Mises Daily

In Defense of Non-Aggression

Matt Zwolinski, a libertarian political philosopher and the founder of the Bleeding Heart Libertarians blog, has a surprising proposal. Libertarians, he suggests, should drop the Non-Aggression Principle (NAP). The NAP holds that “aggression against the person or property of others is always wrong, where aggression is defined narrowly in terms of the use or threat of physical violence.”

Zwolinski raises six objections to the NAP, targeted especially against the way Murray Rothbard interprets it. Supporters of the principle need not worry. The objections don’t hold up.

Zwolinski suggests that, according to Rothbard, it would be wrong to trespass on someone’s property to feed a three-year old child whom someone was starving to death. The person starving the child isn’t aggressing against him, but trespass is aggression.

That is nonsense. To starve someone who cannot leave is to murder him. You don’t have to touch somebody to kill him: there isn’t a special libertarian concept of murder, different from the ordinary one. Neither is it the case that you are free to violate people’s rights, so long as you do so on your property. Rothbardian libertarianism is not the doctrine that each person is an absolute despot over his own property.

Zwolinski finds another flaw in the NAP. If, as Rothbard thought, industrial pollution violates the NAP, then must we not prohibit the slightest bit of smoke blown onto someone’s property, if the owner objects? Further, he asks in an earlier post, what if someone objects to a few photons of light beamed at him: should so trivial a matter be treated as harm? The NAP, taken strictly, threatens to derail nearly all human activities. If Rothbard replies to this that pollution below a certain level does not count as harm, why does he get to decide the limits of harm?

I don’t think Rothbard made the absurd claim that the limits of harm were for him to decide. Rather, he recognized that setting the limits of harm is matter of convention, settled by the understanding that prevails in a society. Zwolinski here falls into a mistake that many libertarians make. They deny a role to convention in delimiting the boundaries for the application of a concept: unless “nature” settles the matter, use of a concept is an all-or-nothing affair. Zwolinski‘s objection about risk fails for the same reason. Why must a supporter of the NAP hold that either all risks of harm must be prohibited or none? Once more, that dread word “convention” must not be uttered. Or is it rather that he thinks that Rothbard rejects it? Let us leave Zwolinski to sort out his own confusions on this question.

Zwolinski is not always wrong. He rightly notes that the NAP does not tell us what property rights people have. He is also correct that “aggression” in the principle must be understood to cover violations of property rights, as well as direct physical assault. Certainly Rothbard understood the NAP this way. But why, immediately before pointing this out, does he claim that a prohibition of fraud isn’t compatible with the NAP, because fraud is not physical violence? Is it too much to expect Zwolinski to realize that his point about the meaning of aggression invalidates his own objection regarding fraud?

Zwolinski concludes by suggesting that rather than deal with his objections by adding more epicycles to the NAP, we should, in a Copernican Revolution, put aside the idea that the NAP is the center of the moral universe. Zwolinski’s analogy limps: Copernicus offered an alternative to Ptolemaic astronomy but Zwolinski confines himself to posing objections to an existing theory. By the way, Copernicus’s theory has epicycles in it as well.

Zwolinski responds. Gordon writes:

My view of the starving child case differs from Rothbard’s, but I don’t think it follows from his holding that a parent has no duty to feed his child that the parent may prevent someone else from doing so, e.g., by forbidding him entry into his house. The parent’s lack of a positive obligation to feed the child does not entail the parent’s right to ensure that the child die.

I did not say that what counts as harm is conventional. Rather, when we are dealing with certain types of harm, setting the boundaries of harm is---I ought to have said in part—conventional. It is not conventional that slavery is wrong. What I object is a claim of this sort: “If slavery is wrong, then a thirty-year indentured servitude contract is wrong too, Then so is a slightly less onerous contract.Then there is no logical stopping point; a labor contract that to the slightest degree limits someone’s future options is also wrong.” That is a familiar sorites argument, and the answer to it, I think, is that we see clearly that some labor contracts are all right and some are not, but that the exact bounds of acceptable labor contracts are a matter of convention.

I think that your original post suffers from not making clear your target. Is it 1) The “aggression” version of the NAP; 2) the “property rights” version of the NAP; 3) One or both versions of the NAP, as interpreted by Murray Rothbard; 4) Murray Rothbard’s political philosophy, regardless of whether particular views of his are entailed by one or both versions of the NAP; 5) The “aggression” NAP taken as an axiom that entails all other parts of libertarian theory; 6) The NAP, in one or both versions, taken as an exceptionless principle of morality rather than as a principle of justice; 7) several of the previous items?

Is the NAP a Useless Tautology?

Julian Sanchez has carried criticism of the Non-Aggression Principle (NAP) to a new level. The principle tells us not to commit aggression; but, as Matt Zwolinski and others have pointed out, you don’t know what counts as “aggression” unless you know what rights people have. You can’t judge who the aggressor is simply by seeing who uses force first. The person who does so may be responding to a violation of rights and not be an aggressor at all. The NAP cannot, then, be used as an axiom to derive the rest of libertarian theory.

Sanchez goes further. The NAP is a tautology that adds nothing of importance to moral theory. A right is, by definition, a claim that is enforceable. “But all the real action is in the definition of rights; invoking the NAP adds nothing. It is tantamount to saying ‘only enforce rights that are really rights.’ To establish your right over (say) your car just is to establish that I ought not to take or use it without your permission (perhaps barring extraordinary circumstances, the parameters of which will tend to be implicit in the argument establishing the right). It is neither necessary nor illuminating to add the additional premises that taking what you have a right to counts as ‘aggression,’ and that one ought not to aggress.”

Here Sanchez has focused on the wrong word. He says, in effect, “Of course you should only enforce an enforceable claim. What else do you propose to enforce — a non-enforceable claim?” He is certainly correct that you shouldn’t enforce a non-enforceable claim, but he has missed something. He has not paid enough attention to “claim.” If you have a moral claim, then something is owed to you. Moral claims are personal. But some moral theories don’t tie the use of force to claims.

As an example, someone might favor transfers of wealth from billionaires to the poor on the ground that this will increase utility. The person might further hold that force can properly be used to do this. In taking this view, the person need not have rights in mind at all. The argument isn’t that the poor have a right to the transfers of wealth, so that if the transfers aren’t made, the poor have been deprived of what is morally owed to them. Rather, the theory holds that transferring wealth in this circumstance is a good thing to do and that’s all you need to justify using force.

In brief, there are non-rights based moral theories. The NAP, by tying the use of force to rights-violations, rules out using force to achieve moral goals not founded on persons’ claims. It is thus not a tautology.

Sanchez might answer that the NAP adds nothing to “People have rights” or a list of these rights. These already exclude moral theories not based on rights. This answer is also not correct. Someone who favored the wealth transfer might say that enough of an increase in utility overrides the billionaires’ property rights; the billionaires can be forced to transfer their wealth if they don’t want to do it. Again, this isn’t to say that the poor have a right to the transfer. Some moral theories include both rights and other considerations as well that justify using force. The NAP blocks using force that doesn’t respond to a rights violation, so it does add to “People have rights.”

Sanchez is correct that the NAP doesn’t by itself block a theory that includes non-libertarian rights, but this doesn’t make it useless for libertarians. The NAP doesn’t do everything, but it does do some things.

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