The best that science can do–cross-post

Can a materialist believe in the theory of evolution?  I doubt it.

Back when I was in junior high and high school, I remember being given flow chart-style expositions of what textbooks call “the scientific method”.  It went something like this:  1) ask a question; 2) formulate a hypothesis; 3) do an experiment; 4) if your hypothesis is verified, it gets promoted to a “theory”; 5) keep doing tests; 6) eventually, the “theory” gets bumped up to being a “law”.  There are certainly criticisms that could be made of this.  Flow charts always do some violence to what is fundamentally a creative process.  The “hypothesis” stage is often unnecessary for science fair-type projects–often a student would (and logically should) remain agnostic about the outcome of his experiment until the data is in, but his teacher forces him to “hypothesize” some answer in deference to “the scientific method”.  A decade as a research scientist and I still don’t know what the difference between a “theory” and a “law” is supposed to be.  But, given that the point is to introduce junior high kids to scientific ways of thinking, the standard exposition isn’t bad.

One thing that’s good about it is that it gets across the idea that scientific explanations have varying degrees of certainty.  “Science” doesn’t always speak with the same assurance.  If you don’t believe in blackbody radiation, you’re crazy.  If you don’t believe in dark matter, the evidence right now weighs against you, but your opinion is respectable, and I wouldn’t be shocked if it turned out to be right.  If you think string theory is bunk, you are (I suspect) in agreement with a silent majority of physicists.

So I started thinking–how far does scientific certainty go?  There’s a school of thought that says that natural sciences never achieve real certainty:  every theory is just one experiment away from disproof.  So, for example, the 1/r^2 laws for electricity (Colomb) and gravity (Newton) have been very well tested.  Still, that gives no certainty that a slightly more accurate measurement wouldn’t find deviations.  And, in fact, we do predict and observe slight deviations due to QED and general relativity, respectively.  I expect that someday deviations from these theories will also be found, when we can test extreme enough conditions at high enough accuracy.

But not all scientific theories present themelves as exact and fundamental in this way.  Consider the following three theories:  1) the connection between statistical mechanics and thermodynamics; 2) evolution by random genetic variation and natural selection; 3) the existence of souls of animals.  The first is due to Boltzmann, Maxwell, and Planck; the second to Darwin; the third to Aristotle.  I think it is flatly impossible–inconcievable–that any of these three theories could be disproved by any future observation.  As soon as you understand these theories, you realize that they must be true; the only logically contingent question is whether the circumstances for their application are ever actually realized (and these questions have obviously affirmative answers).

Not only does the process of natural selection not tax our credulity; we realize that, assuming there are heritable traits and that some traits give one a leg up in the reproductive race (and who could doubt either claim?), natural selection will happen, given only enough generations.  It would take divine intervention to stop it from happening.  It doesn’t matter if we don’t know exactly how mutations happen or how a given adaptive trait functions.  The theory is independent of these details.

Similarly, it could be that we have much to learn about the particles that make up atoms, but none of that can affect the laws of statistical mechanics.  The identification of entropy with a multiplicity of microstates and of temperature with entropy’s energy derivative (and, for a gas, with the average kinetic energy) are permanant gains in knowledge.  They have to do, not with unexplained mathematical rules, but with identifying what things (entropy, temperature) fundamentally are.  When one understands what entropy is, one sees that of course it will never decrease for a closed system.  The most basically questionable part of thermodynamics is the first law, because it depends on energy conservation, a presumed fundamental law of nature of whose veracity we can never really be certain.  (It’s one of those permanantly-one-experiment-from-disproof laws.)

Then there’s Aristotle’s claim that living beings have substantial forms.  Moderns scoff at this “unscientific” idea, but of course it’s used in every page of every medical textbook in existence.  We assume that things like substantial unity (that we can identify what is and isn’t part of the organism), function (ask your doctor what the function of the liver is, and see if he chides you for asking an unscientific question), and identity through material change will apply to living things, and we are not disappointed.  Zoologists and paleantologists make predictions based on the assumption that animals are self-moving, and that they will act for their own preservation and propagation, and these predictions are confirmed.  Substantial unity–the “soul”–is certainly scientific.  It may not be just scientific–it is also ontological–but it’s not less than scientific, because the scientists could never do without it.

