The key to the rule of law is to find the "highest common denominator" (to twist a mathematical expression). The highest common denominator is the set of laws that every one will accept, or at best not reject (denominator is derived from the Greek word “nomos”, which means law). The aim is to identify laws that most people will support.Some basic laws are accepted by everyone everywhere, regardless of their religion or cultural background. These laws are universal because they seem to be built into human nature. We do not need someone to teach us that these things are wrong. We all know that these laws are right.

Definition of a Law

A law has two parts.

1. An action or behaviour is forbidden. Laws do not tell us what we can do. They prescribe things that we must not do. The specification of the law must be sufficiently precise that anyone can understand what actions are prohibited.

2. A penalty is prescribed for non-compliance. Those who break a law receive a negative sanction or punishment. This penalty is applied by a community authority.

The penalty turns a moral statement into a law. Greed might be morally wrong, but there is no civil punishment for being greedy, so it is not a law.

Penalties for Crime

The penalties for crime must have the following five characteristics.

1. Justice

The penalty must fit the crime. The severity of the punishment should match the seriousness of the crime. A serious crime must have a tougher penalty than a minor one. 

2.  Mercy

Mercy is sometimes more important than justice and harsh punishments are not always appropriate. If the person breaking a law has made a thoughtless mistake, they should be shown mercy and allowed to make a fresh start.  We all make mistakes, so we all need mercy at times.

3. Caution

Innocent people should not be punished. A society should be cautious when applying punishments, so that the innocent are protected.

4.  Restitution

The penalty should benefit the victim of the crime. As far as is possible, the punishment should restore the victim to the situation they were in before the crime occurred. If the harm they received is permanent and cannot be restored, they should receive financial compensation to help them cope.

5.  Deterrence

The punishment should also deter the criminal from breaking the law again.  If the person is incorrigible, this may not be possible. However, the punishment should at least make them worse off than they were before they committed the crime. This will discourage future adventures with crime. Breaking the law should never benefit the offender.

These five elements of punishment, justice, mercy, caution, restitution and deterrence must be balanced against each other, without any one dominating the others. None of these elements is sufficient justification for punishment on its own.

Two Universal Laws

The following laws are universal laws that everyone accepts. They are the highest common denominator for human society

Taking something that belongs to another person without their permission is stealing. This is something that everyone understands. Even small children get upset when another child takes their toys. This is the first universal law.

You shall not steal

Stealing takes various forms.

• Breaking into a person’s house and taking things;
• Finding something that another person has lost and selling it;
• Borrowing something from another person and losing it;
• Using another person’s equipment without permission;Fraud
• Embezzlement;
• Breaking a contract to sell or buy something at an agreed price;
• Carelessly driving into another person’s car and robbing them of their transport;Driving with an insecure load that falls off and damages passing cars;
• Allowing a rubbish fire on a property to spread onto a neighbour’s backyard and destroying their garage.

Two questions help determine whether theft has occurred. Did the goods taken belong to someone else? Were the goods or service taken without their permission?

Penalty

The penalty for stealing must ensure that the victim is fully compensated for their loss. They should get back the items that were stolen. If the stolen goods have been sold or destroyed, the victim should get sufficient money to buy replacement goods. If the stolen item has been damaged, the thief should pay for any repairs that are needed. The victim should get additional money to cover the income that was lost through the theft. They should also get sufficient recompense to cover all the expenses of tracking and proving the case against the thief.

In most cases, the thief would pay three or fourfold restitution to fully compensate their victim for the inconvenience of the theft. If the goods stolen are tools and equipment used in production processes, the loss is likely to be greater, so more compensation will be required. The theft of a power tool that I need for my work will justify greater compensation than the theft of a radio of equal value that I only listen to for entertainment.

Making three or fourfold repayment for all the goods stolen would discourage a thief from further stealing. To make restitution, the thief will often have to take out a loan at a high interest rate. The hard work needed to repay the loan will make stealing an unattractive lifestyle choice.

The level of repayment should depend on whether the level of responsibility for the damage. If two cars crash into each other after being caught by a wind gust, neither driver can be held accountable. If one driver was driving, carelessly, he should compensate the other driver for the damage, before repairing his own car. If both drivers were being careless, they should share the expense.

Hitting or striking another person without their permission is a crime. Kicking, biting head-butting and punching are different forms of assault.

You shall not assault another person

Assault can also involve a variety of weapons.

• Guns;
• Knives;
• An out-of-control car that hits another person.
• A stone picked up from the side of the road and thrown deliberately at another person;

If two men are fighting and thy crash into an innocent bystander, they are both guilty of assault. However, if the bystander has come closer to watch the fight, they are mostly responsible for their own fate.

Rape is a particularly serious form of assault, as in addition to the physical, harm, it causes spiritual and emotional harm.

Murder is and extreme form of assault. The actions are often the same, but the consequences are more serious. Murder is wrong in every religion and every culture. Gangsters and thugs may seem to kill people quite casually, but even they know it is wrong. 

