Thursday, December 19, 2013

A Natural Reduction

One of the great advantages of the naturalist world view is how it all hangs together. The workings of the mind can be explained in terms of the workings of the brain, which can be explained in terms of the workings of the brain cells, which can be explained in terms of the electrical and chemical properties of molecules, which can be explained in terms of the physical properties of the particles of which those molecules are composed. And the same goes for anything else in the universe: stars, moons, clovers....

Now, I will admit that some of the links in that proposed chain of explanation are not as strong as others: the mind-brain link, for example. But the overall scheme seems sound, and the naturalistic world view can count innumerable successes as evidence of its truth: the technologies of transportation, agriculture, communication, medicine, and psychiatry, to mention just a few. Put this against the abject failure of alternative ways of thinking: what did Christianity (just to pick on one alternative) accomplish in the 1500 years before scientific thinking arose?

At any rate, even when precise explanations are lacking, there doesn't seem to be any strong argument why the gaps cannot be filled out in a naturalistic way.

It seems, though, that many atheist philosophers are no longer satisfied with this reductionistic picture.  The recent book Mind and Cosmos, by atheist philosopher Thomas Nagel, argues that there are aspects of subjective experience that can't be explained by reductionistic means. (Short version here.) Another atheist philosopher, Philip Kitcher, whom I have the greatest respect for, disagrees with Nagel but seems to agree that the reductionist program has not accomplished the task it set out to do. "Unity fails at both ends," writes Kitcher.

For once, I agree with Professor Feser: if naturalism fails to give us a unified picture of everything, then it is time to abandon naturalism and seek a different explanation, rather than to cling to a failed program.

But I am not as pessimistic as these philosophers. Perhaps that's merely ignorance on my part. But some of the anti-reductionist arguments I've come across seem just silly, and, as I already said, there don't seem to be any good arguments for the impossibility of naturalistic explanation. I remain a hard-core reductionist, and I'm going to try to defend that view.

Next: Do the laws of physics lie?

36 comments:

  1. One of the great advantages of the naturalist world view is how it all hangs together.

    Do you have a good definition of naturalism that avoids Hempel's dilemma?

    Now, I will admit that some of the links in that proposed chain of explanation are not as strong as others: the mind-brain link, for example.

    How does your reductionistic chain terminate (if it does terminate)? Do you believe there is some smallest corpuscle out of which all other matter is composed? Can matter and all the forces be reduced into one kind of entity (perhaps this is what Kitcher means when he say unity fails at both ends)?

    If other metaphysical positions better account for the mind-brain link then shouldn't they be preferred over naturalism?

    But the overall scheme seems sound, and the naturalistic world view can count innumerable successes as evidence of its truth: the technologies of transportation, agriculture, communication, medicine, and psychiatry, to mention just a few.

    Why does naturalism get credit for any of these successes?

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    1. Jayman, your questions require a comprehensive defense of naturalism, which this short post wasn't intended to provide. A few quick responses:

      "Can matter and all the forces be reduced into one kind of entity?"

      Yes, to a large extent this has already been accomplished in the Standard Model of elementary particles - see my book linked in the sidebar.

      "If other metaphysical positions better account for the mind-brain link then shouldn't they be preferred over naturalism?"

      No, because the overall coherence of the world view is critical. If naturalism can account for everything in the universe EXCEPT the mind-brain link, then it seems far more likely that we have not yet understood the mind-brain link than that some supernatural properties need to be introduced.

      "Why does naturalism get credit for any of these successes?"

      Well, for example, compare the germ theory of disease with previous attempts: demons, humors, qi, etc. Which is more naturalistic? Which has been more successful?

      Similarly, fertilizing crops works better than praying to gods, airplanes work better than magic carpets, telephones work better than ESP.... Need I go on?

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    2. Robert:

      The definition of naturalism is of utmost importance in addressing further issues. If you can't get around Hempel's dilemma then naturalism is dead on arrival.

      According to Wikipedia's entry on the Standard Model, there are 61 elementary particles and you refer to elementary particles (plural). This is not a unity.

      Feser's Thomism, for example, seems to have just as much coherence as your undefined naturalism and makes better sense of the mind. This is why I'm wondering why we should favor naturalism over Thomism (not that the only alternative is Thomism).

      As for the alleged successes of naturalism, it is impossible to answer what theory of disease is more naturalistic without a definition of naturalism. Humorism, for example, sounds naturalistic to me. If I am to credit naturalism for germ theory should I not dock it for humorism? Furthermore, the supernaturalist (another term that's difficult to define) accepts the existence of germs, fertilizer, airplanes, and telephones. It is just as compatible with scientific success.

