Thursday, December 27, 2012

Reductionism


**Note: I recently participated in the National Novel Writing Month, and this post is an adaptation of a chapter from that project, so it doesn't quite read like a standard post. A more technical summary of reductionism can be found on Less Wrong's reductionism sequence, and specifically this page.**

Plenty of materials have unique properties, but they're not fundamentally unique. The unique properties are traceable back to small differences in the underlying arrangement of matter- number of valence electrons in the outermost shell, or atomic weight, or electronegativity, etc. But the same structure is underpinning all of it. Materials aren't fundamentally complex, they're fundamentally simple- made up of electrons, neutrons, and protons. That's it.

Reality isn't fractal; the huge differences we see on the macro level don't translate to huge differences on the atomic level. You can zoom in farther and farther, and eventually you come to a level where everything is made out of the same basic stuff, and it's just the arrangement of that stuff that makes all the difference.

Thoughts and desires aren't fundamentally complex either. Sure, they're big and complicated at a macro level, but if you zoom in far enough, it's all electrical charges running around in your brain. There's no substance to them, no form, except that our bodies- our hardware- interpret them to mean something. Thoughts aren't real things outside of the environment of your own brain. Humans are really good at interpreting the thoughts of other humans because we share that context- our brains know about thoughts because our brains have thoughts. But there isn't some 'thought' form that actually exists in physical reality.

Consider the following thought experiment: you write the word 'blue' on a piece of paper, and when you place a rock down on the paper, the rock turns blue. Then, if you put the rock down on another paper with the word 'green' written on it, the rock turns green. What would this experimental result mean for your belief system?

For me, it would utterly destroy my belief system, because this result is fundamentally absurd. The words 'blue' and 'green' don't actually mean anything on their own. Green and blue are fundamental things, but the words 'green' and 'blue' aren't. From the rock's point of view- I can't believe I just said that, since rocks obviously have no point of view- they're just a collection of ink molecules spread out over the paper's surface. They only mean something in the context of the language they're written in- only people who read and speak english would know what those words meant.

If we saw this experimental result, there's only three possibilities I could think of to explain it. Either the rock does speak english, or someone who speaks english is controlling the rock, or 'green' and 'blue' are real things. Fundamental things. Things on which the laws of nature act. Obviously the words 'green' and 'blue' aren't real things outside of the english language, but thoughts...

And that's why religion is defeated by reductionism. Because if what religion claims is true, then thoughts are something other than neurons firing. And if that's true, then the brain is just an interface for something much bigger, much more complex. It's just a piece of machinery that interprets the form of thoughts into electrical signals capable of controlling material bodies.

Now you might ask, what's so wrong with that? Isn't that what people mean when they talk about souls?

Well, that's not actually how brains work. If you damage one part of the brain, the victim is left unable to speak. If you damage another, he falls asleep without warning. If you stimulate another part with electrodes, the test subject literally becomes a sociopath, no longer hindered by moral attachments. In the real world, the brain affects thoughts, not the other way around. It's not that the brain is some conduit that allows thoughts through, and brain damage means those thoughts come through muddled or somehow less clear. It's that damaging the brain fundamentally alters those thoughts. It alters the way we think, not just the output. Sociopaths aren't just outputting actions as if they have no conscience, they're thinking and making decisions as if their conscience doesn't exist.

More fundamentally, physics only acts on particles, not on forms. Physics doesn't care that you've assembled the particles into the shape of an airplane- it just goes ahead and applies gravity, strong force, weak force, and electromagnetism to each and every particle, and calculates the interaction of each particle with each neighboring particle, and the result is a solid object that flies through the air if you go fast enough. The form is important to us, but it's not important to physics.

But even if the soul was a thing, and even if the brain was acting purely as an interface between the mysterious soul and the physical world, we still have a problem. We've now posited the existence of a fundamentally complex thing- either that, or we're positing some simple “soulitrons” that combine to make up a soul. But the whole reason we wanted to invoke a soul in the first place was so that we could get away from the idea that all humans are is a complex arrangement of simple things! If we're willing to say souls are complex groups of soulitrons, then why aren't we willing to say that human behavior is better explained as being complex groups of electrons, protons, and neutrons?

At this point, the religious may raise an objection: I've already said that's it's possible someone who speaks english is controlling the metaphorical rock. What about God? Surely you can't rule out the mystery of God as the explanation of a soul?

There's really two problems with this. First, mysterious answers to mysterious questions simply aren't helpful. And second, now we're positing God as a fundamentally complex thing. What is God made of? Goditrons? God is infinitely more complex than we are. We can't posit God as a “necessary being” as a solution to the fundamental complexity problem- or, notably, the first mover problem- because the idea of God is way more complicated than, well, pretty much any other explanation.

9 comments:

  1. I feel silly saying this, but I'm still not quite following. Perhaps this deserves multiple reads (and when I'm less tired). Never fear! I'll be back! :)

    ReplyDelete
    Replies
    1. ^There's a solid chance this is because I've communicated it poorly.

