How physicists handle the idea of Free Will?

[fbs7]

I have always been quite curious how physicists reconcile the concept free will with the determinism of physics.

By determinism I mean the one at macroscopic level, because I know that at quantum level most of the things are based on probabilities. So there's no free will for an electron.

But, at macroscopic level, everything seems to have some equation that determines its future, even if that's chaotic and very difficult (for us) to predict. So there's no free will for the Moon, as we'll know its exact position million of years in the future; in the same way, there's no free will for a drop of water falling in a waterfall - it's future is pre-determined, even if it is very difficult for us to calculate that.

Similarly, there's no free will for a computer, given for the same set of inputs it will always produce the same outputs.

So if I'm to believe in physics determinism, I should give up on the concept of free will, because like a computer whatever choice I'm going to make has been pre-determined by my history, genetics, inputs, environment and so forth - even if that choice may be, to our current capabilities, unpredictable, because it would depend on a very complicated equation.

That is very depressing, and as I love physics and much as I love my free will, I just don't think about that. So how do physicists answer that dilemma - is there free will in physics?

 

[Doc Al]

What do you mean by 'free will'?

 

[fbs7]

What do you mean by 'free will'?

That's a good question, and I bet every person will have a different answer. I think this one from Merriam-Webster reflects my thinking:

free will (noun)
1. ..
2. freedom of humans to make choices that are not determined by prior causes or by divine intervention

 

[Doc Al]

Can you give an example of making a choice not determined by prior causes. Not sure what that would mean.

 

[fbs7]

Can you give an example of making a choice not determined by prior causes. Not sure what that would mean.

I reckon you don't believe in free will.

That's a perfectly good point of view - nothing wrong in that. I understand you don't need to reconcile that with physics determinism.

 

[Doc Al]

I reckon you don't believe in free will.

Still waiting for an example so I can understand what you mean by the term.

 

[fbs7]

Still waiting for an example so I can understand what you mean by the term.

The way I see it, free will is when Joan d'Arc chose to be burned instead of saving herself by reneging her beliefs. The way I see it, it was her choice.

 

[Ryan_m_b]

The way I see it, free will is when Joan d'Arc chose to be burned instead of saving herself by reneging her beliefs. The way I see it, it was her choice.

Is it possible to choose what you believe? Clearly her beliefs were strong enough so that when she weighed up the possible options to her burning to death was more desirable than condoning her beliefs.

The point being here that when you "make a choice" you unconsciously and consciously weigh up the ramifications of the options. How you judge the options is based on your accumulated life experience which was largely/entirely out of your control. So imagine that Alice is observed her entire life by Bob and that Bob has a team of expert psychologists. If Bob observes Alice presented with a choice he and his team could use the data and knowledge they have to build a predictive model and predict how Alice will make her decision because what she chooses will be based on her judgement which is built from past experience.

 

[chingel]

Are you sure her actions weren't determined by her past and brain wiring?

 

[fbs7]

So if I write "ABC", then before you read my post it's already pre-determined that you're going to answer "DEF", based on your past experiences, brain wiring, environment, history, etc...?

That is, no quantum processes can modify that, no still-undiscovered factors can influence it, there's nothing else besides working just like a computer - known outputs for known inputs?

 

[Ryan_m_b]

So if I write "ABC", then before you read my post it's already pre-determined that you're going to answer "DEF", based on your past experiences, brain wiring, environment, history, etc...?

Yes I don't see why not. My entire personality is a combination of how my biology reacts with my environment over time, what I know and what I can do is also a product of this. Put the two together and no matter what I do there is a reason that has its basis in some past event.

That is, no quantum processes can modify that, no still-undiscovered factors can influence it, there's nothing else besides working just like a computer - known outputs for known inputs?

Even if we propose there was some sort of quantum randomness how does that bring back "free will"? If anything that's less free. With regards to the rest yes, the physical brain and it's physical mechanical processes are not only all that we have found they are all that is indicated.

(Also just some advice but you might want to consider asking for the title of this thread to be modified to "How scientists..." and moved to the biology forum. Physics isn't really the discipline you want to study if you are looking into cognition and behaviour)

 

[ModusPwnd]

What do you mean by 'free will'?

I think in the context of this question free will is best described as downward causation.

 

[Doc Al]

I think in the context of this question free will is best described as downward causation.

What does that mean?

 

[ModusPwnd]

What does that mean?

Simply that the question of free will from a physics perspective is essentially (IMO) a question about downward causation. Rejecting the possibility of downward causation is rejecting free will and finding a case of downward causation tentatively leaves free will on the table.

 

[Ryan_m_b]

Simply that the question of free will from a physics perspective is essentially (IMO) a question about downward causation. Rejecting the possibility of downward causation is rejecting free will and finding a case of downward causation tentatively leaves free will on the table.

And what exactly is "downward causation" and how does it factor into this specifically?

 

[Doc Al]

What do you mean by 'downward causation'?

