Pharyngula

The more sophisticated creationists like to toss the name “Alvin Plantinga” into arguments — he’s a well-regarded philosopher/theologian who favors Intelligent Design creationism, or more accurately, Christian creationism. I’ve read some of his work, but not much; it’s very bizarre stuff, and every time I get going on one of his papers I hit some ludicrous, literally stupid claim that makes me wonder why I’m wasting time with this pretentious clown, and I give up, throw the paper in the trash, and go read something from Science or Nature to cleanse my palate. Unfortunately, that means that what I have read is typically an indigestible muddled mess that I don’t have much interest in discussing, and what I haven’t read is something I can’t discuss.

Well, we’re in luck. Plantinga has written a short, 5 page summary of his views on evolution and naturalism, and it’s lucid (for Plantinga) and goes straight to his main points. The workings of the man’s mind sit there naked and exposed, and all the stripped gears and misaligned cogs and broken engines of his misperception are there for easy examination. Read it, and you’ll wonder how a man so confused could have acquired such a high reputation; you might even think that philosophy has been Sokaled.

Begin at the beginning. He doesn’t think much of atheism, and as we’ll discover, doesn’t like naturalism or evolution at all.

As everyone knows, there has been a recent spate of books attacking Christian belief and religion in general. Some of these books are little more than screeds, long on vituperation but short on reasoning, long on name-calling but short on competence, long on righteous indignation but short on good sense; for the most part they are driven by hatred rather than logic.

Hmm. It’s not a good start when the author is so oblivious to irony that he opens his paper with a name-calling screed in which he lambastes others for writing name-calling screeds. Especially when, as we read further, we discover that Plantinga is the one lacking in competence, good sense, and logic.

Plantinga’s claim is straightforward. Naturalism, the idea he defines as the claim that “there is no such person as God or anything like God”, is in “philosophical hot water” and is untenable, and specifically, it is in complete contradiction to evolution — “you can’t rationally accept both evolution and naturalism”, contra Dawkins’ claim that evolution made it possible to be an intellectually fulfilled atheist.

Very straightforward, but it sounds like lunacy. Plantinga’s going to have to be very, very persuasive indeed to convince me of that claim.

The way he does this starts off well. He points out that we naturalist/evolutionist types are also materialists who believe human beings are just material objects with no souls, that we operate on principles described by chemistry and physiology, and that we evolved. That’s quite right. He gives the impression that he doesn’t believe any of this (and I know from his other writings that he doesn’t), but that is my position, and that of just about any other modern atheist you might name. Now let us consider the implications.

But while evolution, natural selection, rewards adaptive behavior (rewards it with survival and reproduction) and penalizes maladaptive behavior, it doesn’t, as such, care a fig about true belief. As Francis Crick, the co-discoverer of the genetic code, writes in The Astonishing Hypothesis, “Our highly developed brains, after all, were not evolved under the pressure of discovering scientific truth, but only to enable us to be clever enough to survive and leave descendents.” Taking up this theme, naturalist philosopher Patricia Churchland declares that the most important thing about the human brain is that it has evolved; hence, she says, its principal function is to enable the organism to move appropriately:

Boiled down to essentials, a nervous system enables the organism to succeed in the four F’s: feeding, fleeing, fighting and reproducing. The principal chore of nervous systems is to get the body parts where they should be in order that the organism may survive … . Improvements in sensorimotor control confer an evolutionary advantage: a fancier style of representing is advantageous so long as it is geared to the organism’s way of life and enhances the organism’s chances of survival [Churchland's emphasis]. Truth, whatever that is, definitely takes the hindmost.

What she means is that natural selection doesn’t care about the truth or falsehood of your beliefs; it cares only about adaptive behavior. Your beliefs may all be false, ridiculously false; if your behavior is adaptive, you will survive and reproduce.

Yes, exactly! Just believing in something, whether it is Christianity or physics, doesn’t mean it is necessarily true. Our brains attempt to model the world for functional purposes and lack any inherent, absolute means to detect truth. I agree 100% with what he’s saying, but now watch as he takes this foundation and runs it off the rails.

He imagines a hypothetical population of creatures living on another planet who operate entirely on these rules. What will happen to their beliefs?

