>> Loren: "I hope that Dembski is suitably cautious when offering
>> probability calculations for abiogenesis and the evolution of
>> complexity. Overly-simplistic and already-refuted calculations, which
>> claim to demonstrate small probabilities, are a dime a dozen. It
>> would be a mistake to use such calculations to claim that the design
>> hypothesis has been *proven*. Such premature claims would create
>> unnecessary arguments for Dembski and draw attention away from the
>> goal of establishing design as a valid hypothesis."
>
> I suppose the major mistake is in thinking that the systems we know
> about and can define are the only systems relevant to the problem.
> What we can say is that no one has yet proposed models of abiogenesis
> and the evolution of complexity which yield favourable probabilities.
> Hence the need for more research on the part of those who are disposed
> to believe that such models will one day be found.
I think it is more accurate to say the following: We cannot yet
calculate the probabilities (for abiogenesis and the evolution of
complexity) for the models we already have. For example, what is the
probability that the bacteria flagellum could evolve via the
evolutionary mechanisms we already know? We don't yet have enough data
to calculate that. We don't know enough empirical details.
> The concern I have is that whilst I think the methodological approach
> to recognising design is defensible, is can be interpreted as reviving
> the "god of the gaps" concept. That is: if all other avenues fail,
> and we can't think of any other ways of explaining the data, we
> conclude intelligent design. I find a tension between this and what I
> consider to be a healthy Christian perspective: that design is
> pervasive.
I agree that extra-natural assembly should not simply be the
explanation-of-last-resort.
All scientists should want to gather better data, build more detailed
and more accurate models, rule out models which don't work, AND search
for possible new mechanisms. All scientists should want to do all of
these things, regardless of whether they personally favor extra-natural
assembly, theistic evolution, naturalistic evolution, or something else.
This cooperative approach might lead to the conclusion, "Sound empirical
models predict that known natural mechanisms can account for the event."
It might lead to the conclusion, "We do not have sound (or sufficiently
thorough) empirical models, but we believe that known natural mechanisms
can account for the event, and future improvements in empirical
knowledge, elegant models, and computing power will eventually allow us
to prove this." It might lead to the conclusion, "No known natural
mechanisms could account for this event. There are empirically sound
reasons for ruling out all known natural mechanisms."
The third option --- no known natural mechanisms --- is not simply the
explanation-of-last-resort when the second option fails. By improving
the empirical accuracy of existing models and mechanisms, the third
option can be argued for positively. This is no easy task. And
scientists can disagree about whether they believe the existing data
favors the second or third option.
Even if scientists agree on the third option --- no known natural
mechanisms --- they can disagree about a variety of meta-scientific
conclusions. [A supernatural event occurred. Super-human technology
brought about the event. An as-yet unknown natural mechanism is
responsible for the event. A very unlikely (natural) event occurred. A
very unlikely (natural) event occurred, but there are many different
causally disconnected universes.] Both scientific and non-scientific
arguments can be used to make this decision.
Because the third option does not compel supernatural explanations,
scientists who reject the supernatural can still pursue data which
favors the third option. Because the first and second options do not
exclude supernatural design and guidance, theistic scientists can pursue
data which favors those options. In this way, I hope we can avoid two
mistakes: (1) Seeing extra-natural assembly as an explanation-of-last-
resort; (2) Over-selling the extra-natural assembly hypothesis on the
basis of weak models and premature data.
More about science-and-supernatural-explanations in
http://www.calvin.edu/archive/asa/199702/0110.html
> What is the link between universal design and Dembski's
> "design inference"?
Evidence for extra-natural assembly of life is evidence against the
hypothesis that the laws of nature are designed for life to self-
assemble. Evidence for self-assembly of life is evidence against extra-
natural assembly. I hope that Dembski has made his "design inference"
inclusive of both kinds of design. If Dembski has not done this, he
will be in a difficult position. Evidence for universal design in the
laws of nature --- evidence that they are designed for the self-assembly
of life and complexity --- will become evidence *against* his "design
inference."
Loren Haarsma