Proving Libertarian Morality: Reclaiming the High Ground

One of the central challenges faced by libertarians is the need to prove that libertarian moral theory is universally correct, while statist and collectivistic moral theories are incorrect. Until moral rules can be subjected to the same rigour and logic as any other propositions, we will forever be stymied by subjectivism, political prejudices and the argument from effect.

Why is this approach so important? Why bother with the grueling task of building a logical framework for the examination of moral rules – and the even more grueling task of communicating that framework to others? Well, as I have argued in previous articles, the freedom movement has made remarkably little progress throughout history. Von Mises wrote seminal works disproving the economic efficiency of socialism and communism in the 1920s – now, eighty years later, Western societies are still sliding into the predicted morass of ever-expanding state power, ever-increasing public debts and declining economies. Although free market economic theories have made some progress in academia (and even the popular media!) they have done nothing to even slow down – let alone reverse – the constant expansion of state power.

In my view, the reason for this is simple: libertarians have never won the argument from morality. These days, none of our opponents argue that the government is more efficient than the free market, or that communism will set us free, or that private property is theft. All the old socialistic shibboleths have been laid to rest – and yet still people support government power, because they believe that government power is moral. Most people believe that the government takes care of the poor, old and sick, protects us from enemies both corporate and militaristic, educates the young, builds us roads, blah blah blah – we’ve all heard the same nonsense since the dawn of time. All we say in response is that the government is inefficient at doing these things, and that the free market would be better – none of which touches the central rationale of state power, which is that people believe that it is good.

Our enemies understand the power of the argument from morality far, far better than we do. They constantly harp on the virtue of state power, starting in kindergarten with environmentalism, ‘friendly cops’ and the need for ‘childproofing.’ The world is dangerous, children hear, and capitalists want to kill you with smog, but your friendly government is always eager to serve, help and protect. Children first experience state power as firm, kindly and friendly teachers – so how could they see and appreciate the violence that underpins the government?

How can we oppose this? How can we best work to undo the endless propaganda of pro-state school, media and prejudice?

By learning from history, that’s how. To win a battle, one must first ask: how were similar battles won in the past?

The closest historical analogy to our current situation occurred in the 15th and 16th centuries, during the rise of the scientific method. The early pioneers who advocated a rational and empirical approach to knowledge faced all the same prejudices that we face today – all the same irrationality, entrenched power of church and state, mystical and subjective ‘absolutes’ and early educational barriers. Those who advocated the primacy of rationality and empirical observation over mystical ‘insights’ and Biblical fundamentalism faced the determined opposition of those wielding both cross and sword. Many were tortured to death as heretics for their intellectual honesty – we face far less risk, and so should be far braver in advocating what is true over what is believed.

In order to attack the false morality of state power, we must start from the beginning, just as the first scientists did. Francis Bacon did not argue that the scientific method was more ‘efficient’ than prayer, Bible texts or starvation-induced ‘visions.’ He simply said that if we want to understand nature, we must observe nature and theorize logically – and that there is no other route to knowledge.

We must take the same approach with defining and communicating morality. We must begin using the power and legitimacy of the scientific method to prove the existence and universality of moral laws. We must start from the beginning, build logically and reject any irrational or non-empirical substitutes for the truth.

What does this look like in practice? All we have to do is establish the following axioms:

  • Morality exists.
  • Moral rules must be consistent for all mankind.
  • The more consistent a moral theory is, the more valid it is.
  • Libertarianism is the most consistent moral theory.
  • Therefore, libertarianism is the most valid moral theory!

Sound like a tall order? But give me three thousand or so words, and we can at least take a swing at the first three.

To start from the very beginning… do moral rules – or consistently preferred human behaviour – exist at all?

There are only two possibilities when it comes to moral rules, just as there are in any logical science. Either moral rules exist, or they do not. (In physics, the question is: either physical rules exist, or they do not.)

