William Dembski: Is intelligent design testable?
(Dembski quotations are given in the numbered paragraphs, my reactions
in the ones marked "P.R.")
1. Eugenie Scott ... wants to make clear to her audiences that the
designer of intelligent design is really none other than the "Big G" of
the Christian faith.
P.R.: She is right! An intelligent designer is either God, the only
creator, or it is a human or a higher creature. Dembski's model examples
for claiming that ID doesn't necessarily require God include archeology,
forensics, etc., where the designer clearly is human, and SETI, where
the designer - if there is any ETI at all - is a creature of the same
creator, just as humans are. ID therefore cannot refer to anyone else
but God, either directly or indirectly. And if we are dealing with
biology, which is the only field we are interested in, in the context of
ID, God is the only possible intelligent designer.
7b. Is intelligent design falsifiable? Is Darwinism falsifiable? Yes to
the first question, no to the second. ... If it could be shown that
biological systems like the bacterial flagellum ... could have been
formed by a gradual Darwinian process ..., then intelligent design would
be falsified ...
P.R.: For a specific example (e.g. flagellum), this is correct.
8. On the other hand, falsifying Darwinism seems effectively
impossible. To do so one must show that no conceivable Darwinian pathway
could have led to a given biological structure. ...
P.R.: Correct!
9. The fact is that for complex systems like the bacterial flagellum no
biologist has or is anywhere close to reconstructing its history in
Darwinian terms. Is Darwinian theory therefore falsified? Hardly. I have
yet to witness one committed Darwinist concede that any feature of
nature might even in principle provide countervailing evidence to
Darwinism. ...
P.R.: Correct! (However, Darwin gave a few examples which he said would
falsify his theory). - The problem is that any theory claiming that a
process whose mechanism is unknown occurred supernaturally is, in
principle, always falsifyable (in the sense Dembski describes in 7b),
namely by verifying that a natural mechanism is sufficient. But any
theory claiming that a process whose mechanism is unknown occurred by a
purely natural, reductionistic mechanism can, in principle, never be
falsified: an unknown mechanism may always be awaiting detection and
verification. Falsification of an ID origin requires knowing just ONE
feasible Darwinian mechanism, but falsification of a Darwinian origin
requires knowing ALL formulatable mechanisms to be impossible. This
asymmetry shows that ID and Darwinism are not alternative scientific
explanations on the same level. - A related problem with ID is its
strict "either - or": either a process occurs naturally or it occurs
supernaturally, implying that God has nothing to do in a naturally
occurring process, which clearly contradicts biblical theology. He
gifted creation at least with Van Till's functional integrity, if not
with continuing, more concrete providential actions. How about the
possibility of God causing a natural process to occur despite an
infinitesimally small probability? - The basic problem with Darwinism,
on the other hand, is that no test is feasible for its fundamental
premise that the known evolutionary mechanisms were sufficient to
produce the biosphere of the Earth within the past 4 billion years
(macroevolution in the sense of producing fundamentally novel functions
is required).
10 ... Miller takes this admission of ignorance by DeRosier and uses it
to advantage. ... he writes: "Before [Darwinian] evolution is excoriated
for failing to explain the evolution of the flagellum, I'd request that
the scientific community at least be allowed to figure out how its
various parts work." But in the article by DeRosier that Miller cites,
Miller conveniently omits the following quote: "More so than other
motors, the flagellum resembles a machine designed by a human."
P.R.: Miller's request must be granted. And DeRosier didn't say that the
flagellum was intelligently designed, just that it appeared so.
11. So apparently we know enough about the bacterial flagellum to know
that it is designed or at least design-like. ... one can determine
whether a system is irreducibly complex without knowing the precise role
that each part in the system plays (one need only knock out individual
parts and see if function is preserved; knowing what exactly the
individual parts do is not necessary). ...
P.R.: The flagellum is certainly design-like; whether it is designed is
a different matter. - The knock-out test would be convincing if the
parts to be tested were atomic, indivisible. This is not the case.