So consider any particular belief on the part of one of those creatures: what is the probability that it is true? Well, what we know is that the belief in question was produced by adaptive neurophysiology, neurophysiology that produces adaptive behavior. But as we’ve seen, that gives us no reason to think the belief true (and none to think it false). We must suppose, therefore, that the belief in question is about as likely to be false as to be true; the probability of any particular belief’s being true is in the neighborhood of 1/2. But then it is massively unlikely that the cognitive faculties of these creatures produce the preponderance of true beliefs over false required by reliability. If I have 1,000 independent beliefs, for example, and the probability of any particular belief’s being true is 1/2, then the probability that 3/4 or more of these beliefs are true (certainly a modest enough requirement for reliability) will be less than 10(to the power -58). And even if I am running a modest epistemic establishment of only 100 beliefs, the probability that 3/4 of them are true, given that the probability of any one’s being true is 1/2, is very low, something like .000001.[7] So the chances that these creatures’ true beliefs substantially outnumber their false beliefs (even in a particular area) are small. The conclusion to be drawn is that it is exceedingly unlikely that their cognitive faculties are reliable.

(First, an amusing aside: footnote [7] is an acknowledgment of the assistance of someone else in doing those calculations. He needed help from an expert to multiply simple probabilities? Does being a philosopher mean you’re incapable of tapping buttons on a calculator?)

I think you can now see what I mean when I say Plantinga’s ideas are muddled lunacy. This is the same innumerate error creationists make when they babble about the odds of a single protein of 100 amino acids forming by chance; they assume that it’s all a matter of sudden, spontaneous good fortune that a protein (or in this case, a brain) has all of its traits fixed, with no input from history or the environment. In Plantinga’s imaginary materialist/naturalist world, beliefs are only the product of random chance.

In Plantinga’s world, if we queried the inhabitants with some simple question, such as, “Is fire hot?”, 50% would say no, and 50% would say yes. This world must be populated entirely with philosophers of Plantinga’s ilk, because I think that in reality they would have used experience and their senses to winnow out bad ideas, like that fire is cold, and you’d actually find nearly 100% giving the same, correct answer. Plantinga does not seem to believe in empiricism, either.

What it does mean, though, is that if there are ideas that are not amenable to empirical testing, such as “I will go to heaven when I die”, those ideas have a very low probability of being true. We can think of those as being the product of random input, in some ways, and since they cannot be winnowed against reality, they are unreliable.

Plantinga has heard this objection before, sort of. He’s heard it, but it hasn’t quite penetrated; he recites the common objection with some garbling.

What sort of reception has this argument had? As you might expect, naturalists tend to be less than wholly enthusiastic about it, and many objections have been brought against it. In my opinion (which of course some people might claim is biased), none of these objections is successful. Perhaps the most natural and intuitive objection goes as follows. Return to that hypothetical population of a few paragraphs back. Granted, it could be that their behavior is adaptive even though their beliefs are false; but wouldn’t it be much more likely that their behavior is adaptive if their beliefs are true? And doesn’t that mean that, since their behavior is in fact adaptive, their beliefs are probably true and their cognitive faculties probably reliable?

Almost. So close, and yet he still doesn’t get it. A large part of our behavior will be functional (not contradicting reality) and some of it will even be adaptive (better fitting us to reality), and a lot of it will be neutral (contradicting reality, perhaps, but in ways that do not affect survival), but this does not imply that our cognitive faculties are necessarily and implicitly reliable. We could have highly unreliable cognition that maintains functionality by constant cross-checks against reality — we build cognitive models of how the world works that are progressively refined by experience.

Plantinga really thinks that one of the claims he is arguing against is that materialists/naturalists assume our minds are reliable.

But of course we can’t just assume that they are in the same cognitive situation we think we are in. For example, we assume that our cognitive faculties are reliable. We can’t sensibly assume that about this population; after all, the whole point of the argument is to show that if evolutionary naturalism is true, then very likely we and our cognitive faculties are not reliable.

To which I say…exactly! Brains are not reliable; they’ve been shaped by forces which, as has been clearly said, do not value Truth with a capital T. Scientists are all skeptics who do not trust their perceptions at all; we design experiments to challenge our assumptions, we measure everything multiple times in multiple ways, we get input from many people, we put our ideas out in public for criticism, we repeat experiments and observations over and over. We demand repeated and repeatable confirmation before we accept a conclusion, because our minds are not reliable. We cannot just sit in our office at Notre Dame with a bible and conjure truth out of divine effluent. We need to supplement brains with evidence, which is the piece Plantinga is missing.

He’s reduced to a bogus either/or distinction. Either we are organic machines that evolved and our brains are therefore collections of random beliefs, or — and this is a leap I find unbelievable — Jesus gave us reliable minds. Seriously. That’s what his argument reduces to. He flat out says it.