If moral rules do exist, where do they exist? Certainly not in material reality, which does not contain or obey a single moral rule. Moral rules are different from the rules of physics, just as the scientific method is different from gravity. Matter innately obeys the rule of gravity or the second law of thermodynamics, but ‘thou shalt not kill’ is nowhere inscribed in the nature of things. Physical laws describe the behaviour of matter, but do not contain a single prescription. Science says that matter behaves in a certain manner – never that it should behave in a certain manner. A theory of gravity proves that if you push a man off a cliff, he will fall. It will not tell you whether you should push him or not.

Thus it cannot be said that moral rules exist in material reality, and neither are they automatically obeyed like the laws of physics – which does not mean that moral laws are false or irrelevant. The scientific method does not exist in reality either – and is also optional – but it is neither false nor irrelevant.

Subjecting moral theories to the scientific method will provide the same benefits that subjecting physical theories to the scientific method did. Before the rise of the scientific method, the behaviour of matter resulted from the subjective whim of gods and devils – just as morality is now. Volcanoes erupted because the mountain-god was angry; good harvests resulted from human sacrifice. No absolute physical laws which limited the will of the gods were believed to exist – and so science could never develop. Those who profited from defining physical reality as subjective – mostly priests and kings – fought the subjugation of physical theories to the scientific method, just as those who profit from defining moral reality as subjective – mostly politicians and soldiers – fight the subjugation of moral theories to the scientific method.

The rise of scientific truth resulted from the expansion of the scientific method, which was a methodology for separating accurate from inaccurate theories by subjecting them to two central tests: logical consistency and empirical observation – and by always subjugating logical consistency to empirical observation. If I propose a perfectly consistent and logical theory which says that a rock will float up when thrown off a cliff, any empirical test proves my theory incorrect, since observation always trumps theory.

A further aspect of the scientific method is the belief that, since matter is composed of combinations of atoms with common, stable and predictable properties, the behaviour of matter must also be common, stable and predictable. Thus experiments must be reproducible in different locations and time. I cannot say that my ‘rock floating’ theory is correct for just one particular rock, or on the day I first tested it, or at a single location. My theories must describe the behaviour of matter, which is universal, common, stable and predictable.

Finally, there is a generally-accepted rule – sometimes called Occam’s Razor – which states that, of any two explanations, the simpler is probably the more accurate. Prior to the Copernican revolution, when Earth was considered the center of the universe, the retrograde motion of Mars when Earth passed it in orbit around the sun caused enormous problems to the Ptolemaic system of astronomical calculations. ‘Circles within circles’ multiplied enormously, which were all cleared away by simply placing the sun at the center of the solar system.

Thus any valid scientific theory must be (a) universal, (b) logical, (c) empirically verifiable, (d) reproducible and (e) as simple as possible.

Now the methodology for judging and proving a moral theory is exactly the same as the methodology for judging and proving any other scientific theory.

The first question regarding moral theories is: what are they? Simply put, morals are a set of rules claiming to accurately and consistently identify preferred human behaviours, just as physics is a set of rules claiming to accurately and consistently identify the behaviour of matter.

The second question to be asked is: is there any such thing as ‘preferred behaviour’ at all? If there is, we can begin to explore what such behaviour might be. If not, then our examination must stop here – just as the examination of ‘ether’ ceased after Einstein proved that the speed of light was constant.

The proposition that there is no such thing as preferred behaviour contains an insurmountable number of logical and empirical problems. ‘Preferred behaviour’ must exist, for five main reasons. The first is logical: if I argue against the proposition that preferred behaviour exists, I have already shown my preference for truth over falsehood – as well as a preference for correcting those who speak falsely. Saying that there is no such as thing as preferred behaviour is like shouting in someone’s ear that sound does not exist – it is innately self-contradictory. In other words, if there is no preferred behaviour, then one should oppose anyone who claims that there is preferred behaviour. However, if one ‘should’ do something, then one has just created preferred behaviour. Thus preferred behaviour – or moral rules – must exist.

