DOES ID = DI?
Reflections on the Intelligent Design Movement
Professor of Physics and Astronomy Emeritus
Calvin College, Grand Rapids, Michigan, USA
Preliminary remarks
I was asked to speak today on the topic of the Intelligent Design movement
that is gaining attention mostly in the US. The Planning Committee suggested
that, although the ID movement is not prominent in the UK, your membership
might find it of some value to become more aware of what this movement
represents and how it is being received. And since questions regarding
the character and detection of divine action are central to the ID agenda,
a conference on the question, How Does God Act in the World? provides
a particularly fitting context for our examination of the ID movement.
Given the usual limitations of time, I shall have to be brief and will
be unable to provide documentation for many of my judgments.
The Cultural Context of the ID Movement
Religiously motivated opposition to scientific theories, especially to
theories about biotic evolution, is not a new phenomenon. Nonetheless,
both the forms of opposition and the labels devised to name
the opposing viewpoints do change over time.
Young-earth special creationism, for instance, is rooted in the
conviction that the first three chapters of Genesis constitute a factual
chronicle of divine creative acts. Read as a chronicle, the text appears
to posit that over a period of six 24-hour days God conferred form on
the material that was given being at the beginning of time, perhaps 6,000
years ago. From that viewpoint, biological evolution is unnecessary
(because each basic kind of living creature was given its form by an independent
form-conferring act) and it is generally considered to be impossible
as well (either because matter was never given the requisite capabilities
to organize into living forms, or because of insufficient time).
Old-earth special creationism, on the other hand, accepts the scientifically-derived
chronology of cosmic history. Nonetheless, it retains a commitment to
the necessity of special creation and the impossibility of biological
evolution.
The way in which special creationist beliefs are presented varies considerably
with context. Within their own religious communities, special creationists
are free to argue their cases by appeal to the Bible or to theological
commitments. But efforts to get special creationism into the public school
science classroom required the adoption of a different strategy. Consequently,
an approach called scientific creationism was formulated without
reference to its religious roots and was intended to function as a scientific
alternative to biological evolution.
Judged on its scientific merit, however, scientific creationism is generally
considered to be a dismal failure. This failure, combined with other considerations,
has led most special creationists to abandon their call to present scientific
creationism in the public school science classroom as an alternative to
evolutionary theory.
But it is important to realize that the fundamental religious concerns
that originally led to the scientific creationist movement remain undiminished.
There are still large numbers of parents who find the teaching of evolution
to be religiously offensive. Whether the public school intends it or not,
teaching biological evolution without offering some creationism-like alternative
is taken by many religiously devout parents to be a violation of the religious
neutrality that the state is required to maintain. To parents who are
committed to special creationism of any sort, it appears as if the public
school is promoting the religion of the enemy—often designated as
Darwinism.
These parents have been heartened over the last decade by the growing
visibility and political vigor of a relatively new movement that calls
its viewpoint “Intelligent Design” (ID). Its beginning is best
marked, I believe, with the publication of the book, Darwin on Trial,
by Berkeley law professor Phillip E. Johnson. In that popular book Johnson
decried the way in which, in his judgment, the preachers of Darwinism
had come to dominate the secular educational system by insisting that
biological evolution be taught as an established fact. By Johnson's measure,
Darwinism was popular not because it was substantiated by the weight of
empirical evidence, but because it functioned to promote the naturalistic
worldview of an entrenched scientific establishment.
I believe the next major advance for the growing ID movement was the publication
of the book, Darwin's Black Box, by biochemist Michael J. Behe.
Behe called attention to a number of specific biological systems and biotic
structures that struck him as exhibiting a quality—he called it irreducible
complexity—so remarkable that it could not possibly be the outcome
of unguided natural processes alone. Therefore, argued Behe, these structures
must have been intelligently designed.
Meanwhile, yet another academician with attractive credentials (advanced
degrees in philosophy, mathematics, and theology) was working on a theoretical
strategy that, in his judgment, placed the full analytical power of formal
logic, mathematics and information theory on the side of the ID movement.
In his recent book, No Free Lunch, William A. Dembski argues at
length (as he did in his earlier work The Design Inference) that
there are natural objects in the world that we can clearly identify as
objects that could not be the outcome of natural processes alone. From
this he concludes that they must, therefore, be the products of intelligent
design.