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    3. I don't see Hempel's dilemma as presenting any sort of fundamental obstacle to naturalism. I could make the same point about (say) Christianity. Do you believe in the Christian god as currently understood? Or as understood in some future ideal theology? Hempel raises an intersting question about how to define physicalism, but it's not a fundamental contradiction that destroys the coherence of the concept.

      I also don't see 61 particles as a problem. Would you only be satisfied with a physics that employed only one fundamental entity? Why is that? Why should we expect the universe to be restricted in that way?

      My point about the unity of the naturalist view is not about the number of fundamental entities, but about the way all phenomena are reducible to physical phenomena.

      Sure, theism is compatible with scientific success. But it has in no way contributed to that success. It is not necessary to pray to God to construct or operate a cell phone. It is not necessary to make a burnt offering before taking an antibiotic. These thing work on naturalistic principles alone.

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    4. Hempel raises an intersting question about how to define physicalism, but it's not a fundamental contradiction that destroys the coherence of the concept.

      I agree it doesn't destroy the coherence of the concept. But it does suggest that naturalists can continually move the goalposts. Today ESP contradicts naturalism, but I could see it being viewed as compatible with some future naturalism if enough self-described naturalists accepted its existence. The distinction between natural and supernatural seems too unclear to me to base your metaphysics on such a view.

      Would you only be satisfied with a physics that employed only one fundamental entity? Why is that? Why should we expect the universe to be restricted in that way?

      Your quote from Kitcher ("Unity fails at both ends") suggests he thinks reductionism has failed because of the lack of unity. I would say that if reductionism is true, then we should expect there to be one fundamental entity. There is not one fundamental entity so I'm not a reductionist.

      My point about the unity of the naturalist view is not about the number of fundamental entities, but about the way all phenomena are reducible to physical phenomena.

      But how is that any more unifying than Feser saying all phenomena can be reduced to act and potency (or some such thing)? My point is that multiple metaphysical accounts are unified in some sense so this does not set naturalism apart.

      Sure, theism is compatible with scientific success. But it has in no way contributed to that success.

      Without a good definition of "natural" I don't think it gets credit for the success or failure of any piece of technology. And we can turn around your example and note that Thomists could describe antibiotics in terms of act and potency and the four causes. We might as well give Thomism credit for things too.

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  2. I would second Jayman's comment. Kepler, Galileo, Newton, Leibniz, Pascal, etc. were not naturalists in your sense but firmly committed Christians. In fact that was generally true of scientists up until the time of Maxwell. It is only relatively recently that the general run of scientists have turned secular. So why does naturalism get the credit for the advances of modern science?

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    1. Because Newton, et. al., didn't employ Christian principles in their theories, they employed naturalistic principles.

      Newton is a good case: he attempted to understand chemistry along non-naturalistic (alchemical) lines. But who today talks about Newton's chemistry?

      The point is not about what scientists believe, but about what principles they employ. Even if the majority of working physicists today were Christians, that wouldn't change the fact that no Christian principles are needed for contemporary physics.

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    2. Because Newton, et. al., didn't employ Christian principles in their theories, they employed naturalistic principles.

      But they may have employed the metaphysics that was informed by their Christianity.

      Newton is a good case: he attempted to understand chemistry along non-naturalistic (alchemical) lines. But who today talks about Newton's chemistry?

      How was Newton's alchemy non-naturalistic? If it had worked I imagine that you would be playing it up as another success of naturalism.

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  3. Put this against the abject failure of alternative ways of thinking: what did Christianity (just to pick on one alternative) accomplish in the 1500 years before scientific thinking arose?

    Go here to find out...

    http://www.amazon.com/Gods-Philosophers-James-Hannam/dp/1848311508/ref=sr_1_1?ie=UTF8&qid=1387565478&sr=8-1&keywords=gods+philosophers

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  4. @Jayman "According to Wikipedia's entry on the Standard Model, there are 61 elementary particles and you refer to elementary particles (plural). This is not a unity.

    Feser's Thomism, for example, seems to have just as much coherence as your undefined naturalism and makes better sense of the mind.
    "

    How many elementary particles does Feser's model say there are? Some different number?

    Feser believes, or says things which lead his readers to believe, that the Hard Problem of consciousness is explicable entirely in terms of "ordinary corporeal features of certain kinds of ordinary material substances."

    At any point, from nuclear physics to neuroscience, does this model ever stray from the description schema "everything our best science says, plus some observationally inert bolt-ons"?

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    1. @Staircaseghost, Thomism is not a theory or model of physics. My point is that reductionism seems to be false in a world with 61 elementary particles (instead of one). Thomism is compatible with any number of elementary particles and so can't be critiqued along the same lines.

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    2. But then, neither "reductionism", nor "naturalism", nor "physicalism" are theories or models of physics. I'll bet you dollars to donuts if you ask a developmental biologist where babies come from, he will not say "Naturalism. Next question."

