Boudry et al. on irreducible complexity

December 14, 2010 • 1:41 pm

Coincidentally, the latest issue of Quarterly Review of Biology, which contains Michael Behe’s paper on microbial evolution in the lab, also has a strong critique of Behe’s ideas about “irreducible complexity” by a group of Belgian philosophers headed by Maarten Boudry.  Their paper is called called “Irreducible incoherence and intelligent design:  a look into the conceptual toolbox of a pseudoscience”, and you can find a free copy here or here.

The main idea is that Behe (and other ID advocates) have gone back and forth between two views of irreducible complexity to avoid being pinned down and refuted with data.  Here’s Behe’s notion of irreducible complexity, as defined in his book Darwin’s Black Box:

By irreducibly complex I mean a single system composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning. An irreducibly complex system cannot be produced directly (that is, by continuously improving the initial function, which continues to work by the same mechanism) by slight, successive modifications of a precursor system, because any precursor to an irreducibly complex system that is missing a part is by definition non-functional. An irreducibly complex biological system, if there is such a thing, would be a powerful challenge to Darwinian evolution (Behe 2006, p. 39).

As most of us know, Behe maintains that such irreducibly complex (IC) systems supposedly could not evolve in an adaptive, step-by-step Darwinian way, since the adaptive function supposedly appears only at the end of the process. Ergo an intervening intelligent designer (aka Jesus) must be responsible for such systems.

Boudy et. al, however, show that Behe and his minions have used two distinct interpretations of this notion:

To be sure, it is not difficult to find examples of biochemical systems in which the removal of just one part damages the whole system. But consider Behe’s phrases “effectively ceases functioning” and “by definition non-functional.” There are two possible reconstructions of his definition: 1) the term “functioning” refers exclusively to the basic function currently performed by the whole system (e.g., the rotary motion of the bacterial flagellum) and does not pertain to other possible functions, in other contexts, when one or more components are removed; and 2) the phrases “effectively ceases functioning” and “non-functional” include any function that the impaired system or one of its components may perform in other contexts. In principle, it is not very hard to discover whether a system exhibits IC in the first, weak sense. Leaving aside the ambiguity regarding the natural “parts” into which the system must be decomposed (Dunkelberg 2003; Sober 2008, pp. 135-160), it suffices to knock out these parts one after the other to see if the system can still perform its basic function. Again, evolution by natural selection is perfectly capable of producing complex functional systems exhibiting IC in this weak sense.

. . . In fact, only an IC system in the second, strong sense would be to evolutionary theory, because it would rule out evolutionary precursor systems and function shifts of the system’s components. However, it is hard to see how Behe could even begin to demonstrate the existence of such a system without defaulting to the classical “argument from ignorance” (Pigliucci 2002, p. 67). Interestingly, Behe has disingenuously taken advantage of this very ambiguity in answering his critics.

Boudry et al. then recount the history of Behe’s evasions about these two senses and show that “clarifications” by others such as Dembski have in fact made matters worse.   It turns out that there are simply no data that Behe and his followers would accept as showing a real Darwinian origin of the biochemical systems they see as “irreducibily complex”.  During his testimony at the Dover trial, for example, Behe demanded more than just plausible Darwinian scenarios for the origin of IC; he said he wanted this:

Not only would I need a step-by-step, mutation by mutation analysis, I would also want to see relevant information such as what is the population size of the organism in which these mutations are occurring, what is the selective value for the mutation, are there any detrimental effects of the mutation, and many other such questions.

No bloody way can evolutionists ever provide that kind of data for systems that evolved in the distant past!

If you’re interested in the notion of “irreducible complexity”, and want an up-to-date analysis of its scientific and philosophical problems, Boudry et al. is a good summary for the layperson.


Boudry, M., S. Blancke, and J. Braeckman.  2010. Irreducible incoherence and intelligent design:  a look into the conceptual toolbox of a pseudoscience. Quart. Rev. Biol. 85:473-477.

25 thoughts on “Boudry et al. on irreducible complexity

  1. Nice takedown. Bait and switch, the key wrench in the toolbox of the religious. If it isn’t IC its switching between a potential deist God and Jesus and his angels.

