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.