Syllogistically, this is:

  1. The proposition is: preferred behaviour must exist.
  2. Anyone who argues against the existence of preferred behaviour is demonstrating preferred behaviour.
  3. Therefore no argument against the existence of preferred behaviour can be valid.

How else do we know that moral rules exist? Well, all matter is subject to physical rules – and everything that is organic is in addition subject to certain requirements, and so, if it is alive, has followed preferred behaviours. Everything that lives, for instance, needs fuel and oxygen in order to stay alive – even plants strain for sunlight. Any living mind, of course, is an organic part of the physical world, and so must be subject to both physical laws and has followed preferred behaviours – to argue otherwise would require proof that consciousness is not composed of matter, and is not organic – an impossibility, since it has mass, energy, and life. Arguing that consciousness is subjected to neither physical rules or preferential choices would be like arguing that human beings are not subject to gravity and can flourish without eating. Thus it is impossible that anyone can argue against preferred behaviour, since if he is alive to argue, he has followed preferred behaviours such as breathing, eating and drinking.


  1. All living organisms require preferred behaviour to live.
  2. Man is a living organism.
  3. Therefore all living men are alive due to the existence and practice of preferred behaviour.
  4. Therefore any argument against preferred behaviour requires the existence of preferred behaviour.
  5. Therefore no argument against the existence of preferred behaviour can be valid.

Since the scientific method requires empirical corroboration, we must also look to reality to confirm our hypothesis – and here the existence of preferred behaviours is fully supported. Almost every human being believes in moral rules of some kind. There is much disagreement about what constitutes moral rules, but everyone is certain that moral rules are valid – just as scientific theories disagree, but all scientists accept the validity of the scientific method itself. Disproving something that everyone believes in is almost impossible. One can argue that the Earth is round and not flat – which is analogous to changing the definition of morality – but one cannot argue that the earth does not exist at all – which is like arguing that there is no such thing as preferred behaviour.


  1. For a scientific theory to be valid, it must be supported through empirical observation.
  2. If preferred behaviour exists, then mankind should believe in preferred behaviour.
  3. Almost all men believe in preferred behaviour.
  4. Therefore empirical evidence exists to support the existence of preferred behaviour – and the existence of such evidence opposes the proposition that preferred behaviour does not exist.

The fourth argument for the existence of preferred behaviour is also empirical. Since human beings have an almost-infinite number of choices to make in life, to say that there are no principles of preferred behaviour would be to say that all choices are equal. However, all choices are not equal, either logically or through empirical observation. To take one example, if food is available, almost all human beings eat every day. If not themselves subjected to violence, human beings are generally not violent. Almost all parents choose to feed and shelter their children. There are many examples of common choices among humankind, which indicate that preferential behaviour abounds and is part of human nature – and requires that any theory claiming otherwise must explain away this teeming evidence.


  1. Choices are almost infinite.
  2. Most human beings make very similar choices.
  3. Therefore not all choices can be equal.
  4. Therefore preferred choices must exist.

The fifth argument for the existence of preferred behaviour is biological. Since all organic life requires preferential behaviour, we can assume that those organisms which make the most successful choices are the ones most often selected for survival. Since man is the most successful species, and man’s most distinctive organ is his mind, it must be man’s mind that has aided the most in making successful choices. The mind itself, then, has been selected as successful by its very ability to make successful choices. Since the human mind only exists as a result of choosing preferred behaviour, preferred behaviours must exist.


  1. Organisms succeed by acting upon preferred behaviour.
  2. Man is the most successful organism.
  3. Therefore man must have acted most successfully on the basis of preferred behaviour.
  4. Man’s mind is his most distinctive organ.
  5. Therefore man’s mind must have acted most successfully on the basis of preferred behaviour.
  6. Therefore preferred behaviour must exist.

Due to the above problems, any argument against the existence of preferred behaviour can be dismissed as incorrect.