Johnson, Behe, Dembski and other advocates of ID ask that claims of this
sort to be evaluated as scientific claims, with all concerns about
religious motivation set aside. We could do that, but I believe that our
first steps toward an understanding of the ID movement must be to become
familiar with its fundamental goals and its peculiar vocabulary. Knowing
the movement's goals will help us understand some elements of its rhetorical
strategy. Becoming familiar with the movement's vocabulary is necessary
because of a strategy that I find to be characteristic of ID literature:
key terms that are essential to the development of the case for ID are
often given meanings quite different from what their normal usage might
suggest.
ID's Mission: The Defeat of Naturalism
In the judgment of leading ID advocates, the worldview of naturalism
has effectively dominated not only the arenas of higher education and
professional science but also the pre-college public educational system.
Support for the ID movement comes primarily from persons who agree with
this assessment and are deeply disturbed by it. The ID movement is
committed to the defeat of naturalism. But naturalism comes in many
variant forms that must be carefully distinguished from one another. I
find the following distinctions essential:
(1) Following theologian David Ray Griffin, I use the term maximal
naturalism to denote the comprehensive worldview built on the premise
that Nature (considered to be a purely physical/material thing) is all
there is—there is no other form of being, no God or gods—and
that there is no ultimate purpose in Nature's existence, character, or
historical development.
(2) I use the term minimal naturalism to denote the family of worldviews
that make no commitment either for or against the existence of any deity,
but do reject the idea of supernatural action in which a deity
would interrupt the flow of natural actions by coercively overpowering
or superceding the actions of members of the universe.
(3) Naturalistic theism builds its worldview on the premise that
there is a God who acts purposefully and effectively in the world, but
this divine action is always persuasive and never coercive. In contrast
to the several forms of supernaturalistic theism, naturalistic
theism rejects supernatural action on the metaphysical grounds that it
would violate the essential natures of God, the world, and the God-world
relationship.
(4) The term methodological naturalism is often employed to denote
the idea that the natural sciences have the competence to investigate
natural actions alone and that science must remain agnostic with regard
to any form of divine action.
Which of these forms of naturalism does the ID movement reject? There
may be some variation in the ID literature, but the consensus seems to
be that it doesn't really matter very much. In the judgment of most ID
proponents, the distinctions outlined above are effectively meaningless
because all of these versions of naturalism agree on the key proposition
that the ID movement rejects—that there is no way to detect divine
action empirically.
One of the chief claims of the ID movement is that design is empirically
detectable. That being the claim, then each and every one of the forms
of naturalism listed above—because they uniformly reject the empirical
detectability of divine action—is the target for defeat. To the ID
movement, any God whose actions are not empirically detectable would be
of no value in defeating naturalism.
But if naturalism is the enemy, why is so much of ID's rhetoric
directed toward Darwinism? The answer, I believe, is that Darwinism
is taken to be the conjunction of biological evolution and purposeless
maximal naturalism. The label “Darwinism” is commonly employed
to characterize biological evolution as a way of accounting for the formational
history of life that is both “thoroughly naturalistic” and “nonteleological.”
But which form of naturalism does “thoroughly naturalistic”
entail? If it involves only minimal or methodological naturalism,
then a number of theistic worldviews could accommodate it. Some theists
would even welcome it. But if the term Darwinism is presumed to entail
maximal naturalism, then Darwinism effectively becomes an atheistic
worldview. This is, I believe, the rhetorical impact most commonly intended
in ID literature, especially when the reader is offered the binary choice—either
Darwinism or design. In ID literature, the term “Darwinism”
is effectively used as a label that tells the reader, Warning! Maximal
naturalism included.
Similar concerns must be raised when Darwinism is referred to as a “nonteleological”
theory. If the characterization “nonteleological” entails the
rejection of purpose or intention at all levels of consideration,
then “Darwinism” is once again functioning effectively as a
substitute label for “maximal naturalism.”
There is, however, some disagreement within the ranks of ID advocates
about whether something like the common ancestry thesis itself entails
maximal naturalism, or whether common ancestry is acceptable so long as
it requires something more than natural processes alone. Johnson, for
instance, holds common ancestry and maximal naturalism to be inseparable,
while Behe and Dembski accept common ancestry, provided that it is dependent
on natural processes being occasionally supplemented by acts of intelligent
design.
