Comments on: Free will and deterministic predictions

By: Andrew Mahone

Andrew Mahone — Thu, 01 Dec 2011 01:05:02 +0000

Wouldn’t the prediction function, in a model that must necessarily include the predictor itself, be noncomputable? I’m pretty sure an algorithm can’t have absolute knowledge of it’s final result as an intermediate value, and any attempt to consider all possible final results has the possibility of the algorithm running forever or only being able to report, if it’s clever enough, that the result is indeterminate (I’m not aware of any such theorem having been proven, but it feels correct and I think might follow fairly directly from the halting problem). I’m not convinced the impossibility of the predictor, if I’m right, kills determinism. That we lack a predictor is not the same thing as our actions being fundamentally unpredictable. The interesting thing is that evidence of determinism does not appear to impact the illusion of free will, and I’m satisfied to exercise that illusion while strongly believing free will to be illusory.

By: Simon Ferrari

Simon Ferrari — Sun, 19 Apr 2009 22:26:35 +0000

I’ve always maintained a “soft deterministic” stance when thinking about free will. Basically, I hold that the person you are has been determined by your biological makeup and everything that has happened to you. So you’re actually making a choice “freely,” it’s just that the person you are, making the choice, has been largely determined already.

People looking at this from a revamped version of religious theories of free will (if it has to happen, or if God knows it will happen, is it free?) are going to confuse the forest for the trees here.

By: David Michael

David Michael — Fri, 31 Oct 2008 19:37:55 +0000

Forget the example I gave. It is a bit confusing. (My instinct is that it’s possible in principle for that example to be deterministic, but only if true randomness is possible, and I don’t know if it is…)

The fact that no accurate prediction can be made is pretty much the crux of it, and you’re correct in saying that my thought experiment doesn’t succeed in showing that free will exists. (In my defence, I wrote in my post that I had to “tentatively conclude” that I have free will. You’ve made that conclusion slightly more tentative.) However, all the myriad possibilities of predictions, predictions of predictions, reactions to predictions, etc., make the waters a lot murkier, and I think they’ll have to be waded through a lot more thoroughly before we can come to a conclusion either way.

By: Chaospet

Chaospet — Fri, 31 Oct 2008 04:21:20 +0000

Now I am a bit confused. If it’s impossible for the machine – which by hypothesis knows every detail about the laws of physics and all the physical details of the universe – to calculate whether A or B will follow from X, then that by definition seems to be an indeterministic universe.

But back to your original thought experiment, the point I am trying to make is that there won’t be any deterministic predictions being proven wrong by anyone’s freedom. Rather, no accurate prediction can be made – which on the face of it has nothing to do with freedom (unless you have a particular way you want to spell out what freedom means), but with the simple fact that the prediction itself is a causal factor that determines the person’s behavior.

By: David Michael

David Michael — Wed, 29 Oct 2008 22:28:46 +0000

I agree completely, and I mentioned in an earlier comment that I think free will and determinism are compatible. I am less concerned with disproving determinism than I am with proving that free will exists. In the example you gave, the person may or may not be free. But suppose there’s a situation in which the machine predicts the following: “if I predict X, then the person will do A or B, and if I predict Y, then the person will do C or D.” There is nothing un-deterministic about that (as far as I can see), and it seems likely that if there is no way to distinguish in the prediction between two equally likely options, there is room for freedom of will somewhere. Still not proven a priori of course.

By: Chaospet

Chaospet — Wed, 29 Oct 2008 02:48:23 +0000

Consider a situation in which there are only two options for the stubborn fellow, X and Y. The machine can calculate that if it predicts X, the person will do Y, and if it predicts Y, the person will do X. There is no failure on the machine’s part to calculate what the person will do, nor is there a failure of determinism – the inability to make an accurate prediction to this person is simply a result of the fact that the person’s knowledge of the prediction will be a factor in determining his behavior.

By: David Michael

David Michael — Tue, 28 Oct 2008 22:11:22 +0000

Yes, I see your point. But what do you mean by “the machine would know that it couldn’t” make an accurate prediction? Remember, it’s just a machine that’s been programmed to map out the universe from beginning to end. If it gets to the point that the machine simply can’t work out what someone will do, then this seems to me to show that our actions can’t be overdetermined. If they were, it would have to make the correct prediction, would it not?

By: Chaospet

Chaospet — Tue, 28 Oct 2008 03:52:45 +0000

This is interesting, but I’m not sure the thought experiment is actually possible. In creating a model of the future based on the laws of physics, etc, we will have to take into account the impact that the predictions will have on people’s behavior (as has been noted). So imagine a simple case – a stubborn person who is determined not to do anything that it is predicted he will do. The predicting machine would simply be *unable* to make accurate predictions to this stubborn person (at least in many cases) – but the machine would know that it couldn’t, based on its deterministic calculations of how the person would react to any predictions he was given. So, it’s not clear how any of this undermines determinism…

By: David Michael

David Michael — Sun, 26 Oct 2008 13:43:11 +0000

That sounds interesting but very confusing. I looked up Maharshi on Wikipedia, but still don’t quite understand…

By: Sue

Sue — Fri, 24 Oct 2008 03:30:57 +0000

Ramana Maharshi pointed out that the only choice you really have is whether to identify with the body or not.

And that the moment you identify with the body you become helplessly bound to all of its yes/no/maybe dichotomies and all of the universal patterns of relationship within which the body is entangled, including the karmicly determined/inherited patterns of the particular body-mind-psyche that you have chosen to identify with.
Which of course is going to disintegrate and die, and you know very well that this is so.

The world of klik-klak and its relentless pattern patterning. Klik-klak being completely indifferent to the well-being and survival of any and every biological form that arises within the pattern.