Very well put warr.The way I see the mind is a kind of unfathomably complex cavern, and that free will at the level of thought simply doesn't exist. There may be uncertainty at he quantum level which leads to inherent unpredictability, but I believe that if you knew enough variables about a brain at any given time, you could perfectly predict how a person would react (both physically and mentally) to any set of external and internal stimuli. I fail to understand how the human brain is any different than throwing a ball at a set of stacked cans. Knwoing the exact arrangement of the cans, each of their mechanical properties, surrounding temperature, humidity, relative altitude, longitude, latitude, location of earth relative to the sun, the ball's angular and linear momentum, shape, materials, etc, etc, would allow us to, at least in limit of our perceived reality, perfectly predict the final arrangement after all is said and done. Sure, on a quantum level we might not be able to perfectly predict this, but this event will occur in the exact same way to our brain an infinite number of times simply because the difference would be too minute. I just see the brain as a far more complicated version of this. It seems a bit pretentious that just because the brain is many orders more complex than other types of physical systems that it operates on some different principle altogether.
I think many people fail to realise the complexity of the human brain, here are some basic estimates:
the brain contains approximately 100,000,000,000.0 (billion) individual neurons,
each neuron with multiple synaptic connections numbering approximately 10^15 (one QUADRILLION)
operating at about 10 impulses/second,
that gives us about: 10,000,000,000,000,000.0 synaptic operations per second!!!
10 QUADRILLION OPERATIONS PER SECOND!
Really thinking about the scale of those numbers brings new light to the feats that humans are capable of...