by William A. Dembski


Intelligent design begins with a seemingly innocuous question: Can objects, even
if nothing is known about how they arose, exhibit features that reliably signal
the action of an intelligent cause? To see whats at stake, consider Mount
Rushmore. The evidence for Mount Rushmores design is directeyewitnesses saw
the sculptor Gutzon Borglum spend the better part of his life designing and
building this structure. But what if there were no direct evidence for Mount
Rushmores design? What if humans went extinct and aliens, visiting the earth,
discovered Mount Rushmore in substantially the same condition as it is now?
In that case, what about this rock formation would provide convincing
circumstantial evidence that it was due to a designing intelligence and not
merely to wind and erosion? Designed objects like Mount Rushmore exhibit
characteristic features or patterns that point to an intelligence. Such features
or patterns constitute signs of intelligence. Proponents of intelligent design,
known as design theorists, purport to study such signs formally, rigorously, and
scientifically. Intelligent design may therefore be defined as the science that
studies signs of intelligence.

Because a sign is not the thing signified, intelligent design does not presume
to identify the purposes of a designer. Intelligent design focuses not on the
designers purposes (the thing signified) but on the artifacts resulting from a
designers purposes (the sign). What a designer intends or purposes is, to be
sure, an interesting question, and one may be able to infer something about a
designers purposes from the designed objects that a designer produces.
Nevertheless, the purposes of a designer lie outside the scope of intelligent
design. As a scientific research program, intelligent design investigates the
effects of intelligence and not intelligence as such.

Intelligent design is controversial because it purports to find signs of
intelligence in nature, and specifically in biological systems. According to the
evolutionary biologist Francisco Ayala, Darwins greatest achievement was to
show how the organized complexity of organisms could be attained apart from a
designing intelligence. Intelligent design therefore directly challenges
Darwinism and other naturalistic approaches to the origin and evolution of life.

The idea that an intrinsic intelligence or teleology inheres in and is expressed
through nature has a long history and is embraced by many religious traditions.
The main difficulty with this idea since Darwins day, however, has been to
discover a conceptually powerful formulation of design that can fruitfully
advance science. What has kept design outside the scientific mainstream since
the rise of Darwinism has been the lack of precise methods for distinguishing
intelligently caused objects from unintelligently caused ones.

For design to be a fruitful scientific concept, scientists have to be sure that
they can reliably determine whether something is designed. Johannes Kepler, for
instance, thought the craters on the moon were intelligently designed by moon
dwellers. We now know that the craters were formed by purely material factors
(like meteor impacts). This fear of falsely attributing something to design,
only to have it overturned later, has hindered design from entering the
scientific mainstream. But design theorists argue that they now have formulated
precise methods for discriminating designed from undesigned objects. These
methods, they contend, enable them to avoid Keplers mistake and reliably locate
design in biological systems.

As a theory of biological origins and development, intelligent designs central
claim is that only intelligent causes adequately explain the complex,
information-rich structures of biology and that these causes are empirically
detectable. To say intelligent causes are empirically detectable is to say there
exist well-defined methods that, based on observable features of the world, can
reliably distinguish intelligent causes from undirected natural causes. Many
special sciences have already developed such methods for drawing this
distinctionnotably forensic science, cryptography, archeology, and the search
for extraterrestrial intelligence (SETI). Essential to all these methods is the
ability to eliminate chance and necessity.

Astronomer Carl Sagan wrote a novel about SETI called Contact, which was later
made into a movie. The plot and the extraterrestrials were fictional, but Sagan
based the SETI astronomers methods of design detection squarely on scientific
practice. Real-life SETI researchers have thus far failed to conclusively detect
designed signals from distant space, but if they encountered such a signal, as
the films astronomers did, they too would infer design. Why did the radio
astronomers in Contact draw such a design inference from the signals they
monitored from space? SETI researchers run signals collected from distant space
through computers programmed to recognize preset patterns. These patterns serve
as a sieve. Signals that do not match any of the patterns pass through the sieve
and are classified as random.

After years of receiving apparently meaningless, random signals, the Contact
researchers discovered a pattern of beats and pauses that corresponded to the
sequence of all the prime numbers between two and one-hundred and one. (Prime
numbers are divisible only by themselves and by one.) That startled the
astronomers, and they immediately inferred an intelligent cause. When a sequence
begins with two beats and then a pause, three beats and then a pause, and
continues through each prime number all the way to one-hundred and one beats,
researchers must infer the presence of an extraterrestrial intelligence.
Heres the rationale for this inference: Nothing in the laws of physics requires
radio signals to take one form or another. The prime sequence is therefore
contingent rather than necessary. Also, the prime sequence is long and hence
complex. Note that if the sequence were extremely short and therefore lacked
complexity, it could easily have happened by chance. Finally, the sequence was
not merely complex but also exhibited an independently given pattern or
specification (it was not just any old sequence of numbers but a mathematically
significant onethe prime numbers).

