8 ms·

As the final section shows, this is more about the question of determinism vs indeterminism. Depending on your particular ontological and epistemological leanin

As the final section shows, this is more about the question of determinism vs indeterminism. Depending on your particular ontological and epistemological leanings, that question and the question of free will may be the same, or conflating the two may be a category error. I personally fall in the latter camp, but this was an interesting foray into the musings of a brilliant mind.

tacotime 12y ago
So you're saying the world can be deterministic and you can still have free will? That would mean you would have to believe in something like souls then, right? Something outside of this physical world that influences your physical existence? I'm not questioning your views just trying to understand.
- cokernel 12y ago
  There are varieties of compatibilism (the view that determinism and free will are compatible) that do not require the existence of souls. I'd suggest taking a look at Daniel Dennett's _Elbow Room_ for one example. The Stanford Encyclopedia of Philosophy has an article on the subject: http://plato.stanford.edu/entries/compatibilism/ http://plato.stanford.edu/entries/compatibilism/
  - __m 12y ago
    i never had the patience to follow that mind juggling, or "word jugglery" as Kant calls it. For me as a programmer free will would mean something like: var a:Int = 2 var b:Int = 3 println("\(a+b)") >> 42 where transistors take the place of neurons
  - DougH5000 12y ago
    Compatibilists redefine free will, similarly to those who redefine "god" as "nature" or "the universe". Sure, anyone can define any term the way they want, but it simply causes confusion to the majority of people who don't hold such definition. Rather, it's best to abandon some terms as fiction, and create new ones surrounding the concept you are looking to address. Better books on the topic are Sam's _Free Will_ or Trick's _Breaking the Free Will Illusion_. http://www.samharris.org/free-will http://www.samharris.org/free-will http://breakingthefreewillillusion.com/ http://breakingthefreewillillusion.com/
- drdeca 12y ago
  I don't follow. How does free will+determinism imply an outside influence? I see no convincing reason that an entirely deterministic thing can't have "free will". Though I don't remember ever having found a definition of "free will" that I've found satisfactory. I don't think compatibilism implies a belief in anything "supernatural" though. (quotes to indicate things potentially not being exactly the right term, or other similar indications)
- salmonellaeater 12y ago
  The world can be deterministic and still allow free will with respect to a real observer. In some sense it doesn't matter if a person's actions are in principle predictable when there is no observer who can actually make those predictions. You'd have to measure and simulate the entire universe to predict a single particle's future.
  - Rapzid 12y ago
    But it would just be an illusion no? If the discovery were made that the universe is entirely deterministic it wouldn't matter whether any one person could, or any number of people, could produce accurate meaningful predictions. The truth alone would VERY disruptive.
    - thaumasiotes 12y ago
      > The truth alone would VERY disruptive. This is clearly untrue. The discovery has already been made that events in the universe happen in one of two ways: 1. "deterministically", the way you think would be VERY disruptive 2. determined by chance This isn't disruptive; people just ignore it.
      - Rapzid 12y ago
        Sources?
    - afafsd 12y ago
      The great Australian philosopher David Stove was of the opinion that the main function of philosophers is to save the rest of us the trouble of thinking about these sorts of things. When a useful professional in another field such as you or I starts wondering about these sorts of issues, he can simply pick up a philosophy book, note that a bunch of smart people have already thought this issue through, put labels on every possible position, argued through the consequences of each, and still failed to come to any consensus about it. And then we can say "Whew, glad someone's already taken care of that" and get back to our useful lives without worrying our pretty little heads about it too much. So if you do find yourself worrying about free will, I suggest reading the vast amount of pre-existing literature on the subject and unburdening yourself of feeling like you should be making progress on it.
- plaguuuuuu 12y ago
  We consider free will important because we like to think we make our decisions based on our own individual identity, rather than physical properties of the universe that predetermine what we will do. Even if free will exists, our mechanism for arriving at a decision to do one thing over another thing pretty much needs to be context-dependent - i.e. we make that decision based on some line of reasoning (whether correct or not). At the same time, everything we've experienced and consider to be part of our own individual identities, the stuff that defines our free will, is incorporated as a part of that context. So many people argue that free will and determinism are still pretty much compatible. Nevermind all the other crap we like to pretend doesn't influence our decisions like whatever crazy hormones happen to be elevated at the time.
