I won't define the words “free will” because, as someone once put it, “that is an argument that never ends”. In other words, it would take up this entire piece... and more.
All I can do is refrain from offering an alternative definition and simply question what other people say on this subject. In that simple respect, definitions don't matter. Without a definition, people can still make mistakes in what they say about free will, chaos, indeterminism, choice, etc.
Though, of course, if there were an agreed upon definition of the words “free will”, many problems could - or would - be solved. The problem is that there isn't one and perhaps there couldn't be one. After all, the words “free will” aren't like the word “cat” or “house”: they're closer to a word like “truth” or even “wrong”. (Of course some philosophers have also made a song and a dance about words like “cat” or “house”!)
There are many newfangled defenses of free will.
For example, it's said that complexity can explain free will in certain respects. Chaos or quantum non-determinism have also come into the debate in recent decades.
The argument is that complexity is required to have a developed brain. And large brains are required for free will. Such complexity gives a “system” (or a person) the ability to make choices.
Does all that guarantee free will?
I can't see how complexity in and of itself can give us free will. It does in the sense that if we can't decipher all the causal antecedents of our actions, then perhaps we must be free. On the other hand, it may not matter one bit whether or not we know all the causal antecedents of our actions – they may still determine our actions. After all, couldn't a simple being – or even a machine – perform an action?
I accept that brains are complex. Everyone does. I just don't know how complexity alone gives us free will.
And I don't see how you can squeeze free will out of chaos or non-determinism either.
You Could Have Done Otherwise
How does the possibility that X (a person) “could have done otherwise” give X free will? Like complexity, how does free choice spring from such non-determinism (if that's what it is)?
How does the possibility - or even the actuality - of making a different promise, for example, free us from determinism? Choice X is fully causally determined. And the choice not to do X is also fully causally determined. The reason why X, rather than not-X, is chosen, will be a fully causal reason (as well as vice versa).
You can now say that if you could have made decision not to do X, rather than to do X, that's all that matters. In other words, that choice itself determines the freedom of the will; regardless of the fact that both X and not-X were fully causally determined. (That's the “common-sense position”.)
What about self-prediction? If you can't predict your own actions, then aren't your actions chaotic and uncontrolled?
Can an agent's own measurements of his own body or brain/mind states help the matter?
Isn't it impossible for an agent to measure everything that leads to one of his actions or decisions? That would seem to point away from free will. Though other people appear to argue that it's a position in support of free will. What such people argue is that this person (or “system”) not being able to measure small “deviations in the initial conditions” works towards his free will, rather than against it?
What about other people failing to predict our actions? Does that give us free will?
Why would that matter? I couldn't predict the actions of a machine or robot; though that wouldn't give it free will. And even computer programmers sometimes – or many times - can't predict the calculations or actions of their computers.
Even if someone can't predict an adult human being, that doesn't guarantee free will. I may not be able to predict a robot or computer's actions. In fact I won't be able to unless I've programmed it myself and even then (see the Turing machine section) that can't be guaranteed.
Human beings can be seen as deterministic systems whose random inputs (or the things which happen indeterministically) don't have a noticeable impact on the system – or on how they behave at the “macro scale”. In other words, when you interact with a human being, his quantum nature may appear irrelevant to his general behaviour (at least in observational terms).
What would a “randomised input into a deterministic machine” give us anyway? Not free will. What would it give a machine?
Slight deviations in a system don't seem to guarantee that a system is chaotic or indeterministic either. These deviations happen to the system/person. The system can still be deterministic. However, if you factor in quantum indeterminacy, it's still an open case whether or not such a thing guarantees free will. I think the argument can go in the opposite direction. Either that, or quantum phenomena are largely irrelevant at the level of the cognitive (or even sub-cognitive) systems of the brain (though I may be wrong on that). What I mean is that even though the brain is a “quantum system” (everything is), that may not impact on the issue of free will (as such).
The following may help with the earlier talk about introducing something random into a system.
I'm not saying here that a Turing machine has free will in anything like the sense a human being may have free will. It's a parallel case cited to try and help explain the nature of randomness as it's used in the free will debate. I don't think Alan Turing, for one, saw what he said - or did - in terms of free will. (He used the word “intuition”; though, admittedly, that can be said to amount to the same - or to a similar – thing.)
In other words, this isn't a general point about Turing machines and their ability to appear as persons or replicate human behaviour. It's not a point about the Turing Test. It's a point about Turing machines.
Think here of early Turing machines and the requirement for them to be able to follow their own rules or show what some people called “initiative”. It was said that a programmer could engineer an element of randomness into the computer (or into the programme). That was what was Alan Turing tried to do with his “Manchester computer”. That seems to have meant that such randomness (as it were) would bring about “intuition” (or initiative) in the Turing machine – or even free will!
In any case, when (not if) a random element is introduced into a Turing machine (a computer), and then that computer manages to follow rules not laid down by the programmer (then as a result it solves its own problems), then there's no “appearance” about it. In this limited respect, it is free from its programmer. Or it has a “will” which is independent of the humans who created it; as well as of its programmers. This isn't to say that it has either a mind or a (free) will in the human sense; though the independence (or even freedom) is certainly real.
I think it would also be correct to say that a Turing machine “could have done something else” with the same input. That is, the same random change (mentioned by Turing) to the Turning machine can have different results in terms of what it produces (say, a different calculation or even a different action – though a calculation is an action of sorts).... What am I talking about? These things happen already with computers (or their programmes).
Politics & Morality
Some people believe [free will] to be a “political concept”. Then again, perhaps it's always been a political - or at least a moral - concept. And it might well have been (in some cases at least) that issues in metaphysics and the philosophy of mind might have been needed to provide the groundwork (as it were) for the political or moral positions on free will.
Over large time-periods philosophy has an influence on these issues. Though the minutia rarely does. This discussion, for example, has been more or less besides the point when it comes to the day-to-day political and moral issues of free will.