Dembski expresses his position as follows:
…intelligent design is not a form of anti-evolutionism. [On the contrary,
ID is] fully compatible with large-scale evolution over the course of
natural history, all the way up to what biologists refer to as “common
descent.”
But…intelligent design is not willing to accept common descent as
a consequence of the Darwinian mechanism. The Darwinian mechanism claims
the power to transform a single organism … into the full diversity
of life that we see both around us and in the fossil record. If intelligent
design is correct, then the Darwinian mechanism of natural selection and
random variation lacks that power.
The Darwinian Mechanism
The question then becomes, what is “the Darwinian mechanism”?
Does it, for instance, include all natural processes that may have contributed
to the formational history of life on earth? There is some ambivalence
and inconsistency in the ID literature on this matter, but my judgment
is that most references to “the Darwinian mechanism” exclude
a number of relevant natural processes that may have played important
roles in life's formational history. Behe and Dembski, for example, consider
only the most strictly gradualistic form of variation and selection. Biological
events that go beyond the most minuscule of mutations are placed outside
the category of “Darwinian” processes. In some cases, the process
of natural selection is limited by the demand that selection be based—from
beginning to end—only on the final function of some structure. The
roles of functional precursors that may have had functions different from
the final one are effectively excluded.
Another restriction on the menu of relevant natural processes considered
by Dembski arises from his requirement that scientific explanations regarding
evolutionary processes, if they are to be included in his consideration,
must be causally specific. Full causal specificity—a listing
of every relevant process and its effects—is, of course, the goal
of all scientific explanations, but it is often very difficult to achieve,
especially in the reconstruction of life's formational history. That's
just a fact of life in evolutionary biology, as well as in many other
areas of science.
That being the case, then Dembski's demand for full causal specificity
becomes highly problematic. Many scientific hypotheses regarding the manner
in which new biotic structures came to be actualized might fall short
of full causal specificity—even though they may be highly plausible
applications of mechanisms that are at least partially understood. Only
those mechanisms that are now fully understood, it seems, can be
placed on the menu of relevant natural processes contributing to the Darwinian
mechanism. That might be strategically attractive, but it closes the door
to an abundance of creative and potentially fruitful exploration—the
sort of disciplined speculation that characterizes modern science.
What does it mean to be “intelligently designed”?
Stated as succinctly as I am able, the core scientific claim of the
ID movement is, in effect, this: “We have firm empirical evidence
that some biotic system X could not possibly have been assembled (at least
not for the very first time) by purely natural processes; therefore X
must have been intelligently designed.” I have long said that
to evaluate this claim, two questions must be asked: (1) On what evidence
and reasoning do ID advocates base their claim that X could not have been
actualized by natural processes alone? (2) What does it mean to say that
X was intelligently designed? For the moment, let's focus our attention
on question (2).
What do ID advocates actually mean when they say “X was intelligently
designed”? Presuming that intelligent design is some form of action,
what kind of action? And, action by what sort of agent?
We speak often today of things that have been designed. Cars are designed;
clothing is designed; buildings are designed. Suppose, then, we were to
walk into the headquarters of a major automobile manufacturer and ask
to observe the process of cars being designed. What kind of activity would
we be shown? Would we be taken to the assembly line to see cars being
put together by human hands and mechanical robots? No, we would be taken
to the “design center” where we would see people working with
their minds to conceptualize new cars of various styles to achieve the
manufacturer's intentions in the marketplace. In other words, to say that
a car was designed is to say that a car was purposefully conceptualized.
In contemporary parlance, the action of design is performed by a mind,
intentionally conceptualizing something for the accomplishment of a purpose.
This mind-like action of designing is clearly distinguishable
from the hand-like action of actualizing (assembling, forming,
arranging, constructing) what had first been designed. On a tour of an
automobile manufacturing facility, for instance, we would have no difficulty
in distinguishing the mental work done at the design center from the manual
work done on the assembly line.