  - aaronblohowiak 12y ago
    To me, this argument is a strong defense of the "self", but does not address the "free" part at all. It is like saying that a rock is free to weigh more than a marshmallow because of the complicated history that lead it to being this rock.
    - dan_bk 12y ago
      Exactly my thought as well. I believe we keep telling us stories about a "free will" because we're afraid of that thought because we misinterpret it. Most people answer unreflected things like "that would be like living in a prison". Also we have learned to judge everything and everyone. How can we expect people to completely drop all kinds of judgement?
      - Tomte 12y ago
        Why would we stop judging?
        dan_bk 12y ago
        Not sure I understand your question correctly. We should stop judging. Because nobody has been able to show "free will" is more than just another belief (as in religion) and it is therefor no basis for rational discussion. And if free will does not exist, our concepts of "merit" (on the positive side) or "guilt" (on the negative side) are worthless and should be abolished. That's why there should be no judging at all. (Note: No judging does not mean nobody goes to prison for crime. It simply means we must redefine "punishment" as "a neutral sanction" or better: "protection from happening again".)
- eseehausen 12y ago
  Other people have answered this well, but I think that the question of determinism vs. indeterminism is essentially the question of an ordered universe vs. a random one (or picking a point between those two extremes). If that's the case, then what we are usually talking about when we speak about somebody acting freely or having free will has little to do with that discussion. To get to your question about what free will would be then: I'm not a huge fan of a pure concept of free will, though we talk about people acting more or less freely often enough that it's worth thinking about. I think then that a useful definition of "free will" might simply be a measure how much somebody's actions are able to be in accord with their desires. How an outside observer would ever gauge that as well as what actions, desires, and the two being in accord would mean are obviously murky philosophical territory, but it's pretty late. To answer at least one obvious rejoinder, actions and desires can certainly be reduced to particles and the like, but they are phenomena that have qualities we wouldn't ascribe to particles. For instance, it makes little or no sense to say that a particle has a nice smile. In much the same way, we generally mean something different when we say a person wants to do something and a particle wants to do something.
  - danbruc 12y ago
    Is there any good definition of free will at all? Given somebody is in situation X and has options A and B then the choice to do one or the other can either be completely at random or on the other extreme depend completely on the situation X (including the person with the brain and all the memories and the complete environment). Or it may be a mix of both where the situation affects the probability distribution. But none of these scenarios matches what I would call free will, making a choice that is neither random nor a deterministic consequence of the situation, but I can not even think of any mechanism outside of the spectrum from randomness to deterministic consequence.
    - eseehausen 12y ago
      This issue you're running into is why I think trying to think about free will in that context is a category error. The concept doesn't make sense when it's something that depends on randomness or determinism. Instead, I think it's useful to think about how we use it in actual practice, which is generally something like, "is a person more or less self-directed" where self-directed means that their actions are consistent with their observed character and expressed desires. That's not particularly satisfying if you're raised in a culture that puts a lot of value on free will as a concept, but I think it may be the best we can do.
- Confusion 12y ago
  A conception of 'free will' that is considered to be impossible if the universe is deterministic has a difficult question to answer: how does non-determinism enable it? Suppose I'm making up my mind whether to buy some item. There is some last-nanosecond non-deterministic quantum event that causes a neuron to fire, that wouldn't otherwise have fired, and I buy the item. What was 'free' about my decision if that quantum event was not caused or influenced by 'me'? Non-determinism informally says that some things in the universe may be unpredictable. If my decisions depend on unpredictable events in the universe, how are they 'free'? It sounds like 'at the mercy of random events in the universe'. So it's not that the world can be deterministic and you can still have 'free will', it's rather that if the world was non-deterministic, you still couldn't have that sort of 'free will'.