Evolution, thermodynamics, and the soul are certain knowledge because they are formal knowledge.  They have to do with patterns that we recognize, and as such they have a real intelligibility that material knowledge–e.g. knowledge of the fundamental laws of the matter that makes us up–lacks.  To one who apprehends that he has a soul–that he is a unity of drive, intelligence, and action–it wouldn’t make sense to be told that scientists have done some very careful tests of the cells in his body or of his psychological states, and they have learned that he actually has no principle of unity, that “he” is nothing but an arbitrarily identified aggregate of matter.  Whatever these scientists have been doing, they could only have been learning more about the matter that incarnates the vital pattern he calls himself.  The existence of the pattern is not open to doubt once one has apprehended it.

We all realize that this idea of the soul is philosophically tinged.  We expect to have to defend it from the empiricists and materialists.  “What part of the body is the ‘soul’ in?” they jibe, and we Aristotelians roll are eyes and answer back something like “What part of the statue is the ‘shape’ in?  What pigment in the painting is the ‘pattern’made of?”  The funny thing is that all other definitive scientific theories are in the same boat.  If he really refuses to believe anything he can’t touch or see, the materialist should not believe in natural selection.  If we “zoom in” to the life story of any individual organism, natural selection disappears.  It’s not some kind of magical force that smites the unfit.  Any given animal that died before reproducing was killed by something else–hunger, disease, predators, etc.  No particular animal died because of natural selection, just as no particular cell in your body houses your soul.  Substantial forms and evolution are in the same boat.  Similarly, if one “zooms in” to a single atom or molecule, the concepts of entropy, temperature, and pressure become meaningless.

It would seem that mid-twentieth century physics’ reductionist turn was at least partly mistaken.  Vocal reductionists like Stephen Weinberg made high-energy physics–fundamental laws about elementary particles–the measure of all knowledge.  If I’m right, one can only have real and certain knowledge to the extent that one’s theory conceptually divorces itself from these fundamental laws.  Statistical mechanics works by throwing away everything but energy and multiplicity.  Evolution works by throwing away everything but heritability and adaptivity.  Aristotelian biology (i.e. anatomy and physiology) works by cataloging form and discarding matter.  (Thinking themselves materialists, biologists like to say that they “turn over” the basic properties of the matter in living beings to the chemists and physicists, but the fact that they can “turn over” this subject and continue on their way without trouble shows that it is actually formal causality that they’re dealing with.)

22 Responses

  1. There are experiments that could, in principle, be done that would disprove free will. Indeed, a few have been done that have arguably come close.
    I don’t know what use a “soul” is without that.

  2. Also , you would seem to be arguing that a “materialist” could not be a historian, as he can’t see the past directly, and you seem to assume that evolution has never been observed in a laboratory.

    I’m not an atheist, I’m an agnostic. But it would take far more evidence than has ever been adduced to make me think there is actually a soul. Heck, I only HOPE they don’t end up disproving free will.

  3. A soul is a substantial form: a principle of unity and intelligibility. Nonrational organisms have souls, so free will isn’t a crucial component.

  4. Evolution certainly could happen in a laboratory, but recognising it would mean taking a wholistic approach to the population. If you look at the travails of a single microorganism in your lab, for example, you won’t see natural selection.

  5. By “soul,” Bonald doesn’t mind the sort of spooky ectoplasm ghost stuff that people like Dennett and Internet atheists often ridicule. It is something more sober and simple.

    It goes back to Aristotle. When he was examining the natural world, he noted an interesting fact: that there was some kind of ‘unity’ in natural objects (esp. organisms), on a level above their mere material components. Think about a dog — its body is composed of many different tissues and organs, which are composed of cells, which are in turn arrangements of carbon molecules, and so on… but there is something to the nature of the dog itself that makes it work as a single, sustaining unit. After all, the food it eats, the air it breathes, the parasites and fleas that inhabit it are *not* the dog even though they are mixed (materially) with it.

