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Science

Physicist Unveils a 'Turing Test' For Free Will 401

KentuckyFC writes "The problem of free will is one of the great unsolved puzzles in science, not to mention philosophy, theology, jurisprudence and so on. The basic question is whether we are able to make decisions for ourselves or whether the outcomes are predetermined and the notion of choice is merely an illusion. Now a leading theoretical physicist has outlined a 'Turing Test' for free will and says that while simple devices such as thermostats cannot pass, more complex ones like iPhones might. The test is based on an extension of Turing's halting problem in computer science. This states that there is no general way of knowing how an algorithm will finish, other than to run it. This means that when a human has to make a decision, there is no way of knowing in advance how it will end up. In other words, the familiar feeling of not knowing the final decision until it is thought through is a necessary feature of the decision-making process and why we have the impression of free will. This leads to a simple set of questions that forms a kind of Turing test for free will. These show how simple decision-making devices such as thermostats cannot believe they have free will while humans can. A more interesting question relates to decision-makers of intermediate complexity, such as a smartphone. As the author puts it, this 'seems to possess all the criteria required for free will, and behaves as if it has it.'"
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Physicist Unveils a 'Turing Test' For Free Will

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  • by TWX ( 665546 ) on Monday October 21, 2013 @04:00PM (#45193747)
    Wouldn't the presence of self-awareness be a prerequisite, so just about every device should fail, before even getting to the actual test?
    • "Wouldn't the presence of self-awareness be a prerequisite, so just about every device should fail, before even getting to the actual test?"

      I'll reply to you.

      I think I just decided that Siri is what a Loebner Prize contest bot would look like "if it was developed for real with some money behind it."
      http://en.wikipedia.org/wiki/Loebner_contest [wikipedia.org]

      In that contest, they "waste time" trying to trick the bots with edge case questions. For Siri, you know it's a bot, but you ask "is this answer useful". To me that is

    • Does a turtle have free will to walk around and eat what it wants to? Does a turtle have self awareness? I don't know, but that's my idea of something that has free will, but no self awareness.
    • by Prune ( 557140 )
      Oh come on, this is already answered in TFP:

      It is important to note that satisifying the criteria for ass igning oneself free will does not imply that one possesses consciousness. Having the capacity for self-reference is a far cry from full self-consciousness."

      Source: the horse's mouth http://arxiv.org/pdf/1310.3225v1.pdf [arxiv.org]
      • by Jane Q. Public ( 1010737 ) on Monday October 21, 2013 @11:22PM (#45197337)

        "It is important to note that satisifying the criteria for ass igning oneself free will does not imply that one possesses consciousness. Having the capacity for self-reference is a far cry from full self-consciousness."

        Except that this is a bald statement, without anything to back it up, and which is very likely false.

        There are other statements in the paper that I would consider grievous errors. For example, on p. 13, the author states:

        "Installed in the computer or smart phone, the operating system is computationally universal and capable of fully recursive reasoning. (There is a subtlety here in that computational universality requires that you be able to add new memory to the computer or smart phone when it needs more â" for the moment letâ(TM)s assume that additional memory is at hand.) Consequently, the operating system can simulate other computers, smart phones, and Turing machines. It certainly possesses the capacity for self reference, as it has to allocate memory space and machine cycles for its own operation as well as for apps and calls."

        Which I consider to be patently false. For one thing, he is crossing a rather serious boundary between computation and reasoning. He apparently considers them equal, which is a false premise to start with, and which makes shaky ground indeed on which to build the rest of his comment.

        As Douglas Hofstadter demonstrates with thorough precision in his "Godel, Escher, Bach" book, it takes a minimum amount of complexity (far beyond anything we have built) in order to show any meaningful degree of self-reference. Your typical Turing machine has not, in fact, shown itself capable.

        A Turing machine is a "complete" computational machine in that any calculation that can be done on one can be done on another. But nobody has ever discovered how to make them do the kind of things the author asserts.

        The whole thing, to me, looks like yet another physicist / mathematician attempting to make the giant leap from physics to metaphysics, and falling face down in the gap between. Given the statements I have read in this paper, I simply cannot take it seriously.

    • How could any device fail a self-awareness test?

      All devices need to be aware of themselves. Know exactly where their memory bytes are, how to use its processor, and output to the screen. Devices could not function without a highly detailed and absolute awareness of self.

    • by geekoid ( 135745 )

      why do you assume self-awareness is needed to have free will? and how to you define self awareness?

