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Tuesday, September 15, 2009

That Mysterious Life Force

I'm reading John Gribbin's The Scientist, a thoroughly whig history of science. At one point, celebrating the great advance the dismissal of vitalism represented, he writes, "By the end of the nineteenth century it was clear that there was no mysterious life force at work in organic chemistry..."

This is the kind of thing you see all the time in discussions of vitalism... but it is thoroughly ahistorical. Recall that the mechanical philosophers had dismissed Newton for positing "a mysterious gravitational force," and that science later advanced by positing "a mysterious electrical force" and "a mysterious magnetic force." The idea that there was "a life force," given these precedents, was a perfectly respectable scientific hypothesis, and, if it had been found, it would have been no more mysterious than gravity, electricity, or magnetism. (And given the repeated failure, after over a century of promises, of reductionists to produce life from non-life, perhaps it will yet prove to be a fruitful hypothesis!)

12 comments:

  1. The idea that there was "a life force," given these precedents, was a perfectly respectable scientific hypothesis, and, if it had been found, it would have been no more mysterious than gravity, electricity, or magnetism....perhaps it will yet prove to be a fruitful hypothesis!

    I disagree in that there is a significant difference between the posited "life force" and the other forces you listed. In the other cases, the force posited (be it gravity, electricity, or magnetism) had a clear predictive model behind it. In the case of gravity, the posited "gravitational force" was intimately associated with a equation that specifies its value. That equation, combined with Newton's general laws of motion, allows you to predict the movement of celestical bodies and how they relate to each other, as well as behavior in vacuums.

    While Newton did not know why such a force exists in the first place, his positing of a gravitational force made quantitative predictions, and allowed a more parsimonious description of our observation.

    This is sharply different from the "vital force", which lacked any associated predictive model and adds nothing to your ability to explain why life is able to exist and how it differs from non-life. It comes with no associated equation or even any difference in anticipation.

    Now, with that said, scientists have made significant progress in finding what life needs in order to form and exist, and so in that (contrived) sense, are identifying the "vital force". Schroedinger, for example, identified life with the extraction of negentropy from the environment to keep a body far from equilibrium with its environment. And "negentropy" isn't some black-box concept like the vital force; rather, it uses a formerly-unrelated field, thermodynamics, to clearly specify how much negentropy a given fuel source has, and how far a system remains from equilibrium with its environment.

    But this hypothesizing is completely unrelated to the historical use of the term "life force", which was associated with no predictive model whatsoever and added nothing to our understanding, even as a placeholder.


    (And given the repeated failure, after over a century of promises, of reductionists to produce life from non-life, ...)

    How are you defining life here? Viruses can be generated by mixing a few non-living chemicals (in the sense that they don't self-replicate) together. Do you not consider viruses to be a form of life? Biologists are split on this one, so it's not much of a bullet to bite. However, they do use resources from their environment to sustain and replicate themselves, and they possess RNA. Seems pretty narrow to exclude them.

    Some scientists discount viruses on the grounds that they need a specific environment to survive in, and have to use another organism to make copies (or near-copies) of themsevles. But then, so do most males :-P

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  2. It's all "will." What's the big deal?

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  3. Silas, gravitational force and electrical force were formulated as vague ideas first (for instance, gravitational force by Kepler) and only later received mathematical form. And those positing a 'vital force' fully anticipated that it would turn out to have a mathematical form just like other forces did.

    In other words, first you posit a force, then you look for the mathematical laws describing its operation. The mechanists had turned out to be wrong about the scientific fecundity of other forces -- why not vital force as well? The opint being it is foolish for Gribbin to mock the vitalists, as if they should have known in advance the result that we only know because of their researches.

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  4. Like I said, Gene, if you define "force" broadly enough, to include "the set of necessary and sufficient conditions for a phenomenon to manifest", then yes, you are always correct to posit a force, including a vital force. If the above definition is used, then even I believe in a vital force.

    But Gribbin, based on the passage, is criticizing a use of "force" that goes beyond the extremely general one; he's talking about the "mysterious life force" previously believed in that had some kind of existence separate from the laws of chemistry, and it is this belief in its irreducibility that he said had sufficient counterevidence at the end of the nineteenth century.

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  5. By the way, what's your take on viruses?