    For a living organism, the “soul” is its form, and Aristotle had very good reasons (still valid today) to think that forms are real and co-existent with matter. It is not true that if a reduces to b, then a *is* b — the counterexample of the bronze statue suffices to show that.

  6. Soul?
    What are its properties? What are its effects on anything else? How do you test it? How do you falsify it?

  7. Dirichlet, Bonald:
    Oh, I can believe in Forms in the philosophical sense. Here’s an example :
    My problem with souls, even the not-explicitly-christian-religious kind, is as the commenter below so eloquently states: what are the scientific implications of souls? How do you test for them?
    Don’t get me wrong, I’m not one of those people who believe that Metaphysics is useless, the question about whether there is a God, for instance, is not meaningless – it has a yes or no answer even if there may in reality, never be a way for humans to be sure. But I am a fan of the scientific method and rationalistic metaphysics and , much as I hate it, I can’t say that anything has ever been able to disprove the “Hard Materialists”. We may very well be in a universe whose existence is totally accidental and contingent on local physical laws and our existence may be purely physical and purely unnecessary.

    I do believe there is a purpose behind things, but I know I can’t prove it, and I know I can’t prove what that purpose is, so I certainly don’t blame others who come to wholly religious or wholly materialistic conclusions provided they’ve looked at the available evidence.

  8. All the properties of the organism are properties of the soul.

    A clear demonstration of its existence is that the matter making up an animal will change throughout its life while the animal remains demonstrably the same organism.

  9. The problem is that in evolution there is no function apart from circumstance. Something that is “for” something in one circumstance may be used “for” something else in another another circumstance, abandoning the original purpose with nothing except the changes in circumstance to make it “for” the new “purpose.” And if it results in more genes being passed on it will be selected for that “purpose.”

    I don’t think most Thomist philosophers appreciate how radically the theory of evolution undermines teleology in biology, though teleology may still exist at other levels.

  10. “All the properties of the organism are properties of the soul.”
    — You can’t possibly think that this is not totally glib, and entirely meaningless. Replace the word “soul” with the word “flardyshmoob” or anything else, and absolutely nothing changes about the assertion.

    “A clear demonstration of its existence is that the matter making up an animal will change throughout its life while the animal remains demonstrably the same organism.”
    — So does a crystal have a soul if I replace every atom in it, gradually, with another atom of the same element? Does a lake have a soul since it continues to exist as a “demonstrably the same” object even though almost every water molecule it contains now was not part of it a decade ago? Does a fungus? I could go on, but you get my point.

    Face it, you can believe in souls if you want, that’s your prerogative. But let’s not pretend that it’s a belief based on science. There is absolutely no coherent idea as to what a “soul” is, no way to test this incoherent idea, no way to falsify it. Being a physicist I have no doubt in my mind that if you’re being honest with yourself this is plainly obvious to you.

  11. Your example of a crystal does show that the crystal is a form which is distinct from the atoms that make it up. (Actually, when we go to scales that small, quantum indistinguishability starts to be an issue, so it’s not clear if we can say that we’ve swapped two identical atoms and that a real change has taken place–but that’s just a detail. I understand your point.) Really, if you talk about animals at all, I don’t see how you can deny that they have some form, a pattern of vital processes, if you will, that is distinct from their matter. Do you think it’s ever legitimate to identify a pattern? Is the distinction between hardware and software fallacious? If not, I don’t see how you can object to hylemorphic composition in principle, and “soul” just means the form (vital pattern) of a living organism.

  12. Bonald –

    “Your example of a crystal does show that the crystal is a form which is distinct from the atoms that make it up.”

    — Sure, I think we all agree that this is true, at least in the sense that we, as human beings, like to organize things in such a way.

    “Actually, when we go to scales that small, quantum indistinguishability starts to be an issue, so it’s not clear if we can say that we’ve swapped two identical atoms and that a real change has taken place–but that’s just a detail.”

    — Actually, that’s sort of what I was driving at. After all, the same happens with human beings. My atoms are continuously replaced with indistinguishable atoms.