  • by stewsters ( 1406737 ) on Monday October 21, 2013 @04:01PM (#45193771)
    "such as thermostats cannot believe they have free will while humans can."
    Do thermostats really believe things?
  • by Quantus347 ( 1220456 ) on Monday October 21, 2013 @04:01PM (#45193775)
    The fact that a smartphone (Or I assume by extension any personal computer) can qualify should be an indcator that the test itself is flawed. Just like how many early definitions of Life applied to Fire (breaths, eats, grows, responds to outside stimuli, etc) even though it is just a chemical reaction.
    • Re: (Score:2, Insightful)

      by Anonymous Coward
      But technically so are you.
      • Depends on who you ask. Some people would not necessarily believe that he or she is 'just a chemical reaction'. As unhip as it is, I really don't think I'm 'just a chemical reaction'. I have will. I don't know about the rest of the world, but I know I have a will. Now when you come back and start flaming me for believing what is known as a properly basic belief (that I am real), just keep in mind that you're not real and therefore your arguments to the contrary matters about as much as cleverbot's.

        I think the big problem with believing that people are real is that it feels supernatural. And since arm chair scientists are allergic to the idea that there exists a nature outside of our nature (that is a super nature or supernatural - not to be confused with magic), they will go through gyrations to deny such an obvious truth as in that 'I am real'.

        Now cleverbots, bring on the pitchforks. Be sure to downvote this to (Score:-1 Probably a Christian) if you have mod points.

      • Note the "just" qualifier in "it is just a chemical reaction". A fire is a chemical reaction and nothing more. We are chemical reactions and something more, and it's that "something more" that makes us alive. Defining what that "something more" consists of is an ongoing problem for everyone from physicists to biologists to philosophers to clergy.

        He was merely pointing out that for some attempts at defining what "something more" is, fire would also errantly qualify as life.

    • Early definitions of fire may have been flawed, but our current definitions for life are pretty arbitrary. The definition of life is engineered to include the things we want to include among the living.

      It is pretty easy to come up with a definition of free will that specifically includes people and excludes computers (e.g. smartphones), but what purpose would that serve?

      We have a definition of life that puts bacteria and humans as equals. I'm sure some people would feel like we are more alive than bacteri

    • At what arbitrary point does a chemical reaction jump from being 'just' a chemical reaction to being a chemical reaction that qualifies as 'life'?

      Note that this is fundamentally human-centric question. Life is a word that we made up, there is no intrinsic property of life. If I take a handful of carbon, water, and trace elements, then use a magic machine to put them together in a new shape that farts and asks for tea, I've not imbued the items with some material substance that was not there before to make i

      • by s.petry ( 762400 )

        At what arbitrary point does a chemical reaction jump from being 'just' a chemical reaction to being a chemical reaction that qualifies as 'life'?

        Note that this is fundamentally human-centric question. Life is a word that we made up, there is no intrinsic property of life.

        True that we made up the word life, but untrue that it has no property. It's also worth pointing out that we are the only species that can communicate complex concepts, that we know of, so it's not a relevant point to make. For all we know whales could have defined "life" long before us and we don't understand what they are saying, or species that went extinct millions of years ago could have been first to discuss "life".

        While I agree that we can't pinpoint a precise definition of "thing" that makes some

    • The funny thing about definitions is we often don't understand what they are describing until later on, and when we finally do we may wind with a definition which lies in contrast to our initial intuition. A good example would be "temperature." You may start out only with an idea that somethings feel warm or cold. Then you discover that you can use a thermometer to be quantitative about it, so now temperature is defined by the expansion of a particular liquid at normal pressure. But that doesn't make sen

    • by geekoid ( 135745 )

      "even though it is just a chemical reaction."
      Like humans.

  • by SeanTobin ( 138474 ) <byrdhuntr.hotmail@com> on Monday October 21, 2013 @04:02PM (#45193783)
    My smartphone definitely has free will. I can not predict when it will reboot on its own, when it will freeze on a screen or when it will lie to me about notifications. I think it not only has free will, but is also a sociopath!
    • by ImprovOmega ( 744717 ) on Monday October 21, 2013 @04:39PM (#45194277)

      Don't forget the random auto-"corrections" that it makes to what you type. Sometimes I think my phone is trying to get me killed...

      [Text to Wife] Honey I'll be picking up some (chicken) chicks to eat tonight. See you at (home) hate you (gorgeous) gordo lady! P.S. (Veronica) Erotica at work was crazy today, tell you all about it later.

    • An abbott in "A Canticle for Leibowitz" had a balky piece of high technology in his office and shouted something to the effect "It has a soul, I tell you! It knows the difference between good and evil and it has chosen evil!".