      It turns out to be really difficult (at least for me) to separate reductionist ideas from forms, because human beings communicate exclusively through forms (read: higher-level models of reality, rather than lower-level enumerations of fundamental things). For example, right after I finished arguing against "thoughts" being more than electrical signals, I proposed a "thought experiment" XD

      The best thing I could recommend if you're interested in getting a better handle on reductionism would be to read through the LessWrong sequence. Unfortunately, that takes a long time, and a lot of his stuff does tend to require a background in math, science, computer science, and/or philosophy (awesome if you have that background, not so helpful if you don't)

      Delete
    2. Not much of any of those in my background, I'm afraid. But I'm a Philosophy major, so perhaps as I learn more I might be able to understand more as well. I'll keep this in mind and come back to it sometime when I might be able to understand it better :) Thanks for your patience!

      Delete
  2. Nice, I have bookmarked this and will come back to give it a second read to make sure I understand where you are comming from.

    You mentioned LessWrong, have you read the Harry Potter Methods of Rationality fic? There is significant discussion about forms and such. Also an interesting discussion that, basically, the Wizarding world works on Aristotalein physics instead of Newtonian or quantum.

    ReplyDelete
    Replies
    1. Yes! I lost two weeks of my life to HPMOR back in September. I also recently mentioned it in a grad school application- which I figure will either get me immediately accepted or booted to the curb. Two possible outcomes, which I'm pretty sure make the odds 50/50. I like those odds! ;)

      I haven't read ch. 86 yet though, since I feel like I need to go back and reread the whole thing to remember everything that's going on. Maybe next time I have two weeks to spare....

      Delete
  3. I am so sorry and I feel a little silly writing this... but I don't understand! I followed your line of reasoning (which I thought was very clearly expressed) up until "But even if the soul was a thing". Then it diverges away from the set of things my brain can handle.

    Neuroscience data is incompatible only with one type of interface, the purely passive directional one. It's obvious that the brain is not a purely passive interface to translate "soul-thoughts" into physical correlates. The brain is computing at least something -- it cannot even theoretically be seen as a complex mechanism to parrot a computation done elsewhere. Entire brain structures do not make sense unless at least some of the computation is performed there (such as the lateral geniculate nuclei, with their 6-fold replication of retinal input). Perhaps it would be worth it to complete the argument by elaborating on why your readers should want to discount other types of interface models.

    When believers say that man is a composite of soul and body (mind/matter spiritual/physical etc), they mean that human beings are made up of two *different* components. Different means different. It's methodologically inconsistent with the hypothesis to look at material reality, abstract the properties of material reality and then demand that they apply to a component that was declared other-than-material in the first place. Thoughts may or may not transcend their neural correlates, but it is not by ascribing customary compositional properties to them that we will resolve the issue.

    >"if you zoom [in to a thought] in far enough, it's all electrical charges running around in your brain."
    If you zoom far enough into a thought-form, you'll get word-forms, object-forms, relation-forms, not electrons. You'll get the components of the thought, not the components of its neural correlate. If you can think electrons when you think of a thought seen up close, you are embracing a worldview that negates even the possibility of something non-material existing. It's a legitimate position, of course, but holding a materialistic position is not evidence for other positions being wrong.
    Strict materialism is, of course, entirely incompatible with religion. To say that religion is defeated by reductionism, though, seems a bit too much. The two rest on incompatible worldviews. I have yet to see a convincing case for why materialism should be considered satisfactory. One could just as easily hold that materialism, far from accommodating all the available data, explains away as "non-real" all the things it fails to capture. If we could just make the part of reality that does not fit disappear from view, all theories would be perfect theories.

    I found the last part of the post, when complexity is brought up in connection to the soul first and then to God, entirely baffling. I don't understand why the "complexity" of the soul would make any difference whatsoever. It would be helpful if you could clarify the rationale.

    This post is centered around the nature of thoughts. I came across the same type of issue 15 years ago, in the context of dreaming activity. My illustrious professor of brain and cognitive sciences taught that dreams are nothing more than random firing of neurons in the brain. The firing was specifically occurring to consolidate and transfer information into long-term memory. Then I had a "blue and green stone" moment, and materialism came down crashing for me. It was not a religious experience per se, but it forced me to rethink what I knew of the nature of reality.

    On to better world models!

    ReplyDelete
    Replies
    1. Hi Cami,

      Very thoughtful comments. I'll do my best to unpack my thinking on the points you raised (though it's been awhile since I wrote this!)

      "Neuroscience data is incompatible only with one type of interface, the purely passive directional one... Perhaps it would be worth it to complete the argument by elaborating on why your readers should want to discount other types of interface models."

