Dr Libet and Free Will I've added this quote to
"Free Will: An Illusion" by Vexen Crabtree (1999):
“That something in the brain really is performing the role of an observing self is suggested by the work of Benjamin Libet at the University of California, San Francisco. Dr Libet used eletroencephalography to look at brain activity during the process of making simple decisions such as when to move a finger. He showed that the process which leads to the act starts about three-tenths of a second before an individual is consciously aware of it. In other words, the observer is just that: an observer, not a decider. This may explain the feeling that most people have experienced at one time or another of having deliberately done something that they had not actually wanted to intended to do.”
The Economist (2006)
This is supported by a wealth of neurological evidence that our brain functions and works on strict deterministic, physical principles with no element of 'free will'. What we think is free will, is really the combined results of billions of events, all caused by previous events, that cascade back to long before we were even born. That all our thoughts, feelings and 'choices' are biochemical in nature is the biggest challenge for free will: There is simply no place in the system of human neurology for free will to play a part.
My page as quoted above examines many other aspects of free will, including the telling truth that if free will existed, social justice would be undermined and become valueless: Punishment and deterrents such as fines, and good parenting, all rely on the fact that we can train people to behave in a certain way
because we know that behaviour has causes external to the individual. The more free will there is, the less we can justify trying to improve other people.