Wednesday, April 14, 2010

Is Evolution Guided or Unguided?

Michael Ruse has criticized Alvin Plantinga for being critical of evolution. Plantinga defends himself in a letter published in The Chronicle of Higher Eduaction: Evolution, Shibboleths, and Philosophers.

I want to address one particular point that Plantinga makes because it's relevant to the issues that come up in the accommodationist wars.
"Why," asks Ruse, "does Plantinga feel this way?" Because, he says, "In his view, Darwinism implies that there is and can be no direction in life's history." Still another missed distinction. As far as I can see, God certainly could have used Darwinian processes to create the living world and direct it as he wanted to go; hence evolution as such does not imply that there is no direction in the history of life. What does have that implication is not evolutionary theory itself, but unguided evolution, the idea that neither God nor any other person has taken a hand in guiding, directing or orchestrating the course of evolution. But the scientific theory of evolution, sensibly enough, says nothing one way or the other about divine guidance. It doesn't say that evolution is divinely guided; it also doesn't say that it isn't. Like almost any theist, I reject unguided evolution; but the contemporary scientific theory of evolution just as such—apart from philosophical or theological add-ons—doesn't say that evolution is unguided. Like science in general, it makes no pronouncements on the existence or activity of God.
Plantinga is allying himself with Eugenie Scott and other accommodationists who fiercely defend the idea that science can't address issues such as purpose. In fact, Genie fought hard to remove references to "unsupervised, impersonal, unpredictable and natural process" from a statement on evolution by the National Association of Biology Teachers back in 1995 [NCSE v National Association of Biology Teachers].

I disagree with Plantinga, and with the National Center for Science Education. The idea that evolution might be guided by God is a legitimate question for scientists to address. After all, if it's true then parts of evolutionary theory might have to be revised. I do not accept the claim that scientists must avoid this question because it comes from religion.

When you are thinking like a scientist there's only one possible conclusion. There is no scientific evidence to support the hypothesis that the history of life on Earth was guided by God. Everything we know about the history of life is consistent with an entirely natural process—one that's characterized by chance and contingency. It is perfectly reasonable as a scientist to state this position clearly. This is not stepping outside of the boundaries of science.

Let me explain my position by using an analogy. Imagine the claim that aliens visited the Earth 3.5 billion years ago and seeded our planet with cyanobacteria. After much investigation scientists find no support for such a claim. Is it legitimate for them to conclude that aliens are not responsible for life on Earth? Of course it is. All scientists know that you can't prove a negative but that doesn't mean you can't assign probabilities and behave accordingly.

Philosophers aren't likely to get upset if scientists make statements denying that aliens are responsible for life as we know it. That's because belief in alien visitors isn't one of those kooky ideas that demands special status. However, if scientists make the more general claim that life appears to have evolved by purely natural processes then this gets their dander up. All of a sudden science is threatening religion and this is not allowed. It's "philosophical naturalism" and not "methodological naturalism." It's not science according to Plantinga and many accommodationists, including Michael Ruse. Bollocks, I say.

Scientists call it as they see it. If that upsets the theists then they had better learn to deal with it instead of whining about the science being illegitimate.

Science says that evolution is not divinely guided, based on what we know today.


13 comments :

  1. Ruse claims I am an "open enthusiast of intelligent design." ("Open" enthusiast? Is enthusiasm for intelligent design supposed to be something you should shamefacedly conceal, like addiction to watching soap operas?)

    Yes, enthusiasm for ID is something of which you should be ashamed. Next question.

    ReplyDelete
  2. "Science says that evolution is not divinely unguided, based on what we know today."

    Nor is it divinely guided.

    ReplyDelete
  3. Plantinga: "Like science in general, it makes no pronouncements on the existence or activity of God, [therefore, God]."

    Every data point collected (in every scientific field) that doesn't support the creator god hypothesis increases the improbability of said hypothesis. All the data so far points to no god. At what point do you suppose Plantinga will reject the hypothesis for lack of supporting evidence?

    ReplyDelete
  4. I don't see why you would phrase the conclusion as "Aliens are not responsible for life on earth" as opposed to "There is no evidence that aliens are responsible for life on earth." In the example you give, it is certainly possible that our lack of evidence for alien involvement is part and parcel of our lack of evidence about precisely how life arose. And so isn't it appropriate to be clear about what is excluded by the evidence we do have, and what is unknown because of evidence we don't have?

    ReplyDelete
  5. Science says that evolution is not divinely unguided...

    Um, are there too many negatives in that sentence, or have I completely misunderstood what you're saying?

    In fact, Genie fought hard to remove references to "unsupervised, impersonal, unpredictable and natural process" from a statement on evolution by the National Association of Biology Teachers back in 1995

    Given the American legal situation, that was probably necessary, whatever reasonable inferences may be drawn from the science (cue Mr. Bumble).

    ReplyDelete
  6. It's not science according to Plantinga and many accommodationists, including Michael Ruse. Bullocks, I say.

    I think you meant "bollocks". There is a substantial difference.

    Plantinga states that "God certainly could have used Darwinian processes...". Well, yes, but where's his evidence? Perhaps if we keep flinging the burden of proof in their direction, the theologians' knees will eventually buckle.

