Tuesday, July 4, 2017

Randal, Reductionism, and Something About Mary

So I was having a pleasant little bit of a Twitter back and forth with theologian and apologist Randal Rauser on philosophy of mind.  Then I went about part of my holiday weekend and when I checked Twitter again I had my mentions blown up and saw that our exchange had attracted some others and got more than a bit testy, and I think confused.


Bad things happen when you try to discuss something like philosophy of mind on a platform like Twitter.

Randal then wrote a blog post regarding the discussion with others on Twitter, which prompted me to finally make good on my comment to Randal about writing my own post about why I thought reductionism wasn't all that implausible.


I should start off by pointing out why I think reductionism of the mind is plausible - but rather than write all that out, I should point to an excellent comment by The Thinker over on Randal's blog which points out that given everything we know about physics - particularly about the atoms that make up our very material brains it effectively rules out the idea that there's something else out there that can affect our brains without violating the known laws of physics.  Given that said laws are extremely well established, we should be very skeptical of things which claim to violate them.

So by reductionism about the mind, I mean to say that mental events just are physical events in the brain, and nothing more.

Randal attacks this notion head on using a very well known objection known as "qualia".  Here's a quote from Randal in his comment section where he gives an excellent and succinct presentation of the problem:

"If a thought/sensation just is a pattern of neurons firing then every property of the thought/sensation is a property of the pattern of neurons firing.

With that in mind, imagine a neuroscientist who perfectly understands the pattern of neurons firing when a patient tastes cinnamon. But that neuroscientist has himself never tasted cinnamon. Is it your view that the neuroscientist would know the taste of cinnamon just as if he himself had sucked on a cinnamon stick all in virtue of knowing the pattern of neurons firing in the brain of the person who tasted cinnamon?"

I must admit that this kind of objection always struck me as a bit odd, and I think I have a response to the problem that seems to resolve the issue for the reductionist. That said, I'm no expert on the topic so perhaps I'm making a mistake with this and so I invite Randal or anyone to point out exactly where this response goes wrong or is confused.

In short, I think people who use the qualia objection don't take the reductionist conception of mind as far as they should when they craft their thought experiment.

Dat Qualia Tho

The response is that a thought/sensation isn't "just a pattern of neurons firing" it's a pattern of neurons firing through the relevant parts of the brain which can produce the thought/sensation.

Since I'm a computer engineer and I have some professional experience with analog computers, which I think the brain is a kind of - lets use an example to illustrate what I think is going on.

Think back to when we used analog televisions with analog broadcasts.  So your local TV stations had giant transmitters which would encode all of the video and audio information of a TV show and send it out over the air waves embedded in electromagnetic energy.   Each TV at the time had an antenna and a tuner, which would be set to the right channel, which would then decode that electro-magnetic signal and pass it through a variety of electronics which would then produce the audio and video of the show.

So to go to Randal's example of the taste of cinnamon, the taste of cinnamon is a specific pattern of neurons which fire in a part of the brain when they receive a specific stimulus.  This is the signal in our TV analogy.  The neuroscientists would be like an engineer who received the signal on an antenna and hooked that up to an oscilloscope.  Via the o-scope, the engineer can measure everything there is to know about the electromagnetic signal: Frequency, amplitude, etc. but the engineer can't actually watch the TV show unless he ran that signal through the proper electronics in the a TV set that would be able to decode the video and audio information.

This doesn't mean that there was something more to what happened in our antenna's and TV sets when they received the signal and decoded it to produce the video and audio - it was the signal combined with the TV electronics which produced the video and audio.

Something About Mary

One famous thought experiment about qualia is Mary's Room which is very much like Randal's example with cinnamon.  What I'd like to do is to take my analogy and apply it a bit more.  I'm not going to detail Mary's room, so if you're not already familiar with the thought experiment, click the link!

One thing to point out is that knowledge about "what it is like to see red", on a reductionist theory of mind would itself be physical changes in the brain.  We do know that when try to use our memory or knowledge to think of things like images, or sounds parts of the brain that are involved with processing those sensory inputs are involved.

