About Rationally Speaking

Rationally Speaking is a blog maintained by Prof. Massimo Pigliucci, a philosopher at the City University of New York. The blog reflects the Enlightenment figure Marquis de Condorcet's idea of what a public intellectual (yes, we know, that's such a bad word) ought to be: someone who devotes himself to "the tracking down of prejudices in the hiding places where priests, the schools, the government, and all long-established institutions had gathered and protected them." You're welcome. Please notice that the contents of this blog can be reprinted under the standard Creative Commons license.

Monday, March 26, 2012

Here we go again

by Leonard Finkleman

I currently have two other posts in various stages of completion, but I’m mad about this now. Discussions about headphones and human nature or the transformative beauty of classification can wait (1). A new gauntlet has been thrown down.

 More accurately: a musty, worn, thoroughly decrepit gauntlet has been thrown. “Diseased” might also be an accurate descriptor, if you go for Dawkins’ whole “viruses of the mind” thing.

 Nine decades after its state hosted the “monkey trial” of John Scopes (2), the state senate of Tennessee has passed “teach the controversy” legislation that undermines science education by overemphasizing disputes between scientists (3). As is usually the case with such legislation, “the theory of evolution” has been singled out. A group of friends recently asked my thoughts, in my capacities as a philosopher of biology, on why this issue keeps cropping up.

I could swim (and, in a sense, have swum) in all the ink that’s been spilled on this subject. The probability that I can offer anything new or uniquely insightful is marginal at best. Still: this is war, or at least as close to it as academics get. One makes what contributions one can to the effort.

Alfred North Whitehead famously suggested that the safest generalization about Western philosophy is that it consists of a series of footnotes to Plato (4). It’s true that almost every live debate in philosophy is over some issue that can be traced back to Socrates’ disciple (5). Consequently, I’m probably not going out on much of a limb when I say that we should blame Plato for our current troubles.

To be sure, biologists and philosophers of biology have been doing that for a while. Ernst Mayr — perhaps the greatest popularizer of Darwinian theory in the twentieth century — claimed that “typological essentialism,” attributable to Plato by way of Aristotle (6), has been our greatest obstacle to general acceptance of evolutionary theory. David Hull, who wrote a vitally important paper entitled “The Effect of Essentialism on Taxonomy: Two Thousand Years of Stasis,” apparently agreed.

But this is a red herring in the current debate. As far as I can tell, no one involved in the Tennessee legislation is concerned with the metaphysical status of abstract forms, or the utility of type specimens in biological classification. No: this a debate about belief and knowledge, and if there is any debate in philosophy that really isn’t anything more than a series of footnotes to Plato, it’s this one.

Ask philosophers what is meant by the term “knowledge,” and by far the most common definition you’ll get is “justified true belief.” Some will hem, others will haw, and a few will point at something behind you and run away when you turn to look, but “JTB theory” has been philosophers’ starting point in epistemology (i.e., the study of knowledge) for more than 2500 years (7). Its origin: the Platonic dialogue “Meno,” wherein Socrates seeks the distinction between knowledge and other sorts of belief. If one comes to hold a belief in some true proposition in a justifiable way (e.g., through logical proof), then that belief qualifies as knowledge; everything else — all those potentially unjustified or untrue beliefs — is “mere opinion.”

This is our inheritance in epistemology: a choice between knowledge and the sort of thing your thirteen-year-old cousin posts in a Facebook status update. If one isn’t talking out of her brain, so to speak, then she must be talking out of her butt. Our culture generally hasn’t taken to heart the precise details of Plato’s version of JTB theory: most importantly, Plato argued that sensory input cannot qualify as knowledge, where most of us are perfectly happy to accept sense experience as known (8). Nevertheless, the brain/butt dichotomy is deeply ingrained in the way we regard knowledge claims. I hear it from my students all the time: anything that isn’t demonstrably true is liable to be dismissed as “just an opinion.” You can test this at home by answering the following question: if I hold a belief that hasn’t been proved true, then what is that belief? Quod erat demonstrandum.

Back to the debate over evolution: partisans such as those supporting the Tennessee bill have gotten a lot of mileage out of the old “evolution is just a theory” canard, and I don’t think it’s coincidental that the claim is only a small mental hop away from “it’s just an opinion.” The layperson is left with the intuitive sense that belief in evolution is either unjustified or untrue, and this intuition is strengthened by overemphasis of the “controversy” over evolutionary theory. The (distinctly American) reticence to accept evolutionary theory need not have anything to do with religion, as is often assumed; rather, it’s that theoretical knowledge falls outside the realm of what Plato would have called knowledge, and so qualifies as what the layperson considers opinion.

Of course, there’s a mistake in this way of thinking. Plato’s dilemma is a false one. I’ve actually gone so far as to ban use of the word “opinion” in my classes in order to guard against this error (which always makes for some admittedly sadistic fun when I have students read from a translation of “Meno”). There is a third way, and we need to recognize that some beliefs can’t be known, but are more justifiable than mere opinion.