  - selmnoo 12y ago
    Oh jeez, there's no happy way of looking at this is there. Seriously though -- this is extremely depressing to me, it's literally giving me terrors right now. It's reducing all that I love and value to nothingness. How do you guys deal with this?
    - tfgg 12y ago
      I personally go with a computability/compatability argument. If 'you' are some sort of process analogous to a computer program, you can be totally deterministic yet unpredictable. You can't predict in advance the outcome of running some program, c.f. halting problem, without simply running the program slightly faster. Running the program slightly faster is identical to the initial process anyway, since it must get exactly the same inputs. Hence, you are a computational process experiencing itself, everything you feel is valid and no-one can take that away from you :)
    - Confusion 12y ago
      An important thing in what I wrote is that it only applies to certain sorts of free will. The sorts of free will it applies to include the idea of 'free will' that many scientifically educated (and usually philosophically untrained) people have. Let's call it the 'natural' or 'naive' idea of free will. In that view, free will and determinism are incompatible. However, as others have pointed out in parallel answers, there are 'compatibilist' views in which free will and determinism are compatible. The sorts of 'free will' that those views apply are different from the naive idea of free will and the important point to take away from that is: it may not be clear to you or me what the phrase 'free will' actually means. I do not subscribe to compatibilist views, because they define 'free will' as something that I do not believe is worth wanting. However, that begs the question: what is a definition of 'free will' that I do believe is worth wanting? And I have found that I cannot answer that question: I cannot define it satisfactorily in a way that is amenable to philosophical analysis, while all definitions that can be analyzed are unsatisfactory. So it boils down to this: I believe it is important to have 'free will', but I cannot define what it means to have free will. As I cannot become unhappy about not having something that I do not understand clearly enough to reason further about, my life is effectively no different from never having thought about 'free will' at all. So that's how I deal with it. In a way that is unsatisfactory to many people, because it seems to allow for a bit of 'insert magic here' just to satisfy my emotional need for the existence of some intuitive notion of free will. To which all I can say is: yes, I believe that believing "I don't understand" and being happy is better than believing "the best answer we can come up with is depressing" and not being happy.
- Schiphol 12y ago
  The idea that free will is compatible with determinism (this position is called, shockingly, compatibilism) is actually the most popular view in the philosophical debate about free will, and has nothing to do with mind-body dualism. Some ways folks have tried to defend compatibilism (see http://plato.stanford.edu/entries/freewill/ http://plato.stanford.edu/entries/freewill/ for discussion of what follows): motivating the idea that free will is grounded on choice on the basis of one's desires, or on choice that makes sense given one's values. There are other ways, linked to the idea of it being possible that you had chosen otherwise, and on a metaphysics of modality (i.e., of what it is for something to be possible, or necessary) compatible with determinism.
protez 12y ago
Whenever I face the arguments of determinism vs. indeterminism, I wonder how indeterminism would be defined in a purely indeterministic world. I don't know. But in this seemingly deterministic universe, we define indeterminism as a negative sense to the deterministic dynamics we observe, but we can't do it in a positive sense. All of our conceptions of "indeterminism" and random/chaos like concepts is all "determinism-biased" in that sense. Maybe, determinism might be a tiny, tiny small subset of a huge set of indeterminism, as if integers are a tiny subset of all real numbers. There's no such a thing as integers vs. real numbers. Integers are also just real numbers. In that sense, determinism might be a small part of indeterminism.
- hiker 12y ago
  > In that sense, determinism might be a small part of indeterminism. I agree. The astonishing thing about quantum mechanics to me is that it describes how deterministic laws emerge from completely non-deterministic processes. For example, in quantum electrodynamics, a photon going from A to B, chooses a random path with a well defined probability density assigned to each possible path. When you do the math, it turns out that the shortest path between A and B is the most likely one and that's why the classical "deterministic" law that light goes in straight lines is a good approximation for large distances. Yet the path which the photon chooses to take is completely random, chosen by the photon's free will, if you will.
- backlava 12y ago
  But we would still have the concept of determinism in the macro world even if physics turns out not to be deterministic in the small.
