[I originally posted the following to the Meta Reiterations list. I thought
the issue was sufficiently interesting to justify posting it here too.]
In my critique of the Design Inference (Metaviews 096), I wrote that Dembski
tends to conflate his own usage of the term "specified complexity" with the
same term as used by other writers, even though it seems very unlikely that
those other writers are using it in the same sense.
A particularly good example of Dembski's confusion appears in his latest
Metaviews article (098):
"Specified
complexity is a form of information, though one richer than Shannon
information, which focuses exclusively on the complexity of
information without reference to its specification. A repetitive
sequence of bits is specified without being complex. A random
sequence of bits is complex without being specified. A sequence of
bits representing, say, a progression of prime numbers will be both
complex and specified. In _The Design Inference_ I show how inferring
design is equivalent to identifying specified complexity
(significantly, this means that intelligent design can be conceived
as a branch of information theory)."
Here, Dembski states that "A repetitive sequence of bits is specified
without being complex." As an example of a repetitive sequence of bits, I
take one in which all the bits are 1's. Under some definitions of specified
complexity, this sequence may well fail to have this property. But, using
Dembski's own definition, this sequence *does* have specified complexity
with respect to the chance hypothesis that the bits are independent
equiprobable random variables, assuming the number of bits is sufficiently
large.
By Dembski's criteria, a suitable specification would be "all bits 1" or
"all bits the same". Indeed, Dembski chooses a similar specification in his
Caputo example. Depending on which of these specifications we choose, the
probability of the specified event is either equal to or double the
probability of a specific "random" sequence of bits, and therefore has the
same (or just one bit less) specified complexity.
Dembski seems to be confusing his own definition of complexity (which is a
probabilistic one) with the more commonly used complexity measure of
Kolmogorov and Chaitin (which is an algorithmic one). The two concepts are
quite different and give very different results!
The whole issue of specified complexity is a red herring, as far as the
Design Inference is concerned. What Dembski's own method requires him to
show is that the probability of some "specified" biological
structure evolving naturally is very small. If he can do that, he will have
achieved something of great interest. Dembski's transformation of
probabilities into complexities only serves to obfuscate this simple idea.
Richard Wein (Tich)
--------------------------------
"Do the calculation. Take the numbers seriously. See if the underlying
probabilities really are small enough to yield design."
-- W. A. Dembski, who has never presented any calculation to back up his
claim to have detected Intelligent Design in life.
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