Chance, necessity,  and the war against science

by Massimo Pigliucci 

A review of The Design Inference: Eliminating Chance
Through Small Probabilities. William A. Dembski. Cambridge University Press, Cambridge, UK,
1998. 272 pp. $54.95 (ISBN 0-521-62387-1 cloth). 

(Published in BioScience 50(1):79-81, 2000)

To a superficial observer, so wonderful a regularity may be admired as the effect of either
chance or design; but a skillful algebraist immediately concludes it to be the work of
necessity. (David Hume)

Here we go again. More than 200 years after Hume's (1779) devastating critique of the
argument from design, somebody else is trying to mathematically demonstrate the
impossibility of natural explanations for the order of the universe, and of biological
evolution in particular. To be sure, William A. Dembski's book explicitly talks about
evolution in only one section spanning a mere seven pages, and quoting only one
evolutionist, Richard Dawkins. However, the book has been hailed (e.g., in the
endorsements assembled here) as a revolutionary contribution to design theory (the latest
incarnation of "creation science"). Furthermore, it is soon to be followed by a more explicit
attack by Dembski on evolution, Uncommon Descent, which "seeks to reestablish the
legitimacy and fruitfulness of design within biology" (click here).

What is the "design inference," and why, as evolutionists and scientists, should we care
about the concept? The answer to the first question: a mix of trivial probability theory and
nonsensical inferences. The answer to the second one: this book is part of a large,
well-planned movement whose objective, I contend, is nothing less than the destruction of
modern science and its substitution with a religious system of belief. Let me briefly
explain both claims.

The basic tenet of Dembski's book is that there are three possible explanations for any
observed set of events: regularity, chance, and design. Regularity describes such
phenomena as the rising and setting of the sun. Chance is most simply exemplified by
the outcomes of tossing a fair coin. Design can be found--according to Dembski--in
biological evolution, cryptography, plagiarism, and the suspicious doings of one
Democratic election commissioner in New Jersey named Nicholas Caputo (more on him
later). Dembski then proposes what he calls an "explanatory filter" to determine which
explanation correctly accounts for any particular phenomenon. The filter works by
successive exclusion: if something is not a "regular" natural phenomenon, it may be
chance or design. If it is not the former, it must be the latter. This kind of reasoning is, of
course, quite trivial, and it was worked out in probability theory well before the appearance
of this book. As Dembski himself acknowledges, the statistician Andrei Kolmogorov had
all the pieces of the puzzle in place by 1965.

But never mind that. If Dembski had simply defined "design" as what in biology is known
as "necessity" (Monod 1971), his book would have reduced to another case of somebody
reinventing the wheel. Instead, he goes much further, asserting that "in practice, to infer
design is not simply to eliminate regularity and chance, but to detect the activity of an
intelligent agent" (p. 62). This claim is what turns his opus from triviality to nonsense.

Although Dembski cloaks his logic with semi-obscure (and totally useless in practice)
pseudo-mathematical jargon and symbolism, the essence of his argument is easy to
understand. It is best exemplified by his own treatment of the above-mentioned New
Jersey election commissioner. Nicholas Caputo, nicknamed "the man with the golden
arm," was charged with electoral fraud because in 41 elections he oversaw, 40 had seen
the Democrats at the top of the ballot and only one had the Republicans placed first. The
probability of this occurring by chance in the random drawings that Caputo claimed to
have conducted is less than one in 50 billion. Regardless of the odds, however, the New
Jersey Supreme Court did not convict Caputo because, after all, even very unlikely events
can occur by chance. In the absence of additional evidence, the Court simply ordered
Caputo to change the way in which the drawings were conducted to avoid "further loss of
public confidence in the integrity of the electoral process." (Who says that jurists have no
sense of humor?)

Dembski--as would anyone else with a bit of common sense and an elementary
understanding of probability theory--concludes that the Court indeed had enough evidence
to convict. Why? Because additional information available at the time--that is, that there is
an advantage in being first on a ballot and that Caputo was a Democrat--clearly pointed to
design, not chance. In other words, chance can be discarded as a reasonable alternative if
two conditions hold: the probability of an event is very small, and the information available
about that event allows someone to specify a particular pattern in advance. To put it even
more simply, the following sequences from flipping a coin, TTHTTHTHHT and
HHHHHHHHHH, have exactly the same probability of occurrence. However, your
suspicion that the first one is genuinely random, whereas I created the second by simply
typing the letters on a keyboard, would indeed be correct.