The third way, between knowledge and opinion, is science.

I won’t dwell too much on what science is or how science gets practiced. All we need to bear in mind is that scientific beliefs are justifiably held, but only provisionally believed to be true (if at all), and so mark a halfway point between knowledge and opinion. The scientist gathers data, then develops theories that explain those data. It’s sort of like a particularly twisted connect-the-dots picture (9). Data are like dots: they represent what’s given at the start. Theories are like the lines we draw between the dots: they fill in what we hope is the best picture that includes everything that’s given. The point is that the final picture is, at best, inferred from the only stuff we have to work with, i.e., the dots. So too are all scientific theories inferences from data.

This is what’s particularly insidious about legislation like that recently passed by the Tennessee senate: no good scientist or science teacher should ever deny that scientific theories ought to be questioned. No one ever sees, say, gravity; what we see are things falling down (on Earth, at least), and the “picture” we infer when we connect those “dots” is what we call gravity. This wouldn’t qualify as knowledge in the Platonic sense, since there may be other ways to justifiably connect the dots and so it’s possible that the theory may be untrue. If we remain beholden to Plato’s false dichotomy, all scientific theories are just opinions. Luckily, scientists don’t see the world in the binary brain/butt way. Between acceptance of knowledge and rejection of opinion, the scientist tests scientific beliefs, which is what “teach the controversy” legislation ostensibly endorses. If this were all the Tennessee senate intended, the bill would be completely uncontroversial — kind of like passing a law instructing math teachers to let their students use long division.

But that isn’t what they intend. While I’m optimistic enough to believe that the intention of legislation of this sort is not to undermine science generally, it’s clear that the goal of “teach the controversy” is to call into question a small number of politically inconvenient scientific theories (10). Thus a war for Darwin, but not for Newton.

Ultimately, this is what I take to be the weakness in the enemy’s offensive strategy. By accepting the way science works, even those who wish to teach the controversy implicitly endorse the inferential derivation of theory from data; that is, they would accept that the dots (data) are given, and that all controversy is over the inferred pictures (theories). If teaching the controversy is effective at all, it can only be effective at undermining acceptance of evolutionary theory — in particular, evolution by means of natural selection, as opposed to (say) evolution by means of inheritance of acquired characteristics. But that’s not our opposition’s target. They aim at evolution itself, and evolution is not theory, it’s data. Evolution is a sequence of fossils leading from Albertosaurus sarcophagus to Tyrannosaurus rex; it is the necessity of a new flu vaccine each year; it is the increase in average human height over the past two centuries; it is the phalanges in a whale’s flipper. These are given. Natural selection — the controversial part — is the theory. To deny that evolution happens because natural selection might be false would be like denying that things fall down because Newton was wrong.

So go ahead. Try to erase the picture. The dots will remain. As long as that’s the case, obscurantist forces have already lost the war, no matter how many small victories they may claim.

(1) These have been your coming attractions. Please enjoy our feature presentation!

(2) If you should need to bring yourself up to speed on State of Tennessee vs. John Thomas Scopes (1925), you can go here. Or you can read this. Or you can rent this. Or you can wait until this comes to town. My point is that you have options.

(3) Proponents argue that the purpose of the bill is simply to encourage critical reasoning skills in science. I teach critical reasoning. I know critical reasoning. This is not critical reasoning; if it were, there would be no need for a loaded appeal singling out “biological evolution, the chemical origins of life, global warming and human cloning” (who learns about human cloning in grade school, anyway?).

(4) Some of us have taken this quote to heart more than others. Personally, as a philosopher of biology, I prefer to think of myself as a footnote to Aristotle. It’s all moot: neither philosopher used footnotes, let alone any that mention me.

(5) A brief, tangentially-related tidbit: according to the Stoic philosopher Diogenes Laertius, Plato’s birth name was actually Aristocles; “Plato” was a wrestling name, literally translating as “broad.” I find this endlessly amusing, as it calls to mind an analogy with some philosophy student in the year 4500 having to slog through a textbook unit entitled “Hulkamania.”

(6) For those of you who find that last part baffling, given that the whole purpose of Aristotle’s “Metaphysics” seems to be dismantling Plato’s philosophy: don’t worry. Ernst Mayr was, in fact, bafflingly wrong on this point.

(7) D’oh!

(8) Go ahead: raise your hand if you don’t believe that your hand exists. Good luck with that one.

(9) The dots aren’t numbered and there’s absolutely no indication of what the picture should look like from the outset. Knock yourselves out, kids.

(10) A quick Google search doesn’t turn up very much in the way of legislation challenging the Many Worlds interpretation of quantum mechanics. Perhaps the country is being run by modal realists.


