Sam Harris has written a book attacking the concept of free will, and in so doing has already received wince-inducing slams from philosophers, notable among them Patricia Churchland's. Stung from this, Harris sought out another philosophical foe (although another of the Four Horsemen), one of the most famous living philosophers, Daniel Dennett. Where Churchland's comments only implied that she didn't think Harris's arguments were worth an extended response, Dennett's directly states as much. It's a fun read.
(By the way: reading this frankly brutal takedown of Harris by another of the Four Horsemen, it's hard to imagine another intellectual movement which openly and honestly exhibits its intellectual differences like this, and a lot of credit is due. That said, I hardly think this is about to cause a rift among the ardent philosophical naturalists of the world, which may say something about how important this discussion actually is.)
I'm not going to summarize the points made between Dennett and Harris, but rather point out some heuristic meta-arguments that might be informative. A fair question to begin any discussion of free will is: how will the answer affect our actions either way? Suppose that tomorrow, an air-tight incompatibilist argument emerges saying no, there is no such thing as free will, and even Dan Dennett throws up his hands: what will happen differently? How could this affect our decisions? After all, it was already all going to happen that way anyway, right? And we go about our business, as we were already going to. OR, a compatibilist argument emerges that says yes, we have free will, and here is proof of this concept - what would Sam Harris do differently after this revelation? So is this the 2014 version of trying to calculate how many angels can fit on the head of a pin? That is, are we debating a problem that only seems to exist because of other (bad) assumptions we're making? Some incompatibilists would likely say yes, that free will is a concept (like theism) that people think is coherent only because of the historical inertia of other assumptions or values we desperately want to preserve. This is all to say: if it's not clear how an answer to this question could ever affect anyone's decisions, then it's possible the concept itself is meaningless in the first place. (Never mind the practical value, which is not in question. It must certainly be zero.)
Nonetheless, it remains an interesting problem (I suspect because it's foundering on submerged bad assumptions), like the nature of consciousness, which is why I'm writing this blog post and you're reading it. So first, briefly, here are three points that no-free-will incompatibilists should better address or answer.
1. Our current understanding of morality and individual responsibility is destroyed by the removal of free will. As Dennett points out, this is not an argument for free will; if there's no free will, then we lose morality, and too bad for us. But to say that no-free-will incompatibilists like Harris do not give this point enough time given its importance would be too kind.
2. If there is no free will, then all of causality is an illusion as well. Why? Because every event has in some sense "already happened" (was set in motion at the Big Bang), or it's unknowable noise. That is to say, we're watching a movie, and what happens at 1 hour 12 minutes in was determined when the film was recorded, and it's not going to change, and the image of the man kicking the soccer ball doesn't cause the image of the soccer ball to move any more than anything else on the film. As with the observation about morality above, this also does not make an argument against no-free-will incompatibilism. But the problem with causality does follow directly from this position, and it's ignored by said incompatibilists, and has profound implications for epistemology and the scientific method.
3. If there is no free will, how can there be a "now"? If everything is caused and determined, then we're in a frozen block of space-time or a movie. A subjective sense of free will is certainly not an argument for free will. But it is very difficult to understand how there could be a sense of a present moment if there is no such thing as the present moment - that is, of a changing point in time that is asymmetric and special because it seems to be influencing other points in time, that cannot in turn influence it.
4. Libet's button-pushing experiment disproves only one fragile model of free will (though Dennett doesn't bring it up in his review). An easy solution, though one that would support a free will that most of us would not like, is epiphenomenalism, where the decision is being made by an entity with free will whose process our conscious selves do not have access to. Certainly if free will exists in any entity on Earth, it's humans, and humans are having this argument - but even proving that humans have not a shred of free will is different than proving that the universe we're in does not allow it.
