Say a guy wanders into town and commits an act of aggression (murder for example). He has entered into no agreement that he would not murder. He has broken no contract. Can he be punished for the act? And if he is punished, where does the legitimacy of the punishment come from? Who is to say that he committed a crime at all?
Short answer: No.
Less short answer: According to the NAP, yes, but (fortunately) human society does not operate according to a pure NAP. According to NAP, retaliatory violence must be classified as “aggression” as it is initiation of force without the aim of defending anything (it is purely destructive) but in ordinary language, retaliation is retaliation and aggression is aggression. The two are distinguishable by looking at the past events that led up to the use of force in question. If you murder my child and I kill you in retaliation, this is not “aggression” in ordinary language, it’s retaliation - your initial act of murder, however, was aggression.
Clayton -
I posted this theory on another thread. The discussion quickly turned to the LIbertarian theory on punishment and aggression. below is the original theory and an amendment
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Bill Smith Posted: Sun, Oct 31 2010 4:24 PM
by Bill Smith on Sunday, October 31, 2010 at 11:17am
In the paper “Toward a Libertarian Theory of Guilt and Punishment for the Crime of Statism” by Walter Block. The author puts forth a scenario in which a convicted car thief is forced to make restitution to the victim plus an equal amount for the punishment of his crime. Two teeth for one. That theory got me thinking about ways to deal with Law enforcement , the court system,correctional facilities, and the rehabilitation of criminals.
In Libertarian theory if there is no victim there is no crime. Victimless Crimes are just an attempt by one group to force another to adopt their moralities or principals. That is not a matter for the Justice system to decide. Once this theory is adopted it will immediately free law enforcement officers, judges, and jailers of costly time consuming and detrimental functions.
In our present system of justice the police catch a car thief, he is found guilty by a jury of his peers and the judge sends him to prison for say five years. What happens next? The taxpayers including the victim cut a check for the police the courts and the jail. The criminals wife and kids go on Welfare so we pay for them too. The victims car gets wrecked in the police chase but at least he has the satisfaction of knowing that this guy won’t be able to steal his new car for five years.
Consider this,the police catch a car thief. He is found guilty. The court then decides on a monetary judgement against the defendant. This will include restitution to the victim for his property, for his pain and suffering et al. A judgment would be placed on the defendant for the cost of his apprehension and trial. He is then remanded to a privately owned Penal Institution. Where he can apply for a job at a competitive wage and work until all parties are made whole. If he chooses not to work in the Widget factory, Farm or whatever for profit business venture this institution offers he will not have enough money in his account to purchase meals or rent a comfortable cell. However if he does decide to work and prosper in his new found profession he may then be awarded performance based wage increases and the opportunity to work overtime, gaining an early release. What happens next? Well maybe the guy gets out and steals back the car he bought you. Or maybe the guy applies for a job at the local widget factory. When asked for his qualifications he can proudly say I did a five year sentence in two and a half and I’m the best damn widget maker you ever saw.
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I think we may be debating semantics. Suppose we drop the concept of punishment altogether. We can then focus only on restitution. A man commits murder. He is found guilty. You can then impose a penalty that would include the estimated income the victim would have made for the rest of his life plus pain and suffering paid to friends and family that have a legitimate claim. This would apply also to rape as there are pain and suffering issues for the victim and family. In the case of murder you may want to let the victims immediate family have a voice in the sentencing part of the trial. They may want the guilty person to make restitution with his life rather than money.
Ironically, the word that ultimately gave rise to English punishment, Greek poine (via Latin poena), meant “restitution payment”. (Source)
Short answer: Yes.
Individuals that violate conventions against torts like murder can and will be punished in a society of ordered anarchy. Historically, common law systems that codify these emergent conventions (without being overidden by legislation) suggest the death penalty for the crime of murder, but other penalties are possible (such as “outlaw status”, or a fine equivalent to the median life-time income payable to the victims family).
These questions are ass-backwards. It is the criminal that must provide a justification for murdering another individual.
assuming you have to sign a contract to be punished…
However, I do not believe in punishment, but let me explain what I mean… I don’t believe that putting criminal in a cage helps him to “change”. It only damages him more. Also it is very expensive. I do not believe in death penalty either. I believe in compassion, understanding, help and rehabilitation.
brilliant, didn’t know that 
Nobody entered into an agreement that they wouldn’t kill him for murdering.
Says who? And to whom must he justify his action?
So then there is no “crime”. Aggression is self policed through feedback, and hopefully the feedback will be negative. Right?
This closes the doors on compulsory trials. There would only be arbitration if two parties agree to it. Which they might want to do rather than engage in personal combat.
Says the rules that emerge as Nash equilibria in civil society. He doesn’t have to justify it to anyone. If he wants to avoid the conventional punishment he will try to convince the agents of justice that it was a justified killing.
Is this question geared specifically towards the NAP, is it asked in the most genral and universal treatment of the terms used,etc?
Yes.
You should have said so in your original post. Disregard my responses, since they do not assume the NAP as the organizing principle of society. Outside of “moral intuition” (which sometimes conflict) I don’t see a way to verify or falsify a metaphysical proposition like the NAP.
Proving that it wouldn’t be a means to the ends of its advocates would falsify it.
I disagree. Consider these two propositions:
P1: The initiation of physical force against persons or property, the threat of such, or fraud upon their persons or property is wrong.
P2: If P1 is the organizing principle of society, then the end we are seeking will be achieved.
P2 is falsifiable by experience (at least in principle), but P1 doesn’t appear to be. Also, P1 is closer to the traditional NAP than P2.