It seems difficult to believe that anyone would advance this as an
argument
for evolution.
No one did or has. The point was that the claim that the four
propositions entail microevolution is not quite right, and you
apparently endorsed the claim. A criticism of the logic of an argument
to some specific conclusion does not constitute an argument to some
contrary conclusion.
vdw continues:
Take it up with Mark Ridley. The reference is his textbook
**Evolution** which
got rave reviews from many high profile Darwinists.
You apparently endorsed the claim in your pamphlet. If it is mistaken,
it doesn't matter whether it came from Ridley or not. Or whether high
profile Darwinists endorsed it or not.
vdw continues:
Again, difficult to believe that anyone would advance this as an
argument
for evolution.
But again, no one did. The point was that the claim that microevolution
is a mathematically necessary consequence of the initial four
propositions is simply mistaken. And, again, perhaps the first person
to recognize that fact was Darwin himself. Given some other fairly
fairly plausible assumptions, microevolution is reasonably expectable,
but that is a vastly different matter than being mathematically
necessitated by the initial four propositions - and it is that claiam
that you endorsed.
vdw continues:
Remember that the purpose here is to outline the case for and against
evolution
in simple terms in a SHORT pamphlet. A certain amount of simplification
is
required.
True, but when the point being made _depends_ upon the simplifications
rather than upon the substance the simplification is supposed to be a
simplification of, then the situation gets a bit problematic. It seemed
to me that your underlying presupposition was that any data that can be
accomodated by two competing theories is irrelevant in adjudicating
between them. And that principle is, I think, wrong. To use a case
related to the one I mentioned yesterday, Copernican and Ptolemaic
astronomy could _both_ accomodate data concerning retrograde motion, and
could do it with essentially equivalent degrees of accuracy. But the
_way_ in which the Copernican system could accomodate that data compared
to the way the Ptolemaic system had to accomodate it, was taken to count
strongly in favor of the Copernican system. And that is a very common
sort of case. That being so, the general presupposition - upon which
your argument rested - that data that can be accomodated by competing
theories is irrelevant to adjudications between them, is not merely a
simplification. The case you were trying to make, it seems to me at
least, disappears when the 'simplification' disappears.
vdw continues:
This concern is alleviated by the fact that I really don't care which
version
of intelligent design theory a person favors over the modern theory of
evolution.
The point is, that the mere fact that microevolution can be accomodated
by both evolutionary theory and intelligent design theory - of whatever
sort - does not _by itself_ imply that microevolution is irrelevant to
relative assessments of the theories involved. It may be, but mere
accomodatability does not show that - regardless of what version of
design theory one has in mind.
Don't get me wrong. I have been arguing in print and in talks for years
that there is nothing inherently irrational or non-scientific in
building theistic themes into scientific systems. And pamphlets of the
sort envisioned here can certainly have a place in the larger dispute.
But the more accurate they can be - without leaving behind the intended
audience - the better.
Del Ratzsch