## torsdag 19 maj 2011

### Free Will and Finite Precision Computation 4

Daniel Dennet advocates a compatibilism of determinism and free will, expressed as a capacity of human beings developed by evolution to avoid (unpleasant) things by voluntary action:

Seeing a brick being thrown at us by some unfriendly agent, we typically choose to duck. Dennet argues that we do that by free will, since it would also be possible to choose to not duck and take the hit to get a case to bring to court.

Dennet argues that either the future is fully determined by the past (Laplace demon) or the future is fully undetermined in the quantum sense that the next position of an electron is not determined but subject to throwing a dice.

In either case we cannot really influence what is going to happen, and thus we cannot exercise any free will: whatever happens, happens. Yet Dennet claims that we have a free will in the sense that we can decide to avoid certain things, but not all: We will not have time to duck if the brick is replaced by a bullet.

I get the impression that Dennet's resolution of the apparent contradiction between a free will and full determinism/indeterminism, is a scholastic resolution in the sense that something essential is being missed and nothing really new is brought in to solve the eternal free will problem.

Would finite precision computation be helpful? The idea here is that little things may be left to be decided by the dice while major things are predetermind by a finite precision Laplacian demon. More precisely, we know that
• there are major things that we cannot do even if we would like to (limited free will): e g fly like a bird.
• there are major things we can do which we have decided to do (according to a predetermined master plan): e g go to college.
• there are little things which we can decide by free will, which we could leave to the dice if we cannot decide: e g meat or fish for dinner.
This opens to a finite precision resolution of the free will problem:
• big things determined by a finite precision Laplace demon/master plan of ours
• little things decided by a dice.
In extreme cases a small thing could become big and would then be described as a strike of luck or accident: to win on the lottery or get hit by a falling brick.