Over at the Discovery Institute's blog, Winston Ewert has a post up explaining, one more time, what specified complexity is. Since I am given a mention near the end, perhaps it's worth a look.
For those not steeped in ID rhetoric, “specified complexity” is a term coined by William Dembski. It is an attribute that a given event or object may or may not possess. “Complexity” just means “low probability,” while “specified” indicates the event or object conforms to an independently describable pattern. Where specified complexity is found, it is claimed, design is in some way implicated in the event or object's origination. For example, any sequence of heads and tails in one thousand tosses is as unlikely as any other. But one thousand heads is also specified, and we suspect that design is afoot. Maybe the coin was loaded, maybe it was tossed dishonestly, maybe it was not tossed at all and just placed heads-up on the table, but something more than mere chance or natural law is going on.
The question is how to respond to this trivial observation. If you're a normal person you just yawn. You say that's fine for tinker-toy examples about coin-tossing, where probability calculations are easy and we have plenty of experience to help us distinguish the usual from the unusual patterns. But in any case where we are genuinely uncertain as to whether the event or object is the result of design, we are also going to lack the information to carry out relevant probability calculations and to identify the design-suggesting patterns. So the concept of specified complexity is unlikely to find any non-trivial applications.
But if you're an ID proponent you see instead a stunning insight into fundamental truths of the universe. You claim to have discovered a mathematically rigorous method for distinguishing design from non-design in nature. In particular, you claim that you can apply this method to biological structures to prove that there is intelligent design in nature. You are also careful never to back this up with a non-laughable calculation of the sort the method demands.
With that background, let's consider what Ewert has to say (note that he is responding specifically to a post by Joe Felsenstein):
Specified complexity is a probabilistic argument, but it requires that you use some other method to determine the probability of an event. For example, if one wishes to use specified complexity to argue against Darwinian evolution, the probability according to Darwinian evolution must be calculated. Felsenstein claims that originally specified complexity was defined to compute probability on chance alone, ignoring the effects of natural selection.
That first sentence is gibberish. “Specified complexity” is neither an argument nor a method. That aside, the problem here is that Dembski, in his various writings on this subject, is incredibly vague on how, precisely, one carries out the relevant probability calculations. Look hard enough and you can find him saying just about anything you want him to be saying. But as Richard Wein has documented extensively, in response to Dembski's book No Free Lunch, Dembski routinely writes as though the probability calculations should always be carried out with respect to a uniform distribution, which is what Felsenstein had in mind in referring to chance alone.
But even leaving that aside, we at least have here the heart of the matter. Yes, in applying the concept of specified complexity against Darwinian evolution, the role of natural selection must be incorporated into our probability calculation. But how are we to do that?
However, if specified complexity requires another method to evaluate probability, what good is it? Felsenstein describes it as “a useless add-on quantity, computable only once one has already found some other way to show that the information cannot be put into the genome by natural selection.” Essentially, Felsenstein presents specified complexity as circular. It is true that specified complexity does not in any way help establish that the probability of complex life is low under natural selection. You must have another way of showing that, for example Michael Behe's irreducible complexity, Doug Axe's work on proteins, or Stephen Meyer's work on the Cambrian explosion.
However, all these methods only seek to show that various biological systems are improbable under Darwinian evolution. That is a logical claim distinct from arguing that Darwinian evolution is false. Specified complexity exists to bridge this gap, arguing that we are justified in inferring the falsity of Darwinian evolution on the basis of the low probabilities established by these other arguments.
Ewert has simply conceded Felsenstein's point here. Assertions of specified complexity are entirely parasitic on prior arguments about irreducible complexity and the like. It is those prior arguments that are doing all the work, and not any subsequent claims about specified complexity. For example, if Behe's claims about irreducible complexity were correct, then that would all by itself be a very strong argument against evolution. No probability calculation would be needed to make it stronger. But since Behe's claims are not correct, no calculation based on the assumption that they are is going to be relevant.
