William A. Dembski
Center for the Renewal of Science and Culture
1402 Third Ave., Suite 400
Seattle, WA 98101
Design's Departure from Science
Should design be permitted back into science generally, and biology in
particular? Scientists bristle at the very thought. For scientists who are
atheists, design is an accident of natural history. Indeed, with no divine
architect to start creation on its course, any designing agents, including
ourselves, must result from a long evolutionary process that itself was not
designed. For the atheist, design occurs at the end of an undesigned
natural process, and cannot be prior to it.
What about scientists who are not atheists? Sadly, most scientists who are
theists agree with their atheist colleagues that design should be excluded
from science. It's not that they agree with their atheist colleagues that
the universe isn't designed. Indeed, as good theists they believe
whole-heartedly that the universe is designed--and not just by any
designer, but by the God of their religious creed. Nevertheless, as a
matter of scientific integrity they believe science is best served by
excluding design. The worry always is that invoking design will stifle
scientific inquiry, substituting a supernatural cause where scientists
should be seeking an ordinary natural cause.
Against this received view, I want to argue that design should be
readmitted to full scientific status. To make this argument, let me begin
by briefly reviewing why design was removed from science in the first
place. Design, in the form of Aristotle's formal and final causes, had
after all once occupied a perfectly legitimate role within natural
philosophy, or what we now call science. With the rise of modern science,
however, these causes fell into disrepute.
We can see how this happened by considering Francis Bacon. Bacon, a
contemporary of Galileo and Kepler, though himself not a scientist, was a
terrific propagandist for science. Bacon concerned himself much about the
proper conduct of science, providing detailed canons for experimental
observation, recording of data, and inferences from data. What interests us
here, however, is what he did with Aristotle's four causes. For Aristotle,
to understand any phenomenon properly, one had to understand its four
causes, namely its material, efficient, formal, and final cause.
A standard example philosophers use to illustrate Aristotle's four causes
is to consider a statue--say Michelangelo's David. The material cause is
what it's made of--marble. The efficient cause is the immediate activity
that produced the statue--Michelangelo's actual chipping away at a marble
slab with hammer and chisel. The formal cause is its structure--it's a
representation of David and not some random chunk of marble. And finally,
the final cause is its purpose--presumably, to beautify some Florentine
Although much more can be said about Aristotle's four causes than is
evident from this illustration, two points are relevant to this discussion.
First, Aristotle gave equal weight to all four causes. In particular,
Aristotle would have regarded any inquiry that omitted one of his causes as
fundamentally deficient. Second, Bacon adamantly opposed including formal
and final causes within science (see his Advancement of Learning). For
Bacon, formal and final causes belong to metaphysics, and not to science.
Science, according to Bacon, needs to limit itself to material and
efficient causes, thereby freeing science from the sterility that
inevitably results when science and metaphysics are conflated. This was
Bacon's line, and he argued it forcefully.
We see Bacon's line championed in our own day by atheists and theists
alike. In Chance and Necessity, biologist and Nobel laureate Jacques Monod
argues that chance and necessity alone suffice to account for every aspect
of the universe. Now whatever else we might want to say about chance and
necessity, they provide at best a reductive account of Aristotle's formal
causes and leave no room whatever for Aristotle's final causes. Indeed,
Monod explicitly denies any place for purpose within science.
Monod is an outspoken atheist. Nevertheless, as outspoken a theist as
Stanley Jaki will agree with Monod about the nature of science. Jaki is as
theologically conservative a historian of science and Catholic priest as
one is likely to find. Yet in his published work he explicitly states that
purpose is a purely metaphysical notion, and cannot legitimately be
included within science. Jaki's exclusion of purpose, and more generally
design, from science has practical implications. For instance, it leads him
to regard Michael Behe's project of inferring biological design from
irreducibly complex biochemical systems as hopelessly misguided.