PeterWhittaker 12y ago
Indeed - and one can eliminate determinism without resort to QM: Classical mechanics is also indeterministic, you just have to know where to look. Read "Causation as Folk Science" by John D. Norton [1]. He sets out a very simple example of a classical system that behaves indeterministically, analogous if not in fact homologous to how the radioactive decay of a single particle cannot be predicted. The apparatus to demonstrate this consists of a dome with a particular curve (see the paper for details). A sphere placed at the apex of the dome will eventually roll off, in a random direction. But we can predict NEITHER when NOR which direction. And yet it is a fully defined classical system. (And see [2], recently discussed here, to see how relevant and frutiful classical mechanics remains to this day.) (Note that a better word than indeterministic might be acausal, which is the word Norton uses when describing the dome. Either way, one need not resort to QM, regardless interpretation, to demonstrate that determinism does not in fact prevail in our universe. We can all behave in ways that are not predetermined.) [1] http://www.pitt.edu/~jdnorton/papers/003004.pdf http://www.pitt.edu/~jdnorton/papers/003004.pdf [2] http://arstechnica.com/science/2014/08/the-never-ending-conundrums-of-classical-physics/ http://arstechnica.com/science/2014/08/the-never-ending-conu...
- lutusp 12y ago
  > Classical mechanics is also indeterministic, you just have to know where to look. On the contrary, classical (pre-quantum) mechanics is certainly deterministic. The first real challenge to a strict relationship between causes and effects was QM, which (as you may recall) caused Einstein to begin a long campaign against those ideas -- "God doesn't throw dice," and so forth. > But we can predict NEITHER when NOR which direction. Our inability to predict an outcome doesn't constitute an argument against determinism, only the limits of experimental measurements. > analogous if not in fact homologous to how the radioactive decay of a single particle cannot be predicted. That's simply false. A radioactive decay's timing is certainly nondeterministic, but the direction an observed, macroscopic ball takes is deterministic, even if we don't get the memo. Think a bit harder. If Norton could demonstrate the indeterminism of classic mechanics, as opposed to publishing a philosophical paper on the topic, he would win a Nobel prize for undermining a well-established physical principle. But philosophy isn't science. > We can all behave in ways that are not predetermined. We can all behave in ways that we believe to be nondeterministic, but free will remains an open philosophical question.

tacotime 12y ago

So you're saying the world can be deterministic and you can still have free will? That would mean you would have to believe in something like souls then, right? Something outside of this physical world that influences your physical existence? I'm not questioning your views just trying to understand.

cokernel 12y ago
There are varieties of compatibilism (the view that determinism and free will are compatible) that do not require the existence of souls. I'd suggest taking a look at Daniel Dennett's _Elbow Room_ for one example. The Stanford Encyclopedia of Philosophy has an article on the subject: http://plato.stanford.edu/entries/compatibilism/ http://plato.stanford.edu/entries/compatibilism/
- __m 12y ago
  i never had the patience to follow that mind juggling, or "word jugglery" as Kant calls it. For me as a programmer free will would mean something like: var a:Int = 2 var b:Int = 3 println("\(a+b)") >> 42 where transistors take the place of neurons
- DougH5000 12y ago
  Compatibilists redefine free will, similarly to those who redefine "god" as "nature" or "the universe". Sure, anyone can define any term the way they want, but it simply causes confusion to the majority of people who don't hold such definition. Rather, it's best to abandon some terms as fiction, and create new ones surrounding the concept you are looking to address. Better books on the topic are Sam's _Free Will_ or Trick's _Breaking the Free Will Illusion_. http://www.samharris.org/free-will http://www.samharris.org/free-will http://breakingthefreewillillusion.com/ http://breakingthefreewillillusion.com/
drdeca 12y ago
I don't follow. How does free will+determinism imply an outside influence? I see no convincing reason that an entirely deterministic thing can't have "free will". Though I don't remember ever having found a definition of "free will" that I've found satisfactory. I don't think compatibilism implies a belief in anything "supernatural" though. (quotes to indicate things potentially not being exactly the right term, or other similar indications)
salmonellaeater 12y ago
The world can be deterministic and still allow free will with respect to a real observer. In some sense it doesn't matter if a person's actions are in principle predictable when there is no observer who can actually make those predictions. You'd have to measure and simulate the entire universe to predict a single particle's future.