    ReplyDelete
  7. James F. McGrath asks,

    I don't see why you would phrase the conclusion as "Aliens are not responsible for life on earth" as opposed to "There is no evidence that aliens are responsible for life on earth."

    Because the latter is just a mealy-mouthed way of saying the former. I'm aware of the nitpickers distinction between the two sentences but I have a low tolerance for such a distinction.

    ReplyDelete
  8. I presume the directionality of biological evolution is not itself in question here.

    The evolution of species is certainly not a random process.

    It is driven by random events which produce mutations.

    Most importantly these mutations are then filtered by the prevailing environment.

    This is the process of natural selection which gives the development of life its direction. Which, in a limited sense, can be equated to "purpose"

    3. In the example of the watch both atheists and atheists consistently fall into exactly the same trap.

    It is the trap of anthropocentrism whereby any phenomenon that exhibits what can be called "design" or "purpose" must involve a reflection of our own particular mental processes.

    As discussed further in my recent book "Unusual Perspectives" (Ch 10) this is a logical error of the "package deal" variety. Both the watch and the eye can be considered to have design or purpose within this model.

    We consider ourselves to design such things as watches. This arrogance can only be justified in a very limited sense.

    In actuality, watches have evolved! Albeit by a non-genetic mechanism.

    They are products of nature and we merely the vehicles for their evolutionary progress.

    There is absolutely no need to invoke a "designer". Or for that matter a "creator" of what is quite conceivably a continuous automatic process.

    CONTINUED IN NEXT POST

    ReplyDelete
  9. CONTINUATION OF PREVIOUS POST

    A related issue is that of the "fine tuning" of the observed physical constants that critically permit the existence of biology. These have been discussed by many, a particularly exhaustive treatment having been presented by Barrow & Tipler in "The Cosmological Anthropic Principle"

    In chapter 11 of my own book "Unusual Perspectives" this kind of analysis is extended "downstream" to provide, within the context of the unique properties and timely abundancies of the chemical elements, very compelling evidence of further "fine tuning" that not only allows, but essentially makes inevitable, the observed exponential development of technology for which our particular species has been the vehicle.

    Several ways to account for this indisputable "fine tuning" have been proposed.

    1. Creationists have seized upon the evidence to support the idea of a deity or "higher intelligence". I suspect that anthropocentrism alone promotes this kind of interpretation. Adding any kind of "higher intelligence", of course, makes for a very extravagant hypothesis. But it is not disprovable.

    2. The existence of a multiplicity of universes, perhaps infinite, each with a different set of physical properties. So one of them had to get lucky, right? This is favoured by many of those theoretical physicists who choose not to just stick their heads in the sand to avoid the implications of interpretation 1. Again, it can be neither proved or disproved but is even more extravagant.

    3. The "anthropic cosmological principle", the non-superstitious version of which seems to boil down to "we're here, because we're here, because we're here.
    By virtue of its tautologous nature it is not disprovable.

    4. The Everett "many worlds" model, inspired by the "Schrodinger's cat" kind of dilemma that arises from quantum mechanics. This essentially can be viewed as continual bifurcations of our universe such that, in the instance of the cat, in one of the resulting universes is is dead and in the other, alive. The bifurcations, of course, result in a multiplicity of "parallel universes. Again, very extravagant but probably not disprovable,

    5. A far more economical model, derived from consideration of the gross evolutionary patterns that we observe in biology and, more recently technology, is presented in "Unusual Perspectives" the electronic edition of which is available for free download from the eponymous website.

    To properly appreciate the reasoning therein, however, it is very important to first discard the anthropocentric mind-set that leads to problems with concepts such as "purpose" and "design". They, like "gods", "intelligence" and "free-will", are merely components of our inherited mental environments that preclude objectivity.

    ReplyDelete
  10. All scientists know that you can't prove a negative
    ...


    But you can prove a negative.

    TomS

    ReplyDelete
  11. I agree with Prof. Moran's important point.

    I also agree with TomS's point that you can prove a negative.

    Consider "There is no largest integer" or "The square root of 2 is not a rational number" or "There are no unicorns in Prof. Moran's office."

    Often people say you can't prove a negative if it requires searching the universe of cases. But the ancient and famous proofs of the theorems above don't require searching every integer or rational number.

    Although I'm sure I would enjoy visiting Dr. Moran, (if the snow has melted up there) I don't have to do so to prove that there are no unicorns in his office.

    Left Coast Bernard

    ReplyDelete
  12. > All scientists know that you can't prove a negative ...

    I take this to mean a universal negative such as "there are no supernatural agents or aliens nor any Marvin the Martian."

    > ... but that doesn't mean you can't assign probabilities and behave accordingly.

    Yes, quite so, all sensible decisions being along these lines.

    ReplyDelete
  13. Here are a couple examples of negative statements, and I'd like to know whether these can't be proved:

    > All scientists know that you can't prove a negative ...

    > ... but that doesn't mean you can't assign probabilities and behave accordingly.

    And here are a couple of positive statements which I'd like to know whether these can be proved:

    >The reason why humans have the common vertebrate eye is because something or other wanted it that way.

    >Something or other did something or other that made things look like they evolved over many millions of years.

    And I'd like to suggest that it isn't so much being negative that makes things unprovable, as their being vacuous,

    TomS

    Perhaps the

    ReplyDelete