      Neither have I ever purchased a textbook in any of my science classes where "reductionism" was listed as the explanation for any phenomenon.

      Rather, naturalism, Thomism etc. are in the category of after-the-fact philosophers' stories purporting to sum up the results of empirical inquiry and/or provide an underwriting justification for them. That Thomism is compatible with any number of observations, where metaphysical naturalism is not, ought to tell you something about which one has real problems with vacuity. Did you catch the part about how having no positive solution for the HPC separate from naturalism obviates any claim to "make better sense of mind"?

      Individual reductions can be false, but reductionism can't be false, any more than running can be false, or carefulness can be false, because it's a method and not a conclusion. It can only be less or more useful.

      Start naming phenomena. Puppy dogs, polonium, peer pressure.... there's a lot more than 61 (or whatever the number is these days, IANAP). And yet every observable phenomenon in the universe can in principle be accounted for in terms of these elementary entities. If reducing trillions and trillions of things to a few dozen things doesn't count as a successful reduction in your book, then I don't know what you think that word means.

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    3. "Thomism is compatible with any number of elementary particles and so can't be critiqued along the same lines."

      Thomism, according to Feser, is compatible with with all possible discoveries of science.

      And if your theory 'explains' everything, then it explains nothing.

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  5. Staircaseghost:

    I realize that reductionism is not a theory or model of physics but Robert seems to be gesturing to the Standard Model as some kind of support for reductionism. My point is that if reductionism is not understood as leading to a unity then it is compatible with any number of elementary particles. You seem to accept this conclusion when you state that reductionism can't be false. I think our disagreement may be the result of my taking reductionism to lead to a unity while you do not. Your take on reductionism is compatible with naturalism, Thomism, and other metaphysical viewpoints.

    I raised Hempel's dilemma earlier to note that metaphysical naturalism is vacuous on at least some definitions of the term. If you take one horn of the dilemma then naturalism is most likely false. If you take the other horn of the dilemma then naturalism is compatible with souls, ESP, gods, etc.

    BeingItself:

    I would expect true views on metaphysics and ultimate reality to be able to describe everything in our actual world (there may be logically possible worlds that are incompatible with Thomism). Thomism is compatible with any scientific discovery because the study of science would be impossible if certain Thomistic claims (or something very much like them) were false. For example, the discovery of the laws of physics would be impossible if objects did not have final causes (or something very much like them).

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  6. "For example, the discovery of the laws of physics would be impossible if objects did not have final causes (or something very much like them)."

    Could you unpack that? What is the final cause of a tau neutrino?

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    1. I'm not a physicist so this is my layman's understanding after a brief search of the internet. Take it with a grain of salt.

      Apparently a tau neutrino can turn into a muon neutrino so a muon neutrino would be a final cause of a tau neutrino. The broader point being that the regular behavior of a tau neutrino would point to its final causes.

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  7. So does the muon neutrino somehow reach into the past and cause the tau neutrino to change? What is the mechanism of how this alleged "final cause" works?

    I'm really looking for a more general defense of your rather extravagant claim that "the discovery of the laws of physics would be impossible if objects did not have final causes".

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    1. Any mechanism would be described by science. From my brief reading it sounds like scientists know very little about the tau neutrino so I have no answer to that particular question.

      A final cause is just something an object is directed towards, points at, or tends towards. If final causes exist we would expect regularity to be observed. A law of physics is a description of this regularity.

      Consider Newton's law of universal gravitation: F = G * (m1 * m2 / r^2). This law tells us that one body of mass will attract another body of mass. This attraction is a final cause of anything with mass. If objects with mass did not have the final cause, then no law of universal gravitation could be discovered.

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  8. I agree that there must be some regularity in order for laws to be described. But then to tack on this notion "directed towards" seems to me an unnecessary lavishness.



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    1. Why do you think final causes are unnecessary? How would regularity be possible without them (or something like them)?

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    2. I don't see the explanatory or predictive power. Regularity in nature is all that is needed for science to be possible. We don't need the giant sucking sound of final causes.

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    3. I don't see the explanatory or predictive power.

      Final causes explain and predict the fact that regularity exists.

      Regularity in nature is all that is needed for science to be possible.

      But what is needed for regularity to exist? Final causes. The scientist may be able to ignore this but the metaphysician cannot.

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  9. In my view, the kind of physicalism I'm talking about is a theory (or hypothesis, if you like), and it is far from content-free. It puts severe restrictions on what kinds of things can be explained.

    If ESP is to fit inside a physicalist viewpoint, it must operate in such a way as to obey fundamental physical principles like conservation of energy and the speed of light limitation. Precognition can be ruled out, for instance, because it violates causality.