So in the case of Mary, while she may know all sorts of things about the firings of neurons in regions of the brain related to seeing the color red this isn't the same thing as actually stimulating the relevant parts of her brain that enable her to see red in the first place.  So it's not surprising that when she is released from her room and actually has her eyes process light of the right wavelengths that she gets new information.

But I think things can be made stronger for the reductionist.  Lets say Mary has a team of other super brilliant scientists, all of which only wear black and white clothes and use black and white instruments, or otherwise blindfold Mary to prevent her from actually seeing the color red while she's in her room.

Lets say they create a device that is able to inject the right stimulus at the end of the optic nerves, say the pattern of synapses which will cause the neurons in Mary's brain to fire in the precise sequence she knows is related to seeing red.

Then they do this for all the other colors, and Mary is then told what each color she's having represented through her mind by these synapse firings.

Once this is finished, Mary is removed from the machine which stimulated her, and her blindfold is removed.

Mary is then shown colors via her eyes for the first time in her life.

What do we think happens to Mary at this point:

1.) Will Mary gain any new information?
2.) Will Mary be able to correctly identify which color is which based on the information she got in her procedure?

I believe the reductionist can easily answer "No" to (1) and "Yes" to (2) because the reductionist theory is that seeing color really just boils down to a pattern of neurons firing in the relevant parts of her brain.

Importantly, information about that pattern of neurons firing is not going to be equivalent to actually having the pattern of neurons firing in the relevant part of the brain. It's like running a TV signal through an o-scope vs. an analog TV.

A Quick Note To Randal


So just as I hope Randal will point out where I've made a mistake in my thinking, I intend to point out where Randal has made a mistake in his.

In his post Randal says the following:

"The observer effect is a well-established phenomenon in which minds can effect physical events merely by observing them. Consequently, I am left puzzled by the insistence of some that our current understanding of physics precludes the ability of the mind to affect the world."

This is simply wrong headed.  Nothing about the observer effect indicates that there must be some kind of a immaterial mind that therefore has a causal effect on the physical world.

The observer effect can be replicated with a camera or similar physical, non-conscious device, without any human's present.  It's related, I think, to the total entropy created in the physical system which is perfectly consistent with the idea that mental events are physical events.

Similarly, ideas that reductionism is self-defeating by saying that "minds can cause physical events" is a bit of a red herring. The reductionist need not say that there is no such thing as a mind, they deny an immaterial mind. If they think the mind is purely physical, then of course the mind can affect physical reality.

This isn't to say that Randal has done something wrong, a lot of stupid things are said in these discussions and a lot gets lost, especially on Twitter.  As such I can easily see why Randal would interpret things in such a way to see the reductionist saying something incoherent like "we don't have a mind that causes physical events!" and so write his reply.

My point here isn't necessarily to convince dualists, it is to try and stake out a position that shows reductionism isn't incoherent or self defeating.

16 comments:

  1. A few responses.

    First, in terms of qualification, I don't present a "qualia" argument. Rather, I present a knowledge argument which pertains to many distinct mental states including sensations (qualia)m beliefs, and intentions.

    "the taste of cinnamon is a specific pattern of neurons which fire in a part of the brain when they receive a specific stimulus."

    Dualism remains, whether you acknowledge it or not. On the one hand, there are the neurons firing. On the other hand, there is a taste experienced by the subject. You're free to assert that the one just is the other. But asserting something isn't itself an argument that it's so. What reason do you have to think that the pattern of neurons firing just is the same thing as the individual's tasting cinnamon?

    "Nothing about the observer effect indicates that there must be some kind of a immaterial mind that therefore has a causal effect on the physical world."

    I didn't say that the observer effect indicates that "there must be some kind of immaterial mind...." I pointed out that the observer effect shows that the the individuals observation can affect the world.

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    1. Fair enough, it's the knowledge argument.

      You say that dualism remains, I assume you mean that "dualism remains an option" which I can agree with - metaphysical options aren't going to get disproved generally speaking.

      That said, my goal wasn't to argue against dualism as it was to provide a defense of physical reductionism (PR) of the mind by responding to the knowledge argument you provided, which many consider to be a strong argument against PR - which seemed to be at least part of the point of your post ("so much the worse for reductionism").