But in the history of thought about how living things got to be the way
they now are, the word “design” as the name of an action has
often had a different meaning. William Paley, for example, spoke eloquently
of things like the eye as having been designed, much like he would say
that a pocket-watch was designed. Clearly the several parts of a watch
work efficiently and harmoniously to accomplish the task of keeping and
displaying the time of day. Looking at a watch, we would say without hesitation
that such a timepiece had been designed by a watchmaker. Without doubt,
the watchmaker had used his mind to conceptualize the workings of the
watch.
But mind-action alone does not produce a working watch. The watch
must also be actualized by hand-action. As an artisan, the watchmaker
must not only conceptualize the configuration of gears and dials that
comprise a watch; he must also form the various parts and assemble
them into an actual working mechanism. In the context of eighteenth century
natural theology, to say that something had been designed was to say that
it had been both purposefully conceptualized (by mind-like
action) and skillfully crafted (formed and/or assembled
by hand-like action). This traditional meaning of design action was based
on the artisan metaphor. One person, the artisan, performed two actions—mindfully
conceptualizing some artifact and manually crafting what
had first been planned.
What does it now mean to be “intelligently designed”?
Given the ID movement's almost exclusive emphasis on the question of how
things came to be structured as they now are, and given ID's repeated
emphasis on the presumed inadequacy of natural processes to assemble these
structures, it appears that the primary meaning of “X was intelligently
designed” is that “X was constructed in a way that required
the form-conferring action of some non-natural agent called an intelligent
designer.” As an action, intelligent design entails both the
mind-action of conceptualization and the hand-like action of constructing
or assembling some functional structure, with a very strong emphasis
on design as the means of actualization.
What sort of agents are capable of performing the proposed action of intelligent
design? First, of course, they must be intelligent, which in this
context means capable of making intentional choices. However, as
noted above, the intelligent agents of which ID speaks must also be able
to effect what was first chosen, or to actualize what was
first conceptualized.
When considering embodied intelligent agents, such as humans, we
have no difficulty envisioning how the dual action of conceptualizing
and actualizing might be carried out. Paley's artisan-watchmaker could
both conceive of a fitting mechanical clockwork and then proceed to form
the various parts and to assemble them into a functional watch. However,
when ID advocates speak of biotic systems in nature as the products of
intelligent design action they are proposing action by an agent of an
entirely different sort—an umembodied intelligent agent who
can both purposefully conceptualize something and then actualize that
concept in some material/physical structure.
But how exactly does an unembodied agent act in such a way as to effect
or modify some physical/material structure? How, for instance, might an
unembodied intelligent agent act on a bacterium with no flagellum to actualize
a flagellum where none had been before? Dembski and other advocates of
ID generally choose, for strategic reasons, to leave this question unanswered.
Any reference to this action as miraculous, for instance, would
seriously reduce the chances of getting ID into the public school classroom.
Nonetheless, I see no way to avoid the conclusion that ID (Intelligent
Design) is equivalent to DI (Divine Intervention).
Much remains to be said concerning the place of divine intervention in
the universe's formational history. For now, however, let us return to
the question of appealing to empirical evidence to support the contention
that such form-conferring action is necessary.
What Makes Design Empirically Detectable?
How would we come to know that something, say the bacterial flagellum,
had to be intelligently designed (that is, assembled in a manner
that requires some non-natural, form-conferring action by an unembodied,
choice-making agent)? It's very straightforward, says Dembski.
There does in fact exist a rigorous criterion for discriminating intelligently
caused from unintelligently caused objects. … I call it the complexity-specification
criterion. When intelligent agents act, they leave behind a characteristic
trademark or signature—what I define as specified complexity. The
complexity-specification criterion detects design by identifying this
trademark of designed objects.
And what factors are included in this trademark called “specified
complexity”? There are three: 1) contingency, 2) complexity,
and 3) specification.
An object/event is said to be contingent if, while it is fully
consistent with natural laws, it is not wholly determined by them. The
class of contingent objects is large and I see no need to examine it further
here.
A contingent object is said to be specified if it exhibits a distinctive
pattern that is detachable from the particular event/object itself.
A detachable pattern might, for instance, correspond to some independently
derivable sequence of numbers or letters that has no necessary connection
to the object/event being subjected to the complexity-specification criterion.
However, when Dembski considers whether or not some biotic structure is
specified, he seems content to assert that if the structure maintains
any biological function, it is thereby specified. Much could be said about
Dembski's use of this criterion, but in the limited time we have I shall
focus on the remaining trademark, complexity. In particular, we
shall examine Dembski's case for the conclusion that the bacterial flagellum
bears this trademark.