Since we have proved the existence of preferred behaviour, the question of morality now shifts. Since preferred behaviour does exist, what theories can quantify, classify, explain and predict it?

First of all, we must remember that morality is optional. As we all know, every man is subject to gravity and requires food to live, but no man has to act morally. If I steal or kill, no thunderbolt from the sky strikes me down. Moral rules, like the scientific method or biological classifications, are merely ways of organizing the facts and principles of what exists.

The fact that compliance with moral rules is optional has confused many thinkers into believing that because morality is optional, it is subjective. Nothing could be further from the truth! Living organisms are part of material reality, and material reality is rational and objective. Applying moral theories is optional, but that does not mean that moral theories are subjective. The scientific method is optional, but it is not subjective. Applying biological classifications is optional, but biology is not subjective. Choices are optional; consequences are not. I can choose not to eat, but I cannot choose to live without eating. I can choose to behead someone, but I cannot choose whether or not they can live without a head. Morality is thus optional, but the effects of moral choices are measurable and objective. There is no subjectivity involved whatsoever.

Now, since morality exists, the next question is: to what degree or extent does morality exist? As mentioned above, the first test of any scientific theory is universality. Just as a theory of physics must apply to all matter, a moral theory which claims to describe the preferred actions of mankind must apply to all mankind. No moral theory can be valid if it argues that a certain action is right in Syria, but wrong in San Francisco. It cannot say that Person A must do X, but Person B must never do X. It cannot say that what was wrong yesterday is right today – or vice versa. If it does, it is false and must be refined or discarded.

To be valid, any moral theory must also pass the criteria of logical consistency. Since the behaviour of matter is logical, consistent and predictable, all theories involving matter – either organic or inorganic – must be also be logical, consistent and predictable. The theory of relativity cannot argue that the speed of light is both constant and not constant at the same time, or that it is 186,000 miles per second, five fathoms in depth and also green in colour!

However, since moral theories apply to mankind, and mankind is organic, the degree of consistency required for moral theories is less than that required for inorganic theories. All rocks, for instance, must fall down, but not all horses have to be born with only one head. Biology includes three forms of ‘randomness,’ which are environment, genetic mutation and free will. For example, poodles are generally friendly, but if beaten for years, will likely become aggressive. Horses are defined as having only one head, but occasionally, a two-headed mutant is born. Similarly, human beings generally prefer eating to starving – except anorexics. These exceptions do not bring down the entire science of biology. Thus, since moral theories describe mankind, they cannot be subjected to exactly the same requirements for consistency as theories describing inorganic matter.

The final test that any scientific moral theory must pass is the criteria of empirical observation. Thus for instance, a moral theory must explain the universal prevalence of moral beliefs among mankind, as well as the results of human moral ‘experiments’ such as fascism, communism, socialism or capitalism. It must also explain some basic facts about human society, such as the fact that state power always increases, or that propaganda tends to increase as state power increases. If it fails to explain the past, understand the present and predict the future, then it fails.

How does all this look in practice? Let’s look at how the requirement for universality affects moral theories.

If I say that gravity affects matter, it must affect all matter. If even one speck of matter proves resistant to gravity, my theory is in trouble. If I propose a moral theory which argues that people should not murder, it must be applicable to all people. If certain people (such as soldiers) are exempt from that rule, then I have to either prove that soldiers are not people, or accept that my moral theory is false. There is no other possibility. On the other hand, if I propose a moral theory which argues that all people should murder, then I have saved certain soldiers, but condemned to evil all those not currently murdering someone (including those being murdered!) – which is surely incorrect.

If, to save the virtue of soldiers, I alter my theory to argue that it is moral for people to murder if someone else tells them to (a political leader, say), then I must deal with the problem of universality. If Politician A can order a soldier to murder an Iraqi, then the Iraqi must also be able to order the soldier to murder Politician A, and the soldier can also order Politician A to murder the Iraqi. This problem cannot be solved, and so my theory is proven invalid.