  • Daniel Dennett "Free Will Evolves" 2004 - makes the same argument.

  • FTA:

    The proof is an extension of Turing’s halting problem in computer science. This states that there is no general way of knowing how an algorithm will finish, other than to run it. What’s more, any attempt to determine the decider’s decision independently must take longer than the decider itself.

    Since when does a simulation need to take longer than reality? The author assumes that a human mind is the most efficient vehicle to arrive at that human's decisions. This is not necessarily the case. I can run a simulation of an old computer on a much faster new computer to figure out what the old computer will do before it does it.

    • Since when does a simulation need to take longer than reality?

      It doesn't. WOPR taught us that. It ran through thousands of nuclear engagement simulations and scenarios in just a few minutes, and any real engagement would last for at least an hour.

      I'm not sure whether my thermostat has free will or not. I have been asking it repeatedly "are you a decider?", and I can't decide if it lacks enough decision making ability to answer or knows I'm testing it and is refusing to answer on the grounds it may incriminate itself.

    • by Prune ( 557140 )
      No, he doesn't assume that. This is what you get for reading a slashdot summary rather than the original paper, which contains sentences such as

      The indeterminate nature of a decision to the decider persists even if a neuroscientist monitoring her neural signals accurately predicts that decision before the decider herself knows what it will be.
      Source: http://arxiv.org/pdf/1310.3225v1.pdf [arxiv.org]
  • "This states that there is no general way of knowing how an algorithm will finish, other than to run it. This means that when a human has to make a decision, there is no way of knowing in advance how it will end up. In other words, the familiar feeling of not knowing the final decision until it is thought through is a necessary feature of the decision-making process and why we have the impression of free will."

    The conclusion from the halting problem to human decision making doesn't hold. Even if we allow th

    • by Prune ( 557140 )
      The only thing sloppy here is the slashdot summary and poor journalistic reporting. This is not what the original paper reasons at all. A usual, go to the primary reference: http://arxiv.org/pdf/1310.3225v1.pdf [arxiv.org]
      • by Prune ( 557140 )
        PS the author explicitly states that someone may simulate the decider's decision process faster than the decider and predict the outcome of the decision before the decider makes it. What's discussed is the indeterminancy of the decision to the decider himself.
  • Just because an entity's actions or decisions may be predictable does not mean that they have any less free will, it only means that previously identified habits or patterns have been identified which can be reasonably shown to influence the outcome.

    If a small child puts their hand on a hot stove for the first time and they get burned, the fact that they aren't liable to do that again is fairly easy to predict, but isn't remotely an indication that some of their free will has been taken from them. If anything, the fact that they are not consciously making the specific choice to avoid their own discomfort in the future only affirms their free will, even though this is an expected and predictable response.

  • Questions 2 and 4 pretend to be yes/no questions, but if you pay attention the answer to both is "sometimes." Yet the supposed test requires those questions to be answered yes or no.

    Garbage in, garbage out.

  • Have you ever asked: What is the best place to draw the boundary of this system (or rather the boundary of each nested semi-autonomous subsystem), especially in cases where it isn't crystal clear, like an ant colony, a virus+modified-host lifesystem, a port city.

    The best boundary definition is probably informational (process-description-oriented) rather than physical-snapshot based. Question: Which subset of stuff around here acting together has the most to do with (the most influence over) its own evolutio

  • Saying an iPhone is conscious (an important component of free will) just because it tries to run your life is silly pseudoscience meant for news articles and not real thought. An iPhone runs your life because Apple programmed it that way.

    • An iPhone runs your life because Apple programmed it that way.

      An iPhone runs your life because you chose to let it. The question remains, did you have free will in that decision? Let's ask Siri for her opinion.

  • by edibobb ( 113989 ) on Monday October 21, 2013 @04:27PM (#45194131) Homepage
    Does a random number generator have free will?
  • by mythosaz ( 572040 ) on Monday October 21, 2013 @04:33PM (#45194197)

    1. It’s your birthday. Someone gives you a calfskin wallet. How do you react?
    2. You've got a little boy. He shows you his butterfly collection plus the killing jar. What do you do?
    3. You’re watching television. Suddenly you realize there’s a wasp crawling on your arm.
    4. You’re in a desert walking along in the sand when all of the sudden you look down, and you see a tortoise, Tony, it’s crawling toward you. You reach down, you flip the tortoise over on its back, Tony. The tortoise lays on its back, its belly baking in the hot sun, beating its legs trying to turn itself over, but it can’t, not without your help. But you’re not helping. Why is that?
    5. Describe in single words, only the good things that come into your mind about your mother.