Behe's mouse-trap model doesn't apply that easily. Knocking out a
component protein might destroy all activity, but a slightly simpler
derivative of the protein might be found which makes the whole system
work just a little less efficiently. This is just what Darwinism claims.
But this is what would have to be shown impossible to prove
irreducibility - a proposition every bit as immense as Darwinism's task
of verifying that an evolutionary path was possible. In virtually all
specific cases of complex systems, Darwinists are incapable of proving
that its origin by evolution works, and IDers appear to be incapable of
proving that it doesn't.
12. ... the positive evidence for Darwinism is confined to small-scale
evolutionary changes like insects developing insecticide resistance.
This is not to deny large-scale evolutionary changes, but it is to deny
that the Darwinian mechanism can account for them. Evidence like that
for insecticide resistance confirms the Darwinian selection mechanism
for small-scale changes, but hardly warrants the grand extrapolation
that Darwinists want. It is a huge leap going from insects developing
insecticide resistance via the Darwinian mechanism of natural selection
and random variation to the very emergence of insects in the first place
by that same mechanism.
P.R.: This is correct. Microevolution, in the sense of uninterrupted
series of small random changes where each intermediate is selected (or
at least neutral), is no problem. But as soon as a series of several
specific, but non-selected random steps are required, the probability of
their combined occurrence very rapidly drops to virtually zero. By the
way, even for insecticide resistance, a Darwinian origin has not been
shown to be possible when it requires new enzymes which cannot be
imported from elsewhere.
15. ... SETI researchers would legitimately count a sequence of prime
numbers (and less flamboyantly though just as assuredly a narrow
bandwidth transmission) as positive evidence of extraterrestrial
intelligence. ... Eugenie Scott would not be complaining about SETI not
having proposed any "testable models." Instead she would rejoice that
the model had been tested and decisively confirmed.
P.R.: SETI is irrelevant for ID in biology as, by definition, the
speculative ETIs are intelligent, but subhuman biological systems are
not. If ETIs were responsible for life on Earth, this would just push
the origin problem one step further back - to the origin of the ETIs.
This also applies to F. Crick's "directed panspermia" - the few orders
of magnitude of increased probability he gets are entirely
insignificant.
16. Now what's significant about a sequence of prime numbers from outer
space is that they exhibit specified complexity ... But what if
specified complexity is also exhibited in actual biological systems? In
fact it is... I address this in my forthcoming book (No Free Lunch), but
such calculations are out there in the literature (cf. the work of
Hubert Yockey, Robert Sauer, Peter Rüst, Paul Erbrich, Siegfried
Scherer, and most recently Douglas Axe -- I'm not enlisting these
individuals as design advocates but merely pointing out that methods for
determining specified complexity are already part of biology).
P.R.: Is extremely low probability of occurrence of systems of specified
complexity equivalent to confirmation of ID? The problem is that no
amount of (scientific) improbability for an event or series of events
can prove (theological) ID. The best we can get from such calculations
(including my own) is convincing presumptive evidence that science is at
a loss for finding a plausible natural solution - and that belief in an
autonomous origin of life and autonomous macroevolution requires faith.
For theological reasons (faith out of a free personal decision), we can
never prove God, not even by ID.
18. ... we don't have any experience with unembodied designers, and
that's clearly what we're dealing with when it comes to design in
biology. ...
P.R.: What is an "unembodied designer"? If it's God, the situation is
clear. If not, it may be an angel, or perhaps an ETI consisting of pure
energy or exotic particles or cosmic strings or whatever. But any of
these must be intelligent creatures made by God. ID cannot get rid of
God - which places the ID program outside of science. It is not just a
question of defining science, or a "demarkation problem", since any step
of the ID program going beyond probability calculations is a step of
metaphysical faith. Science cannot go beyond the "don't know", apart
from looking for other natural explanations.
20. It is no objection at all that we don't at this time know how an
unembodied designer produced a biological system that exhibits specified
complexity. ... The only reason to insist on looking for non-telic
explanations to explain the complex specified structures in biology is
because of prior commitment to naturalism that perforce excludes
unembodied designers. It is illegitimate, scientifically and rationally,
to claim on a priori grounds that such entities do not exist, ...