Is the Bacterial Flagellum Complex?
Following his presentation of what he takes to be the general theoretical
warrant for asserting the need for non-natural, form-conferring action
by an unembodied agent, Dembski holds up the assembling of the bacterial
flagellum as the premier example of a particular biotic structure for
which this action was essential. Granting the contingency of this
biotic system and setting aside the question of its specification,
let us focus on Dembski's argument that it bears the trademark called
complexity.
According to Dembski, to say that any biotic system X is complex
is to say that the probability of its actualization (its coming to be
assembled or constructed as a distinct biotic structure) must be less
than the “universal probability bound,” a
= 10–150;
or, to say it more concisely, X is complex if P(X) < a.
Note that this makes the “complexity” of X a property, not of
X itself, but of the means by which it came to be actualized. This unorthodox
employment of the word complexity is an essential element in Dembski's
case for intelligent design.
Dembski's criterion for complexity is quite easy to state, but is not
easily applied. The principal difficulty arises when we examine precisely
what must be taken into account when P(X), the probability that X will
be actualized, is computed.
Dembski gives explicit consideration of this crucial matter and leads
us to the following position: To determine if X is complex (Dembski's
meaning) we need to compute the value of P(XN), the probability that X
could be actualized by the joint action of all relevant natural processes—all
pure chance opportunities, all regularities described by
deterministic laws, all contingent histories influenced
by evolutionary algorithms, and the like. Given that clarification,
Dembski's criterion becomes, X is complex if P(X|N) < a.
But there is, of course, an obvious epistemic difficulty here. In no case
do we know with certainty all relevant natural ways in which some
biotic system may have historically come to be actualized. If “N”
represents all relevant natural causes, both known and unknown,
and if we use a lower case “n” to designate only those natural
causes that are known to be relevant, then it is clear that the
best we can do is calculate P(X|n).
In some cases this limitation of knowledge might be inconsequential. If
we know enough to make the calculated value of P(X|n) > a,
then the question of complexity can be settled (X is not complex) without
an exhaustive knowledge of all relevant natural processes. But what if
our knowledge is inadequate to do the probability calculations? What if,
for instance, we were able to propose one or more plausibility arguments
regarding the kinds of natural processes that are likely to contribute
to P(X|N), but were not yet able to translate these arguments into numerical
values for probability?
Dembski does seem to recognize this as a problem when he remarks, “Now
it can happen that we may not know enough to determine all the relevant
chance hypotheses [which here, as in most instances, means all relevant
natural processes (hvt)]. Alternatively, we might think we know the
relevant chance hypotheses, but later discover that we missed a crucial
one. In the one case a design inference could not even get going; in the
other, it would be mistaken.” In principle, this epistemic problem
should introduce a considerable degree of modesty in all assessments of
probability values related to the question of the complexity of any particular
biotic system. Complexity—in Dembski's unorthodox sense—is an
elusive quality. Our ability to determine the presence or absence of it
is severely hampered by our limited state of knowledge regarding the specific
way in which natural causes have contributed to the formation of biotic
structures.
However, the more we learn about the self-organizational and transformational
feats that can be accomplished by biotic systems, the less likely it will
be that the conditions for complexity—as Dembski employs this
term in relation to specified complexity—will be satisfied
by any biotic system. For example, in reference to the power of evolutionary
algorithms—natural processes that effectively search for increasingly
better performance at some task—Dembski acknowledges that “An
evolutionary algorithm acts as a probability amplifier. …
But a probability amplifier is also a complexity diminisher.”
That being the case, and given our incomplete knowledge of these probability
amplifiers, Dembski's approach is highly likely to produce numerous false
positive claims for the presence of what he calls “complexity.”
On numerous occasions Dembski asserts, in effect, that “natural causes
cannot generate specified complexity.” Given the definition of specified
complexity, however, such statements are, at best, only trivially true
or tautological. The principal requirement for exhibiting specified complexity
is the requirement that some structure/system cannot be (or is highly
unlikely to be) actualized by natural causes. The question is, however,
Are there any actual objects that demonstrate this quality? If there exist
no biotic systems that actually have this Dembski-defined quality of specified
complexity, then there would be no need to “generate” it
in the first place.
