Robin said:
"Anything that involves free choice is, by definition, unpredictable" But you never did give this definition.
Perhaps the source of the confusion has to do with what free will means. Free will is sometimes referred to as "volition" in order to distinguish it from "freedom." Volition can be thought of as your ability to make choices, whereas freedom can be thought of as your ability to choose in a particular situation. Volition is an absolute -- you either have it or you don't. In contrast, your degree of freedom depends on your circumstances.
For example, if I lock you in jail, I remove your freedom to go wherever you want. However, I do not remove your volition (that is, your ability to make choices). Similarly, the laws of physics keep you from having the freedom to flap your arms and fly. However, you still have volition.
Our choices may very well be constrained, but as long as we have the ability to make choices, we have free will.
The one you did give (from Webster) said that "free" meant "free from external circumstances". That is the one I am using also.
If you're a determinist, then
all circumstances -- both internal and external -- are the result of cause and effect. It can also be argued that at conception human beings have no internal circumstances, therefore all of our internal circumstances are caused by external circumstances. Therefore, as far as free will is concerned, internal and external circumstances are exactly the same; both are affected by cause and effect, and both are the result of prior causes.
If you believe that our circumstances always completely
determine our behavior, then you must believe that we do not have the ability to make choices. If you believe that our circumstances only
influence our behavior, then you believe that we have the ability to make choices -- that we have free will.
In other words, if your action is determined by causes, then you don't have any choice but to take the action that is determined by the causes. If your action is only influenced by causes, then you can potentially choose any action you want regardless of those causes.
That is not to say that with free will your decisions aren't
influenced by your circumstances, just that your decisions aren't always completely
determined by them.
Deterministic free will is as free from external circumstances as uncaused free will is, it is just not free from internal circumstances.
"Deterministic free will" doesn't make any sense because determinism dictates that EVERYTHING (including internal circumstances) is ALWAYS the absolute result of cause and effect. Therefore, if you're a determinist, then you would believe that we don't have free will (i.e. the ability to make choices).
I always imagine that even if I change my mind a millisecond before acting that there will be some reason for this change. But if I change my mind at any time for no reason at all I don't personally consider that to be free will. A choice free from bias, external influence, habit etc might be good, but a choice free from intelligence, knowledge, experience would not.
It doesn't matter whether you change your mind an hour before you act or a millisecond before you act. It also doesn't matter whether you consider that all choices have reasons (both free will and determinism support this notion). The only question is whether the resulting action is always completely determined by prior causes or might only be influenced by them.
I would agree that a choice that isn't influenced by carefully weighing both external and internal circumstances wouldn't be a good choice. However, that doesn't mean that you don't have the ability to make whatever choice you want, good or bad (and people make bad choices all the time).
I can't see what else there is and nobody is prepared to describe precisely what is meant by a free choice so I can only go by what I can definitely identify. And if nobody can give me any good reason to reject determinism other than "it would be depressing" and "you can't prove it", then it is a good working hypothesis on the available evidence.
Hopefully, this has cleared up what is meant by free choice. And if you don't think we have free choice, that's OK. In fact, you're in very good company. Scientific evidence supports determism, and there has never been a non-causational event reliably observed in the history of the world. Then again, human behavior is very complex, so it would be very difficult to demonstrate a human behavior that could be proven to be non-causational.
Like you said, nobody knows for sure whether we have free choice or not. There are a lot of people who hold that until science has proven something to exist, there is no reason to believe in it. By the same logic, some hold that things that are unprovable (such as the existance of God) should never be believed. Ironically, determinism itself is arguably unprovable.
As I was pointing out in previous posts (back when we were talking about ethics) there
are possible implications to not believing in free choice. Our justice system assumes free choice. On a basic level, the belief in free will allows us to hold people responsible for their actions. None of this has any bearing on whether or not free will actually exists (I've never made an argument one way or the other as to whether free will actually exists), just that there are implications to whether or not you
believe that free will exists.
And that is all I am saying on the subject. If you make a free choice to change your mind and rebut these points and I am happy to let you have the last word.
Apparently, I have "chosen" to rebut these points despite my previous "decision" not to. Was I was exercizing free will by doing so, or was it simply the result of cause and effect? That's the question that frankly nobody knows the answer to.
-Bri