Michael Ruse’s Darwin and Design
is the third book in his trilogy on evolution, the first being Monad and
Man: The Concept of Progress in Evolutionary Biology, the second being Mystery
of Mysteries: Is Evolution a Social Construction? All three books are
written for a non-specialist audience and all three try to place evolutionary
thought and the debate around evolution into the wider cultural climate of the
times. In Darwin and Design Ruse takes on the relation between the
theory of evolution and the argument from design as one of the classical
ways to prove that there has to be a God. Aiming at the non-specialist the
debate is not developed systematically or presented in formal clothing, but
enfolds as Ruse leads us through the history of the argument from design and
the unfolding of Darwinism and the theory of evolution. Ruse starts with the
versions of the argument from design in Plato and Aristotle, distinguishes
between a realistic reading of it (i.e. there really is design by God)
and Kant’s methodological reading of it (i.e. we have to see the world as if
it was designed to formulate the laws of biology), and sees the argument from
design in British natural theology employed as a justification of science: If
the laws of nature are God’s design, then it cannot be against faith to do science
(as a means to understand God’s ways).

The teleological language used in
the argument from design is congenial to the language of functions in biology,
it seems. The function/telos of the eye is to see, the function of the
heart to circulate blood — and so on. Darwin himself often writes in a
teleological fashion. One of his favorite pictures of the process of evolution
is the similarity to breeding, which obviously involves the farmer planning his
breed. So the question is: What keeps Darwin’s (and other evolutionist’s) usage
of functional or teleological expression distinct from the cosmological view of
the argument from design?

Ruse is not very explicit about the
formal structure of the argument from design, but introduces an important
distinction between the two major steps in that argument. The first premise of
the argument Ruse calls "the argument to (organized) complexity".
This is a premise won by observation. We see around us highly complex living
systems. Once we look into the details of the working of the human eye or the
metamorphosis of a butterfly we see what immensely structured entities or
processes we encounter. Given this complexity the decisive step, according to
Ruse, is the "argument to design", namely that the observed
complexity is design. Ruse takes the name "argument from design" a
misnomer, since it is tautological that design requires somebody doing the
designing. The crucial step, therefore, rather is that complexity is taken as
design. This step involves two sub-steps, it seems. The first sub-step
underlines that complexity is something to be explained. Complexity is not
random. Explained such this sub-step trades on the definition of "complexity",
and seems to be unproblematic. Scientists, naturalists, and religious people agree
on the need to explain the occurrence of organized complexity in nature. The
decisive second sub-step in the argument to design is the statement that
nothing but design explains complexity. It is a negative claim arguing
to design as the only/best explanation. It is here that Darwin and the theory
of evolution enter, and it is here where the argument from design crumbles.
What the theory of mutation ("inherited variation" in Darwin’s first
version of his theory) and selection provides is exactly some such explanation
of complexity as adaptation to a (complex) environment. Since there is the
interplay of (random) mutation and selection (of better adaptive traits), there
is a mechanism — even an "algorithm" the workings of which can be
ascertained ex post — to increase complexity, to get "design"
out of chaos. Functional talk in biology is justified as talk about the
adaptive nature of (acquired) traits of a species. The trait is not given (by
God) to the species in order to fulfill that function, but only those have
survived selection that had a trait which in the given environment could more
or the less fulfill the needed function and at least put them in advantage in
comparison with those that died out. Ultimately teleological talk is founded in
a causal account: Cats are not good in creeping in order to catch their
prey, cats still exist, because they have been — and are still — good
at creeping up to their prey.

Starting from this general idea —
and the corresponding ban of design from science — Ruse takes us through the
development of the theory of evolution and its testing itself (how early
evolutionist were not sure about the nature of adaptivity, what the importance
of homology of organs in different species is, why there isn’t group selection,
what optimality models are good for, constraints on evolution — and so forth).
The idea of a function of x can at last be understood as x taking part in
achieving some positive valued state for a working system. Given this analysis
one may think that Ruse is going too far claiming that talking of design is nothing
but a metaphor; design pointing to a designer is, of course, metaphorical,
since nature is no intentional designer; but referring to the structure of a
working system there seems to be a neutral — and cosmological uncommitted —
sense of speaking of the systems/organism design. This is the reason why there
will be no reduction of the language of biology to the language of physics, as
Ruse also stresses.

The second part of the book shows
that the theory of evolution is no longer mainly a "secular religion"
as it was in the days of "Darwin’s bulldog" Huxley, but has become a
many-faceted scientific field. So Ruse in his last chapter can have short track
with today’s proponents of "intelligent design" in evolution.

Ruse’s book shows that there is no
place for the cosmological argument as an argument to the design of organisms
in biology. That by itself does not show that there cannot be other
cosmological arguments referring, for example, to the supposed fine tuning of
the physical constants and other features of macro-physics. Natural Theology —
especially with analytic philosophers like Swinburne, van Inwagen, Plantinga —
is not as dead as Ruse tells us.

The ideas set out in Ruse’s book
could have been presented more succinctly in a systematic way, but that surely
would have made harder reading for many interested in the topic. And for anyone
interested in the historical interplay and unfolding of the natural theology of
design and the theory of evolution Ruse’s way of presenting the debate has
certainly merits in its own right.

© 2004 Manuel Bremer

Manuel Bremer, Heinrich-Heine-Universität
Düsseldorf, Germany

Categories: Philosophical