"Behe deliberately intends to leave open the possibility of
irreducibly complex systems arising by *natural* means (e.g., as
a result of natural laws and processes operating upon
specifically chosen boundary conditions of the original,
primordial creation). What he denies is that irreducibly complex
systems could have arisen by processes which are both
selectionist and gradualist."
I have to say that this message (the possibility of irreducibly
complex systems arising by *natural* means) does not come across
to me from reading Behe's book. The emphasis seems to be on an
original richness in biological information, subsequently
expressing itself in history. Thus:
Page 192: "The only way a cell could make a flagellum is if the
structure were already coded for in its DNA".
Page 231: "... the simplest possible design scenario posits a
single cell - formed billions of years ago - that already
contained all information to produce descendant organisms, ..."
Natural means can lead to the genotype being expressed, but it
is not apparent from the book that the genotype itself can be a
product of natural means. Those "specifically chosen boundary
conditions of the original, primordial creation" would need to
be information-rich.
Del also wrote:
"For one thing, whether or not irreducibly complex systems could
or could not be generated by some *natural* means (perhaps,
again, involving specially selected cosmic initial conditions)
is simply not Behe's issue - it is whether or not such could be
generated by *Darwinian* means (defined, again, in terms of
selectionist, gradualist processes)."
The above points (re "natural means" and "specially selected
cosmic initial conditions) come up again here. But I want to
focus this time on the emphasis on "Darwinian means". It seams
to me that Behe's argument goes beyond this.
Behe writes:
"Clearly, if something was not put together gradually, then it
must have been put together quickly or even suddenly. ... Two
ways to rapidly assemble complex systems have been proposed by
scientists in recent years. Let's briefly consider those
proposals, ..." (pages 187-188).
My first point is that Behe is not just interested in Darwinism.
Behe considers symbiosis theory and complexity theory. The
conclusions are that neither explain the ultimate origins of
irreducibly complex systems.
My second point is that Behe is arguing against purely natural
explanations:
"... the straightforward conclusion is that many biochemical
systems were designed. They were designed not by the laws of
nature, not by chance and necessity; rather, they were planned.
..." (page 193).
I appreciate Del's input to this exchange very much, including
comments on exaptation. The above parts have sent me back to
Behe's book, to refresh my mind on several points. I write
primarily to clarify my own thinking - feedback welcome.
Best wishes,
David J. Tyler