I also cannot logically argue that is wrong for some people to murder, but right for other people to murder. Since all human beings share common physical properties and requirements, having one rule for one person and the opposite rule for another is impossible – it is like proposing a physics theory that says that some rocks fall down, while others fall up. Not only is it illogical, it contradicts the observable facts of reality, which is that human beings as a species share common characteristics, and so cannot be subjected to opposing rules. Biologists have no problems classifying certain organisms as human because they share common and easily-identifiable characteristics – it is only moralists who seem to have this difficulty.

Furthermore, if my moral theory ‘proves’ that the same man should not murder one day, but should murder the next day (say, when he steps out into the Iraqi desert), then my position is even more ludicrous. That would equivalent to arguing that one day a rock falls downward, and the next day it falls upward! To call this any kind of consistent theory is to make madness sanity.

Since scientific theories require logical consistency, a moral theory cannot be valid if it is both true and false at the same time. A moral theory which approves of stealing, for instance, faces an insurmountable logical problem. No moral theory should, if it is universally applied, directly eliminate behaviour it defines as moral while simultaneously creating behaviour it defines as immoral. If everyone should steal, then no one will steal – which means that the moral theory can never be practiced. And why will no one steal? Well, because a man will only steal if he can keep the property he is stealing. He’s not going to bother stealing your wallet if someone else is going to immediately steal that wallet from him. Any moral theory proposing that ‘stealing is good’ is also automatically invalid because it posits that property rights are both valid and invalid at the same time, and so fails the test of logical consistency. If I steal from you, I am saying that your property rights are invalid. However, I want to keep what I am stealing – and therefore I am saying that my property rights are valid. But property rights cannot be both valid and invalid at the same time! Similarly, any moral theory which advocates rape faces a similar contradiction. Rape can never be moral, since any principle which approves it automatically contradicts itself. If rape is justified on the principle that ‘taking pleasure is always good,’ then such a principle immediately fails the test of logical consistency, since the rapist may be ‘taking pleasure,’ but his victim certainly is not. (The same goes, of course, for murder and assault.)

Thus subjecting moral theories to the scientific method produces results which conform to rationality, empirical observations and plain common sense. Murder, theft, arson, rape and assault are all proven immoral. (Universal and positive moral rules can also be proven – i.e. the universal validity of property rights and non-violence – but we shall talk about that another time!)

To aid in swallowing this rather large conceptual pill, here is a table which helps equate theories of physics and biology with scientific theories of preferred (or moral) behaviour:







Organic Matter

Preferred behaviour for mankind


A rock

A horse

A man

Sample Rule


The desire for survival


Sample Theory



Property rights

Sample Classification





Matter cannot be created or destroyed, merely converted to energy and back.

If it is alive and warm-blooded, it is a mammal.

Stealing is wrong.


Atoms share common structures and properties, and so behave in predictable and consistent manners.

Organic matter has rules – or requirements – that are common across classifications.

Human beings share common rules and requirements.


Logical consistency, empirical verification.

Logical consistency, empirical verification.

Logical consistency, empirical verification.

Negative Proof Example

If mass does not attract mass, theories relying on gravity are incorrect

If organisms do not naturally self-select for survival, the theory of evolution is incorrect.

If communism succeeds, theories based on the universal value of property rights are incorrect.

In conclusion, it is safe to say that (a) moral rules exist, and (b) moral theories must be subjected to the scientific method, just as theories of physics and biology. Furthermore, any moral theory based on non-universal or self-contradictory principles is demonstrably false.

If libertarianism is to succeed, we must examine all moral theories and commandments in this light – otherwise we relinquish moral truth to our enemies, which will only ensure our continued failure.

Stefan Molynuex, is the host of Freedomain Radio (, the most popular philosophy site on the Internet, and a "Top 10" Finalist in the 2007-2010 Podcast Awards.

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June 2024

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