Now I don't want to give the impression that I'm advocating a return to
Aristotle's theory of causation. There are problems with Aristotle's
theory, and it needed to be replaced. My concern, however, is with what
replaced it. By limiting scientific inquiry to material and efficient
causes, Bacon fed into a mechanistic understanding of the universe that was
soon to dominate science.
To be sure, mechanism has its advantages. Back in the 17th century the
French playwright Moliere ridiculed Aristotelians for explaining the
medicinal properties of opium in terms of its "dormitive power." Appealing
to a final cause like "dormitive power" is of course totally
unenlightening. Much better is to know the chemical properties of opium and
how those properties take advantage of certain nerve centers in the brain.
Mechanistic explanations that describe how something works without
speculating about its ultimate meaning or purpose seemed a much safer
course for science, and one that promised to, and in fact did, yield much
Mechanism is still with us, though not the deterministic form that
dominated from Newton to the quantum revolution. In our own day scientists
concentrate on undirected natural causes, and take as their preferred mode
of scientific explanation a combination of deterministic laws and chance
processes. Chance and necessity, to use a phrase we've already seen, set
the boundaries of scientific explanation, and woe to anyone who would
reintroduce a sterile and moribund teleology into science.
Why Reinstate Design?
Faced with a discredited Aristotelian science, a marvelously successful
modern science, and an entrenched opposition within the scientific
community against design, why should anyone want to reintroduce design into
science? The short answer is that chance and necessity have proven too thin
an explanatory soup on which to nourish a robust science. In fact, by
dogmatically excluding design from science, scientists are themselves
stifling scientific inquiry. To a generation suckled on naturalism's teat,
this will no doubt seem counterintuitive. Nevertheless, the case for
reintroducing design within science becomes compelling as soon as we attend
to certain relevant facts.
The first glimmers that excluding design from science places an artificial
restriction on science come from admissions by scientists opposed to
design. The arch-Darwinist Richard Dawkins begins his book The Blind
Watchmaker by stating that "Biology is the study of complicated things that
give the appearance of having been designed for a purpose." Statements like
this echo throughout the biological literature. In What Mad Pursuit Francis
Crick, Nobel laureate and co-discoverer of the structure of DNA, writes
that "Biologists must constantly keep in mind that what they see was not
designed, but rather evolved."
Granted, the biological community thinks it has accounted for the apparent
design in nature apart from any actual design (typically through the
Darwinian mechanism of mutation and selection). The point to appreciate,
however, is that in accounting for the apparent design in nature,
biologists regard themselves as having made a successful scientific
argument against actual design. Scientific refutation is a double-edged
sword. Claims that are refuted scientifically may be wrong, but they are
not necessarily wrong. Alternatively, for a claim to be scientifically
falsifiable, it must have the possibility of being true.
To see this, consider what would happen if microscopic examination revealed
that every cell was inscribed with the phrase "Made by Yahweh." Of course
cells don't have "Made by Yahweh" inscribed on them, but that's not the
point. The point is that we wouldn't know this unless we actually looked
at cells under the microscope.
Design always remains a live option in biology. A priori prohibitions
against design are easily countered, especially in an age of diversity and
multiculturalism where it is all too easy to ask Who sets the rules for
science? Nonetheless, once we admit that design cannot be excluded from
science on first principles, a weightier question remains: Why should we
want to admit design into science?
To answer this question, let us turn it around and ask instead Why
shouldn't we want to admit design into science? Leaving aside Aristotle's
doctrine of causes, what's wrong with explaining something in terms of
design by an intelligent agent? Certainly there are many everyday
occurrences which we explain by appealing to design. Moreover, in our
workaday lives it is absolutely crucial to distinguish accident from
design. We demand answers to such questions as, Did she fall or was she
pushed? Did someone die accidentally or commit suicide? Was this song
conceived independently or was it plagiarized? Did someone just get lucky
on the stock market, or was there insider trading?
