Smith examines the argument that minor acts of aggression are morally permissible if they result in good consequences that offset an unjust act.

George H. Smith was formerly Senior Research Fellow for the Institute for Humane Studies, a lecturer on American History for Cato Summer Seminars, and Executive Editor of Knowledge Products. Smith’s fourth and most recent book, The System of Liberty, was published by Cambridge University Press in 2013.

In Six Reasons Libertarians Should Reject the Non‐​Aggression Principle, Matt Zwolinski presents sundry arguments to buttress his case that the non‐​aggression principle (NAP) should be viewed as a defeasible presumption. In this essay I will deal only with his second point–according to which minor infractions of the NAP are morally permissible when they result in significant benefits–and leave his other arguments for a later time.

I am devoting so much space to this issue, not because Zwolinski presents much of an argument, but because his examples typify a form of argument that is exceedingly common. Libertarians have been discussing similar hypotheticals for as long as there have been libertarians. If you and your libertarian friends have ever spent too much time in a bar, then you almost certainly have heard or even posited examples that fall in the same category as the examples given by Zwolinski.

Zwolinski basically engages in arguments from examples. As Immanuel Kant pointed out, this is a problematic approach because examples do not explain themselves. Their significance, if they have any, can be discerned only with the aid of a general theory, so philosophers with different theories will interpret the same example in different ways. Unfortunately, Zwolinski has only told us that he thinks the NAP is a defeasible presumption, so unless he specifies some criteria of defeasibility (see Part 1) we don’t have much of a theory to work with, nor do we have anything more than a floating fragment of a paradigm.

Zwolinski claims that, according to a strict interpretation of the NAP, “No amount of aggression, no matter how small, is morally permissible. And no amount of offsetting benefits can change this fact.”

This fuzzy account fails to distinguish a theory of justice from a more general theory of ethics (a point I raised in Part 1). To commit an unjust act entails that the victim has a claim of redress against the aggressor, often in the form of reparations. And though matters of justice and injustice normally harmonize with our fundamental moral principles, this is not always the case. There may be exceptions.

Suppose that a mother with a starving child has no realistic course of action except to steal food from a grocery store. In this and in similar “emergency” situations, I would argue that the theft might be morally justifiable. However, it would still be unjust. That is to say, the mother would be obligated to compensate her victim (the grocery store owner), and should she refuse, the victim would have the option (which he need not exercise) to take legal action against the thief. Libertarian justice is concerned with rights, their violations, and restitution, not with the moral worth of actions per se. The owner of the food does not forfeit his property rights because of the needs of the mother, however legitimate and severe her needs may be.

Let us suppose that the opposite is true. Let us suppose that the mother, in virtue of the need to save her child from starvation, did not commit an unjust act against the owner of the grocery store by taking food without his consent–in short, let us suppose that her action was just. From this it follows that the mother had a right to the food, in which case we could not properly call her action “theft” at all. Moreover, if the mother had a juridical right to the food she took, this would mean that the grocery store owner had an enforceable duty to let her take the food. Thus, if he used force in an effort to stop the mother, then he would be guilty of violating her rights and could be prosecuted in a court of law.

Zwolinski continues with this hypothetical:

But suppose, to borrow a thought from Hume, that I could prevent the destruction of the whole world by lightly scratching your finger?

Although I don’t recall encountering this hypothetical in Hume’s writings, it may be based on Hume’s famous remark (A Treatise of Human Nature, Book II, Section III), ‘Tis not contrary to reason to prefer the destruction of the whole world to the scratching of my finger.” In any case, Zwolinski’s version is a prime instance of what I call itsy‐​bitsy counterexamples to a general principle. Itsy‐​bitsy hypotheticals can be used against virtually any moral or juridical principle–including, I suspect, principles that Zwolinski himself would defend–so they may be dubbed counterexamples for all occasions.

The itsy‐​bitsy counterthrust to general principles consists of positing very minor exceptions to a rule, and then concluding that only a rigid dogmatist would fail to admit the legitimacy of those exceptions.

Now, true enough, if Zwolinski could save the world by scratching my finger, then that would be a reasonable price to pay for saving every human being. But since the destruction of the world would entail my destruction as well, we must wonder why I would not gladly permit Zwolinski to scratch my finger, which would make his action voluntary and not aggressive at all.

Of course, a notable feature of itsy‐​bitsy hypotheticals is that they can be adjusted to meet the demands of the philosopher. In our case, Zwolinski might stipulate that he could save the world only by scratching the finger of an unwilling victim. If Zwolinski is unable to convince me (or anyone else) about the urgent need to scratch a finger, then he might have no recourse except to use force rather than persuasion to achieve his noble goal of saving mankind.

If Zwolinski told me that he could save the world by scratching my finger, then, in all probability, I would write him off as a nutcase and tell him to go away. There is a good reason for my reaction, namely the probable fact that Zwolinski would be unable to explain and justify the supposed connection between cause (a scratch) and consequence (saving the world). We do not live in a world where scratching fingers can save the earth from destruction, so I would have no reason to take Zwolinski seriously.

Only in some alternate world, a world with different causal laws than the world we know, might the finger‐​scratching hypothetical make sense. But in a natural‐​law moral theory of the sort that most libertarians defend, our theory of justice is based on certain presuppositions about the causal relationships among human beings and their physical environment. Suppose, for example, that a self‐​identified witch threatened to cast a spell on Zwolinski that would cause his penis to disappear–a power that was seriously discussed in the famous witch hunter’s manual, Malleus Maleficarum (1486).