Ewert's claim that assertions of specified complexity allow us to go from “extremely improbable” to “impossible” is just fatuous. Behe, in Darwin's Black Box, did not seem to think that an argument beyond his claims of irreducible complexity was necessary to conclude design. Quite the contrary. He went straight from his observations about irreducible complexity to talking about loud, piercing cries of design. Likewise, Douglas Axe claims that his work establishes the extreme functional isolation of modern proteins. It is those claims, and not any probability calculations based on them, that pose the challenge to Darwinian evolution.
In other words, Ewert seems to imagine the conversation has gone like this:
ID PROPONENT: Irreducible complexity poses a serious challenge to evolution.
EVOLUTIONIST: But you've only shown that evolution is extremely improbable! You haven't quite shown that evolution is impossible, and that's what we're going to cling to.
EWERT: But here are some back-of-the-envelope probability calculations, and here are some further claims about specifications, and now we have transitioned from extremely improbable to impossible. Trump card played!
In reality the conversation has gone like this:
ID PROPONENT: Irreducible complexity poses a serious challenge to evolution.
EVOLUTIONIST: No it doesn't, for obvious reasons.
EWERT: But here are some assertions about specified complexity based explicitly on the assumption that irreducible complexity does pose a challenge to evolution.
EVOLUTIONIST: Since your assertion is based on a false premise we don't really need to bother with the details. But having looked at the details, here are a bunch of reasons why your calculations are nonsense, and here are reasons why your claims about specifications are the equivalent of drawing the target after the arrow has landed.
But Ewert is just getting warmed up. You see, after boasting that the concept of specified complexity makes possible the key transition from extremely improbable to impossible, Ewert writes this:
Some critics of intelligent design regard this as an obvious point. If complex life were prohibitively improbable under Darwinian evolution (an idea these critics certainly reject), Darwinian evolution would clearly be false. They find it difficult to believe that specified complexity was developed to defend such an obvious point. However, other critics insist that low probabilities of complex life would not provide evidence that we should reject Darwinian evolution.
Did I just win? Didn't he just effectively say that sensible critics understand that nothing beyond claims of irreducible complexity (which in Ewert's telling establish low probability) are needed to refute evolution? Didn't he just acknowledge that claims of specified complexity serve only to establish an obvious point? Apparently it is only especially intransigent critics of evolution, who behave as in my first dialog above, who need to learn about specified complexity.
And who are these dumbass critics who are denying the obvious? Well, Ewert provides quotes from three of them. And one of them is me! Of course, it goes without saying that the quote is out of context. In fact, it is so laughably and preposterously out of context that it deserves a post of its own. So we'll save that for next time.
Good stuff... I can't believe they are trying to revive this now. I could never really figure out the point of SC. If IC is a special case of SC, then the whole argument should be over IC, and once IC is debunked, game over.
@2: as for the timing, I wonder if it has anything to do with Dembski's recent announcement that he's putting aside ID and focusing on other subjects. Could be that Ewert sees himself as taking up the torch, or it could be that he's emboldened to redefine what SC is/take it in a new direction because he doesn't expect Dembski to push back.
the concept of specified complexity makes possible the key transition from extremely improbable to impossible
Isn't this exactly backwards? As Ewart notes, "Specified complexity is a probabilistic argument", so it literally can't be about "impossibility" in the strict sense of the term. Indeed, I thought the whole point of irreducible complexity was to show that some biological features were literally "impossible" to evolve (which as Jason notes would be a sufficient argument against evolution were it correct). I don't understand how a probabilistic argument is supposed to get one to "impossible".
This is another instance of Ewert being imprecise. “Specified Complexity” is only partly a probabilistic argument. Separate from the probability calculation is an assertion that the event or object is also specified. It is the combination of low probability with specificity that gets you all the way to impossible, at least according to ID folks.
Thanks Jason, but I still don't understand how any probabilistic argument can get one to impossibility, or serve in any form as an adjunct to other arguments to get you there. Probability and possibility are two logically distinct notions, and something that is vastly improbable is still not "impossible" in any formal sense.
