that they've observed to exhibit fairness)?

Do you think that they'll as readily share toys with him (as they would with the ones that they've observed to exhibit fairness)?

Do you think that they'll as readily come to his aid in times of need (as they would with the ones that they've observed to exhibit fairness)?

That's my point (do you see it?).