Hindyhat: Godwins law is the whole 'hitler thing' (which I wanted to avoid mentioning him directly)
Hence I believe it is quite a futile claim that humans are incapable of freedom. I say possible until proven otherwise.
Humans in prisons are under an anarchy of sorts, there are two things that usually happen.
"They inevitably form a government" (gang leader type deal)
Or
"They shiv each other" (ruled by their emotions, etc)
Rarely do most exercise self-control, and usually then, only when the warden (The Law) is near.
Some might be capable of self-control, these usually don't end up in prison anyway, and of that group of self-controlled people the majority of it usually does so only because of Law. Cut out the law, and you have less people who exercise self-control. The remaining group of self-controlists are grossly outnumbered, and subject to becoming the victims of those who cannot.
Lets use a scenario of 4 people.
In an anarchical society: You have Dob, Rob, Job, and Sarina.
Dob is married to Sarina.
Rob is a self controlled individual, who owns a piece of bread.
Job is a raider.
Job is hungry, and he doesn't want to waste time growing his own wheat, milling it, and baking it to make bread: He 'steals' (no law, so it technically isn't stealing now is it?) the piece of bread from Rob.
Rob doesn't like this, as that is his only piece of bread, and he was saving it for dinner.
Rob and Job fight to defend their territory, and Rob dies in the fight. Job wins the piece of bread, and eats his victory.
Full, and satisfied, Job now wants to feed his other appetite. He wants to get lucky.
Now, next door, is Dob, and Sarina. Sarina is one hot, sexy, luscious piece of bread so to speak. Curves, blonde hair, blue eyes, full lips, the works...a goddess.
Now since there is no law, rape does not exist, its just passing on your genes afterall, and doing what nature tells you.
Job catches Sarina in the field, rapes her brutally, rapes her again, and does this for several days, until Dob has enough, and a fight insues to protect his mate.
Dob is killed, and Sarina is taken, and bears a daughter to Job.
The daughter grows up, and Sarina grows old.
Job rapes his daughter. But rape doesn't exist.
His daughter bears a son named Tamo.
Tamo is special needs, due to the incest.
Tamo is quickly killed because he is useless to his father/grandfather. This is not against the law, it is merely protecting the family genes right?
Basically, this example is just a story, and not entirely complete on the list of possibilities, but it shows what is possible when Law is destroyed. Sure, Rob, and Dob could have won the fight, but the possibility remains that Job being a raider wins the fight as well, and justice is not served as he has his way, what ever way that might be. He is ruled by his emotions, instincts, drives, hormones, and etc. Not self-control, there is no Law to guide it, protect it, enforce it.
Job represents the criminal element that already exists in Governed society, now let loose to be free in his work without Law to hinder him. Dob and Sarina represent the family unit, as well as Special Victims. Rob represents the labouring forces, the worker, the wealthy, the market.
People don't exercise self control for the most part, because they don't have a guide to do so, and without a law, and those to uphold it (which inevitably leads to government to maintain its integrity), mankind relies on his crude nature. Which leads to theft, rape, murder, etc, in order to gain the things he wants.