If I say it is literally impossible for me to run across the US in an hour, I can invoke physical limits (such as the amount of energy required to move my mass at the speed of 2,680 miles/hour versus the metabolic limits of human physiology, or the fact that a human body would be burned up by the frictional heating of the atmosphere when travelling at that speed). But it would be silly to invoke some sort of probabilistic argument about how fast humans are likely to be able to run as a way to demonstrate that it is impossible.
Improbability can play no role in arguing for actual formal impossibility. (And this itself glosses over the important differences between various types of possibility, such as logical possibility vs. physical possibility.)
'Impossible' is Jason's shorthand and the word doesn't actually appear in Ewart's article. Ewart only says that SC bridges the gap between 'improbable' and 'infer evolution false.' So I wouldn't get too wrapped around the axle about impossible vs. merely improbable just yet, he might not try to show impossible.
We will have to see what he says about specificity, but given that it's probably about goals or end-state patterns it relates to the concept of probabilities of sets of outcomes that would all count as a 'success' If you can properly characterize the probability of the set of all possible things counting as success, and that probability is extremely low, then you might indeed infer design. But for biological systems we can't, and I'm guessing they'll do a poor job of treating the subject anyway.
Consider as an example a medium putting on a show, who says "I'm getting a Mark." An audience member responds "My dead husband's first name was Mark!" Should we calculate the probability of the medium guessing that specific person's dead husband's name, or should we calculate the probability of all possible audience responses that the medium would count as a hit? The former calculation might cause you to infer supernatural intervention, the latter calculation would not. The difference is in properly understanding the set of all possible outcomes that would count as a success. Which we can't do for stuff like biological eyes, so it seems very premature to infer either that evolution is false or that supernatural events are required as an explanation.
A few months back over at PT, Nick pointed me to a "philosophy of science" paper by Stephen Meyer. Meyer therein -as well as in his two recent books - spends much ink on the thesis that naturalism + supernaturalism is better at explaining the world than naturalism alone. Which I think boils down to "if I believe in an agent god, then this god has to do something". The problem is figuring out what this god did or does.
We saw commenters in the Ruse post opting for the science is one narrative and religion is another (actually multiple) tactic. Religion uses different (and as far as I can tell unknown) methodologies to develop their narratives, but apparently they have a much truth value as science. ID/creationism doesn't seem to believe this or wouldn't be trying so hard to replace science with their alternative narrative - they certainly don't think the two are compatible.
"You are also careful never to back this up with a non-laughable calculation of the sort the method demands."
As confirmed here:
Very nicely done, Jason.
This is another instance of Ewert being imprecise. “Specified Complexity” is only partly a probabilistic argument. Separate from the probability calculation is an assertion that the event or object is also specified.
Ewert, like many other creationists, does not accept the arrow of time. In algorithmic specified complexity (ASC), the topic of his dissertation, specification associates a second probability with the target. ASC is the log-ratio of two probabilities. Having put considerable (way too much) effort into understanding Ewert's misunderstandings, I'll bet that he's back-applying his present notion of specified complexity.
Joe Felsenstein will respond to the post that you have, at The Panda's Thumb. I'll be responding at The Skeptical Zone, hopefully later today, to the third post in Ewert's series.
Glad you liked the post, Tom. I'll look forward to reading the further posts by you and Joe.
I've now posted Part Two if you're curious.
Are you sure Dembski coined the term "specified complexity"? I was under the impression that the term "specified complexity" was coined in 1973 by a gent named Leslie Orgel, whereas it's unclear if Dembski ever used the term before 1998.
It would appear that Dembski adopted Orgel's terminology while, at the same time, working up a definition for said term somewhat different than Orgel's original definition. In this, Dembski was simply following the time-honored Creationist tactic of attaching Creationist-friendly redefinitions/caricatures to genuine terms of scientific art.