Simplicity, Complexity and Design

Friend of the CADRE, David Heddle, at He Lives has an excellent post entitled "Suboptimal Design?" which is dated March 7, 2005, in which he analyzes an attack on Behe's theory of irreducible complexity and intelligent design by a blogger using the psuedonym Perakh. Perakh makes the following point:

As I have argued before (Perakh 2004), contrary to Dembski’s persistent assertions, complexity is certainly not just disguised improbability. Examples to the contrary abound. Imagine a pile of stones. Each stone has some irregular shape that resulted from a series of chance events. Among these irregularly shaped stones we find a perfectly rectangular brick. It has a simple shape which can be described by a short (i.e. simple) program containing only three numbers – width, length, and height. On the other hand each of the irregularly shaped stones can be described only by a more complex program containing many numbers. However, the probability of a rectangular brick being a result of chance is low: the brick is reasonably (with a high probability) assumed to be a product of design. For irregularly shaped stones the opposite is true – the probability of their origin in chance is larger than in design. Here the relationship between probability and complexity is opposite that prescribed by Dembski’s definition (but compatible with the definition of Kolmogorov complexity – see, for example, Chaitin 2003).

In this example simplicity rather than complexity is a marker of design. I submit that the described example shows not only that Dembski’s definition of complexity fails for certain situations but also that, generally, a more reasonable statement is that simplicity points to design while complexity as such points to chance (more about this in Perakh 2004).

If this is so, then the first part of Behe’s IC concept – complexity - is more reasonably construed as an indication of “blind” evolution rather than of design.

David makes a very astute response:

As I understand, according to Perakh, Behe claims complexity and irreducibility (of functionality) are necessary to signal design. Or, if you like, low probability and functionality. The and is crucial. As is the fact that, nowhere in this definition, is extreme, inexplicable simplicity precluded from signaling design.

So Behe’s definition does not mean a perfectly rectangular stone, because of its simplicity, does not signal design—it just doesn’t signal the type of design he is investigating, i.e. the design of complex systems. It (the rectangular stone) is a sort of trivial design in the sense that it is beyond dispute—nobody would argue that the 1×4×9 monolith in 2001: A Space Odyssey would occur naturally.

To compare a perfectly rectangular stone to a garden variety stone, obviously of a more complex shape, and which all would agree is more likely to be naturally occurring, and to say that this has anything to do with Behe’s arguments, is wrong in at least two ways:

1. Behe does not say that simplicity cannot signal design

2. Behe does not say that non-functional complexity (the natural stone) is a signal of design

Perakh’s conclusion that “simplicity points to design while complexity as such points to chance” is sensible (if the complexity is not functional), but it does not refute Behe, as I understand him (which may be flawed) who (a) (I speculate) would not deny that extreme, inexplicable simplicity (a perfectly rectangular stone) points to design and (b) would not argue that complexity per se points to design, but only functional and irreducible complexity.

As noted by commentor Jim Price:

Perkah misunderstands both Behe and Dembski when he claims that "[A]ccording to Behe and Dembski, the more complex a system, the more likely it was designed". For Dembski, complexity per se isn't important, what matters is 'specified complexity'. For Behe, complexity per se isn't important, what matters is 'irreducible complexity'. The adjectives are crucial to their arguments. In fact, it's fair to say that their entire body of work consists of fleshing out what they mean by the adjectives. Hence it's very ironic that Perkah claims that 'Behe has not provided a definition of 'complexity'. Behe isn't trying to define 'complexity', he's trying to define something else, something he calls 'irreducible complexity'.

Both Mr. Price (probably no relation to Layman) and David Heddle are making a very important distinction. The science of Chaos (is it still considered a science?) had complexity as its cornerstone. The butterfly curve measured in chaotic equations is very, very complex, but I doubt anyone in the ID movement would consider the randomness built into systems to be the result of intelligence (other than in the broad sense that the randomness involved is the result of the physical laws that appear to be to precise to have been randomly generated as discussed in the teleological argument for God). Rather, it is the complexity coupled with the usefulness. A very, very simple item can be "irreducibly complex" or have the "specified complexity" if it appears to be designed perfectly for a particular system to work.

Excellent work, David.

Note added: 3/22: A e-mailer notified me that I made a mistake in saying that Perakh was a pseudonym. He said Perakh probably refers to Mark Perakh who posts at http://www.talkreason.org -- the author of "Unintelligent Design" (Prometheus Books, 2004). My apologies to Mr. Perakh.

Macht said…
I made some similar comments here about the differences between "mere" complexity and Behe's IC and Dembski's SC.
BK said…
Just read through the discussion. Very interesting. But at least now I know why I hadn't seen you blog it -- it isn't on your blog (which I highly recommend everyone interested in the crossroads of science, technology, philosophy and religion turn into regular reading).
Macht said…
Yeah, I should have made it more clear that I was commenting on somebody else's blog. Thanks for the kind words.