 

[ModusPwnd]

Oh, sorry. Downward causation is simply cause and effect working from 'top' level complex processes down to the fundamental 'low' level processes. Physicists generally work under the assumption of reductionism which has been (somewhat) fruitful but at the moment universal reductionism is just an assumption. There is no evidence that all complex phenomenon can be reduced to the physics of the basic constituents (though that is our working hypothesis).

Here is one read about it, http://www.ctnsstars.org/conferences/papers/The%20physics%20of%20downward%20causation.pdf Note that I am not supporting the idea of downward causation in this thread, I am simply casting the notion of Free Will as an issue of downward causation.

 

[Ryan_m_b]

I am simply casting the notion of Free Will as an issue of downward causation.

The link you provided has no mention of free will. How specifically do you think that downward causation means that free will is left on the table? I'm sorry if I've missed something but so far all I've seen is your assertion that downward causation could preserve free will (whatever that means) with no evidence to back it up.

 

[ModusPwnd]

If the actions we make are a function of the micro state, then there can be no free will. Will emerges as a macroscopic phenomenon. If that macroscopic phenomenon is completely a function of the micostate, then any action of that will is not free. But if that macroscopic state is capable of exercising a downward cause and effect then that will is free. That is, the macrostate is the cause rather than the effect.

 

[Ryan_m_b]

If the actions we make are a function of the micro state, then there can be no free will. Will emerges as a macroscopic phenomenon. If that macroscopic phenomenon is completely a function of the micostate, then any action of that will is not free. But if that macroscopic state is capable of exercising a downward cause and effect then that will is free. That is, the macrostate is the cause rather than the effect.

Why is that different from from any form of mechanical feedback? And why can an event be both a cause and an effect?

 

[ModusPwnd]

Why would it be the same as any form of mechanical feedback? Why would it be both a cause and effect? I am not sure what you are getting at.

 

[Ryan_m_b]

Why would it be the same as any form of mechanical feedback? Why would it be both a cause and effect? I am not sure what you are getting at.

You are saying that micro state actions lead to emergent effects (I agree here) then you say that the emergent effects feed back to affect the micro state (I agree here) but then you suggest that this allows free will. Why? What is special about emergent effects that they get to opt-out of the fact that they are caused by past actions? Very specifically this is the statement I take issue with:

if that macroscopic state is capable of exercising a downward cause and effect then that will is free. That is, the macrostate is the cause rather than the effect.

 

[e^(i Pi)+1=0]

Modus,this would be a better topic in the philosophy section. You are simply not going to get much thoughtful discussion from this topic here, as evidenced by the direction this thread has taken.

 

[ModusPwnd]

All emergent effects were not created equal. Some can be reduced to functions of micro states, most cannot. Of those most we just assume that they can be in principle - but that has not been shown. If they cannot be reduced (even in principle) and they can exert a downward causation then that would satisfy as Free Will (IMO).

 

[Ryan_m_b]

All emergent effects were not created equal. Some can be reduced to functions of micro states, most cannot. Of those most we just assume that they can be in principle - but that has not been shown. If they cannot be reduced (even in principle) and they can exert a downward causation then that would satisfy as Free Will (IMO).

I get that but I completely fail to see how it relates to free will. Perhaps we're operating under different definitions here.

 

[daveb]

I think (and correct me if I'm wrong), free will would mean a person chooses A over B without any kind of determining factor. That is, it is totally random which choice is made. The problem with this is you can't scientifically state there are no underlying motivations, since you can never show that scientifically something does not exist, only that it does.

Of course, if the OP means something else by free will, then I'm at a loss to chime in.

 

[Ryan_m_b]

I think (and correct me if I'm wrong), free will would mean a person chooses A over B without any kind of determining factor.

I'd agree that this is the common definition however I don't think it is realistic and as you then go onto say...

That is, it is totally random which choice is made.

This is bizarre to me because if it is random then it is hardly free will either!

Personally I use the term "will" to mean the conscious action of making decisions. The "free" part for me refers to the extent of options the physical and social environment allows me.

EDIT: Good example of this, on the news the presenter just said "industry sources have confirmed that the manager did resign under his own free will and was not pressured by others to go." In other words it was free will because there were no blatant social pressures.

 

[Doc Al]

I think (and correct me if I'm wrong), free will would mean a person chooses A over B without any kind of determining factor. That is, it is totally random which choice is made.

But why would you call something totally random free will? (I can sort of see the free part, but not the will.)

 

[Q_Goest]

Hi Ryan, maybe I can help clear this up.

Why is that different from from any form of mechanical feedback? And why can an event be both a cause and an effect?

