"What, precisely, do you believe a government is?"

If it's a good government it's an organization that takes as much resources as it needs from its citizens to help its citizens in ways that volunteerism currently won't help with well enough.

"Why do they need a *government* to coordinate their aid?"

See above.

"Us libertarians think the difference between a government and a private organisation is the government takes taxes, effectively at gunpoint, even from those who don't want to pay for something. We don't see how that is a necessary part of coordinating aid."

As people shouldn't want to murder, they should want to pay taxes, therefore taxes are only coercive for people who are in the wrong, because taxes are the best system so far to cover the shortfalls of volunteerism.

I'm all for a completely voluntary system as soon as someone thinks of one that will prevent too many people from starving, etc.

Bob