  2. Its amazing that Behe wants such a burden of proof from science, but is perfectly fine to read one book (the Bible) and accept that Jesus rose from the dead and that fixes sin for some reason. The only way he would disbelieve the myths of dusty farm people is to go back in time and do genetic analysis on all creatures leading up to man.
    The rest of us are just fine with fossils and DNA, thanks very much, bye bye.

    1. >>The only way he would disbelieve the myths of dusty farm people is to go back in time and do genetic analysis on all creatures leading up to man.

      Yup. They want perfect evidence for evolution — but don’t ever try asking any of them for a demonstration that Jesus isn’t imaginary-man 1st class. They’d also prefer not to address what the thing is that the word “God” is supposed to label. That’s where faith comes in for them. The burden on proof is always on the rational person, in their minds. They don’t have to be bothered with either logic or evidence for their dusty tales. They have faith!

  3. I refuse to acknowledge the existence of the Roman empire until I see precise census records for every single town, village, and hamlet that was ever under Roman rule.

    Seems reasonable.

  4. New theory: Jesus is irreducibly complex and therefore could not have existed. Prove otherwise, cretinous DIdiots. What components was he built from? Smoke and mirrors? Deceit and obfuscation? Fantasy and fabrication?

  5. The mousetrap of desperation has been thoroughly deconstructed for the umpteenth time.

    Behe should be impressed by his own tenacity — in spite of his cognitive “parts” not being all there at once.

  6. I fully expect you to be quoted as saying
    Even gnu atheist Jerry Coyne admits –
    “No bloody way can evolutionists ever provide that kind of data for systems that evolved in the distant past!”

  7. What Behe produces is irreducibly simplistic claptrap.

    By his requirements I would not be able to demonstrate that I drove to work today without a detailed analysis of my route, air pressure, tire pressure and traffic pressure, and my motivation, state of mind and those of the drivers around me. Behe puts the “more” in moron.

    1. …and things have only gotten worse for Behe since.

      still, I can’t help but see the title:

      Dr. Doolittle

      and my brain inevitably returns the song:

      “My Friend the Doctor”

  8. Since Behe is the one claiming that something “could not have happened” the onus is on him to show there is no way it could have. He cannot shift the responsibility by demanding evidence that it actually did happen that way. Just like a criminal case, all you need to show is that it was possible.

  9. >>If you’re interested in the notion of “irreducible complexity”, and want an up-to-date analysis of its scientific and philosophical problems, Boudry et al. is a good summary for the layperson.

    Yes, it is indeed. But, interested in IC/ID? Nah! What is there to be interested in? ID doesn’t even have the beginnings of a hypothesis and the “irreducible complexity” module is nothing but a series of stupid, confused and/or dishonest criticisms of the theory of evolution. That’s been shown repeatedly, and now in a new way by Boudry et al. Even if the IC criticisms were valid, they do not amount to a competing hypothesis. Criticisms of the other guy’s ideas are no substitute for ideas of your own.

    What is the hypothesis that the “irreducible complexity” claim is supposedly serving by attempting to damage the theory of evolution? The phantom “intelligent designer” has never been identified and so, naturally, no attempt has been made to demonstrate that this “designer” is capable of designing, constructing, or otherwise doing anything. All necessary parts of a hypothesis of “intelligent design” are still missing.

    Why should anyone care what these ID fools think about a real scientific theory when they have exactly nothing to offer in its place?

  10. What I would want to know from the IDers is, ok, if god or some other intelligent agent made the parts, how did they make them, and how did they assemble them? What are the physical forces that are needed to be able to manipulate matter so that it forms the precise molecular arrangement that is needed for the parts? How are those parts assembled and held into place before the living organism is jump-started?

    What is the interface between the creator and the creation? There must be some point where the creator removes the machinery to get the point where we are today, so what was the machinery that put them together from nothing?

    I suppose it is not the Intelligent Design I am looking for, but the Intelligent Manufacture.

      1. Ah, I see there is no point asking the question, as the answer from William A. Dembski

        “As for your example, I’m not going to take the bait. You’re asking me to play a game: “Provide as much detail in terms of possible causal mechanisms for your ID position as I do for my Darwinian position.” ID is not a mechanistic theory, and it’s not ID’s task to match your pathetic level of detail in telling mechanistic stories.

        So the goal of ID is to only say that ID exists, and declare that as victory, and nothing else. That’s just a pathetic attitude from IDers, but I guess I expected that really, since there is no intellectual curiosity in them to possibly progress their own conclusions.

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