When I wrote my recent post on the alleged circularity of specified complexity, I did so in a deliberately provocative way. I wrote it emphasizing my agreement with keith s, in an attempt to shake things up and make people think. I felt that both sides of the debate here on uncommon descent were speaking past each other. I wanted to people to re-evaluate their understand of specified complexity. It seems many people found the result confusing. I’m sorry about that.
My attempt was prompted by this portion from a recent post:
We can decide whether an object has an astronomically low probability of having been produced by unintelligent causes by determining whether it has CSI (that is, a numerical value of specified complexity (SC) that exceeds a certain threshold).
This section seems to be saying that we can establish astronomically low probability under chance hypotheses by appealing to specified complexity. As I attempted to elaborate in my last post, that would be circular reasoning. Now, I think VJTorley is clearly intelligent enough not to make such a blatantly circular argument. But I can also why ID critics would see this as circular.
I took the provocative and odd approach to making my point because I’ve been repeatedly making this point. However, none of my past attempts appear to have actually worked. When Liddle objected to the design inference, I stated exactly the same point I just made. As I wrote there:
She has objected that specified complexity and the design inference do not give a method for calculating probabilities. She is correct, but the design inference was never intended to do that. It is not about how we calculate probabilities, but about the consequences of those probabilities. Liddle is complaining that the design inference isn’t something that it was never intended to be.
I wrote the same idea in previous posts on this blog:
Dembski’s development of specified complexity depends on having established that the probability of structures like the bacterial flagellum is absurdly low under Darwinian mechanisms. Specified complexity provides the justification for rejecting Darwinian evolution on the basis of the absurdly low probability. It does nothing to help establish the low probability. Anyone arguing the Darwinian evolution has a low probability of success because of CSI has put the cart before the horse. You have to show that the probability of the bacterial flagellum is low before applying CSI to show that Darwinism is a bad explanation.
Going further back I wrote:
Remember, CSI is always computed in the context of a mechanism. Specified Complexity is nothing more than a more rigorous form of the familiar probability arguments. If you try to measure the specified complexity of arbitrary artefacts you will run into trouble because you are trying to use specified complexity for something it was not designed to be. Specified complexity was only intended to provide rigour to probability arguments. Anything beyond that is not specified complexity. It might be useful in its own right, but it is not specified complexity.
So despite the portrayal in some coners, this isn’t a new admission or concession on my part. I’ve been trying to make this point repeatedly. The fact is, I’ve grown weary of trying to convey this point.
Some are inclined to suggest that I’m incorrect, and that what I’ve stated isn’t Dembski’s argument. Some suggest that Dembski has attempted to silently change what he argued because his original version did not actually work. None of that is true. As far back as 1999, Dembski wrote:
Does nature exhibit actual specified complexity? This is the million dollar question. Michael Behe’s notion of irreducible complexity is purported to be a case of actual specified complexity and to be exhibited in real biochemical systems (cf. his book Darwin’s Black Box). If such systems are, as Behe claims, highly improbable and thus genuinely complex with respect to the Darwinian mechanism of mutation and natural selection and if they are specified in virtue of their highly specific function (Behe looks to such systems as the bacterial flagellum), then a door is reopened for design in science that has been closed for well over a century. Does nature exhibit actual specified complexity? The jury is still out. (Metanexus: Explaining Specified Complexity)
Dembski doesn’t say that life is improbable because it exhibits specified complexity. Rather, he says that life is improbable because of Behe’s argument of irreducible complexity. It argues that it exhibits specified complexity as a consequence of that probability. He doesn’t regard specified complexity as an established fact. Rather he explicitly stats the “jury is still out.” The specified complexity argument is explicitly contingent on the irreducible complexity argument. In other words, this has been the intended interpretation of Dembski’s work as far back as 1999.
I hope that some light has been shed on the issue of specified complexity.