- Rapzid 12y ago
  But it would just be an illusion no? If the discovery were made that the universe is entirely deterministic it wouldn't matter whether any one person could, or any number of people, could produce accurate meaningful predictions. The truth alone would VERY disruptive.
  - thaumasiotes 12y ago
    > The truth alone would VERY disruptive. This is clearly untrue. The discovery has already been made that events in the universe happen in one of two ways: 1. "deterministically", the way you think would be VERY disruptive 2. determined by chance This isn't disruptive; people just ignore it.
    - Rapzid 12y ago
      Sources?
  - afafsd 12y ago
    The great Australian philosopher David Stove was of the opinion that the main function of philosophers is to save the rest of us the trouble of thinking about these sorts of things. When a useful professional in another field such as you or I starts wondering about these sorts of issues, he can simply pick up a philosophy book, note that a bunch of smart people have already thought this issue through, put labels on every possible position, argued through the consequences of each, and still failed to come to any consensus about it. And then we can say "Whew, glad someone's already taken care of that" and get back to our useful lives without worrying our pretty little heads about it too much. So if you do find yourself worrying about free will, I suggest reading the vast amount of pre-existing literature on the subject and unburdening yourself of feeling like you should be making progress on it.
plaguuuuuu 12y ago
We consider free will important because we like to think we make our decisions based on our own individual identity, rather than physical properties of the universe that predetermine what we will do. Even if free will exists, our mechanism for arriving at a decision to do one thing over another thing pretty much needs to be context-dependent - i.e. we make that decision based on some line of reasoning (whether correct or not). At the same time, everything we've experienced and consider to be part of our own individual identities, the stuff that defines our free will, is incorporated as a part of that context. So many people argue that free will and determinism are still pretty much compatible. Nevermind all the other crap we like to pretend doesn't influence our decisions like whatever crazy hormones happen to be elevated at the time.
- aaronblohowiak 12y ago
  To me, this argument is a strong defense of the "self", but does not address the "free" part at all. It is like saying that a rock is free to weigh more than a marshmallow because of the complicated history that lead it to being this rock.
  - dan_bk 12y ago
    Exactly my thought as well. I believe we keep telling us stories about a "free will" because we're afraid of that thought because we misinterpret it. Most people answer unreflected things like "that would be like living in a prison". Also we have learned to judge everything and everyone. How can we expect people to completely drop all kinds of judgement?
    - Tomte 12y ago
      Why would we stop judging?
      - dan_bk 12y ago
        Not sure I understand your question correctly. We should stop judging. Because nobody has been able to show "free will" is more than just another belief (as in religion) and it is therefor no basis for rational discussion. And if free will does not exist, our concepts of "merit" (on the positive side) or "guilt" (on the negative side) are worthless and should be abolished. That's why there should be no judging at all. (Note: No judging does not mean nobody goes to prison for crime. It simply means we must redefine "punishment" as "a neutral sanction" or better: "protection from happening again".)
eseehausen 12y ago
Other people have answered this well, but I think that the question of determinism vs. indeterminism is essentially the question of an ordered universe vs. a random one (or picking a point between those two extremes). If that's the case, then what we are usually talking about when we speak about somebody acting freely or having free will has little to do with that discussion. To get to your question about what free will would be then: I'm not a huge fan of a pure concept of free will, though we talk about people acting more or less freely often enough that it's worth thinking about. I think then that a useful definition of "free will" might simply be a measure how much somebody's actions are able to be in accord with their desires. How an outside observer would ever gauge that as well as what actions, desires, and the two being in accord would mean are obviously murky philosophical territory, but it's pretty late. To answer at least one obvious rejoinder, actions and desires can certainly be reduced to particles and the like, but they are phenomena that have qualities we wouldn't ascribe to particles. For instance, it makes little or no sense to say that a particle has a nice smile. In much the same way, we generally mean something different when we say a person wants to do something and a particle wants to do something.