    • If they pass that portion of the test, engage them in some more dialog - more rhetorical in nature than direct questions...

      6. In a magazine you come across a full-page photo of a nude girl.
      7. You show the picture to your husband. He likes it and hangs it on the wall. The girl is lying on a bearskin rug.
      8. You become pregnant by a man who runs off with your best friend, and you decide to get an abortion.
      9. Last question. You're watching an old movie. It shows a banquet in progress, the guests are enjoying ra

    • 1. Itâ(TM)s your birthday. Someone gives you a calfskin wallet. How do you react?

      A: now if I only had some money to put in it. Please give me money.

      2. You've got a little boy. He shows you his butterfly collection plus the killing jar. What do you do?

      A: I'm a butterfly, you insensitive clod!

      3. You're watching television. Suddenly you realize there's a wasp crawling on your arm.

      A: "Mom! There's a wasp on my arm! Come downstairs and kill it for me!

      4. Youâ(TM)re in a desert walking along in the sand when all of the sudden you look down, and you see a tortoise, Tony,

      A: my tortoise's name is Filbert.

      5. Describe in single words, only the good things that come into your mind about your mother.

      A: she brings my dinner down into the basement, does my laundry once a month whether I need it or not, and kills wasps that crawl on my arms. Those are all single words, aren't they?

    • by Prune ( 557140 )
      I couldn't figure it out until I saw the last question and the images from Bladerunner popped up in my memory.

      Well done, sir.
  • Before I even consider this, I'd like to have a rigorous definition of free will... although I'm not really sure what it is that makes me want that.

  • From Time Bandits:

    Kevin: Yes, why does there have to be evil?
    Supreme Being: I think it has something to do with free will.

    Yet the questions in the article didn't seem to cover the subject of "evil". Can a phone with supposed free will do evil, or is it just infected with a bug or virus? Here's Jessica Rabbit's take:

    I'm not bad. I'm just drawn that way.

    Like many cartoon characters, Jessica evidently is sentient, yet she lacks free will. Silly wabbit.

  • I'm sure that given a strict interpretation of the set of criteria listed, not many folks would likely have free will. The first questions 1-3 sort of indicate the ability to make a decision, but the last question "can you predict your decision in advance?" is likely to be true for many decisions that people might make.

    For example, a movie comes out (say like gravity or elysium). Certainly, you are a decider (you can choose to go or not go to the movie and say bicycle or go to a party), and you can make y

  • Oh, not again. (Score:4, Informative)

    by Animats ( 122034 ) on Monday October 21, 2013 @04:40PM (#45194295) Homepage

    Again, someone ran into the halting problem and thought they could say something profound about it. Worse, they got tangled up with "free will", which is theology, not physics or compute science.

    A deterministic machine with finite memory must either repeat a state or halt. The halting problem applies only to infinite-memory machines. A halting problem for a finite program can be made very hard, even arbitrarily hard, but not infinitely hard.

    As a practical matter, there's a widely used program that tries to solve the halting problem by formal means - the Microsoft Static Driver Verifier. [microsoft.com] Every signed driver for Windows 7 and later has been through that verifier, which attempts to formally prove that the driver will not infinitely loop, break the system memory model with a bad pointer, or incorrectly call a driver-level API. In other words, it is trying to prove that the driver won't screw up the rest of the OS kernel. This is a real proof of correctness system in widespread use.

    The verifier reports Pass, Fail, or Inconclusive. Inconclusive is reported if the verifier runs out of time or memory space. That's usually an indication that the driver's logic is a mess. If you're getting close to undecidability in a device driver, it's not a good thing.

    • by Prune ( 557140 )
      "someone" in this case refers to a respected physicist and quantum information theorist who at least deserves that you at least bother to criticize what's in the actual paper rather than a lousy slashdot summary, rather than putting up a strawman completely unrelated to anything the author actually claims. http://arxiv.org/abs/1310.3225 [arxiv.org]
  • [Smartphones] 'seems to possess all the criteria required for free will, and behaves as if it has it.'

    It doesn't have "free" will. It's actually the will of the application developers imposed upon your device. But you let them when you installed their app, so it's ok.

    I'm not sure physicists are the best people to decide what has free will or not (or even exhibits the behavior of having free will). Free will involves not just having choices, but making the choice based on a difference in the weighing of various factors. Choosing at random is not free will, though choosing to choose at random is. Assigning a

    • by Prune ( 557140 )
      Your musings are explicitly addressed in the paper. As usual, the journalist reporting on the research, and worse, the slashdot summary, manage to completely misrepresent and sensationalize. Go to primary sources: http://arxiv.org/abs/1310.3225 [arxiv.org]
    • by geekoid ( 135745 )

      "It doesn't have "free" will. "
      ah, so you have the definition of free will?
      Please, enlighten us.

