Free will
General
Free will is the notion that we ourselves can decide what we want
to do. I think that means that our actions cannot be predicted by
any natural means. One thing that is certain is that we have a
feeling of free will, but this might be an illusion. I think a
definition of free will should include the feeling of having it
and some unpredictability for actions performed by free will.
Spiritual free will
One explanation for free will is that an immaterial spirit belongs
to each person which somehow influences the material brain with its
free will. Then of course the question arises how free will appears
in this spirit and how it is influenced by the world. Surely it must
amount to some kind of probability for different free will actions
from the spirit. Worse for this kind of explanation is that the
existance of this spirit has never been deducted or how it influences
the brain. I think this makes it a very improbable explanation.
Robots
When Newtons theory ruled the physics world Laplace formulated his
famous demon. A beast that could calculate every particles mass and
speed in the whole universe. This creature could then predict every
event in the future and in the past. With this view we would all be
robots. This has profound implications for for example guilt. Can you
hold a person guilty of something he was predetermined to do?
Quantum mechanics
Quantum mechanics seemingly contain pure stochastic behavior and as
such it makes Laplaces demons task impossible. There could also be a
better deterministic theory that we do not understand but I will
assume it is pure stochastics for the moment. Another objection is
that it could be deterministic on the macro level as the stochastic
fluctuations even out. But I do not think this have to happen, there
could be chaotic processes that magnifies the fluctuations to macro
level. If so, this produces an undeterministic free will even though
we could calculate probabilities for actions stemming from this free
will. We become a kind of stochastic robots. That quantum fluctuations
can be magnified to macro level is proved by the background radiation
where probably quantum fluctuations saw the seeds for stars and
galaxies when they were magnified at the big bang.
Uncalculability
Roger Penrose has developed a theory where our brains have certain
parts where there are physical processes that can not be calculated.
He bases this theory on Gödels theorem among others. I do not know what
this would implicate, maybe our actions would not be predictable even in
a stochastic sense. Personally I think all processes in the universe is
calculable and predictable, at least in a stochastic sense. Penroses
theory implies that there might be uncalculable physical processes which
is interesting though.
Summary
I think it is hard to salvage real free will. The quantum induced free will
I think is the most probable way of saving unpredictability in free will.
I think the most probable conclusion is that we are robots ruled by
deterministic chemical reactions. But even so I think the illusion of free will
is good enough.