    So physicalism is falsifiable: if someone can reliably have foreknowledge, then physicalism is false.

    Theism, on the other hand, is completely content-free. God is all-powerful, so any sort of miracle is possible. God "works in mysterious ways," so nothing that happens needs, or can have, an explanation. Theism puts no constraints on what could possibly happen and therefore is unfalsifiable.

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    1. Concerning theism being unfalsifiable, I think it is worse than that.

      A common argument for theism is miracles. Another common argument for theism is the regularity of nature. So for the theist, the regularity of nature is evidence for a god, and when that regularity is violated . . . well that is evidence for a god too!

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  10. Also, I still don't see why it is any less reductionistic to reduce everything to 61 particles than to reduce to one? Sure, one would be prettier (hence the interest in string theory), but why should the world be pretty?

    And also, since neutrinos can oscillate (tau into mu neutrino, and mu into tau neutrino) is it possible that the final cause of the tau neutrino is the mu neutrino, AND the final cause of the mu neutrino is the tau neutrino?

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  11. Robert:

    Your physicalism may be falsifiable because it appears tightly intertwined with some present-day scientific theories. When you defend this physicalism you need to describe it clearly because there does not appear to be some universally accepted definition of physicalism. And if and when one of these "fundamental physical principles" is overturned you'll have to admit physicalism is false.

    Mere theism is no more of a robust metaphysical system than mere atheism. Neither position is content-free, but neither makes much in the way of predictions either. However, on most forms of theism, God is the ultimate explanation of everything, so it is untrue to say that things don't have an explanation on theism. On the other hand, I'd be interested to hear what provides the ultimate explanation on your atheistic account.

    But a particular theistic metaphysical system, such as Thomism, does provide something in the way of predictions. For example, the universe could have had no regularity at all and thus no final causes. But it just so happens that it does exhibit regularity. Thomism seems much more difficult to refute because it starts from more basic principles. It asks what needs to be true for science to be possible and then lets science do its thing. When your metaphysics starts with detailed scientific principles then it is only a scientific revolution away from being proven wrong. Thomism can buffer the waves of any scientific revolution.

    In my comments to Staircaseghost I noted that I understood reductionism to lead to a unity. If you don't, then perhaps we are merely working with different definitions. There can be degrees of reductionism and I don't disagree that some things can be reduced to others.

    Yes, I think it is possible that a final cause of a tau neutrino is a mu neutrino and a final cause of the mu neutrino is a tau neutrino. I've replaced the with a to indicate there could be additional final causes.

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    1. This comment has been removed by the author.

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    2. Tau neutrinos and mu neutrinos oscillate back and forth.

      What is added by piling on this notion of one being the final cause of the other? I just don't see the point of adding that gratuitous layer of unneeded extravagant metaphysics.

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    3. What is added by piling on this notion of one being the final cause of the other?

      A description of being and change in general.

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    4. You do not need the notion of final cause to describe or understand change either.

      I'm starting to suspect you have ulterior motives for holding on to this arcane bit of metaphysics. You certainly don't need it in science. It's clunky and gratuitous.

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    5. You do not need the notion of final cause to describe or understand change either.

      What do you think you need? Why can substance X change into substance Y but not substance Z?

      I'm starting to suspect you have ulterior motives for holding on to this arcane bit of metaphysics.

      Where have I given my motives? I've given some reasons to think final causes or something like them exist. Those reasons stand on their own.

      You certainly don't need it in science.

      You've already admitted you need regularity to do science. So what is needed to describe and understand this regularity in general if it is not final causes?

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    6. Why do I need something additional to explain regularity? Where do these explanations stop?

      Would we then need an explanation of final causes? Like final cause gremlins? And what keeps the gremlins in line? Angels? Or is it turtles all the way down?

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    7. Why do I need something additional to explain regularity?

      Because regularity can't explain itself. Consider a concrete example. Your heart pumps blood through your body. Are you proposing that there is no explanation for this regularity? Or are you going to look for an explanation of this regularity in the powers of the heart itself? Which approach is the science-stopper? If your heart stops beating do you want a doctor who knows what your heart is directed towards or one who does not?

      Where do these explanations stop?

      Given your handle I suspect you know how the Thomist answers that question. God, conceived as Pure Act, is the ultimate explanation. Arbitrary stopping points and infinite regresses are for atheists.

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    8. Just making something up and claiming it is an "ultimate explanation" is not an explanation. Stop pretending to know things you don't know.

      What explains the regularity we observe in nature? Is there an explanation? I have no idea. I don't pretend to know things I don't.

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    9. The Thomist does not just make up God as an ultimate explanation. He deduces God's existence and nature through reasoned argument.

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    10. No. The Thomist learns a myth on his mother's knee. And then later invents extravagant metaphysics to argue for what he believes for other reasons.

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