William A. Dembski
There's an old joke about the philosopher Rudolf Carnap and his method of
doing philosophy. According to the joke, Carnap's method was to begin any
philosophical investigation with the statement "Consider a formal language
L." As the good logical positivist he was, Carnap desired the precision
inherent in formal languages. Unfortunately, precision has its price. Formal
languages are not natural languages and the problems expressible in formal
languages need not connect to actual problems in the real world. With formal
languages the question ever remains whether they adequately capture the subject
under investigation.
Appropriately modified, the joke about Rudolf Carnap can be retold about
Stuart Kauffman and the scientific method he employs in At Home in the
Universe. According to the modified joke, Kauffman's method is to begin any
scientific investigation with the statement "Consider an NK Boolean
network." Indeed, throughout At Home in the Universe just about
every real-world problem gets translated into a toy-world problem involving NK
Boolean networks. As with Carnap's formal languages, NK Boolean networks have
the advantage of complete logical precision. But they also suffer the
disadvantage of losing touch with reality. And it is this disadvantage which
ultimately proves the undoing of Kauffman's project.
In broad terms, Kauffman's project is quite simple. Kauffman wants to
account for the origin and development of life. Now there is a dominant
scientific theory that purports to do just this, namely, the neo-Darwinian
synthesis. Nonetheless, Kauffman is dissatisfied with it. According to Kauffman
the twin pillars of the dominant theory--mutation and natural selection--are
inadequate. Kauffman wants therefore to supplement these twin pillars with yet
a third pillar, what he calls "laws of self-organization."
Unfortunately, just what these laws of biological self-organization are is
at this point far from evident. The subtitle of At Home in the Universe
quite properly reads The Search for the Laws of Self-Organization and
Complexity. To date this search has been unsuccessful. Indeed, Kauffman
admits that he is searching for laws he has yet to find. An obvious question
therefore arises: Whence Kauffman's confidence that such laws even exist?
Kauffman's confidence rests in an analogy. In the non-linear dynamics of
physics and the simulations of computer science, Kauffman finds
self-organizational scenarios that are suggestive of what might have happened
in biology. Kauffman's project therefore is to use non-linear dynamics and
computer simulations to massage our intuitions, make the search for laws of
self-organization seem plausible, and ultimately facilitate the discovery of
such laws. And of course, the main analytic tool for carrying out this project
is his NK Boolean networks.
Before considering the details and merits of Kauffman's project, it will
help to understand the motivation behind it. Throughout his book Kauffman makes
very clear that he is after a non-mysterious account of the origin and
development of life. For Kauffman such a non-mysterious account is one that
appeals only to natural laws and is devoid of any reference to a "master
choreographer" (p.208). Appeals to intelligent design are therefore ruled
out from the start.
All the same, Kauffman is not wholly without a sense of mystery and the
sacred. At the end of his book Kauffman encourages us to "reinvent"
the sacred. Indeed, a religious impulse underlies Kauffman's rejection of
strict Darwinism, with its exclusive dependence on mutation and selection. As Kauffman
sees it, strict Darwinism makes the universe a giant test tube within a
stochastic chemistry lab. To reinvent the sacred, Kauffman needs the universe
to be more than a test tube--it needs to be our home. And for the universe to
be our home, our place in the universe must be assured. Laws of
self-organization hold such a promise. Thus Kauffman will write, "I would
rather life be expected in this unfolding since the Big Bang than that life be
incredibly improbable in the timespan available" (p. 304).
Let us now turn to the details and merits of Kauffman's project. To strict
Darwinists like Richard Dawkins and Daniel Dennett, Kauffman's project will
seem thoroughly misguided. Indeed, what is the point of positing unknown laws
of self-organization to explain biological phenomena when these same phenomena
have already been adequately explained in terms of mutation and selection?
Kauffman's project casts doubt where there ought to be certainty. Kauffman's
project problematizes what ought not to be a problem. For the strict Darwinist,
laws of self-organization are leeches whose only effect is to sap a perfectly
good theory (i.e., the neo-Darwinian synthesis) of its vitality.
Yet for a growing number of dissenters, who view mutation and selection as
inadequate to account for the full diversity of biological phenomena,
Kauffman's project is full of promise. Our choices are, after all, limited. The
order we observe in living systems is either exogenous or endogenous--either it
is imposed from without by an intelligent cause or it arises spontaneously from
the intrinsic properties of matter. For Kauffman exogenous order is mysterious
and to be rejected out of hand. Hence the order must be endogenous. And since
mutation and selection are inadequate to account for the order, still some
third factor must be invoked to yield an adequate explanation of life.
