And now that I went off on that tangent, let me try now to address your *actual* question, which was, "Do we have free will?" or, perhaps a more answerable question, "By what mechanism *might* we have free will?"

The first question I think is unanswerable. I can only say this: It certainly appears to me that I have "free will", and thus I can only live by that appearance. To do otherwise without evidence would be foolish. Of course, you present evidence that seems to point to humans not having free will, but I'll take a stab at answering that in a bit.

The second question is more answerable. And my answer is simply this: The universe, despite what it seems at times, is *not* deterministic. Quantum physics shows us that. Quantum physics limits our certainty of things. In the macroscopic world, we can say with a certainty very close to 100% that a pot of water over a roaring bonfire will boil. As things get smaller on the microscopic level, our certainty rapidly decreases. It is impossible for us to note with certainty both the position and velocity of a subatomic particle. The act of measuring one disturbs the other. Thus, our predictive powers over things on this scale break down. We think we know what will happen when we fire an electron into a metal barrier, but we can only really speak of possibilities and percentages rather than certainty, no matter how tightly we try to control the starting parameters.

As we scale up the ladder to macroscopic objects, that uncertainty seems to disappear. It seems more and more like the universe is deterministic. I can hold a ball two feet above my desk and drop it and feel reasonably certain it will fall to the desk. Likewise, I can place a pot of water over a roaring bonfire and feel "certain" that it will boil.

HOWEVER, it's just a matter of scale. It's counter-intuitive and seemingly illogical, but it's still entirely possible that that ball, when I release it, will move upwards or that pot of water over the bonfire will freeze. How? Well, back on that microscopic scale, things are still happening upredictably. It is entirely within the realm of possibility, even though such possibility is excruciatingly small, that every atom within that ball will suddenly move "upwards" when I release it instead of what is normal, and all the random movements of the atoms cancelling each other out and thus the ball remaning stationary or obeying the laws of Newtonian physics. It's also entirely possible that that pot of water will freeze, for similar reasons.

Now, granted, these possibilities are exceedingly small. For the pot of water example, I learned from Asimov that statistically speaking, if the entire known universe consisted of nothing but pots of water over roaring bonfires, we'd have to wait longer than the expected life of the universe in order to see one freeze. Does this mean we can discount the whole idea, though?

Now, back to the crux of the matter. Free will. Do we have it? Like I said, I can't say for certain we do. I don't think anyone can. But is there a mechanism by which we *might* have it? I think there is. I think just the fact that the universe *is* non-deterministic is evidence enough that free will is a possibility. In order for this to be so, however, I suppose I must define free will as "the ability of a creature to be non-deterministic". It doesn't necessarily address the idea of "choice". In that respect, I can't think of an answer any more than you can, but again, I think it's one of those questions that may not even *have* an answer.

Anyway, as for a mechanism for free will, I'll just furiously wave my hands and say stuff about QM and neurons and what have you. But I'm not really knowledgeable enough about either subject to come up with anything truly convincing, even to myself. But my main point is that since the universe *is* non-deterministic, free will is at least possible.

As for your idea of a universe being a computer program, I think I addressed how that was possible in my last post. But to be more specific to the analogy, it is possible for me to program something and not know how it will come out. I do this by introducing randomness. I do *this* by relying on a random number generator. Now, if I were sufficiently smart, I could still figure out how it would come out, because I would be able to know which number that "random" number generator would spit out each time I called it ("random" numbers in computing are a convenient fiction--that's why they're more properly called "pseudo-random number generators" because with sufficient information, it's possible to predict what the generator will spit out each time it is called.) But say I have a mechanism that works on the quantum level? Could I not then get "true" random numbers (and here I'm relying on vague information in my head that a quantum computer could produce "true" random numbers) and thus have a run of a simulation be completely and totally unknowable to me?

So, let's say I build a computer personality. Let's say I imbued it with the ability to parse its surroundings and make decisions based on those surroundings. It would be trivial for me to introduce a slight bit of randomness into that personality such that even giving perfect knowledge of the "rules" it uses to make decisions, it could still surprise me and make a decision I did not predict.

Is this free will? Most people would say no, I suppose. By my limited definition above, it would be, though. And could it not be that this is really what we have? A bit of randomness that we interpret as free will? I don't know. Humans tend to rationalize their decisions after the fact. We insist we made a decision for reason X, when in fact we were actually under a post-hypnotic suggestion to do X and we came up with a rational explanation for it afterwards (and here I'm stealing from Scott Adams, of all people). I seem to be coming down on the side of "no free will" when I started out to show how it is possible that we have it. But I keep coming back to this: I may not have free will in the traditional sense of being able to "make choices", but I am utterly convinced that the fact that the universe is non-deterministic means that I myself am also non-deterministic. It may be possible to predict with a high degree of certainty what I will do in any given situation if we were to know exactly how my brain makes decisions and exactly what knowledge I'm acting on, but I don't think true, 100% certainty is ever possible. And that to me at least means it's *possible* I have something like free will.

-- Dave