The great Murray Rothbard succinctly captures the thought which undergirds libertarian philosophy in an essay titled War, Peace and the State:
The fundamental axiom of libertarian theory is that no one may threaten or commit violence ("aggress") against another man's person or property. Violence may be employed only against the man who commits such violence; that is, only defensively against the aggressive violence of another. In short, no violence may be employed against a non-aggressor. Here is the fundamental rule from which can be deduced the entire corpus of libertarian theory.
This statement may seem surprising. After all, there is a tendency to see libertarians as a purer—if more hopeless—strain of conservatives. This is a misconception. Conservatives supported the Iraq War, something no sensible libertarian could ever do.
This fundamental antipathy toward aggression can be hard to square with what is known of libertarian thought. Many of us would probably be receptive to a system in which “no violence may be employed against a non-aggressor”; but it is also apparent that the number or us who would readily embrace the libertarian vision is minuscule. There seems to be a disconnect with the principles upon which libertarians say they build their philosophy and the philosophy itself. In short, we need to make apparent the connection between the usual behavior of libertarians, that of denouncing the State, with Rothbard's fundamental axiom:
It is time now to bring the State into our discussion. The State is a group of people who have managed to acquire a virtual monopoly of the use of violence throughout a given territorial area. In particular, it has acquired a monopoly of aggressive violence, for States generally recognize the right of individuals to use violence (though not against States, of course) in self-defense. The State then uses this monopoly to wield power over the inhabitants of the area and to enjoy the material fruits of that power. The State, then, is the only organization in society that regularly and openly obtains its monetary revenues by the use of aggressive violence; all other individuals and organizations (except if delegated that right by the State) can obtain wealth only by peaceful production and by voluntary exchange of their respective products. This use of violence to obtain its revenue (called "taxation") is the keystone of State power.
If we see that taxation requires the use of violence—or, more accurately, the threat of violence—and if we are opposed to violence except against aggressors, it becomes impossible to accept the existence of a large State. This is another example of the chasm between conservatives, who wish only to ameliorate some of the excesses of the State, with libertarians, who wish to come as near as possible with its abolishment.
As an aside, I am not familiar enough with Rothbard's works to know whether he finds the existence of the State itself to be an affront to liberty, or whether, like Robert Nozick for example, he would find a minimal state to be acceptable. I myself find Nozick's case to be convincing, and can think of no reason why Rothbard wouldn't come to a similar conclusion.
Setting this point aside, I do have one issue with which I find myself in disagreement with Rothbard, and for which I turn to St. Thomas Aquinas to better explain myself. As both Rothbard and Thomas recognize, the right to life should be absolute: anyone who aggresses against another's person is in the wrong, and the non-aggressor has every right to defend himself. Rothbard has already made his case; let us hear Thomas answer: Whether it is lawful to kill a man in self-defense?
Therefore this act, since one's intention is to save one's own life, is not unlawful, seeing that it is natural to everything to keep itself in "being," as far as possible. And yet, though proceeding from a good intention, an act may be rendered unlawful, if it be out of proportion to the end.
So far so good. But what of violations of property rights? Something in us recoils when we place the same commitment to reinforcing property rights as we do to those of life itself. We readily empathize with a man who accidentally kills a man in self-defense of his own life, but would find it harder to understand if the man had been killed over a watch. Part of this, perhaps, is the “proportion to the end” of which Thomas speaks. Might there be another reason?
First, we need to see what Thomas believes about property in general. He asks: Whether it is lawful for a man to possess a thing as his own?
Two things are competent to man in respect of exterior things. One is the power to procure and dispense them, and in this regard it is lawful for man to possess property. Moreover this is necessary to human life for three reasons. First because every man is more careful to procure what is for himself alone than that which is common to many or to all: since each one would shirk the labor and leave to another that which concerns the community, as happens where there is a great number of servants. Secondly, because human affairs are conducted in more orderly fashion if each man is charged with taking care of some particular thing himself, whereas there would be confusion if everyone had to look after any one thing indeterminately. Thirdly, because a more peaceful state is ensured to man if each one is contented with his own. Hence it is to be observed that quarrels arise more frequently where there is no division of the things possessed.
A couple of things are of interest here. First, the objections are largely pragmatic. This fits well with Thomas's philosophy of Natural Law. Man, being of a certain nature, behaves a certain way; any system which ignores this will be wholly impractical since it is at odds with the nature of human beings. We see here, in the 13th Century, some very common sense objections to the socialism that would arise in various heretical sects throughout the Middle Ages, and would later be revived in the teachings of Karl Marx, before being passed onto the revolutionaries of the twentieth century to sow destruction throughout the world.
Back to Rothbard. He writes:
It is wrong and criminal to violate the property or person of another, even if one is a Robin Hood, or starving, or is doing it to save one's relatives, or is defending oneself against a third man's attack. We may understand and sympathize with the motives in many of these cases and extreme situations. We may later mitigate the guilt if the criminal comes to trial for punishment, but we cannot evade the judgment that this aggression is still a criminal act, and one which the victim has every right to repel, by violence if necessary.
While he is certainly to be applauded for his clarity, I cannot confess that he is correct. If a starving man were to enter a person's house to procure bread for himself so that he didn't die, we would be hard-pressed to defend the person who expelled the aggressor. But I would also, it must be admitted, find it difficult to accept a situation in which anyone is allowed to any property whatsoever if they have a great enough need for that object. I am reminded of Chesterton's quip in The Man Who Was Thursday: "Thieves respect property. They merely wish the property to become their property that they may more perfectly respect it." If we are not to draw the line where Rothbard does, surely we ought to draw it somewhere. Fortunately, Thomas has already answered our question: Whether it is lawful to steal through stress of need?
In cases of need all things are common property, so that there would seem to be no sin in taking another's property, for need has made it common.
It should be pointed out, that while Thomas answers the question, he still leaves a good deal unsaid. The concept of need is, to put it bluntly, ambiguous—if not for Thomas, certainly for one used to a slew of modern amenities without which we find life to be difficult, but which can by no means be called necessary since man lived for so long without them. Clearly food is a need while cellular phones are not. But this leaves a good deal unsettled.
This essay had already run on for too long, so I will merely suggest two areas for future discussion. First, any attempt to enlarge the acceptable sphere of state action must do so on grounds of meeting an essential need. To take but one possible example, it could be argued that taking from the rich and giving to the hungry is within the rights of the State because the latter have need of food. To pose an objection, any money taken from taxpayers to enrich State employees cannot do more than meet the bare minimum of needs, for anything more is clearly theft. Even if we interpret need in the largest sense possible, all sorts of actions fall well outside acceptable bounds, and require a vigorous defense on their behalf before we should accept them as legitimate.
Second, any attempt to reconcile libertarianism with Catholicism, as it is one of my aims to do, must determine when it is acceptable to violate property rights. Suggesting that property rights are absolute does not strike me as compatible with Catholic teaching. However, since non-aggression is a principle in full accord with Catholicism, I remain optimistic that much common ground remains.