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.
from ScienceBlogs http://ift.tt/1Nu1iNv
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.
from ScienceBlogs http://ift.tt/1Nu1iNv
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