Using the reality of witchcraft as a hypothetical framework, I could easily spin my own dilemmas for the NAP. As I recall, the Malleus Maleficarum discusses two possibilities in regard to a witch’s power to make penises disappear: Either this was an optical illusion of some sort or there was actually a physical detachment. The manual tells the story–which was probably a bit of medieval folk humor that the authors took too seriously–about a witch who placed her stolen penises in a basket that she hid in a tree. When an unfortunate victim gave in to her demands in exchange for having his penis restored, she led him to the tree, told him to climb it and then search the basket for his penis. But the victim proved too greedy. Instead of taking his own penis, he took the largest one in the basket and presented it to the witch for restoration. But she was not fooled, and in retaliation for his deception she reneged on the deal and the poor fellow ended up less than a man.

So how would a libertarian, working with the NAP, analyze some complexities of this situation? For example, suppose the man previously stole a pig from the witch, so she took his penis in retaliation and said she would keep it until he returned her pig. Would this be justifiable, according to the NAP? Well, among other contingencies, we cannot even begin to solve this problem unless we know other options that were available to the witch. If she had the power to steal penises, then it seems reasonable to suppose that she could have used her magical powers to get her pig back by some other means.

We have a similar problem with Zwolinski’s hypothetical. A world in which scratching a finger can save the world from destruction would be a world totally unlike the world we know. And if we wish to base our moral theories on “the nature of things,” then we cannot possibly arrive at a theory of justice appropriate to Zwolinksi’s alternate world unless we understand its causal laws. For instance, it might be possible for Zwolinski to save the world by scratching his own finger, thereby removing the need to aggress against me or anyone else.

Alternate‐​universe hypotheticals are a cottage industry among academic philosophers. Decades ago, while in college, I encountered the following scenario in the first edition of Human Conduct, an excellent text on ethics by John Hospers. Suppose you could cure all the cancer in the world, and prevent all cancers in the future, by willing the death of a single person unknown to you. Would not the death of one innocent person somewhere in the world–a person you don’t even know–be offset by saving millions of lives?

Here again we face the problem of a world with different causal laws than the world we know. And here again we are given no sense of the options that might exist in that alternate world. If, using the power of your mind alone, you could cure cancer by willing the death of one innocent person, then maybe, with a little practice, you could learn how to bypass the middleman and use your mind to cure cancer directly. Other possibilities suggest themselves as well. Are you the only person in this alternate universe with remarkable psychic powers? It seems reasonable to suppose that others would possess the same powers, so perhaps they could assist you in curing cancer without sacrificing an innocent life. Or perhaps you could find someone who is going to die anyway, or who plans to commit suicide, and then get permission to direct your Darth Vader‐​like powers against him or her. Again, no injustice would be involved in this alternative course of action.

Needless to say, such hypotheticals never present us with reasonable alternatives, because to do so would require an explanation of some weird causal properties in a nonexistent world that the philosopher is unwilling–indeed, unable–to explain.

The libertarian theory of justice is based on the world as we know it, not on some magical world about which we know nothing. A different world with different causal laws could very well generate a different theory of justice, but we can say nothing more without knowledge of how that alternate world would work.

Lest I be accused of evading the bull, let’s take him by the horns, put reason aside, and consider Zwolinski’s itsy‐​bitsy hypothetical at face value. Would it be morally permissible for Zwolinski to forcibly scratch my finger in order to save the world from destruction? Would not this itsy‐​bitsy act of injustice be morally offset by its beneficial consequences?

I agree that for Zwolinski to scratch my finger (against my will) would be a small price to pay for saving the world, so I would recommend that he pay the price for his moral but unjust action by compensating me for the scratch. If I should demand reparations, then I doubt if the money involved would amount to much–and I think highly enough of Zwolinski to assume that he would be willing to fork out a few bucks as the price of saving his own life and the lives of everyone else in the world. And in the event that he could not afford to restitute me on a philosopher’s income, I think millions of grateful people–those whose lives he saved–would be more than happy to chip in.

Fortunately, Zwolinski’s next itsy‐​bitsy hypothetical is more realistic and does not suffer from the same problems as the first. In fact, it is positively Obamaesque.

Or, to take a perhaps more plausible example, suppose that by imposing a very, very small tax on billionaires, I could provide life‐​saving vaccination for tens of thousands of desperately poor children? Even if we grant that taxation is aggression, and that aggression is generally wrong, is it really so obvious that the relatively minor aggression involved in these examples is wrong, given the tremendous benefit it produces?

How does one deal with this sort of argument, especially when it comes from a philosopher who calls himself a libertarian? I know of no other way except to repeat what should be obvious to libertarians: Yes, it is unjust to take money at the point of a gun from some people in order to benefit other people, regardless of how Zwolinski may plan to spend the ill‐​gotten gains. If a gun‐​brandishing thief accosts a billionaire in the street and demands $1000, then that act is no less unjust than if the thief had stolen money from a lower‐​income person. One’s rights do not diminish as one acquires more money. The fact that $1000 is pocket change to a billionaire is irrelevant.

If Zwolinski wishes to provide vaccinations for thousands of poor kids, then he should launch a charity drive and raise the necessary funds by voluntary methods. He may regard the tax on billionaires as minor when measured in terms of money, but from a moral perspective there is nothing minor about using force against innocent people. If Zwolinski thinks his itsy‐​bitsy tax, though technically unjust, would be morally permissible, then let him don his Robin Hood costume, arm himself with a bow and arrows, and accept personal responsibility by robbing billionaires himself.

Of course, were Zwolinski to do this, he would risk being hunted down, arrested, tried on numerous counts of armed robbery, and then thrown in jail–even if he stole only a relatively small amount from each billionaire. Would he be willing to take this risk? Perhaps he should. Even if Zwolinski ended up in jail, some of his Bleeding Heart colleagues might view his loss of freedom as more than offset by saving the lives of thousands of children. So let’s all whip out our interpersonal utility calculators and figure out what Zwolinski should do.