Intelligence leaves behind a characteristic trademark or signaturewhat within
the intelligent design community is now called specified complexity. An event
exhibits specified complexity if it is contingent and therefore not necessary;
if it is complex and therefore not readily repeatable by chance; and if it is
specified in the sense of exhibiting an independently given pattern. Note that a
merely improbable event is not sufficient to eliminate chanceby flipping a coin
long enough, one will witness a highly complex or improbable event. Even so, one
will have no reason to attribute it to anything other than chance.

The important thing about specifications is that they be objectively given and
not arbitrarily imposed on events after the fact. For instance, if an archer
fires arrows at a wall and then paints bulls-eyes around them, the archer
imposes a pattern after the fact. On the other hand, if the targets are set up
in advance (specified), and then the archer hits them accurately, one
legitimately concludes that it was by design.

The combination of complexity and specification convincingly pointed the radio
astronomers in the movie Contact to an extraterrestrial intelligence. Note that
the evidence was purely circumstantialthe radio astronomers knew nothing about
the aliens responsible for the signal or how they transmitted it. Design
theorists contend that specified complexity provides compelling circumstantial
evidence for intelligence. Accordingly, specified complexity is a reliable
empirical marker of intelligence in the same way that fingerprints are a
reliable empirical marker of an individuals presence. Moreover, design
theorists argue that purely material factors cannot adequately account for
specified complexity.

In determining whether biological organisms exhibit specified complexity, design
theorists focus on identifiable systems (e.g., individual enzymes, metabolic
pathways, and molecular machines). These systems are not only specified by their
independent functional requirements but also exhibit a high degree of
complexity.

In Darwins Black Box, biochemist Michael Behe connects specified complexity to
biological design through his concept of irreducible complexity. Behe defines a
system as irreducibly complex if it consists of several interrelated parts for
which removing even one part renders the systems basic function unrecoverable.
For Behe, irreducible complexity is a sure indicator of design. One irreducibly
complex biochemical system that Behe considers is the bacterial flagellum. The
flagellum is an acid-powered rotary motor with a whip-like tail that spins at
twenty-thousand revolutions per minute and whose rotating motion enables a
bacterium to navigate through its watery environment.

Behe shows that the intricate machinery in this molecular motorincluding a
rotor, a stator, O-rings, bushings, and a drive shaftrequires the coordinated
interaction of approximately forty complex proteins and that the absence of any
one of these proteins would result in the complete loss of motor function. Behe
argues that the Darwinian mechanism faces grave obstacles in trying to account
for such irreducibly complex systems. In No Free Lunch, William Dembski shows
how Behes notion of irreducible complexity constitutes a particular instance of
specified complexity.

Once an essential constituent of an organism exhibits specified complexity, any
design attributable to that constituent carries over to the organism as a whole.
To attribute design to an organism one need not demonstrate that every aspect of
the organism was designed. Organisms, like all material objects, are products of
history and thus subject to the buffeting of purely material factors.

Automobiles, for instance, get old and exhibit the effects of corrosion, hail,
and frictional forces. But that doesnt make them any less designed. Likewise
design theorists argue that organisms, though exhibiting the effects of history
(and that includes Darwinian factors such as genetic mutations and natural
selection), also include an ineliminable core that is designed.

Intelligent designs main tie to religion is through the design argument.
Perhaps the best-known design argument is William Paleys. Paley published his
argument in 1802 in a book titled Natural Theology. The subtitle of that book is
revealing: Evidences of the Existence and Attributes of the Deity, Collected
from the Appearances of Nature. Paleys project was to examine features of the
natural world (what he called appearances of nature) and from there draw
conclusions about the existence and attributes of a designing intelligence
responsible for those features (whom Paley identified with the God of
Christianity).

According to Paley, if one finds a watch in a field (and thus lacks all
knowledge of how the watch arose), the adaptation of the watchs parts to
telling time ensures that it is the product of an intelligence. So too,
according to Paley, the marvelous adaptations of means to ends in organisms
(like the intricacy of the human eye with its capacity for vision) ensure that
organisms are the product of an intelligence. The theory of intelligent design
updates Paleys watchmaker argument in light of contemporary information theory
and molecular biology, purporting to bring this argument squarely within
science.

In arguing for the design of natural systems, intelligent design is more modest
than the design arguments of natural theology. For natural theologians like
Paley, the validity of the design argument did not depend on the fruitfulness of
design-theoretic ideas for science but on the metaphysical and theological
mileage one could get out of design. A natural theologian might point to nature
and say, Clearly, the designer of this ecosystem prized variety over neatness.
A design theorist attempting to do actual design-theoretic research on that
ecosystem might reply, Although thats an intriguing theological possibility,
as a design theorist I need to keep focused on the informational pathways
capable of producing that variety.

