There is no contradiction between omniscience and free will. That's a rhetorical trap. As was pointed out, any omniscient entity must perforce not be subject to the laws of time. When you remove time from the equation, you must perforce remove cause-and-effect, because cause-and-effect are bound up quite heavily in time. If God knows what tomorrow's lottery numbers
are, that doesn't make the lottery any less random, it simply means that from God's perspective, everything has
already happened.
Similarly, the fact that God knows what I am eating tomorrow morning doesn't mean I'm not going to get up, have a debate with mself over the virtues of
Par Larm vs.
Saltimboca, and eventually decide to make steak and eggs.
The problem with free will as I see it is one of neuroscience. Despite all of our advanced biological and chemical understanding of the brain, no one can tell me with any degree of reliability what happens between the moment someone tells me "your son just got hit by a car" and the moment the adrenaline dump hits. Some nerve signals go somewhere into the depths of the brain, and some other signals come out different parts and start stimulating various glands and tissues -- but
why?
There are two common answers, and I don't like either one.
The first is that free will exists and that there is some element of the persona, whether it's a physical part of the brain or some ethereal spirit/soul/nth dimensional extracranial construct, that performs the function of 'being' your free will. I don't like that because I can't see it, get a grip on it, or otherwise exert any control over it whatsoever. Claiming free will exists but that it's function is hidden from us is lame.
The second is that the universe is deterministic and that, given enough informational capacity, we could eventually narrow down every single chemical and electrical reaction within my brain and come up with a completely 100% accurate model that could predict, given my entire set of circumstances, exactly what my response would be to any given input. I don't like that because it removes my ability to control my own actions. Claiming free will doesn't exist at all sucks.
The only options I have under this exercise are to give up control over my actions, or give up control of my own self-understanding. I don't believe in either of those options. My choice -- and I believe it is a choice -- is to believe that Science is a vastly and horribly limited system of deciding what is 'real' and what is not, and that I can believe my own personal experiences even if Science cannot explain them. As such, I further believe that free will is an aggregate of the ongoing argument between several different layers and subsets of my own personality and that it can be properly understood through psychology and self-reflection even if neurobiology is fail.