      I can't prove that PR is true any more than you can prove dualism is true, but what I can do is show that PR doesn't suffer the devastating defeater you're presenting in the knowledge argument - or at least that's what I'm attempting to do.

      Further I'm trying to show that someone who holds to PR doesn't have to deny the existence of qualia, we just provide a better explanation of what it is, and what "knowledge about" something is on the PR view as well.

      We can give plenty of arguments as to why we think the pattern of neurons firing in the specific region of someone's brain is the same thing as the individuals tasting cinnamon to justify belief in PR, but that's a side issue - all I needed to do was provide a defense of PR.

      As far as the observer effect, you were using the example to strengthen the point that a "mind" can affect the physical world, where you hold that a mind must be in part immaterial, hence the immaterial mind can affect the physical world.

      The point in question is whether or not we need to believe the mind is in part immaterial or if it can be purely physical. I think we can hold the latter, and avoid the force of the knowledge argument.

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    2. It seems to me your talking around my main point rather than addressing it directly. I wrote: "What reason do you have to think that the pattern of neurons firing just is the same thing as the individual's tasting cinnamon?"

      There are many reasons to believe these are distinct (albeit related) entities. Smoke is obviously related to fire. But nobody is going to identify smoke with fire. The sensation of tasting cinnamon is obviously related to the patterns of neurons firing. But what makes you think it is to be identified with the patterns of neurons firing?

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    3. Randal,

      I imagine CA has positive reasons for believing in physicalism, but the purpose of this post was to give a defense against the anti-physicalism argument you offered. His goal with the post was simply to show that you haven't provided a good argument against physicalism, not to provide his own argument for physicalism. Let's take things one at a time. Before you make him build a positive case for physicalism, at least let him know what you think about his response to your argument against physicalism.

      By analogy, imagine you wrote a post responding to the problem of evil and CA responded "theism remains. What reason to you have for thinking theism is true?" This would just be changing the topic. Instead of responding to your criticisms of the PoE, CA would be shifting gears and talking about positive arguments for God. Similarly, it seems like instead of responding to CA's critique of the knowledge argument, you're shifting gears and demanding positive arguments for physicalism.

      Like I said, one issue at a time

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    4. Randal - basically what Ron said.

      This post isn't here to defeat dualism as the main goal, it's to provide a defense of physical reductionism, which in light of surviving the knowledge argument, may well be able to triumph over dualism - but the point is to defend physical reductionism. I'm a bit sad you won't comment on that part of the defense.

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  3. "Given that said laws are extremely well established, we should be very skeptical of things which claim to violate them."

    I don't quite understand this argument. Is this any different than saying gravity prevents a wizard from flying because every times I drop a rock, it doesn't fly, so a wizard wouldn't be able to violate physics either ? That would be a bad argument because he's a wizard, so by hypothesis, he could violate physics. So the question then becomes: are there such things as wizards?

    Sean Carroll has repeatedly argued that the Core Theory of particle physics "rules out" substance dualism, because if the Core Theory is true, then we have a complete account of particles, including particles in the brain. And everytime we observe particles they obey the Core Theory, so we have good reason to think there are no immaterial souls messing with the Core Theory. The problem with this argument is that every time we observe a particle, it's somewhere like a particle accelerator where we wouldn't observe the effects of a soul violating the Core Theory, even if souls really do exist. What we'd need to do is look at the particles in a brain and look to see if the Core Theory is being violated. I personally asked Carroll about this and he said no such experiment has ever been conducted, nor is such an experiment currently possible.

    So the fact "CT"( that every observed particle obeys the Core Theory) doesn't seems to confirm or disconfirm dualism or physicalism. P(CT|physicalism) is of course 100%. But P(CT|dualism) is just as high because dualism entails that matter obeys laws uniformly and only deviates from the laws when acted on by a souls, and since dualism says this only happens in our brains, evidence of particles obeying the Core Theory in the lab is exactly what we'd expect on dualism as well.

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    1. Except you need to provide evidence that somehow the particles that make up our physical brains are any different than the other particles, and give a reason to think why we should think souls can only affect particles in the brain.