- danbruc 12y ago
  Is there any good definition of free will at all? Given somebody is in situation X and has options A and B then the choice to do one or the other can either be completely at random or on the other extreme depend completely on the situation X (including the person with the brain and all the memories and the complete environment). Or it may be a mix of both where the situation affects the probability distribution. But none of these scenarios matches what I would call free will, making a choice that is neither random nor a deterministic consequence of the situation, but I can not even think of any mechanism outside of the spectrum from randomness to deterministic consequence.
  - eseehausen 12y ago
    This issue you're running into is why I think trying to think about free will in that context is a category error. The concept doesn't make sense when it's something that depends on randomness or determinism. Instead, I think it's useful to think about how we use it in actual practice, which is generally something like, "is a person more or less self-directed" where self-directed means that their actions are consistent with their observed character and expressed desires. That's not particularly satisfying if you're raised in a culture that puts a lot of value on free will as a concept, but I think it may be the best we can do.
Confusion 12y ago
A conception of 'free will' that is considered to be impossible if the universe is deterministic has a difficult question to answer: how does non-determinism enable it? Suppose I'm making up my mind whether to buy some item. There is some last-nanosecond non-deterministic quantum event that causes a neuron to fire, that wouldn't otherwise have fired, and I buy the item. What was 'free' about my decision if that quantum event was not caused or influenced by 'me'? Non-determinism informally says that some things in the universe may be unpredictable. If my decisions depend on unpredictable events in the universe, how are they 'free'? It sounds like 'at the mercy of random events in the universe'. So it's not that the world can be deterministic and you can still have 'free will', it's rather that if the world was non-deterministic, you still couldn't have that sort of 'free will'.
- selmnoo 12y ago
  Oh jeez, there's no happy way of looking at this is there. Seriously though -- this is extremely depressing to me, it's literally giving me terrors right now. It's reducing all that I love and value to nothingness. How do you guys deal with this?
  - tfgg 12y ago
    I personally go with a computability/compatability argument. If 'you' are some sort of process analogous to a computer program, you can be totally deterministic yet unpredictable. You can't predict in advance the outcome of running some program, c.f. halting problem, without simply running the program slightly faster. Running the program slightly faster is identical to the initial process anyway, since it must get exactly the same inputs. Hence, you are a computational process experiencing itself, everything you feel is valid and no-one can take that away from you :)
  - Confusion 12y ago
    An important thing in what I wrote is that it only applies to certain sorts of free will. The sorts of free will it applies to include the idea of 'free will' that many scientifically educated (and usually philosophically untrained) people have. Let's call it the 'natural' or 'naive' idea of free will. In that view, free will and determinism are incompatible. However, as others have pointed out in parallel answers, there are 'compatibilist' views in which free will and determinism are compatible. The sorts of 'free will' that those views apply are different from the naive idea of free will and the important point to take away from that is: it may not be clear to you or me what the phrase 'free will' actually means. I do not subscribe to compatibilist views, because they define 'free will' as something that I do not believe is worth wanting. However, that begs the question: what is a definition of 'free will' that I do believe is worth wanting? And I have found that I cannot answer that question: I cannot define it satisfactorily in a way that is amenable to philosophical analysis, while all definitions that can be analyzed are unsatisfactory. So it boils down to this: I believe it is important to have 'free will', but I cannot define what it means to have free will. As I cannot become unhappy about not having something that I do not understand clearly enough to reason further about, my life is effectively no different from never having thought about 'free will' at all. So that's how I deal with it. In a way that is unsatisfactory to many people, because it seems to allow for a bit of 'insert magic here' just to satisfy my emotional need for the existence of some intuitive notion of free will. To which all I can say is: yes, I believe that believing "I don't understand" and being happy is better than believing "the best answer we can come up with is depressing" and not being happy.