For downward causation (sometimes called "strong downward causation") to be a reality, neurons would interact not just with neighboring neurons and other immediately local affects, they would also be influenced by the brain as a whole. Rather than neurons being subjected to neurotransmitters acting on it, along with the local electrical field and other direct influences, they would be subjected to additional causes, sometimes called “formal causes”. These additional causes would influence neurons such that the neurotransmitters, the membraine potential and other causal influences acting on the neuron were no longer sufficient to determine how a neuron behaves – a neuron would actually be influenced by an emergent phenomenon. Mental causation as it’s referred to is a form of downward causation. The emergent thoughts and experiences would influence neurons in a way that was above and beyond the influence of those local affects studied by neuroscience.

This type of "downward causation" is favored by some nonlinear dynamicists and others in the "dynamics" crowd, but is obviously not a mainstream view.

 

[Ryan_m_b]

Hi Ryan, maybe I can help clear this up.

Thanks for that

For downward causation (sometimes called "strong downward causation") to be a reality, neurons would interact not just with neighboring neurons and other immediately local affects, they would also be influenced by the brain as a whole. Rather than neurons being subjected to neurotransmitters acting on it, along with the local electrical field and other direct influences, they would be subjected to additional causes, sometimes called “formal causes”. These additional causes would influence neurons such that the neurotransmitters, the membraine potential and other causal influences acting on the neuron were no longer sufficient to determine how a neuron behaves – a neuron would actually be influenced by an emergent phenomenon. Mental causation as it’s referred to is a form of downward causation. The emergent thoughts and experiences would influence neurons in a way that was above and beyond the influence of those local affects studied by neuroscience.

Hmm I'm still not clear of how this would "keep free will" but more than that I could in principle track the effects of a neuron back to the point where what it has done has contributed to its future behaviour (i.e. the firing of neuron A inhibits neuron B which excites neuron C which excites neuron A. A then fires and the firing of A...).

Either way though I feel like we're straying from the OP's question about free will. Unless someone has something to say regarding the OPs definition of free will and what science has to say about it we're done here.

 

[fbs7]

Even if we propose there was some sort of quantum randomness how does that bring back "free will"? If anything that's less free.

Interestingly (for me, at least), while researching the answers that have been posted in this thread, I found this short discussion from professor Michio Kaku

http://www.youtube.com/watch?v=lFLR5vNKiSw

I think his point of view is quite interestingly. If I understood it right, he calls Determinism the concept that the universe is a "gigantic clock", so someone's acts now are predisposed from what happened a million years ago.

But, against that, you have quantum uncertainty, what means that you cannot predict something completely based on a past state - there is always uncertainty, the "wild card". Therefore someone's thinking is unpredictable at some level, and that level of unpredictability is free will.

Therefore, if he's right then it would seem to me that free will versus determinism is the wrong question. The right question is free will versus indeterminism from quantum mechanics.

Also, I wish I understood it better the concept of the Quantum Brain. I'm not sure if that theory is related to this or not.

 

[James Leighe]

Just because you can't predict your actions doesn't mean they are free will, which is an important point made early on.

But in reality, unless you set up some kind of special case, the brain is too large to even be effected by quantum 'randomness'.

 

[Zarqon]

That's a good question, and I bet every person will have a different answer. I think this one from Merriam-Webster reflects my thinking:

free will (noun)
1. ..
2. freedom of humans to make choices that are not determined by prior causes or by divine intervention

I've been thinking on and off about free will for a few years now, and I've come to the conclusion that the biggest problem in dealing with this question is really to define "free will" in the first place. In Merriam-Websters definition for example, it all falls on the word "choice" which is not well defined(*). If you don't include the word choice, then you get simply "an action that is not determined by prior causes or divine intervention", which may just as well be the definition of total randomness.

A huge problem with defining free will is that it falls down to two different opposites:

1) the brain is deterministic, and while this might be consider as "will" it certainly isn't "free", thus there is no free will.

2) the brain acts from randomness, while this makes your choices "free", most people do no consider this as "will", and thus there is no free will.My best explanation for the notion of "free will", is that it is a collection of algorithms and filters in your brain that are based on information from your past gathered experience + genetics + immediate sensory input, in order to arrive at a "choice". The reason why it feels like the choices you make are out of a free will, is that you may not directly be aware of most filters/algorithms in your brain, since there are so many of them, and they all contribute/interact in subtle ways to help you "make the decision".

In addition to that, I think there is some amount of randomness/unpredictability involved in making choices. This may not stem from quantum randomness, but may simply come from the fact that most sufficiently complicated processes demonstrate some form of chaotic behavior, which gives unpredictability. And your brain is most certainly complicated enough for this.

*) for example, Merriam-Websters defines choice as "the act of choosing" which is a rather useless definition in this context.

 

[fbs7]

I think that's a great summarization, Zargon.

Thanks all for the great inputs!

 

[sophiecentaur]

Free will goes along with consciousness. We are only 'conscious' of having made a decision long after it's been made (hundreds of ms delay) so why get hung up as to whether you have any responsibility for the decision? Your brain got on and decided without your conscious help anyway. All you can do, rationally ist to justify it post hoc.