      As of now, we have zero reason to believe that the particles that make up our brains are any different than other particles we can observe. Also since particles that were in our brain eventually cycle out - does that mean the souls can affect them still? What about the ones before, like the particles in our food. Can those be affected by souls? If not, why not?

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    2. Dualism doesn't say the particles in our brains are any different. It says that these are the only particles that souls act on. By analogy, if a theist says God levitated a man, it's not as if they are claiming that the atoms on their body were special, allowing him to levitate. Rather, they are claiming that these are normal atoms, and that God simply singled these ones out to be exempt from physics for a brief period.

      Similarly, brain atoms are the same as the rest and souls single them out for exemption. It's not clear why a soul can't affect atoms outside of a brain, but a theist could easily come up with an explanation. I assume a theist would say God has placed limitations on where souls can act in the world, and limited their domain of action to brain atoms. Strange hypothesis, yes. And there is certainly no reason to think it's true. There are also many reasons to think its false relating to indirect evidence for naturalism, brain-consciousness dependence, etc. However, the truth of the Core Theory of physics cannot be a reason to reject dualism, because dualism predicts that the Core Theory is true, just as the resurrection of jesus predicts that it is a law of nature that dead people cannot rise. Dualism says that the interaction of a soul with the brain is a miraculous event, and in order for something to be miraculous, there needs to be a law of nature being violated. So dualisms don't deny the Core Theory, they affirm the Core Theory and say that it is being violated. And of course, they can't say it's being violated unless it is really a law, so theists would enthusiastically affirm all the evidence for the Core Theory.

      In order for the evidence (E) for the Core Theory to be evidence against dualism, P(E|dualism)<P(E|physicalism). But even on dualism, we would expect particles to obey the Core Theory when they are observed in the lab. So "E" doesn't discriminate. Thus, if dualism fails, it must do so because it's prior probability is lower, and this would have to do with factors independent of E. I certainly think the prior probability of dualism is lower, but it's not because of the Core Theory.

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    3. "Dualism says that the interaction of a soul with the brain is a miraculous event, and in order for something to be miraculous, there needs to be a law of nature being violated. So dualisms don't deny the Core Theory, they affirm the Core Theory and say that it is being violated. And of course, they can't say it's being violated unless it is really a law, so theists would enthusiastically affirm all the evidence for the Core Theory."

      Of course no one believes the beanstalk to the sky grew because Jack threw some regular beans into the dirt, the theory is that Jack threw MAGIC beans into the dirt - it's completely different!

      On a serious note, yes this is exactly getting at the argument from Core Theory against dualism:

      Either physicalism about the brain is true or a small miracle occurs every time any person in the history of humanity has had a thought.

      Given that my post here is about providing a defeater to the "Knowledge Argument" against physicalism of the mind, it seems we have good reason to think that physicalism is more plausible than dualism.

      As an aside - dualists can't say they believe Core Theory to be true when at the same time asserting that there are additional laws of physics that we don't know about which govern what can affect the particles that make up brains vs. what can affect particles outside of the brain.

      At least not if we're calling laws of physics the rules that govern what can affect physical particles.

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    5. "Either physicalism about the brain is true or a small miracle occurs every time any person in the history of humanity has had a thought."

      Yes, a dualist would be happy to affirm this. So what we need now is an argument that those miracles aren't happening. How does the Core Theory give us those reasons? Here is a formal argument that the evidence for the Core Theory doesn't give us those reasons.

      1) P(particles observed in lab perfectly obey Core Theory | physicalism) is high
      2) P(particles observed in lab perfectly obey Core Theory | dualism) is equally high
      3) if P(E|H1)=P(E|H2), then E doesn't raise the probability of either relative to the other
      4) therefore, the observation that particles perfectly obey the Core Theory in the lab doesn't raise the probability of physicalism relative to dualism.

      Defense of premise 2: dualism says that particles obey the Core Theory unless acted on by a soul, and since souls only act of brain particles, dualism *entails* that the particles in the lab would perfectly obey the Core Theory, because lab particles are not brain particles.

      Don't get me wrong. Dualism is false. But the reason it is false is because a) there is strong evidence that naturalism is true, which indirectly supports physicalism; 2) there is strong evidence that consciousness depends on a brain: 3) physicalism is much simpler and dualism doesn't make up for its complexity with any explanatory advantages.