Specified complexity confirms design regardless whether the designer
responsible for it is embodied or unembodied.
P.R.: On a philosophical level, Dembski is right in calling an a-priori
exclusion of an unembodied designer illegitimate. But science as such
cannot deal with unembodied designers! Science is quite correct in
looking for "non-telic explanations". I heartily sympathize with Bill's
challenge to Eugenie Scott, but his attempt to keep ID within science is
unsuccessful. By mixing up science and metaphysics, he is falling into
the same trap as Scott. She doesn't seem to realize that atheism is just
as religious and outside science as theism.
21. ... At best one can say that there is consilience, i.e., that the
broad sweep of evolutionary history as displayed in the fossil record is
consistent with Darwinian evolution. Design theorists strongly dispute
this as well (pointing especially to the Cambrian explosion)...
P.R.: The relevance of the Cambrian explosion is being challenged by
claims of Precambrian metazoan precursors (Fortey R.A., Briggs D.E.G.,
Wills M.A. "The Cambrian evolutionary 'explosion' recalibrated",
BioEssays 19 (1997), 429-434; Abouheif E., Zardoya R., Meyer A.
"Limitations of metazoan 18S rRNA sequence data: implications for
reconstructing the phylogeny of the animal kingdom and inferring the
reality of the Cambrian explosion", Journal of Molecular Evolution 47
(1998), 394-405; Conway Morris S. "The Cambrian 'explosion': slow-fuse
or megatonnage?" Proceedings of the National Academy of Sciences USA 97
(2000), 4426-4429), although these claims still appear to be tentative.
23. ... Intelligent design can accommodate plenty of evolutionary
change and allows for natural selection to act as a conservative force
to keep organisms adapted to their environments. ... intelligent design
does not push off all explanation to the inscrutable will of God. On the
other hand, intelligent design utterly rejects natural selection as a
creative force capable of bringing about the specified complexity we see
in organisms.
P.R.: ID allows for evolutionary change and natural selection. But if it
"utterly rejects natural selection as a creative force", this is a
judgement based on improbability: "utterly" sounds somewhat exaggerated,
depending on the "creative" events considered, as absolute impossibility
of improbable evolutionary paths can never be proved. Furthermore,
co-agency of God's "hidden options" (such as guiding quantum events or
selecting mutations) with natural processes (which themselves are based
on created natural laws) should not be ruled out a priori.
25. ... Innovation, the emergence to true novelty, eschews
predictability. Designers are inventors. ... Intelligent design offers a
radically different problematic for science than a mechanistic science
wedded solely to undirected natural causes. ...
P.R.: That solutions due to ID cannot be predicted is, in principle,
correct. But ID in biology takes us out of science, not just mechanistic
science. That science lacks metaphysics is not the problem, but that
scientists sometimes peddle metaphysics for science.
28. ... Even if the Darwinian mechanism could be shown to do all the
design work ..., a design-theoretic framework would not destroy any
valid findings of science. To be sure, design would then become
superfluous, but it would not become contradictory or self-refuting.
P.R.: Doesn't this claim make ID, as a whole (not for individual cases),
unfalsifyable?
29. ... Suppose ... I invented some hitherto unknown molecular machine,
... I inserted this machine into a bacterium, ... allowed it to
reproduce in the wild, ... allowing the bacteria endowed with my
invention to consume their unfortunate prey. - 30. ... natural
selection had nothing to do with it. ...
P.R.: Natural selection at least caused it to prevail in the wild,
according to Dembski's story!
32. ... Even if a theory of intelligent design should ultimately prove
successful and supersede Darwinism, it would not follow that the
designer posited by this theory would have to be the Christian God or
for that matter be real in some ontological sense. One can be an
anti-realist about science and simply regard the designer as a
regulative principle ...
P.R.: Who else but the Christian God could be the designer of living
systems (if not of the earthly ones, then of the creative ETIs if they,
in the extreme case, did the designing)? - Science is basically realist,
although an occasional atheistic scientist may be clouded enough to fall
for anti-realism. Dembski's attempt to keep ID within science is
unsuccessful.
Peter Rüst
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