According to Kauffman this third factor is the laws of self-organization.
At this level of generality Kauffman's project remains full of promise. The
laws of self-organization that Kauffman envisages derive their inspiration from
the non-linear dynamics of physics and the simulations of computer science.
Here we have extremely active areas of research that regularly exhibit emergent
properties of complex systems. Moreover, if Kauffman is correct in assuming
that the order we observe in living systems is endogenous, then it makes
perfect sense to treat life as an emergent property of a complex system.
If we delve a little deeper, however, Kauffman's project evaporates into a promissory
note with little or no substance backing it up. Kauffman is notoriously
slippery about defining terms. Order and complexity, the very things his
hard-sought laws of self-organization are supposed to produce, are themselves
never defined. Consider Paley's watch and a rock on a beach. Both can be viewed
as highly complex. Indeed, the instructions to construct a watch and the
instructions to construct an exact replica of an irregularly hewn stone will
both be vast. Moreover, both have an order. How does the complexity and order
of the one differ from the other? Kauffman never clarifies what he means by
complexity and order, or how these concepts apply in one case but not another.
Or consider Kauffman's ubiquitous NK Boolean networks. An NK Boolean network
is a set of N nodes, each of which is assigned a value of 0 or 1, and which in
being reassigned values depends functionally only on the values already
assigned to K fixed nodes (K < N). No doubt, Kauffman's NK Boolean networks
are capable of exhibiting many interesting behaviors. But to call the nodes
"genes," as he is wont to do, and then take what he interprets as
self-organizational behavior by the Boolean network as evidence for
self-organization in the formation and development of life is utterly
gratuitous.
Nowhere does Kauffman even attempt to establish a correspondence between the
mathematical models he runs on his computer and the actual processes matter
must undergo to form a biological system. I find this omission unconscionable,
for it represents a descent into mysticism worse than any Kauffman claims to
avoid. Kauffman will write, "it is not implausible that life emerged as a
phase transition to collective autocatalysis once a chemical minestrone, held
in a localized region able to sustain adequately high concentrations, became
thick enough with molecular diversity" (p. 274).
This is not science, but alchemy (cf. p. 277 where Kauffman actually uses
the word "alchemy" to describe what he is doing). Indeed, once
Kauffman leaves the pristine world of mathematical modeling and computer
simulations, and turns to the messy world of matter in motion, he can do no
better than alchemy. Kauffman's laws of self-organization must do their
self-organizing all by themselves. A supracritical mixture of diverse molecules
(Kauffman's "chemical minestrone") operating according to laws of
self-organization must--if he is right--be able to work the magic of life. Get
the proper mixture and life will emerge.
Nor can Kauffman's approach ever get beyond alchemy. A very damning
admission occurs when Kauffman considers a rather large NK Boolean network in
which N equals 100,000. Previously Kauffman has contended that life constitutes
an attractor for an autocatalytic set of chemicals. Such an auto-catalytic set
will be exceedingly more complicated than the NK Boolean network he is now
considering. And yet Kauffman will admit that finding an attractor even for
this Boolean network will be all but impossible: "I cannot show you an
attractor in such an unfathomable state space" (p. 100). If Kauffman's
stylized mathematical models are unfathomable, how much more nature herself?
Apparently oblivious to how it undercuts his program, Kauffman repeats this
admission later on, and even more forcefully: "It is one thing to talk about
supracritical reaction systems blasting off into the outer space of chemical
creativity, but all confined to a computer model. It is quite another thing to
fathom what might go on in a real chemical system" (pp. 118-9). And fathom
it he never does. Kauffman has not one thing to say about real chemical systems
except the unsubstantiated assertion that the right mixture of chemicals
governed by laws of self-organization will yield life. But the laws of
self-organization he cites are unknown. And even if they were known, there is
no reason to think that we could ever apply them (after all, we know the laws
that govern toy examples like Boolean networks, and can't even apply them
there). Alchemy plus inscrutable laws of self-organization will ever remain alchemy.
All the problems inherent in the origin and development of life are still
there after one finishes the book.
Copyright © 1996 William A. Dembski. All
rights reserved. International copyright secured.
File Date: 11.14.96