Showing posts with label epiphenomenalism. Show all posts
Showing posts with label epiphenomenalism. Show all posts
Thursday, January 30, 2014
Saturday, March 31, 2012
Subjective Experience and Memory
The strange properties of subjective experience are nowhere more evident than in the use of drugs which prevent long-term potentiation - or destroy the capacity for consciousness in the first place. Is there anything it is like to be under anesthesia, or do you just forget that you were tortured?
Note, Harris's focus here is about free will and morality - and to his detriment he completely neglects the robustness of epiphenomenal accounts to the neuroscience experiments he's citing, probably because few people would find an epiphenomenalist account of free will no less distasteful than a total absence of free will. But the question here sends him down an interesting road, and to my knowledge the first clinical test of the global workspace hypothesis of consciousness was in fact by a team of anesthesiologists.
Note, Harris's focus here is about free will and morality - and to his detriment he completely neglects the robustness of epiphenomenal accounts to the neuroscience experiments he's citing, probably because few people would find an epiphenomenalist account of free will no less distasteful than a total absence of free will. But the question here sends him down an interesting road, and to my knowledge the first clinical test of the global workspace hypothesis of consciousness was in fact by a team of anesthesiologists.
Tuesday, March 29, 2011
Button-Pushing Experiments Disprove Only One Fragile Model of Freewill
Experimental evidence continues accumulating which shows that human motor behavior, and conscious awareness of the decision to perform the behavior, are often preceded by neuronal activity. (Classic Libet experiment described here.) This has sometimes been taken as a disproof of free will. This reasoning is flawed. If we believe "if free will exists, then it applies to all human motor behavior, and all neuronal activity engaged with this motor behavior must be conscious". Therefore, for these experiments to be a disproof, at least two assumptions must be true: 1) the entire chain of events from deciding to act to performing the act must take place within consciousness to be called free will, and 2) this simple motor task model must be generalizeable to all decision-making and motor behavior taking place on all time scales.
To #1: it is possible that the decision is made, relative to the depolarization path of the motor act, "prior" to consciousness. If this is always the case, then epiphenomenalism is the correct description of consciousness, even though we could still have free will, because we can still affect future belief states and motor acts. Consequently it's worth asking if in these models, the "originating" neuron(s) is/are really the originating neuron. Acts of apparent free will merely passing through an unconscious pathway would be even less troublesome to the idea of free will than one originating in unconscious neurons.
Analogously, we cannot choose beliefs - we don't have free will about what we perceive and believe, because perception and belief follow necessarily from sense data and from the model of the universe that exists in our brains. When we encounter sense data, we interpret it immediately as representing something and as being causally related to other things in reality. For example, you cannot see someone smile, and DECIDE consciously whether or not to believe that they are smiling, and whether or not to believe that this means something about their emotional state. But this doesn't mean that we are prisoner to those beliefs and that we cannot influence future perceptions and beliefs. If you cross-check those beliefs, you can engage in behaviors the outcomes of which can differ in obvious
ways that then will allow you to update those beliefs.
At the very least, concluding that experimental results of this sort invalidate the idea of free will, you must carry other assumptions about the nature of consciousness and free will besides just "some objects' motions cannot be predicted from prior states, and those objects have conscious experience which in some way influences those motions". The separability of these two parts of free will - the idea of unpredictable output on the one hand and input from conscious experience on the other - is important. What are the requirements for non-conscious objects with unpredictable output? Are there conscious objects with completely predictable output? Another way of asking is whether things without nervous systems can have free will.
To #2, it's worth asking whether there are classes of decisions that are more or less subject to free will; i.e., how much can we generalize these results? Certainly there are cases where free will can be an illusion, but this falls short of disproving the possibility of free will in general. By all means experimenters should continue asking this question in more settings, although a button-push model wouldn't seem to give the nervous system a chance to shine. My suspicion is that if free will exists in any action it's in long-term executive planning.