Not only do we demand answers to such questions, but entire industries are
devoted to drawing the distinction between accident and design. Here we can
include forensic science, intellectual property law, insurance claims
investigation, cryptography, and random number generation--to name but a
few. Science itself needs to draw this distinction to keep itself honest.
In a recent issue of Science (January 23, 1998), a Medline websearch
uncovered a "paper published in Zentralblatt fur Gynakologie in 1991
[containing] text that is almost identical to text from a paper published
in 1979 in the Journal of Maxillofacial Surgery." Plagiarism and data
falsification are far more common in science than we would like to admit.
What keeps these abuses in check is our ability to detect them.
If design is so readily detectable outside science, and if its
detectability is one of the key factors keeping scientists honest, why
should design be barred from the content of science? With reference to
biology, why should we have to constantly remind ourselves that biology
studies things that only appear to be designed, but that in fact are not
designed? Isn't it at least conceivable that there could be good positive
reasons for thinking biological systems are in fact designed?
The biological community's response to these questions has been to resist
design at all costs. The worry is that for natural objects (unlike human
artifacts), the distinction between design and non-design cannot be
reliably drawn. Consider, for instance, the following remark by Darwin in
the concluding chapter of his Origin of Species: "Several eminent
naturalists have of late published their belief that a multitude of
reputed species in each genus are not real species; but that other species
are real, that is, have been independently created.... Nevertheless they do
not pretend that they can define, or even conjecture, which are the created
forms of life, and which are those produced by secondary laws. They admit
variation as a vera causa in one case, they arbitrarily reject it in
another, without assigning any distinction in the two cases." It's this
worry of falsely attributing something to design (here identified with
creation) only to have it overturned later that has prevented design from
entering science proper.
This worry, though perhaps justified in the past, has now been dispatched.
There does in fact exist a rigorous criterion for distinguishing
intelligently caused objects from unintelligently caused ones. Many
special sciences already use this criterion, though in a pre-theoretic form
(e.g., forensic science, artificial intelligence, cryptography, archeology,
and the search for extra-terrestrial intelligence). The great breakthrough
of the intelligent design movement has been to isolate and make precise
this criterion. Michael Behe's criterion of irreducible complexity for
establishing the design of biochemical systems is a special case of this
general criterion for detecting design (see Behe's book Darwin's Black
The Complexity-Specification Criterion
What does this criterion look like? Although a detailed explanation and
justification of this criterion is fairly technical (for a full account see
my book The Design Inference, due out this fall with Cambridge University
Press), the basic idea is quite simple and easily illustrated. Consider how
the radio astronomers in the movie Contact detected an extra-terrestrial
intelligence. This movie, which came out last summer and was based on a
novel by Carl Sagan, was an enjoyable piece of propaganda for the SETI
research program--the Search for Extra-Terrestrial Intelligence. To make
the movie interesting, the SETI researchers actually had to find an
extra-terrestrial intelligence (the non-fictional SETI program has yet to
be so fortunate).
How, then, did the SETI researchers in Contact find an extra-terrestrial
intelligence? To increase their chances of finding an extra-terrestrial
intelligence, SETI researchers monitor millions of radio signals from outer
space. Many natural objects in space produce radio waves (e.g., pulsars).
Looking for signs of design among all these naturally produced radio
signals is like looking for a needle in a haystack. To sift through the
haystack, SETI researchers run the signals they monitor through computers
programmed with pattern-matchers. So long as a signal doesn't match one of
the pre-set patterns, it will pass through the pattern-matching sieve (and
that even if it has an intelligent source). If, on the other hand, it does
match one of these patterns, then, depending on the pattern matched, the
SETI researchers may have cause for celebration.
The SETI researchers in Contact did find a signal worthy of celebration,
namely the following:
In this sequence of 1126 bits, 1's correspond to beats and 0's to pauses.
This sequence represents the prime numbers from 2 to 101, where a given
prime number is represented by the corresponding number of beats (i.e.,
1's), and the individual prime numbers are separated by pauses (i.e., 0's).