>>12050529Free will has to be defined first.
You can define free will as "nothing is deterministic"
Or, you can define free will as "it is impossible to determine the future", aka, even if the universe is deterministic, and you knew this 100%, there is nothing in physical reality that will allow you predict what comes next.
Both of these have the same presentation, that you cannot predict the future. Some philosophically argue that they are the same thing.
Chaos theory builds on the second model: if a deterministic system is sensitive enough to initial inputs, than it can be impossible to simulate. Even if you knew the "brain equation", if you didn't know the exact inputs, all of them, down to the 20th decimal, you'd come out with entirely different results of your predictions.
We can semi-prove that with some systems, its actually physically impossible to predict behavior because we will never be able to measure accurate enough inputs.
Of course, you could predict short term behavior supposedly.
Another thought is that a sufficiently complex system with an emergent property, such as the brain and consciousness, may already be the minimal unit needed for prediction. That is, you can't use reductionism (estimations or functions for whole-parts of the brain), or the predictions are entirely inaccurate. You'd have to, in effect, build the entire-brain as is to predict what it would do in a scenario, at which point you aren't simulating anything.
