Introduction To Philosophy
“Do We Have Free Will?”
1 Overall Summary
Libet considers the question of whether we have free will from an experimental
perspective. He designs his experiment to build on a previous experimental result.
This previous result was that an electrical charge, known as the Readiness
Potential, occurs in the brain about 500 milliseconds before voluntary motor
actions (such as the motion of some body part, like the arm). In other words, in
this previous experiment, about half a second before the subject voluntarily chose
to move some body part, an electrical charge occurred in the part of the subject’s
brain which helps control such bodily motions.
Given that the Readiness Potential occurs 500 milliseconds before certain
voluntary motor actions actually occur, Libet then turns to the question of when
the experimental subjects become consciously aware of the desire to perform
these voluntary motor actions. In particular, Libet was curious about whether the
subjects became consciously aware of the desire to voluntarily perform these
motor actions after the occurrence of the Readiness Potential or not after it. The
results of Libet’s experiment were that, on average, subjects became aware of the
conscious desire to voluntarily perform the motor action (in this case, moving
one’s wrist) about 300 milliseconds
the occurrence of the Readiness
Potential, which was about 200 milliseconds
the actual motion of the wrist.
Roughly, Libet seems to interpret these results as follows: The experiment shows
that the subjects have free will, but that the role of free will is much more limited
than originally thought. For, the process that initiates these voluntary motor
actions occurs unconsciously, without the subject’s awareness. Because of this,
the subjects didn’t really choose to initiate these voluntary actions. Rather, the
subjects only chose to
them to occur. So, although they never consciously
chose to initiate the motor action, they could have consciously chosen to stop
these motor actions from occurring, but did not. Because they can consciously
allow or prevent these motor actions from occurring, they have free will.
Although this is how Libet interprets the results of his experiment, it is far from
clear that his interpretation is correct.