  • This states that there is no general way of knowing how an algorithm will finish, other than to run it.

    The above statement is simply false. What Wikipedia has is closer to what I remember from college:

    Given a description of an arbitrary computer program, decide whether the program finishes running or continues to run forever.

    Halting problem has nothing to do with knowing how a specific computer program will work. Or knowing what the program will return. There are plenty of examples of programs we can safely know will stop. I can look at a specific program and deduce its output. With many programs I can do this faster than running the program. But the general idea is kinda of sound. Some calculations take time or additional data. B

  • Raise up your hand.

    Do it.

    Not really..raise up your hand.



    now.. did you do it?



    And there we are.
  • I have never understood the assumption that free will means choices cannot be known ahead of time. To me, it seems that the presence of free will can potentially mean that outcomes are *more* constrained than in a strictly physical system, i.e., inspection of the quantum mechanical wave function may not lead to a solid prediction on whether I will or will not kill someone, but if I have chosen to follow a moral prohibition against murder, then it can be known (at least to myself) that I will not kill them.

  • Comment removed based on user account deletion
  • Seriously, the whole "do we have free will" case is a prime example of trying to find an answer without knowing what the question is.

    If its about determinism, then quantum mechanics and chaos theory deliver a double whammy to that: one says that you can't predict the behaviour of many complex systems unless you can measure the parameters to perfect accuracy... the other limits what you can measure to perfect accuracy...

  • since we cant know the decision making process for an agent external to ourselves, we devise a turing test — which says nothing more than if it quacks like a duck, it IS a duck (and never mind that we decieve ourselves with decoys and clever ploys).

    however, for our own agency, we can raise the exceptional condition and follow the path through introspection — which is fraught with subjective bias.. if we attain some objectivity in our own comiserations — we do find that almost everything we

  • by johnrpenner ( 40054 ) on Monday October 21, 2013 @05:07PM (#45194617) Homepage

    or as they say — never mistake motion for action. :-^

  • by harvestsun ( 2948641 ) on Monday October 21, 2013 @05:40PM (#45194909)
    The very concept of free will is itself a silly one, devised by simple-minded people. And it has absolutely NOTHING to do with science.

    First of all there really is no such thing as "free will", REGARDLESS of whether the universe is deterministic or not; the concept is by nature a contradiction. The generally accepted definition of free will is "I am the ultimate cause of my actions". To put it another way, "I am the ultimate originator of my will". If you are the religious type, then when you say "you", you're talking about some abstract notion of a soul, and we can't really delve any further. But this is a scientific paper, so "you" means the collection of thoughts, memories, and wills residing in your skull. So really we're saying "my will determines my will", which of course doesn't make sense! You couldn't have "chosen" your "original" will (which went on to determine your future wills); you weren't born yet! It is a prime example of causa sui.

    But moving on to the paper, it's rife with invalid assumptions. For example: "If decisions are freely made, then those decisions can form the basis for condemning people to prison". That assumes that we condemn a person to prison because they made a bad decision and they "deserve it". That's an oversimplification. We condemn people to prison in order to dissuade other people from committing crimes, and to reduce the likelihood of condemned people committing more crimes. Free will and determinism have nothing to do with it.

    Also, the paper never really attempts to form a test for free will. The poor summary is more to blame here than the paper itself. The paper forms a test for the PERCEPTION of free will, which the author arbitrarily defines as "being unable to know the result of a decision before actually making that decision" (which implies recursive reasoning, which is the main criteria for the test). So a thermostat does not have free will because an external device could easily predict its output. But a computer has the perception of free will, because as an extension to Turing's halting problem, it is possible to create algorithms where it is impossible to know the output faster than it takes to actually go through the algorithm.

    What does this really mean, practically speaking? Absolutely nothing. These are concepts that have been discussed for many years; nothing is being added here. It's disappointing that this kind of thing is able to make it to the Slashdot front page.
  • by Stormy Dragon ( 800799 ) on Monday October 21, 2013 @06:04PM (#45195155)

    Humans don't have free will. There's no reason to believe the answer to question #4 is no. The neurons composing our brain deterministically (given a specieid set of stimuli, they had a calculatable response). With sufficient knowledge on the layout and state of someone's brain, you could calculate what their response to a given stimuli would be.

Truly simple systems... require infinite testing. -- Norman Augustine

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