    “Really, if you talk about animals at all, I don’t see how you can deny that they have some form, a pattern of vital processes, if you will, that is distinct from their matter. ”

    — Well, there is a form, but that is true, as I just showed, of ANYTHING. Old rusty nail, grain of sand, a comet, a galaxy… you name it.

    “If not, I don’t see how you can object to hylemorphic composition in principle, and “soul” just means the form (vital pattern) of a living organism.”

    — Ah. Well, you’re more than welcome to define a soul that way, and if you do, I will not argue with your assertion that a soul exists. However, if you poll people on the street, Family Feud style, I very very much doubt that more than a few percent will define a “soul” in this way. Usually the term “soul” refers to something transcendent, something that survives one’s death, something permanent which contains one’s “character”. By your definition the soul disappears when the physical body does — after death. I have no quibble with that.

  13. Hi fafsa,

    You may be right about what the man on the street means by “soul”, said man having a deplorable streak of Cartesian dualism in him. In my defence, my definition isn’t totally perverse; it is the one used by Aristotle and his many followers. Whether souls can survive without matter to inform them is another question. At least for the souls of nonrational life forms, there’s a pretty broad consensus that they cannot.

  14. Bonald — in such a case I have no qualms with your definition of a “soul” other than to find it redundant and entirely unnecessary. However, as your own last sentence implies, there might be a difference between souls of rational and non-rational lifeforms. That, of course, is the beginning of the yellow brick road towards the traditional definition of “soul”.

  15. You put “for” and “purpose” in scare-quotes. You could mean two things by this: (a) that it is not the case that anything is *really* directed toward something or (b) that things can be directed toward different purposes. Obviously you can’t take the latter to imply the former, because it would be a contradiction to say that the things can be directed toward multiple purposes, therefore there are no purposes. If you mean the former, then your claim isn’t obvious to me and I am not sure how evolution implies it. If the latter then I don’t see how this undermines teleology; it only multiples it.

  16. “Whether souls can survive without matter to inform them is another question.”

    So wait, why couldn’t someone accept your current definition of “soul” and still be a materialist?

  17. Isn’t saying that something can be used for any and all sorts of things just another way of saying that it doesn’t really have any particular purpose?

  18. The Man Who Was: “Isn’t saying that something can be used for any and all sorts of things just another way of saying that it doesn’t really have any particular purpose?”

    Take a Swiss army knife. It can be used for one purpose that a knife could serve, such as cutting boxes open, or for all sorts of purposes that a knife could serve (such as cutting pizza, cutting string, poking holes in plastic), and for all the purposes that its other attachments (such as tweezers) might serve, and for an infinite variety of other purposes as emergency might dictate. For example, it might be left on the floor to stop a self-closing door from closing and locking. All the way it stays an object that it makes sense to talk about teleologically.

    Consider a Colt 45 revolver. Will you concede it has a purpose? How about if it is used by cowboys to bash nails into fence-posts? How about if cowboys buy it because it holds up better to bashing nails into fence-posts than a Smith & Wesson Russian model does? If the Colt gains an advantage in the market struggle for survival because it is more fit for a secondary purpose, does that mean there is no such thing as teleology with respect to revolvers?

  19. What often happens though is the primary purpose is completely abandoned and some previously secondary purpose becomes the primary purpose, again pointing to a radical relativity in purpose.

  20. And what often happens is that things chug along much as they were. It would make no sense to talk about such things as species if continuity wasn’t an important feature of the biological environment.

  21. The species problem is a whole ‘nother can of worms.

  22. The only (rather small and unimportant) thing I would add is that as children we were mostly deceived about what a “law” really is in the sciences. The reason evolution is not, and probably cannot ever be, a law is that it is possible that speciation could come about differently elsewhere. The theory of evolution deals with those species we observe on earth, but even biologists who believe in it uncritically do not consider it a scientific law, like the conservation of energy (which is thought to be the same everywhere in the universe).

    I’m not sure if this puts a different spin on the way most people understand the theory, but maybe so.

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