Who owns the argument from improbability? Statistical improbability
is the old standby, the creaking warhorse of all creationists from naive
Bible-jocks who don't know better, to comparatively well-educated Intelligent
Design “theorists,” who should. There is no other creationist argument (if you
discount falsehoods like “There aren't any intermediate fossils” and ignorant absurdities like “Evolution
violates the second law of thermodynamics”). However superficially different
they may appear, under the surface the deep structure of creationist advocacy
is always the same. Something in nature—an eye, a biochemical pathway, or a
cosmic constant—is too improbable to have come about by chance. Therefore it
must have been designed. A watch demands a watchmaker. As a gratuitous bonus, the watchmaker conveniently
turns out to be the Christian God (or Yahweh, or Allah, or whichever deity
pervaded our particular childhood).
That this is a lousy argument has been clear ever since Hume's time,
but we had to wait for Darwin to give us a satisfying replacement. Less often
realized is that the argument from improbability, properly understood,
backfires fatally against its main devotees. Conscientiously pursued, the
statistical improbability argument leads us to a conclusion diametrically
opposite to the fond hopes of the creationists. There may be good reasons for
believing in a supernatural being (admittedly, I can't think of any)but the
argument from design is emphatically not one of them. The argument from improbability
firmly belongs to the evolutionists. Darwinian natural selection, which, contrary
to a deplorably widespread misconception, is the very antithesis of a chance
process, is the only known mechanism that is ultimately capable of generating
improbable complexity out of simplicity. Yet it is amazing how intuitively
appealing the design inference remains to huge numbers of people. Until we
think it through … which is where Niall Shanks comes in.
Combining historical erudition with up-to-date scientific knowledge,
Professor Shanks casts a clear philosopher's eye on the murky underworld
inhabited by the “intelligent design” gang and their “wedge” strategy (which is
every bit as creepy as it sounds) and explains, simply and logically, why they
are wrong and evolution is right. Chapter follows chapter in logical sequence,
moving from history through biology to cosmology, and ending with a cogent and perceptive
analysis of the underlying motivations and social manipulation techniques of
modern creationists, including especially the “Intelligent Design” subspecies
of creationists.
Intelligent design “theory” (ID) has none of the innocent charm of
old-style, revival-tent creationism. Sophistry dresses the venerable watchmaker
up in two cloaks of ersatz novelty: “irreducible complexity” and “specified
complexity,” both wrongly attributed to recent ID authors but both much older.
“Irreducible complexity” is nothing more than the familiar “What is the use of
half an eye?” argument, even if it is now applied at the biochemical or the
cellular level. And “specified complexity” just takes care of the point that any
old haphazard pattern is as improbable as any other, with hindsight. A
heap of detached watch parts tossed in a box is, with hindsight, as improbable
as a fully functioning, genuinely complicated watch. As I put it in The
Blind Watchmaker, “complicated things have some quality, specifiable in
advance, that is highly unlikely to have been acquired by random chance
alone. In the case of living things, the quality that is specified in advance
is, in some sense, ‘proficiency’ either proficiency in a particular ability
such as flying, as an aero-engineer might admire it; or proficiency in
something more general, such as the ability to stave off death. …”
Darwinism and design are both, on the face of it, candidate explanations
for specified complexity. But design is fatally wounded by infinite regress.
Darwinism comes through unscathed. Designers must be statistically improbable
like their creations, and they therefore cannot provide an ultimate explanation.
Specified complexity is the phenomenon we seek to explain. It is obviously
futile to try to explain it simply by specifying even greater complexity.
Darwinism really does explain it in terms of something simpler—which in turn is
explained in terms of something simpler still and so on back to primeval
simplicity. Design may be the temporarily correct explanation for some
particular manifestation of specified complexity such as a car or a washing
machine. But it can never be the ultimate explanation. Only Darwinian natural
selection (as far as anyone has ever been able to discover or even credibly
suggest) is even a candidate as an ultimate explanation.
It could conceivably turn out, as Francis Crick and Leslie Orgel
once facetiously suggested, that evolution on this planet was seeded by
deliberate design, in the form of bacteria sent from some distant planet in the
nose cone of a space ship. But the intelligent life form on that distant planet
then demands its own explanation. Sooner or later, we are going to need something
better than actual design in order to explain the illusion of design. Design
itself can never be an ultimate explanation. And the more statistically
improbable the specified complexity under discussion, the more unlikely does
any kind of design theory become, while evolution becomes correspondingly more
powerfully indispensable. So all those calculations with which creationists love to browbeat their naïve audiences—the mega-astronomical
odds against an entity spontaneously coming into existence by chance—are
actually exercises in eloquently shooting themselves in the foot.
Worse, ID is lazy science. It poses a problem (statistical
improbability) and, having recognized that the problem is difficult, it lies down
under the difficulty without even trying to solve it. It leaps straight from
the difficulty—“I can't see any solution to the problem”—to the
cop-out—“Therefore a Higher Power must have done it.” This would be deplorable
for its idle defeatism, even if we didn't have the additional difficulty of
infinite regress. To see how lazy and defeatist it is, imagine a fictional
conversation between two scientists working on a hard problem, say A. L.
Hodgkin and A. F. Huxley who, in real life, won the Nobel Prize for their
brilliant model of the nerve impulse.
“I say, Huxley, this is a terribly difficult problem. I can't
see how the nerve impulse works, can you?”
“No, Hodgkin, I can't, and these differential equations are
fiendishly hard to solve. Why don't we just say give up and say that the nerve
impulse propagates by Nervous Energy?”
“Excellent idea, Huxley, let's write the Letter to Nature now, it'll only take one line, then we can turn to something easier.”
Huxley's elder brother Julian made a similar point when, long
ago, he satirized vitalism as tantamount to explaining that a railway engine
was propelled by Force Locomotif.
With the best will in the world, I can see no difference at all between force locomotif, or my hypothetically lazy version of Hodgkin and
Huxley, and the really lazy luminaries of ID. Yet, so successful is their
“wedge strategy,” they are coming close to subverting the schooling of young
Americans in state after state, and they are even invited to testify before congressional committees: all this while ignominiously
failing to come up with a single research paper worthy of publication in a
peer-reviewed journal.
Intelligent Design “theory” is pernicious nonsense which needs
to be neutralized before irreparable damage is done to American education.
Niall Shanks's book is a shrewd broadside in what will, I fear, be a lengthy
campaign. It will not change the minds of the wedgies themselves. Nothing will do
that, especially in cases where, as Shanks astutely realizes, the perceived
moral, social, and political implications of a theory are judged more important
than the truth of that theory. But this book will sway readers who are
genuinely undecided and honestly curious. And, perhaps more importantly, it
should stiffen the resolve of demoralized biology teachers, struggling to do
their duty by the children in their care but threatened and intimidated by
aggressive parents and school boards. Evolution should not be slipped into the curriculum
timidly, apologetically or furtively. Nor should it appear late in the cycle of
a child's education. For rather odd historical reasons, evolution has become a
battlefield on which the forces of enlightenment confront the dark powers of
ignorance and regression. Biology teachers are front-line troops, who need all
the support we can give them. They, and their pupils and honest seekers after
truth in general, will benefit from reading Professor Shanks's admirable book.
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