The concept of the "free market" is very well defined. Rothbard defines it here, the wikipedia definition is clear and accurate, Mises talks extensively about what markets are and what the "free" market is in Human Action, and I would simply define it as the sum of all voluntary trades and exchanges between individuals and privately owned companies.
Haha, but can you define voluntary?
There has been a lot of discussion about the concept of free will as of late.
It turns out the concept of free will is terribly hard to define in detail.
For instance, for a voluntary movement of your arm, your arms muscles will receive a 'move' signal PRIOR to the concious part of your brain processing it.
You THINK you took a voluntary choice, yet your arm moved before you were aware of your choice.
So, is this free will, and if so, who's will is it?
And since the term voluntary relies on the concept of free will, what does that tell us about voluntary trades?
The fact that there are both unconscious and conscious movements of muscles doesn't negate the idea of voluntary choice and free will. Your body can react to stimuli and will move before your conscious recognizes this, but you are also capable of deciding to move your arm in advance of actually moving it. If you don't believe me: Keep your arms perfectly still. Now think "I am going to move my arm" but don't move it. NOW move it. Did it work? Did you have the free will to move your arm or is every move of ours predestined and ordered for us? Or is this a trick question since I TOLD you to move it?
Well, the weird thing is that altho you THINK that was a COUNCIOUS desicion the actual consiousness machinery doesn't come into action untill after the muscles got their command to move.
So it seems consciousness is an afterthourgh to your subconciousnes's action.
Or so the research says.
There was this test conducted (not sure where to find it now, but http://en.wikipedia.org/wiki/Neuroscience_of_free_will seems to agree with me) that presented a choice to the test taker.
The test taker then had to point out their choice.
And they found that the choice was already made before the subject could become aware of their choice.
So conciousness may be an illusion of control!
Same goes for reasoning.
There is this part of your brain that is specialized in comming up with explanations based on available information.
It does not care if the reasoning is sane or complete or for that matter even possible in reality (checking that is the task of another region of the brain).
There were some very interesting tests done with people with split brains (the region in question resides on one side of the brain)
By feeding both halfs of the brain different information one half of the brain (that included that mechanism) was coaxed to make up a BS story about what the other part was doing.
See the 3rd paragraph of http://en.wikipedia.org/wiki/Split-brain .
What is left out here is that the half that delt with the chicken contained the 'explanation mechanism' and so it made up a story that included the chicken (because that information was available) to explain the other halfs actions.
So we make up some guestimate explanations and THEN have to check them against reality and available information.
But we are quite capable of convincing ourselfs of stories we make up ourselfs!
I find all this very interesting when watching a phenomenon like bitcoin and people doing all this decision making