But what about the bacterial flagellum in particular? Dembski is quite
confident that he has demonstrated that it is more than sufficiently complex
(difficult to assemble naturally) to satisfy the complexity portion of
the complexity-specification criterion. How did he do the computation,
and what is the standing of his conclusion?
Is the flagellum complex? Computing the crucial probability.
Following Behe, Dembski describes the bacterial flagellum as an “irreducibly
complex system that is unattainable by the Darwinian mechanism.”
He then seeks “to show how irreducible complexity is a special case
of specified complexity, and … to sketch how one calculates the relevant
probabilities to eliminate chance and infer design for such systems. Determining
whether an irreducibly complex system exhibits specified complexity involves
two things: showing that the system is specified and computing its probability….
Specification is never a problem.” That glib remark about specification
deserves attention, but our immediate concern is with Dembski's attempt
to compute P(flag|N), the probability that E. coli's flagellum was actualized
by the joint action of all relevant natural processes.
Curiously, Dembski not only rejects any proposal consistent with the gradualism
that ID presumes to be an essential feature of the Darwinian mechanism,
he also effectively ignores the fundamental role that genes play in providing
the instructions for the development of cellular structures. Instead,
Dembski simply asserts that the probability in question must be computed
by treating the bacterial flagellum as a chance-assembled discrete
combinatorial object. A discrete combinatorial object is an object
that is composed of particular kinds of building blocks that must first
be gathered into one location and then configured in a particular arrangement
to form the complete object.
Dembski then offers a way of calculating (or estimating) the probability
that any discrete combinatorial object would, by pure chance, self-assemble
from the appropriate sort of building blocks. Specifically, we are asked
to imagine a bacterial flagellum arising from the pure chance gathering
of approximately 50 of the right kinds of proteins (and in the correct
proportions) at some spot in the vicinity of the cell wall and plasma
membrane of E. coli and then, again by chance, happening to configure
themselves into a functioning rotary propulsion system for this bacterial
cell.
Not surprisingly, Dembski's computations of the three probability factors
lead him firmly to the expected conclusion: Considered as a discrete
combinatorial object that must self-assemble from the chance localization
of the requisite, chance-assembled molecular components, the probability
of a flagellum assembling itself and attaching itself to the cell membrane
of E. coli is exceedingly small in comparison to the universal probability
bound.
Note carefully, however, what Dembski has actually done with his probability
computation. By his own definition of complexity, the probability value
he needs is P(flag|N), the probability that the flagellum could form by
the joint action of all relevant natural means. However, given
the epistemic limitation we noted earlier, the best he could possibly
do would be to compute P(flag|n), the probability that the flagellum could
form by the joint action of known natural means. But this is not
what he actually computed. What Dembski computed instead is P(flag|dco),
the probability that the flagellum could form by pure chance alone
as a discrete combinatorial object.
But, of course, no biologist has ever taken the bacterial flagellum
to be a discrete combinatorial object that self-assembled in the manner
described by Dembski. Dembski has not defeated any actual biological
proposition. He has, I believe, slain nothing more than an imaginary dragon.
E. coli bacteria possess flagella, not because flagella self-assemble
and self-attach to the cell membrane, but because the genome of E. coli
came to include in its genetic library the coded instructions for growing
the flagellar propulsion system. That being the case, the question relevant
to the issue of intelligent design is not, Could the flagellum self-assemble
as a discrete combinatorial object? but rather, Could that portion of
the E. coli genome that codes for the production of a flagellum have come
about by natural means?
This is not an easy question to answer definitively. How did the rest
of E. coli's genome come about? If by purely natural means, then would
it not seem odd that the small flagellar portion of the genome required
supplemental designer action that rest of the genome did not?
As a matter of fact, the E. coli genome contains genes for the formation
of structures remarkably similar to portions of the flagellum system.
Bacteria like E. coli possess systems for the secretion of select proteins
from the cytoplasm in the cell interior to the extracellular space beyond,
often directly into host cells. Of special relevance here is the type
III secretion apparatus, composed of about 20 proteins, most of which
are homologous to the components of the flagellar biosynthesis apparatus.