The obvious conclusion, so it seems to me, is that evolutionary naturalism can’t sensibly be accepted. The high priests of evolutionary naturalism loudly proclaim that Christian and even theistic belief is bankrupt and foolish. The fact, however, is that the shoe is on the other foot. It is evolutionary naturalism, not Christian belief, that can’t rationally be accepted.

Apparently, because Plantinga cannot imagine a source of information to imperfect minds other than the Christian deities, we’re supposed to conclude that microwave ovens cannot be the product of ape brains shaped by evolution, with new and deeper understanding of the physical world derived by trial and error.

I really cannot take Alvin Plantinga seriously, ever.

Comments

  1. #1 EleaticStranger
    April 7, 2010

    “To which I say?exactly! Brains are not reliable; they’ve been shaped by forces which, as has been clearly said, do not value Truth with a capital T. Scientists are all skeptics who do not trust their perceptions at all”

    And here you betray the fact that you don’t understand Plantinga’s argument. It’s subtle and requires a philosopher’s mind, so you’ll need to take a few undergraduate philosophy classes first. Or you could just take it on authority from other well respected philosophers, say for example those that think it worthwhile to engage Plantinga on this, that the argument, even if not cogent, is not ridiculous. Your analysis is of a piece with creationists who say that evolution is ridiculous because we obviously didn’t descend from monkeys. I mean really, it’s about that level of understanding and sophistication.

  2. #2 Celtic_Evolution
    April 7, 2010

    It’s subtle and requires a philosopher’s mind, so you’ll need to take a few undergraduate philosophy classes first.

    Translation: “It’s bullshit, so it requires a bullshit translator…”

    Luckily, the rest of your post reveals your proficiency in the nuanced language of bullshit…

    Or you could just take it on authority from other well respected philosophers, say for example those that think it worthwhile to engage Plantinga on this, that the argument, even if not cogent, is not ridiculous.

    You could of course provide an actual argument yourself here, instead of leaving it up to your “well-respected philosophers”, whom I note you forgot to cite… or are you not up to the challenge? Seems like someone with your level of arrogance should think himself up to it.

    Your analysis is of a piece with creationists who say that evolution is ridiculous because we obviously didn’t descend from monkeys.

    You fail at analogies. Miserably. Why is it that arrogant fools think they will make points by analogizing their claim with something that supposedly “hits home” with their target, regardless if the analogy is apt or not? I suggest you step away from your first year philosophy class and take a first-year biology class.

    Oh, and stop trolling old, dead threads. Stupidity does not go unnoticed, even in old threads.

  3. #3 https://www.google.com/accounts/o8/id?id=AItOawmas8M0dnMxD4-tr2TwBERZQ6KJkfpdRVw
    April 11, 2010

    Please don’t judge all of us based on Plantinga. In my department (in Stockholm) he is never even considered. I’d say Plantinga is very atypical for a modern philosopher, although more subtle forms of apologetics sneak into otherwise respectable philosophers’ epistemologies now and then. (This is more common on your side of the pond, I think–more theists in the academic world there.) In short, I think you prefer Daniel Dennett (and so do I).

    Just a fun side-note: Keynes convincingly dismisses the idea that claims have some sort a priori probability of 0.5 already in his Treatise on Probability from 1921. It had been seriously assumed by many until then. (From the flawed notion that the principle of indifference applied to the exhaustive set of possibilities A and not A gives them equal prior probability.) But really, in the set of all possible claims, how many are reasonably true? Not half… :-) So the prior probability of a randomly produced claim (or belief) should reasonably be much, much lower than 0.5. Not that this matters one bit, since the rest of the argument is nonsense.

  4. #4 https://www.google.com/accounts/o8/id?id=AItOawmas8M0dnMxD4-tr2TwBERZQ6KJkfpdRVw
    April 11, 2010

    Um, I just realized that exactly half of all possible claims are true, since for every meaningful claim “A” either “A” or “not A” has to be true. :-) So it’s a bit more complicated, but the conclusion that 0.5 is not a reasonable probability for a randomly selected claim stands. Keyne’s example is about the color of a book. Let A be “The book is black.” Obviously this claim can not have an a priori probability of 0.5 since the book can also be blue or red, and, using the same rule for those alternative, the sum of the mutually exclusive alternatives would be greater than one. The probabilities of equiprobable alternatives has to do with how the claims relate to each other (exclude each other). End of random rant!

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