In his Critique of Pure Reason, Immanuel Kant claimed that the most the design
argument can establish is an architect of the world who is constrained by the
adaptability of the material in which he works, not a creator of the world to
whose idea everything is subject. Far from rejecting the design argument, Kant
objected to overextending it. For Kant, the design argument legitimately
establishes an architect (that is, an intelligent cause whose contrivances are
constrained by the materials that make up the world), but it can never establish
a creator who originates the very materials that the architect then fashions.
Intelligent design is entirely consonant with this observation by Kant. Creation
is always about the source of being of the world. Intelligent design, as the
science that studies signs of intelligence, is about arrangements of preexisting
materials that point to a designing intelligence. Creation and intelligent
design are therefore quite different. One can have creation without intelligent
design and intelligent design without creation. For instance, one can have a
doctrine of creation in which God creates the world in such a way that nothing
about the world points to design. The evolutionary biologist Richard Dawkins
wrote a book titled The Blind Watchmaker: Why the Evidence of Evolution Reveals
a Universe without Design. Even if Dawkins is right about the universe revealing
no evidence of design, it would not logically follow that it was not created. It
is logically possible that God created a world that provides no evidence of
design. On the other hand, it is logically possible that the world is full of
signs of intelligence but was not created. This was the ancient Stoic view, in
which the world was eternal and uncreated, and yet a rational principle pervaded
the world and produced marks of intelligence in it.

The implications of intelligent design for religious belief are profound. The
rise of modern science led to a vigorous attack on all religions that treat
purpose, intelligence, and wisdom as fundamental and irreducible features of
reality. The high point of this attack came with Darwins theory of evolution.
The central claim of Darwins theory is that an unguided material process
(random variation and natural selection) could account for the emergence of all
biological complexity and order. In other words, Darwin appeared to show that
the design in biology (and, by implication, in nature generally) was
dispensable. By showing that design is indispensable to the scientific
understanding of the natural world, intelligent design is reinvigorating the
design argument and at the same time overturning the widespread misconception
that the only tenable form of religious belief is one that treats purpose,
intelligence, and wisdom as byproducts of unintelligent material processes.


Bibliography

Beckwith, Francis J. Law, Darwinism, and Public Education: The Establishment
Clause and the Challenge of Intelligent Design. Lanham, Md., 2003.
Behe, Michael J. Darwins Black Box: The Biochemical Challenge to Evolution. New
York, 1996.
Dawkins, Richard. The Blind Watchmaker: Why the Evidence of Evolution Reveals a
Universe without Design. New York, 1986.
Dembski, William A. No Free Lunch: Why Specified Complexity Cannot Be Purchased
without Intelligence. Lanham, Md., 2002.
Forrest, Barbara. The Wedge at Work: How Intelligent Design Creationism Is
Wedging Its Way into the Cultural and Academic Mainstream. In Intelligent
Design Creationism and Its Critics: Philosophical, Theological, and Scientific
Perspectives, edited by Robert T. Pennock, pp. 553, Cambridge, Mass., 2001.
Giberson, Karl W. and Donald A. Yerxa. Species of Origins: Americas Search for
a Creation Story. Lanham, Md., 2002.
Hunter, Cornelius G. Darwins God: Evolution and the Problem of Evil. Grand
Rapids, Mich., 2002.
Manson, Neil A., ed. God and Design: The Teleological Argument and Modern
Science. London, 2003.
Miller, Kenneth R. Finding Darwins God: A Scientists Search for Common Ground
between God and Evolution. San Francisco, 1999.
Rea, Michael C. World without Design: The Ontological Consequences of
Naturalism. Oxford, 2002.
Witham, Larry. By Design: Science and the Search for God. San Francisco, 2003.
Woodward, Thomas. Doubts about Darwin: A History of Intelligent Design. Grand
Rapids, Mich., 2003.

Bibliographic Essay

Larry Witham provides the best overview of intelligent design, even-handedly
treating its scientific, cultural, and religious dimensions. As a journalist,
Witham has personally interviewed all the main players in the debate over
intelligent design and allows them to tell their story. For intelligent designs
place in the science and religion dialogue, see Giberson and Yerxa. For
histories of the intelligent design movement, see Woodward (a supporter) and
Forrest (a critic). See Behe and Dembski to overview intelligent designs
scientific research program. For a critique of that program, see Miller. For an
impassioned defense of Darwinism against any form of teleology or design, see
Dawkins. Mansons anthology situates intelligent design within broader
discussions about teleology. Rea probes intelligent designs metaphysical
underpinnings. Hunter provides an interesting analysis of how intelligent design
and Darwinism play off the problem of evil. Beckwith examines whether
intelligent design is inherently religious and thus, on account of church-state
separation, must be barred from public school science curricula.


William A. Dembski

Baylor University