Tuesday, May 04, 2004

Dembski's Fantasy Land William Dembski's latest turd tome is entitled The Design Revolution: Answering the Toughest Questions About Intelligent Design. It is nothing more than another repackaging of the same bad arguments he's been making for a decade. But one new aspect of Dembski's delusion is that his ideas have become a source of great interest to serious scientists.

For example, he writes:

Specified complexity is a widely used criterion for detecting design. For instance, when researchers in the search for extraterrestrial intelligence (SETI) look for signs of intelligence from outer space, they are looking for specified complexity. (P. 85-86)

There is some equivocation going on here. It is true, in a vague sort of way, that what SETI researchers hope to find is some radio signal from outer space that carries an intelligible message. If that is all Dembski means by “specified complexity”, then I find nothing objectionable in this statement. But this statement comes at the end of a chapter in which Dembski outlines an elaborate probabilstic apparatus for detecting design in biological structures. Dembski's claim to fame among ID folks is his assertion that his convoluted mathematical arguments from the core of a strong case against evolutionary theory. For Dembski, specified complexity is a technical term in probability theory. It holds that status for no one else. Scientists interested in solving actual problems in the lab do not use Dembski's tools, for the simple reason that they are based on bad arguments and sloppy reasoning. In that sense, it is highly misleading to say that specified complexity is widely used.

He goes on to write:

By arranging these questions sequentially as decision nodes in a flowchart, we can represent specified complexity as a criterion for detecting design. This flowchart is now widely known as the Explanatory Filter. (P. 87)

The questions he has in mind are “Is it contingent? Is it complex? Is it specified?” “It” refers to the event in question.

Widely known as the Explanatory Filter? Dembski himself coined the term “Explanatory Filter” to describe the algorithm he uses to determine if a particular event resulted from intelligent design. The only time scientists ever refer to the filter is specifically when they are criticzing Dembski. Like specified complexity, the filter is something that plays no role at all in any serious scientific enterprise. It's existence is widely known only among people who take an interest in evolution/creationism disputes. Once again Dembski is implying that his ideas have gained some currency among scientists.

A third example is:

Certainly the bacterial flagellum is specified. One way to see this is to note that humans developed bidirectional, motor-driven propellers well before they figured out that the flagellum was such a machine. This is not to say that for the biological function of a system to constitute a specification, humans must have independently invented a system that performs the same function. Nevertheless, independent invention makes all the more clear that the system satisfies independent functional requirements and therefore is specified. At any rate, no biologist I know questions whether the functional systems that arise in biology are specified. (P. 111)

One suspects that the biologists Dembski knows form a rather carefully chosen group, but the fact is, once again, that there are no serious scientists who ever use the term “specified” in the way Dembski envisions. In fact, most of the people who have seriously conisdered Dembski's proposal have come to the conclusion that Dembski's ideas about specification are hopelessly vague, and therefore impossible to apply in any nontrivial case.

In each of these examples Dembski is trying to give the impression that scientists find his ideas correct and useful. Actually, they find them to be neither. But since Dembski's book was published by the Christian publisher InterVarsity Press, it is safe to say that the book's intended audience is not likely to know about the current state of affairs in modern biology.


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