It's worth mentioning that it seems strange very strange that our own lack of free will is not obvious to us, given that prediction of the behavior of conspecifics is evolutionarily extremely important. Why the inability to do so exactly, or why the strong appearance that we are the source of action? One speculation is game-theory oriented, that the input-output chain must necessarily be clouded by introducing randomness (which wouldn't really be free will), and our sense of free will falls out of that.
Another attack on the concept is Churchland-like, and questions whether free will isn't just a bad folk idea about human behavior (which I think many enthusiasts of these experiments which agree to). It's worth asking whether belief in something like free will is universal even among non-Western humans - do Solomon Islanders and pygmies have the same belief? - and if so, what it is that predisposes humans to believing this. Do humans with a different conception of agency have different beliefs about this (Aspergers spectrum people)? Finally, do nonhuman animals also believe in free will? I encourage inventive experimentalists to think of a way to support or discredit this hypothesis. If we know different kinds of nervous systems have the same belief we can start understanding what it is we have in common with them that makes us think this.
To #1: it is possible that the decision is made, relative to the depolarization path of the motor act, "prior" to consciousness. If this is always the case, then epiphenomenalism is the correct description of consciousness, even though we could still have free will, because we can still affect future belief states and motor acts. Consequently it's worth asking if in these models, the "originating" neuron(s) is/are really the originating neuron. Acts of apparent free will merely passing through an unconscious pathway would be even less troublesome to the idea of free will than one originating in unconscious neurons.
Analogously, we cannot choose beliefs - we don't have free will about what we perceive and believe, because perception and belief follow necessarily from sense data and from the model of the universe that exists in our brains. When we encounter sense data, we interpret it immediately as representing something and as being causally related to other things in reality. For example, you cannot see someone smile, and DECIDE consciously whether or not to believe that they are smiling, and whether or not to believe that this means something about their emotional state. But this doesn't mean that we are prisoner to those beliefs and that we cannot influence future perceptions and beliefs. If you cross-check those beliefs, you can engage in behaviors the outcomes of which can differ in obvious
ways that then will allow you to update those beliefs.
At the very least, concluding that experimental results of this sort invalidate the idea of free will, you must carry other assumptions about the nature of consciousness and free will besides just "some objects' motions cannot be predicted from prior states, and those objects have conscious experience which in some way influences those motions". The separability of these two parts of free will - the idea of unpredictable output on the one hand and input from conscious experience on the other - is important. What are the requirements for non-conscious objects with unpredictable output? Are there conscious objects with completely predictable output? Another way of asking is whether things without nervous systems can have free will.
To #2, it's worth asking whether there are classes of decisions that are more or less subject to free will; i.e., how much can we generalize these results? Certainly there are cases where free will can be an illusion, but this falls short of disproving the possibility of free will in general. By all means experimenters should continue asking this question in more settings, although a button-push model wouldn't seem to give the nervous system a chance to shine. My suspicion is that if free will exists in any action it's in long-term executive planning.
It's worth mentioning that it seems strange very strange that our own lack of free will is not obvious to us, given that prediction of the behavior of conspecifics is evolutionarily extremely important. Why the inability to do so exactly, or why the strong appearance that we are the source of action? One speculation is game-theory oriented, that the input-output chain must necessarily be clouded by introducing randomness (which wouldn't really be free will), and our sense of free will falls out of that.
Another attack on the concept is Churchland-like, and questions whether free will isn't just a bad folk idea about human behavior (which I think many enthusiasts of these experiments which agree to). It's worth asking whether belief in something like free will is universal even among non-Western humans - do Solomon Islanders and pygmies have the same belief? - and if so, what it is that predisposes humans to believing this. Do humans with a different conception of agency have different beliefs about this (Aspergers spectrum people)? Finally, do nonhuman animals also believe in free will? I encourage inventive experimentalists to think of a way to support or discredit this hypothesis. If we know different kinds of nervous systems have the same belief we can start understanding what it is we have in common with them that makes us think this.
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