  1. You've put in a fairly firm observation/theory distinction there, and one quite high up the content scale.

    Evolution is a fact (and a theory) but isn't the description of the fact of evolution also a theory? It explains the sequence of fossils, that we need a new flu vaccine etc. etc. And those bits of data are themselves theories, explaining funny shaped bits of rock and lab reports on sick people.

    It feels more "facty" because you'd have to be even more stupid, ignorant or dishonest to dismiss the "fact" of evolution than the theory exlaning it.

    Isn't the key those statements that express "beliefs (that) are justifiably held, but only provisionally believed to be true"?

    And I see one huge problem in that epistemologists haven't analysed that: they just keep banging on (and on) about JTB! Surely it's time for philosophy to forget about factive knowledge and start considering what makes things:

    1. Not necessarily true, but
    2. You are rationally obliged to accept them

  2. "But that’s not our opposition’s target. They aim at evolution itself"

    Creationists do not believe in evolution at all. But Intelligent Design supporters actually do believe in evolution -- not in Darwinian evolution but in an "intelligently designed" evolution. ID doesn't meet scientific standards and isn't accepted in biology. Therefore, it shouldn't be taught in school. Global warming on the other hand does not lack scientific support because there is very much evidence for it. There is much controversy about details (is the north pole ice free in 2100 or rather in 2050?) but not about global warming itself.

    Obviously(?) you take denialism of Darwinian Evolution for a much bigger problem than Global Warming denialism. Sorry, this seems to be typical American underestimation of Global Warming...
    (I'm German btw.)

    "Ernst Mayr — perhaps the greatest popularizer of Darwinian theory in the twentieth century — claimed that “typological essentialism,” attributable to Plato by way of Aristotle (6), has been our greatest obstacle to general acceptance of evolutionary theory."

    Small note: I think this wasn't Mayr's idea but August Weismann's. He was also quite popular: "Ernst Mayr ranked him the second most notable evolutionary theorist of the 19th century, after Charles Darwin." (Wikipedia)

  3. Adaptive mutation theories posit intelligent designing. So if it isn't accepted in biology, it's certainly 'acknowledged' (ORIGIN late 15th cent.: from the obsolete Middle English verb knowledge).

    And if 'knowledge' is:
    "1 facts, information, and skills acquired by a person through experience or education; the theoretical or practical understanding of a subject;"
    then perhaps we only need 'justified reliable belief' as the standard definition.

  4. "I’m probably not going out on much of a limb when I say that we should blame Plato for our current troubles." No, no - instead we should blame Platonists! Who were and are so myopic that they never appreciate that in his dialogues Plato himself NEVER speaks, and are so unaware of literary structure that they assume that what a character (usually Socrates) says is what Plato believes. Aristotle should have known better - but evidently didn't.

    And the JTB theory is spelled out in the Theatetus (knowledge = correct opinion plus an account/justification) much more than the Meno, and there Socrates rejects it!

    As a Plato aficianado I couldn't resist this comment - but otherwise . . . a very good article!

  5. This comment has been removed by a blog administrator.

  6. While I agree with Finkleman's main point, as evidence of evolution, he offers:

    "...it is the increase in average human height over the past two centuries;..."

    Is this really true? Auxologists claim that the role of genetics versus environment in the determination of height is complex.

    This is discussed in Walter Fitch's new book "The Three Failures of Creationism" -- see

    The book also deals with some of the fine points of the meaning of evolution as a "theory" -- among other science/creationism debating topics, such as the
    "intelligently designed" concept mentioned by Kris.

    Many people don't know Fitch, who pioneered "phylogenetic trees" and was instrumental in developing techniques of using evolution/molecular biology to anticipate what types of
    vaccines would have to be produced in advance in order to cope with ever-mutating viruses.

  7. This comment has been removed by a blog administrator.

  8. The reason why this keeps cropping up is the same now as it was then. In Scopes' time it was that too many of us were subject to, or subject to constituents who are subject to, "That Old Time Religion." That's the case now as well.

  9. Leonard: re your footnote 8, "Raise your hand...Good luck" etc... Care to elaborate? You were talking about knowledge, right? Maybe you are a specialist in ontological concerns as well. You tell me then, what it means for something to exist in a vacuum, let the hand be the only thing in our known universe. For all we know, it may or may not exist, but it might as well not exist right? And bringing physical science into the argument, it couldn't exist. That's the point of lowering the status of the objective (or disappearing it altogether) so it becomes very overshadowed by the subjective. Any way you slice your peanut butter and plato sandwich, the hand only exists as knowledge transmitted as information to other entities.

    That's why it makes no sense and is therefore nonsense to say 'X exists' instead of 'X exists for...'. In the case of ordinary everyday objects, ''X exists' is best taken as shorthand for 'X exists for 99.99997% of those for whom X is meaningful in some way'.


Note: Only a member of this blog may post a comment.