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.