To put it as simply as possible, the type III secretion apparatus and
the “motor apparatus” of the bacterial flagellum employ similar
building blocks and share numerous structural features. Thus, the genetic
coding for one of these structures is going to be closely related to the
coding for the other.
How does Dembski deal with these similarities and relationships in his
book, No Free Lunch? In essence, he ignores them and proceeds to
deal with the flagellum in complete isolation from closely related structures
in the same E. coli cell. Without explanation, and without even acknowledging
the existence of the secretion apparatus or its relationship to the flagellum,
Dembski simply asserts that since the flagellar apparatus could not self-assemble
by pure chance, it must have required the supplemental action of an “intelligent
designer.” Meanwhile, the fully natural actualization of the closely
related secretion apparatus—part of the bacterium-sans-flagellum—is
effectively granted without comment.
The Bottom Line
In conclusion, ID advocates have every right to argue their case. I would,
however, suggest some modifications in their strategy. Specifically, I
would invite them: 1) to be more candid in stating their theological and
philosophical presuppositions; 2) to be more open and candid about their
religious agenda; 3) to get out of the habit of giving key terms (intelligent
design, chance hypothesis, Darwinism, Darwinian mechanism, complexity,
specification, etc.) unorthodox definitions that tend to confuse the discussion;
and 4) to display the same modesty for their own claims that they demand
of normal science.
As it has so far been presented, the case for ID appears to me to be little
more than this: In the absence of a complete, detailed, causally-specific
scientific account for the actualization of some biotic structure, X,
it is logically permissible to posit that X was formed in a way that required
one or more acts of divine form-conferring intervention. That's true,
of course, but I knew that long before the advocates of ID told me so
in the language of irreducible complexity, specified complexity, or the
complexity-specification criterion. Contrary to the beliefs and hopes
of many, I do not see the ID movement as an advance in the science-religion
interaction.
1 A large portion of
this paper is based on my review essay, "E. COLI AT THE NO FREE LUNCHROOM:
Bacterial Flagella and Dembski's Case for Intelligent Design," available
at the AAAS web site, Dialogue on Science, Ethics and Religion section,
www.aaas.org/spp/dser/evolution/perspectives/vantillecoli.pdf. Additional
documentation and references will be found there.
2 Phillip E. Johnson, Darwin On Trial (Downers Grove, Ill: InterVarsity
Press, 1991).
3 Michael J. Behe, Darwin's Black Box: The Biochemical Challenge to Evolution
(New York: The Free Press, 1996).
4 William A. Dembski, No Free Lunch: Why Specified Complexity Cannot Be
Purchased Without Intelligence (Lanham, MD: Rowman & Littlefield Publishers,
Inc., 2002). Future references to this work will be designated simply as
NFL, p. xyz. See also Dembski's earlier work, The Design Inference: Eliminating
Chance Through Small Probabilities (Cambridge: Cambridge University press,
1998).
5 In anti-evolutionist literature it is often implied that the presence
of randomness in natural processes such as random variation or natural (unguided)
selection completely displaces the idea of goals, purposes or intentions.
But that is simply not the case. Although the idea that each individual
event in evolutionary history is purposefully intended or in conformity
to some predetermined plan may have to be set aside, that does not at all
eliminate the possibility that the evolutionary process as a whole might
well be serving some comprehensive purpose. As an illustration, suppose
there were a completely honest gambling casino in which pure randomness
characterized every roll of the dice, every spin of the wheel, every turn
of the card, etc. Nonetheless, the casino accomplishes its purpose of bringing
a handsome profit to the bank at the end of each day. In fact, the owners
of the casino depend on authentic randomness in their computation of payout
rates in order to accomplish their goal of making a profit. Randomness at
one level does not exclude purpose at another. Randomness can be purposefully
employed.
6 NFL, pp. 314.
7 NFL,
pp. 314-315.
8 NFL, p. 6.
9 See NFL, pp. 18-22, for a discussion on the universal probability bound
and Dembski's employment of it.
10 NFL, p. 123n80.
11 NFL, pp. 182-183.
12 NFL, p. 288.
13 NFL, p. 289.
14 See the review article by Christoph J. Heuck, "Type III Protein
Secretion Systems in Bacterial Pathogens of Animals and Plants," in
Microbiology and Molecular Biology Reviews, June 1998, Vol. 62, No. 2, pp.
379-433
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