Just because God foreknows what will happen does not necessarily mean that He caused it to happen.
That's not the point. The point is that if there really is free will, then the future is at least partially contingent on decisions we haven't made yet. So, there should always be some level of uncertainty as to what the future holds. In other words, the future should not be foreknowable, and God's prophecies should all be probabilistic, rather than definitive.
So God foreknows my decisions...so what? Its not as if I didn't make them. Just because I know what you are going to say before you say it does not mean that you could not have said anything different...its just that you didn't.
Imagine a simple case: you can choose between A and B. If you have free will, then A and B will each have a non-zero chance of being chosen. The chances may be a 50-50, or they may be a 98-2 chance, but they could only actually be a 100-0 if you were completely incapable of choosing one option.
Those chances represent the maximum possible accuracy of any prediction. So, if the chances of A and B are 50-50, then it would not be possible to predict your choice with more than 50% accuracy. If the chances are 98-2, it would not be possible to predict your choice with more than 98% accuracy.
If there is any chance at all that you might choose B, then no prediction, not even one made by God, can have 100% accuracy. God's omniscience doesn't change the underlying probabilities: it only changes how well He knows the probabilities.
except that God and chance are not synonymous. If chance exists, God doesnt
You're using the wrong definition of the word "chance." If you would rather I use the word "probability," I would be happy to do so.
If, however, God takes into account all of our decisions as a part of his overall foreknowledge, we could hypothetically have 100% freewill and God could still foreknow 100% what will occur. The only thing you cant do is decide for yourself the 0% path. If you do, your freewill just got you in a heap of trouble.
This doesn't even sound internally consistent. If you can't choose a given path, the probability of choosing it is zero, and you have no option but to take the other path. Having no option means you have no free will.
But, if you have free will, then there is no 0% path: every path must have a non-zero probability, or you do not actually have free will. God's uber-intelligence does not change these probabilities: the probabilities are part of reality.
But what if we were able to communicate that knowledge backwards in time to a person living in 1919 via some kind of time machine? Would that persons knowledge mean that Hitler lacked free will in 1923 and has suddenly become an automaton? I think not.
I think you're making the same mistake that Phat is. That is, you're trying to establish a direct, mechanistic link between foreknowledge and free will, such that the act of prognosticating causes free will to be destroyed.
That's not the argument. The argument is that free will and prognostication are two phenomena that require the universe to have certain characteristics in order to function; and that the necessary characteristics for each are incompatible. Prognosticating doesn't destroy free will: it only operates as advertised in a universe that couldn't have allowed free will in the first place.
In a nutshell, if there is free will, then there is no "the future," so you can't communicate with the past and claim 100% knowledge of "the future": you can claim 100% knowledge of one possible future, but your future has a less-than-100% chance of being realized from their perspective, so your knowledge of their future still isn't perfect.
Or alternatively, what if the multi-universe view of existence were correct, and God knows what happens on each of the infinite timelines that are created every time a decision was made. Couldn't free will still exist on each of those time lines despite God's knowledge of all time lines?
Yes. This doesn't imply perfect knowledge of the future: it only implies perfect knowledge of the principles governing the future. So, this is more like a "perfect data-modeling ability," rather than a "perfect knowledge."
But, if God's prognostications came from such a scenario, they would take the form of, "If you walk the path of wickedness, there is a 46.3% chance that you will be struck down with syphilis, a 13.8% chance that you will be pistol-whipped by an unsatisfied creditor, and a 23.2% chance of both occurring within one month of each other."
In the Bible, God never gives probabilistic prophesies: He gives definitive ones. So, this scenario is not consistent with the characteristics of the biblical God, either.
Infinite power and knowledge are hard to model and I am not sure that simple means of reasoning about them (which includes my proposals as well) yield correct answers.
That's kind of the point, isn't it? If there is such a thing as infinite power and knowledge, all bets are off: the universe does not operate the way we think it does, and the things we've taken to be physical constants and laws are really just coincidences or divine tricks or something.
So, we give ourselves an ultimatum: Do we trust reason to help us solve questions? Or do we just believe whatever, because reason is clearly bogus? I advocate holding to the path of reason, but I freely admit that that's just a pragmatic decision.
Are you saying that free will has been removed in this example? My argument is that Thomas only described the future, not that he prescribed it.
Again, it's the same error: the action of telling the future plays no active role in the process. Free will is not "removed" or "lost" when somebody foretells the future: rather, if free will exists, this type of prognostication should not be possible.
Perfect prognostication works only if the future is set in stone. Free will implies that the future is not set in stone. The two phenomena are not compatible.