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  6. Jesus Christ, did you even read what I wrote? I didn't say they were correct to posit such a force -- I said it was a reasonable scientific hypothesis, and Gribbin's invocation of "mysterious" here is ahistorical, and ironic, since the mechanists derided Newton's idea gravity as an "occult force" that was not reducible to the motion of particles, and similarly criticized the idea of a "magnetic force." Descartes and other mechanists developed models showing how gravity and magnetism could be reduced to the motion of particles alone -- Descartes, for instance, posited a flow of little screw shaped particles drawing iron to magnets.

    The positing of a vital force was a sensible extension of the discovery that gravitational force and vital force were good, useful models. It just turned out not to bear good results, which the people positing could not have known until after the idea was proposed and then found to fail.

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  7. Jesus Christ, did you even read what I wrote? I didn't say they were correct to posit such a force

    Correct, you didn't. You made the much stronger claim that: "perhaps it will yet prove to be a fruitful hypothesis!"

    The point I was making -- the one you missed -- is that if you interpret "vital force" broadly enough, then, yes, of course you're correct to posit one.

    But there's a big difference between that meaning, and an actual scientific hypothesis, with moving parts, and integration with the rest of the body of scientific knowledge, and constraints on our expectations.

    The earlier forces posited since the start of the Scientific Revolution did that: though they appealed to a "force", it was because they noticed enough regularity to give that force meaning. For example, Kepler noticed a pattern in the orbits of celestial bodies.

    In contrast, the vital force, as meant in the 19th century, could "explain" anything and therefore explained nothing. Why does such-and-such happen? Um, vital force. Why do trees get bigger? Vital force. Smaller? Vital force.

    Yes, the term "force" and its translinguistic equivalents was used in antiquity as a mysterious non-answer to questions -- and Gribbin criticizes these just the same.

    Could you tell us what specific aspect of the vital force "theory" could turn out to be fruitful today, in light of the failures of reductionists?

    No, because if you did, you'd be collecting your Nobel prize right about now.

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  8. 'You made the much stronger claim that: "perhaps it will yet prove to be a fruitful hypothesis!"'

    That's quite true, if we read "much stronger" as "much, much weaker"; since, of course, to say something might turn out to be fruitful says almost nothing at all.

    "'Discussion' with a Marxist or Positivist is senseless. One cannot enter into rational discussion with a "case" whose disease consists in the denial of the order of the logos." -- Eric Voegelin

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  9. @Gene_Callahan: Your claim was stronger because you are saying that now, even given all the scientific knowledge we have, there still remains hope for the vital force "hypothesis" (and I use the term loosely). That is stronger than saying that someone with very limited information is correct to temporarily assume it.

    And I'm still waiting for an explanation about how exactly the vital force (in the 19th century sense) would shed light on anything. All it does is say, "vital force!" in response to any question. Do you know what it would even look like for later discoveries to vindicate you?

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  10. "And I'm still waiting for an explanation about how exactly the vital force (in the 19th century sense) would shed light on anything."

    Um, I'm not sure why you are "still waiting," except that you didn't comprehend:

    "those positing a 'vital force' fully anticipated that it would turn out to have a mathematical form just like other forces did."

    Now, of course, this is not an explanation, just like Newton's force laws do not "explain anything," as the Cartesians ceaselessly pointed out. But it would represent a scientific advance. You (and Gribbin) are ignoring the actual historical situation of the vitalists and reading history backwards. At the time, vitalism was a sound scientific hypothesis, and the vitalists expected to find good force laws just like for gravity, etc.

    "Your claim was stronger because you are saying that now, even given all the scientific knowledge we have, there still remains hope for the vital force "hypothesis"..."

    All sorts of scientific hypotheses get revived after being "soundly rousted" earlier. Heliocentrism was rejected for 2000 years (and for scientific reasons -- Aristotle and Ptolemy were not interested in what Scripture said about the matter!) before making a comeback, atomic theory was rejected for even longer, "occult forces" were banished from science only to return with Newton, and then a mechanistic explanation of gravity returned with Einstein. Silas, we might tomorrow find a good reason to revive ether theory, or re-posit frigorific particles.

    Get your history from real historians of science, Silas, rather than pop dabblers in history like Gribbin.

    Oh, and what do you think about the complete overthrow of reductionism in quantum mechanics, where the behaviour of "atomic" particles turns out to be not atomic at all, but dependent instantaneously on the state of all other particles they have interacted with throughout their entire history, so that ultimately their state depends on the state of the entire universe?

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  11. Oh, and did I mention:

    "'Discussion' with a Marxist or Positivist is senseless. One cannot enter into rational discussion with a "case" whose disease consists in the denial of the order of the logos." -- Eric Voegelin

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