Schiphol 12y ago
The idea that free will is compatible with determinism (this position is called, shockingly, compatibilism) is actually the most popular view in the philosophical debate about free will, and has nothing to do with mind-body dualism. Some ways folks have tried to defend compatibilism (see http://plato.stanford.edu/entries/freewill/ http://plato.stanford.edu/entries/freewill/ for discussion of what follows): motivating the idea that free will is grounded on choice on the basis of one's desires, or on choice that makes sense given one's values. There are other ways, linked to the idea of it being possible that you had chosen otherwise, and on a metaphysics of modality (i.e., of what it is for something to be possible, or necessary) compatible with determinism.

protez 12y ago

Whenever I face the arguments of determinism vs. indeterminism, I wonder how indeterminism would be defined in a purely indeterministic world. I don't know. But in this seemingly deterministic universe, we define indeterminism as a negative sense to the deterministic dynamics we observe, but we can't do it in a positive sense. All of our conceptions of "indeterminism" and random/chaos like concepts is all "determinism-biased" in that sense. Maybe, determinism might be a tiny, tiny small subset of a huge set of indeterminism, as if integers are a tiny subset of all real numbers. There's no such a thing as integers vs. real numbers. Integers are also just real numbers. In that sense, determinism might be a small part of indeterminism.

hiker 12y ago
> In that sense, determinism might be a small part of indeterminism. I agree. The astonishing thing about quantum mechanics to me is that it describes how deterministic laws emerge from completely non-deterministic processes. For example, in quantum electrodynamics, a photon going from A to B, chooses a random path with a well defined probability density assigned to each possible path. When you do the math, it turns out that the shortest path between A and B is the most likely one and that's why the classical "deterministic" law that light goes in straight lines is a good approximation for large distances. Yet the path which the photon chooses to take is completely random, chosen by the photon's free will, if you will.
backlava 12y ago
But we would still have the concept of determinism in the macro world even if physics turns out not to be deterministic in the small.

PeterWhittaker 12y ago

Indeed - and one can eliminate determinism without resort to QM: Classical mechanics is also indeterministic, you just have to know where to look. Read "Causation as Folk Science" by John D. Norton [1]. He sets out a very simple example of a classical system that behaves indeterministically, analogous if not in fact homologous to how the radioactive decay of a single particle cannot be predicted. The apparatus to demonstrate this consists of a dome with a particular curve (see the paper for details). A sphere placed at the apex of the dome will eventually roll off, in a random direction. But we can predict NEITHER when NOR which direction. And yet it is a fully defined classical system. (And see [2], recently discussed here, to see how relevant and frutiful classical mechanics remains to this day.) (Note that a better word than indeterministic might be acausal, which is the word Norton uses when describing the dome. Either way, one need not resort to QM, regardless interpretation, to demonstrate that determinism does not in fact prevail in our universe. We can all behave in ways that are not predetermined.) [1] http://www.pitt.edu/~jdnorton/papers/003004.pdf http://www.pitt.edu/~jdnorton/papers/003004.pdf [2] http://arstechnica.com/science/2014/08/the-never-ending-conundrums-of-classical-physics/ http://arstechnica.com/science/2014/08/the-never-ending-conu...

lutusp 12y ago
> Classical mechanics is also indeterministic, you just have to know where to look. On the contrary, classical (pre-quantum) mechanics is certainly deterministic. The first real challenge to a strict relationship between causes and effects was QM, which (as you may recall) caused Einstein to begin a long campaign against those ideas -- "God doesn't throw dice," and so forth. > But we can predict NEITHER when NOR which direction. Our inability to predict an outcome doesn't constitute an argument against determinism, only the limits of experimental measurements. > analogous if not in fact homologous to how the radioactive decay of a single particle cannot be predicted. That's simply false. A radioactive decay's timing is certainly nondeterministic, but the direction an observed, macroscopic ball takes is deterministic, even if we don't get the memo. Think a bit harder. If Norton could demonstrate the indeterminism of classic mechanics, as opposed to publishing a philosophical paper on the topic, he would win a Nobel prize for undermining a well-established physical principle. But philosophy isn't science. > We can all behave in ways that are not predetermined. We can all behave in ways that we believe to be nondeterministic, but free will remains an open philosophical question.