In his essay, "Liberal Neutrality: A Compelling and Radical Principle," Gerald Gaus suggests that legitimizing coercion requires impartial justificatory reasons -- reasons that it would be unreasonable not to accept as justifying the act in question. I agree. But if there is reasonable pluralism about procedural justice, then it's conceivable that the mere descriptive features of a set of procedures would fail to serve as impartial justification for the imposition of those procedures on someone. That is, if I hadn't personally agreed to abide by a certain set of procedures, and I didn't accept the legitimacy of those procedures (and I were being reasonable about my disagreement), then how could others justify imposing those procedures on me? In the absence of reasonable pluralism, this problem could be avoided by designing a procedure with the "correct" features, which would impartially justify imposing the procedure on people. But if people can reasonably disagree about what would be procedurally legitimate, then it might be impossible to design a system that could be impartially imposed on people.
This leads to an obvious problem. In order to have a functioning society, it seems important that there be a way to legitimately enforce justice by imposing impartial procedures on people who do things like commit crimes or destroy other people's property. As even anarcho-capitalist thinkers allow, purely voluntary settlement of disputes will not always be up to the task of ensuring that justice is served. For example, in For A New Liberty: The Libertarian Manifesto, Murray Rothbard writes:
Even if purely voluntary arbitration is sufficient for commercial disputes...what of frankly criminal activities: the mugger, the rapist, the bank robber? In these cases, it must be admitted that ostracism would probably not be sufficient--even though it would also include, we must remember, refusal of private street owners to allow such criminals in their areas. For the criminal cases, then, courts and legal enforcement become necessary.
Rothbard's understanding of libertarian ethics is not one that I share, but the points at which I depart from Rothbard in practice are typically places where Rothbard is dogmatically opposed to using force, even when I don't think it would be disrespectful of the user of force to do so (in theory, we disagree more fundamentally, but often arrive at the same conclusions). Accordingly, if Rothbard can find a plausible solution to this problem within his more rigid ethical paradigm, it will likely satisfy my requirements as well. So what does he say?
Rothbard envisions that in a society without a centrally imposed set of procedures, individuals would ostensibly maintain a membership with a court organization to help them to settle their disputes. In the event that criminal charges were brought against an individual, the court of the plaintiff party could hold a trial, and if the defendant were found guilty, she would have the opportunity to go to her own court and ask for a second opinion. If her own voluntarily selected procedure resulted in a proclamation of innocence, the two court services could seek a third opinion from an "appeals" court. Rothbard immediately acknowledges the infinite regression he's building, and points out:
But suppose Brown [the defendant] insists on another appeals judge, and yet another? Couldn't he escape judgment by appealing ad infinitum? Obviously, in any society legal proceedings cannot continue indefinitely; there must be some cutoff point.
So basically, Rothbard's answer is, "Well yea, but don't be ridiculous." And to a point, I accept that reply, but it doesn't actually address the question we're posing here. However, even though Rothbard doesn't really solve the problem with which we're grappling, he does provide an important insight: someone who's being accused of a crime needs to have in mind some procedure for establishing his innocence; to simply refuse to participate in the justice system would be unreasonable. That Rothbard takes this for granted is telling.
But to be honest, I was going to make a point about this that I'm no longer comfortable with. So I guess I'll just leave this as it is for now, and maybe come back to the issue later once I've had time to think about it some more.