      Fair enough. There are lots (infinite?) of conceivable models you could propose that would explain the experimental results of "brain damage = thought damage." Why is "thought is purely physical" the best explanation? Two reasons, I think: first, Occam's razor. You can certainly propose epicycles of infinite complexity to explain any phenomenon, but what is your model predicting that is different from the model that all thoughts are ultimately manifestations of physics? Are you predicting brain damage to lead to different kinds of thought damage than a reductionist? Are you predicting an afterlife with demonstrable or measurable characteristics? Are you predicting a non-physical transmission of data or thoughts across non-physical media? Because if you're making the exact same predictions as reductionism, then surely reductionism is a whole lot simpler than any model invoking untestable, unobservable, unquantifiable, etc. etc. variables like “souls”, “forms”, and the like.

      Second, physics appears to be the way the world actually works. No one has ever found anything other than physics to be at work. There are plenty of places we might expect to find thought forms or word forms or soul forms to manifest if they were real things- and manifest in physically testable ways. For example, if psychics were real and stood up to scrutiny, that would be pretty solid evidence against reductionism. Or if out of body experiences actually happened in verifiable ways. Or if ghosts were real. Or if miracles were plentiful and well documented. But such forms appear to be the proverbial invisible dragon in the garage, because nobody expects them to happen. Everybody knows exactly what kind of evidence they're going to have to explain away- the evidence that ends up looking exactly as if thoughts are purely physical things.

      "When believers say that man is a composite of soul and body (mind/matter spiritual/physical etc), they mean that human beings are made up of two *different* components."

      What experimental predictions does this make? If a soul affects a person's actions, and that person's actions are controlled by electrical signals from the brain, are you saying that if you zoom in far enough on someone's brain, you're going to see something other than physics at work?

      The question I'm trying to get at is "where does the magic happen?" If souls have a real and actual impact on observable reality, then where does this impact happen? I've yet to hear a convincing answer to this question.

      Delete
    2. "If you zoom far enough into a thought-form, you'll get word-forms, object-forms, relation-forms, not electrons. You'll get the components of the thought, not the components of its neural correlate."

      I'm claiming the thought and the neural correlate are inseparable- one and the same thing. I'm claiming this on the basis of experimental evidence that says we can manipulate thought by manipulating the neural correlate, and we can observe thought by observing the neural correlate. I know of no evidence to suggest that the two are different things.

      You're right of course that this is a position I hold, and me holding a position doesn't make it any more or less right. But I'm claiming that I hold the position on the basis of literally all the available evidence (there's nothing to even make us suspect it to be otherwise). I would be interested in evidence that runs contrary to this belief.

      "To say that religion is defeated by reductionism, though, seems a bit too much. The two rest on incompatible worldviews."

      I guess I don't think they rest on incompatible worldviews. I strive to believe things such that my only ideological claim is that evidence is valid- every other claim is based on observation (I surely fail on this, but it is my goal). I think the evidence is overwhelmingly on the side of reductionism. Reality didn't have to be this way; it simply is.

      “I found the last part of the post, when complexity is brought up in connection to the soul first and then to God, entirely baffling. I don't understand why the "complexity" of the soul would make any difference whatsoever. It would be helpful if you could clarify the rationale. ”

      I’ll give it a shot- this was an attack on the problem that people who believe in souls think they are solving. When I’ve pressed neo-Platonists on this issue in the past, the general answer I get is something along the lines of “humans can’t be nothing more than combinations of atoms because humans are big and complex and meaningful.” My point is that abstracting complexity to a “soul” isn’t much of a help. Either souls are made up of something simple (soulitrons), and you’re in no better position that you were when humans were made up of atoms, or souls are huge undefinably complex things. We simply do not see huge undefinably complex things in observable reality. Anywhere. Everything is fundamentally simple, not fundamentally complex. Why on earth are we expecting souls to be different? This isn’t a knock-down argument, but it is a common sense question. If everything we observe in nature is one way, why are we positing an invisible and unobservable reality which is exactly the opposite? You would need extremely compelling evidence to conclude such, and most views of the soul I’ve heard in the wild prevent such evidence from existing even in principle (if you’re cynical like me, you think this is because soul-proponents are protecting themselves and their incorrect beliefs from falsification). Again, if such evidence existed, I would love to know about it- souls being real would be a really important fact about reality!

      “Then I had a "blue and green stone" moment, and materialism came down crashing for me. It was not a religious experience per se, but it forced me to rethink what I knew of the nature of reality.”
      I won’t pry, but these stories are always fascinating to me. I find it interesting that nearly all of the Christians I know and respect intellectually eventually give me the same answer when I press hard enough on why they actually believe it: because they’ve had some personal experience that they can’t attribute to anything but God (or in your case… fill in the blank, I guess  )

      Delete
    3. Thank you for your articulate replies. Thanks especially for going through the part on the "complexity" of the soul and making the reasoning explicit. When I don't get things or fail to see a connection where the context says there should be one, my brain literally hurts. I suppose it's a very in-your-face form of cognitive dissonance; I joke with my close friends that I have a "physical vocation" as an error-checker/proofreader. It's one of the great things about having an inflamed brain. You don't get to lie to yourself as to things making sense to you when they don't.

      I hope I get around to writing you a detailed reply. I have a chronic debilitating illness, so it's not a given I will manage in the short term (but that doesn't stop me from wanting to!).

      Delete