[rubidium]

But, the best we know is the laws of physics are not deterministic!

The quantum states that your neurons fire to is unknowable in advance and determined only at the point of measurement.

Therefore, you are _free_ in the exact results of your neural mass are unknowable in advance and truly random. There's certainly a distribution of probability to the randomness... but be free and don't by the deterministic, 19th century nonsense!

[nostrademons]

My physics professor met with the Dalai Lama to discuss this exact point - whether the indeterminacy in quantum mechanics can give rise to free will.

The thing is, the randomness in quantum mechanics isn't really the same as what we talk about with "free will". Quantum mechanics is really a statement about coupling - it finds that you cannot separate the results of a measurement from the act of measuring, and so you will always introduce uncertainty into the measurement of any physical quantity.

There are a lot of possible philosophical interpretations of that. Does it mean nature is inherently random? Or is nature deterministic underneath, but our knowledge of nature is inherently random? Does it leave room for God in the machine? Free will? Are the laws of physics lines of code in a computer program, and we're Sims trying to reverse-engineer them?

Physicists tend not to concern themselves much with these quesions: as far as quantum mechanics is concerned, there is uncertainty in the measurement of any physical quantity, and this uncertainty can be quantified. The laws of physics are just models anyway: they've worked remarkably well at predicting reality, but we'll never know whether they're actually reality, and that's not really the point.

"Free will" usually implies some form of agent that can shape actions in the future. The mind, soul, whatever is a distinct thing that determines our actions. Personally, I'm of the opinion that we don't actually have free will, but I was predestined to believe that I do, and as a model of reality it works fairly well even if it's false, so there's no particular reason to discard that model. Similarly, I don't actually have a "self" - I'm just a collection of neural impulses firing - but it's convenient to believe that I do, so why not?

[clairity]

free will doesn't necessarily require quantum uncertainty. it could also be that the force that set this universe in motion (as opposed to one of the infinitely many other possibilities) is the same stuff that composes our own free will. we simply don't know enough to believe in the lack of free will, either.

[collinmanderson]

If I knew for sure that everything was deterministic, would I decide to live my life differently?

I think I would still experience the ability to discern, make decisions, and take responsibility for the direction of my life.

[clairity]

self-awareness means that you might. it's why there are no sure things in the stock market, for example. we humans incorporate new information swiftly and deftly.

[pmoriarty]

Quantum events might not be completely predictable by our puny human brains, but that doesn't mean that they're not pre-ordained or pre-determined in some sense.

The world could be 100% a "clockwork universe", but we just aren't capable of understanding how it all works or fully predicting what will happen.

To say that something is "random" is more of a statement about our own inability to see a pattern in the data than about the data not having some pattern in it.

[ultraism]

I favor the idea of free will but I don't buy this argument. Everything in the universe is bound by the same physics/quantum mechanics but you wouldn't say a rock has free will.

[ChrisLomont]

Quantum mechanics has the free will theorem: if you have free will, then so do sub-atomic particles.

Thus if you want to have free will, then so does a rock.

[1] https://en.wikipedia.org/wiki/Free_will_theorem

[ultraism]

To me, free will implies choice. I don't see how non-determinism is equivalent to choice. I can see it as necessary but not sufficient. I do not see how the "free will theorem" shows that elementary particles are choosing their spin. It seems that they mean free will differently than I do.

[ChrisLomont]

>It seems that they mean free will differently than I do.

No, they mean it the same way you do; they only made it precise.

You probably suppose a scientist doing an experiment can choose between A and B for some setup. If so, then so can particles, because one can make experiments where a physicist can make a choice affecting the outcomes, and the particles in the experiment can choose their behavior in exactly the same manner.

So, since there are experiments that allow you to "choose" freely, and such experiments have particles able to do whatever you are doing, then either your free will implies their free will, or neither has free will.

Follow the links from the wiki page to learn more. It's quite precise, and is exactly the usual concept of free will.