Intention to kill is an important aspect of murder. The person’s life is taken deliberately. Manslaughter is a less serious form of assault, because the person is killed by accident. These situations are not always black and white. A careless action may result in the death of another. He did not intend to kill the person, but his action did cause the death of another, so he is partly responsibility.For example, if the head flies off the axe of person chopping wood and kills someone walking by, the wood chopper is not guilty of murder. However, if the he knew that the axe head was loose and had come off several times before, the axeman would be partly responsible for the death. In these circumstance, a judge would have to decide how dangerous risky it was to use the axe and how clearly the axeman understood the risk. If he had borrowed it from someone else, he may not have known that the head had flown off several times. In this case, part of the responsibility might lie with the person who owned the axe.

Penalty

The penalty for assault must compensate the victim for any damage to their body. They criminal should provide financial compensation to their victim according to the extent of their injuries. Head injuries or the loss of an eye will require more compensation than a black eye or a broken finger.

Assault is a form of theft, because the injured person’s ability to enjoy life or earn money is stolen.If they injury is permanent, the victim will need compensation for loss of future income. All medical expenses should be paid as well.

If a person is assaulted by someone to whom they owe money, the debt might be cancelled by way of restitution. 

The financial compensation for a sexual assault will take account of the physical, emotional and spiritual harm done. Permanent emotional scars will justify extreme financial penalties. If the assault affects the woman’s prospect for marriage, the compensation should also cover this.Murder is the most serious crime, so it deserves the toughest penalty. In principle, the only penalty proportional to the killing of a human is death of the murderer. If proportionality were the only consideration, the death penalty would be mandatory, because no other penalty can equate to the death of another human? No financial payment can fully compensate for a human life.

Justice understands that the parents of a murdered child might want to kill the killer. However, justice is not justice, if it is not tempered by mercy. Most people will be uncomfortable about applying a death penalty, because they have an abhorrence for taking life. They would be reluctant to kill, even a murderer. Mercy will temper judgment.

The problem with the death penalty is it does nothing for the financial dependents of the victim. It hurts the dependents of the murderer more than it hurts the murderer, so true justice is not really achieved. Payment of financial restitution to the family of the person murdered will generally be a more satisfactory penalty. This payment would have to be large enough to compensate for the loss of the life and to make up for the future earnings lost by the victim’s family. The murderer might have to mortgage his life to be able to make this restitution.Life imprisonment is not a just penalty. The dependents of the victim do not benefit, because it is impossible for the murderer to earn any money to pay restitution. Imprisonment places a burden on society, because they have to pay for the murderer to live in expensive prison system. 

Where a murder is particularly ruthless or cruel, and there are several victims, financial restitution might not be sufficient penalty. A few murderers are so evil, that they have no future in normal society. In these situations, if there are several independent and reliable witnesses to identify the murderer with certainty, justice might require the death penalty. Situations with independent witnesses will be very rare, because most murders are committed in private.

Adultery

Most people will agree on assault, murder, theft as universal crimes. Some will want to include adultery on the list. However, human nature being what is, some people will claim that adultery is not always wrong. Adultery cannot be included in the highest common denominator.

Universal Laws

The two laws above are a universal highest common denominator. Some people might debate about the penalties, but murder, assault and theft are crimes in every culture and religion. Even libertarians with no religion acknowledge these two crimes. We do not need politicians and parliaments to tell us that these are crimes. Everyone knows that they are wrong. 

These universal laws are comprehensive, because they provide protection for life and property. That is about all that law can do. Laws can influence external behaviour, but they cannot change hearts. They cannot make people be good. The most that the law can do is provide limited protection against theft and violence. Law cannot produce good people or eliminate evil.

Limiting Politicians

Punishment of crime allows the civil government to use force against those who break the law. Very few people will accept the right of part of society to control the rest of our society. We never know when we will end up a part of a minority, so few people would agree to the right of a majority to bully a minority (unless they are rich). This means that the civil government must be limited to doing things that everyone can agree on. The highest common denominator provides a constraint on government power, because only thieves, murderers and thugs can be subjected to government force.

Laws that attempt to do more than prevent theft and violence are generally mooted by people who enjoy telling other people how to behave. They usually want to force people to be good. This is dangerous because people disagree about right and wrong. Whereas the two universal laws have universal support, laws that go beyond them produce endless argument and disagreement. Their enforcement results in the views of the politically powerful being forced upon people who do not agree with them. The two universal laws can be applied without one group imposing their views on another, because everyone accepts that these laws are just.

Politicians are particularly dangerous, because they believe that law can solve every problem. They always want the law to do much more than it can, so they go well beyond the highest common denominator and force a wide range of laws onto society. They use political power to force the laws of the majority onto minorities. Even worse, they often force the majority to obey laws supported only by a minority. Laws that are not universally accepted are dangerous for everyone.