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    6. Ehh, I'm not so sure dualists would be happy to affirm that "core theory is false vs. small miracle for every thought."

      I do think we're largely in agreement, the point of the dichotomy above is to start making dualism more implausible. Once we accept the core theory, dualism needs to start making all sorts of additional postulates to work around problems about particles in brains being effected, and then problems about particles cycling out - and then in the end physicalism starts looking like a much better option - especially if we can deal with things like the knowledge argument.

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    7. Every argument for PR succumbs to the logical fallacy of 'begging the question'. In the example of the oscilloscope and the TV program you've got

      1. An optical interface which is not computer but a physical transducer (TV or Oscilloscope) and

      2. A conscious person who sees the optical screen as visible qualia.

      Do you see why this smuggles the physicalist answer into the thought experiment as an a priori conclusion? The signal has not been made visible to the hardware by moving it through circuits, it is the end user whose natural capacity for optical stimulation and visual perception of it which has done that. We can presume that electronic events can be propagated in an isomorphic way to neurochemical events via the eye, but we cannot presume any sort of physical decoding of neurochemical events as colors and images (much less flavors and smells...isomorphism goes right out the window in those cases).

      There's no evidence of any sort of decoding going on. The electronics, eye, and nervous system are all 'coding' differently, but there is no need to ever decode them. We can see this from the way electronics work when we remove the oscilloscope or monitor and nothing changes. No computer could benefit by outputting VRAM to a screen, then input back into a camera and back into VRAM.

      Another clue that the PR hypothesis is false: When people who are blind from birth have their visual cortex stimulated electromagnetically, they do not see glowing spots (phosphenes) like a sighted person does. They see nothing, but they feel tactile sensations, like Braille. The idea then that signals passing through parts of the brain can be presumed to generate qualia automatically is empirically false, or at least empirically doubtful at this point, but even more important is that it is rationally unfalsifiable. There is no rational path to lead us from neurons squeezing out fluids that trigger other cells to execute blind physiological functions to any such things as colors, flavors, or feelings...not without begging the question by smuggling the existence of those things into our physicalism in the first place. Try as we might, there is no justification for the appearance of private sensations (including the sensations of privacy and publicity) from public mechanisms without viewing privacy and sensations from a modus ponens or retrospective vantage point. If we assume qualia from the start, then it is no problem to conjure up a 'just so story' to tie that assumed phenomenon to neurons, brains, electromagnetism, time, information processing, microtubules, quantum, biophotons, turtles, Hermes, or whatever else we decide makes the magic happen.

      The hard problem is how do the reasoning from the opposite view - the modus tollens or prospective view where we begin with no possibility of any such thing as qualia. Now we see (well about 20 or 30% of Western minded people can see in my experience, more for people who grew up with Eastern philosophy) that everything that a brain does can be explained quite clearly from biochemistry without invoking any such things as private sensations. It's really that simple. Mary's Room actually adds unnecessary complication by inserting the notion of 'knowledge' where it is not required. Seeing red is a natural phenomenon. The sensation of 'knowing' about something is another class of qualia - another sense which is cognitive and cogitative rather than optical and visual. That too is a private experience which is impossible to justify prospectively from public mechanisms. It's a fair point from Jackson - yes, seeing red does allow us to 'know what red looks like', but knowing what red looks like isn't different from having seen red. It's a distraction to get bogged down in these linguistic distinctions. Knowledge isn't necessary for consciousness, but qualia is.

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    8. The study you cited about stimulting the visual cortex is interesting, though I don't know enough about the relevant science to judge whether that really disconfirms PR. However, the very fact that there are blind people seems to disconfirm some forms of dualism. If qualia is not caused by/dependent on a physical brain, and is instead caused by/result of an immaterial soul, then it is a mystery why damage to one's physical eyes or brain should have any effect on one's experience of sight. On PR, we would expect damage to eyes/visual cortex to interfere with sight, but that's a bizarre unexplained correlation on dualism. A dualist could explain it by invoking more complex forms on dualism that are tailored to accommodate this data, but this sort of hypothesis tailoring only hurts the plausibility of dualism.

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