The Epistemological Need for Government
The initiation of force is harmful to our lives, and we need to have retaliatory force to live. But it's not just an attack on our lives directly that impairs our lives. Someone initiating force against others affects our lives as well. A disruption of the harmony of interests is a matter everyone should be concerned with.
It's easy enough to say that the initiation of force should be responded to with retaliatory force. Putting it into practice is a lot more difficult. For instance, how do you know whether a particular use of force is an initiation of force, or an instance of retaliation? The person committing the use of force may have an opinion, but it makes no sense to let him be the decider, or everyone will just say they're retaliating.
The problem can be best summarized by an example. Imagine you see one man shoot another dead. Was this an initiation of force or retaliatory force? If it was an initiation of force, it would make sense to use retaliatory force against the shooter. If it was retaliatory force, you would not be justified in using force. Now say you decide it was an initiation of force, and you respond by pulling out a gun and shooting the gunman. Now imagine just as you do this, someone else walks by, and wonders whether you're initiating or retaliating...
The essential problem I'm trying to convey is that there's an epistemological issue with the use of force. Even if you believe that you're using retaliatory force, if others decide that you are the initiator, they'll believe themselves justified in using violence against you.
Retaliatory force is already a risky proposition. In the process of enforcing it, you might get attacked yourself. Criminals are rarely good-natured when it comes to retaliatory force. And it certainly doesn't help that the rest of the population may think you're the criminal, exposing yourself to even greater risk.
So there's an epistemological need for government. The need is for an established method of deciding when retaliatory force is appropriate, and to what extent it is. It needs to be established so that those who enforce the retaliation know that they are not going to be punished for it themselves. They need to be able to show that they followed the appropriate method, came to the decision through an objective method and with objective evidence, and responded in an objectively appropriate way.
This complex decision making on whether any particular act of force is appropriate or not is the key to understanding government. If government were just about wielding retaliatory force, anyone could do it. You might still have people working together to minimize risk, but it wouldn't be necessary. What is necessary is a method for all of the concerned participants of a society to have a method of making these group decisions. For that, you need a structured system that defines what is an appropriate use of force, and judges the specific merits of individual cases.