An important component of Dembski's argument is what he calls "probabilistic resources."
Because the design inference is established on two pillars--the occurrence of a specifiable
("detachable," in the author's jargon) pattern and a small probability of
occurrence--Dembski is faced with the problem of how small such a probability actually
has to be before chance can be ruled out. Instead of relying on the commonly understood
limitation of statistical theory, which recognizes that any probability level is arbitrary and,
therefore, that answers in science are only tentative and always subject to revision,
Dembski wants more, much more. He submits that there is an absolute probability level
that can be used as a universal yardstick for inferring design: 1/2 x 10-150. How did he get
there? By estimating that there are 1080 particles in the universe, that no transition
between physical states is possible at a rate faster than 10-45 seconds (the well-known
Planck time), and that the universe is not likely to exist for a total of more than 1025
years. 1080 x 1045 x 1025 is indeed 10150. The 1/2 multiplier in front of the probability
expression is to insure that our chances of reaching the correct conclusion are better than
one in two (a rather arbitrary number in and of itself, of course). The basic idea here is
powerful: if Dembski can demonstrate that the probability of a molecule of DNA forming in
the primordial soup approaches what he calls this "universal small probability," then life
did not evolve by chance.

Too bad he missed the solution to this riddle, which has been proposed several times
during the last few centuries, most prominently (and in various fashions) by Hume (1779),
Darwin (1859), and Jacques Monod (1971). According to these thinkers, if a given
phenomenon occurs with low probability and also conforms to a pre-specified pattern, then
there are two possible conclusions: intelligent design (this concept is synonymous with
human intervention) or necessity, which can be caused by a nonrandom, deterministic
force such as natural selection. Caputo's doing was the result of (fraudulent) human
design; biological evolution is the result of random phenomena (mutation or recombination,
among other processes) and deterministic phenomena (natural selection). It is
disheartening to see how many people don't seem to be able to understand or accept this
simple and beautiful conclusion.

More than disheartening is the background into which Dembski's book falls. In fact, I find it
rather maddening. I will list a few pieces of additional information and then let the reader
decide if I am justified in inferring a conspiracy behind this book. Dembski's book is
endorsed on the back cover by two people from the same universities where he
matriculated. The inside cover comes with a bold hail by David Berlinski, who represented
the creationist side in a recent PBS debate on evolution versus creation. And Dembski's
list of acknowledgments reads like a "Who's Who" of the neocreationist movement,
including Michael Behe, Phillip Johnson, and Alvin Plantinga. According to the book,
Dembski is "a Fellow of the Discovery Institute's Center for the Renewal of Science and
Culture" (CRSC). A bit scarce as an academic reference, no? The reason may be that the
Discovery Institute (www.discovery. org/crsc/index.html) is a conservative public policy
think tank with the declared intent of promoting the intelligent design theory as "a
scientific research program" that "has implications for culture, politics, and the
humanities, just as materialist science has such implications." A document called "The
Wedge," which has been associated with the CRSC, has recently been circulated on the
Internet (humanist.net/skeptical/wedge.html). The Wedge amounts to a detailed plan for
insinuating intelligent design and other creationist ideas in the public as well as the
academic arenas, with the ultimate goal of overthrowing the current scientific
establishment and establishing a theistic science. Dembski's book can be seen as part of
one of the steps of the Wedge strategy.

Unfortunately, Cambridge University Press has offered a respectable platform for Dembski
to mount his attack on "materialist science"--which, of course, includes evolution. My
hope is that scientists will not dismiss this book as just another craze originating in the
intellectual backwaters of America. Neocreationism should be a call to arms for the
science community. The battle is already raging, and scientists and educators are still not
sure if they should even bother paying attention.

References cited

Darwin C. 1859. On the Origin of Species by Means of Natural Selection. Reprint, New
York: A. L. Burt, 1910.
Hume D. 1779. Dialogues Concerning Natural Religion. Edinburgh (UK): Gilbert Elliot.

Monod J. 1971. Chance and Necessity: An Essay on the Natural Philosophy of Modern
Biology. New York: Knopf.

Oryginal: http://fp.bio.utk.edu/skeptic/Book_Reviews/dembski.htm