"TGM i'm afraid to tell you we are not friends, merely aquaintances from the internet"
Quite true. "Friend" takes a totally different meaning when it's over the internet.
"I have really enjoyed this debate - I have actually been convinced that there is some merit to the idea of privatising the roads (and have for ages been arguing for government investment in infrastructure)"
"TGM we are still at odds i think over the question of health care - if i'm not mistaken - you don't think someone should be forced to pay for another person health care (which is protecting their right to life, a property right over their own body) and yet you do think someone should be forced to pay for a militrary (which is protecting a citizen's right to life...)
I don't see the difference."
Ok, there are three major claims I make about healthcare:
1. A genuine free market approach would be more effective for all but the bottom few percent in the medium-term (i.e. post transition) than state care.
2. A genuine free market approach would be more effective for all in the long-term (more drug development)
3. There is no moral mandate to take someone's money to protect yourself from disease.
Now to address the precise point you make:
Its positive and negative freedoms. I have the freedom not to be harmed by my fellow man, but not the right to not be harmed by nature. The difference between paying for healthcare and paying for defence is that in the one case, the payment is made in order to just support the life, and the other is made to protect the person's life.
There is no "right to live" unless you can support your life yourself, in which case it isn't really a right to life, just property (that right to life is impossible to fulfill in a necessarily mortal population anyway). Paying for healthcare is part of supporting yourself.
I do believe that there is a right to property, so I can conceive of an argument that states that it is valid to defend the property right, even if it involves breaking the property right elsewhere. Here we are trading like with like- property right with property right- rather than trading a genuine right (property right) for a non-existent right (right to healthcare).
I can explain my view here. To take an example I was once asked, suppose a Japanese man (never knew why he was Japanese) is coming to London from Tokyo to kill me, and is at Tokyo airport. I have a Nuclear warhead, and the only way I can thwart him is to fire the warhead at Tokyo, and blow up all of Japan, as well as raining radiation on all of SE Asia, killing approximately 1 billion people. Would I be morally justified in firing the warhead.
My answer is yes, because I have ownership of my body, and so may protect myself. When I fire it, who is to blame? The man trying to kill me.
Now suppose (this is my own addition) that the warhead wasn't actually mine, so I'd be 'stealing' the warhead. Yes, but again, I am not blameworthy for this collateral damage either.
Equally, the billion people in SE Asia have a right to defend themselves against the Japanese man (who is causing/blameworthy for their impending deaths). They can do this by killing me if they want, even though I am innocent, because it would be collateral damage just the same as my killing them is. Of course (as is true in this situation and in almost all realistic situations too) they are better off killing the Japanese man so that I have no reason to fire the Nuke than by killing me.