From: Ivar Ylvisaker <ylvisaki@erols.com>
>"Stephen E. Jones" wrote:
>
>
>> On Thu, 05 Oct 2000 23:58:52 -0400, Ivar Ylvisaker wrote:
>>
>> [...]
>>
>> IY>According to Dembski's The Design Inference, one calculates
>> >complexity (i.e., improbability) by examining all possible (non-design)
>> >hypotheses. This has never been done and I can not imagine that it ever
>> >will be.
>>
>> I would appreciate Ivar quoting where in "The Design Inference" Dembski
>> says that: "one calculates ... all possible (non-design) hypotheses."
The fact that Stephen was unaware that Dembski requires us to
consider all relevant chance hypotheses, a fact which is fundamental to the
design inference, indicates that any claims he has made up until now that
the design inference has actually been applied have been made in ignorance
of what the method of the design inference actually is!
However I don't blame Stephen for this. I blame Dembski, who has been
equivocal and obfuscatory in his descriptions of the design inference. Many
other people (both critics and supporters of Dembski) have made the same
mistake as Stephen.
>Page 222:
>
>"..., we obtain the following definitive statement of the design
>inference (cf. Section 2.2):
>
>"The Design Inference. Suppose a subject S has identified all the
>relevant chance hypotheses H that could be responsible for some event
>E. Suppose further that S has identified (1) a probability measure
>P that estimates likelihoods with respect to the chance hypotheses
>in H...."
>
>The paragraph goes on for half a page and uses lots of mathematical
>symbols that I cannot reproduce in a post like this.
I recommend that the casual reader refer to the equations on pp 50-51, which
present a simplified version of the design inference. In particular, Premise
3 at the top of page 51 says (substituting text for symbols): for all
relevant chance hypotheses that could be responsible for the event, the
probability of the event is small. The full version of the equation (P2 on
page 222) says essentially the same thing, except that it clarifies that the
event must match a specification, i.e. be a specified event.
Dembski also writes:
"In case still more chance hypotheses are operating, design follows only if
each of these additional chance hypotheses gets eliminated as well, which
means that the event has to be an SP event with respect to all the relevant
chance hypotheses and in each case be specified as well." (p 44, footnote)
"Since an event has to have small probability to eliminate chance, and since
the design inference infers design by eliminating all relevant chance
hypotheses, SP(E;H) has to be satisfied for all H in [curly H]." (p 52)
"Given a chance hypothesis H that could conceivably explain E, S [a subject]
is obliged to retain H as a live possibility until a positive warrant is
found for rejecting it." (p 220)
>I substituted
>the word "non-design" for the word "chance" because I thought it
>would be clearer for people who had not read Dembski's book.
>Dembski defines design on page 36 as the "set-theoretic complement"
>of "regularity" and "chance" and later points out that regular
>hypotheses can be treated as special cases of chance hypotheses in
>which single outcomes have high probability.
This is another example of Dembski's obfuscation. Since regularity
hypotheses are simply chance hypotheses which yield a high probability, why
complicate matters by dividing our non-design hypotheses into these two
separate categories, especially as Dembski never bothers to specify a
boundary value to enable us to distinguish between a high probability and an
intermediate one?
>Essentially, Dembski's claim is that if all natural (i.e., non-design)
>explanations can be shown to be extremely unlikely, then we can safely
>conclude design.
>
>
>> IY>If you or others want to propose the hypothesis that complex things
>> >such as the genetic code are always assembled by intelligent beings,
>> >that is fine with me.
>>
>> This is in fact our universal experience that codes "are always assembled
>> by intelligent beings." SETI is based on this.
>>
>> IY>But I don't see how you plan to collect evidence
>> >to confirm your hypothesis.
>>
>> See above. I am not sure that it *is* the "hypothesis".
>>
>> IY>You seem to be stuck with a sample size of one (man).
>>
>> I am not sure what Ivar means. The hypothesis is not about Dembski so he
>> is not the "sample".
>
>By man, I meant mankind. Man seems eager to believe that all gods
>and all things that generate complexity, especially those in outer
>space, must be man-like. But why should this be true? If there is a
>Creator, is He so limited that He ran out of ideas when He created man?
>
>[snip]
>
>
>> IY>Further, this is not Dembski's approach. Dembski says that he is not
>> >proposing "design" as an hypothesis; rather, he is proposing to deduce
>> >design by eliminating all alternative hypotheses to design.
>>
>> I would like appreciate Ivar quoting where "Dembski says that he is not
>> proposing `design' as an hypothesis."
>
>Page 68:
>
>"The design inference is in the business of eliminating hypotheses,
>not confirming them. .... Because the design inference is eliminative,
>there is no "design hypothesis" against which the relevant chance
>hypotheses compete...."
Yvar, I think what Dembski means here is just that the design hypothesis
doesn't compete with other hypotheses in the design inference. Although it
may sound like he's saying that there's no design hypothesis at all, he
obviously can't mean that. The design hypothesis is what Dembski is trying
to establish. The important point is that he establishes it purely by
eliminating all non-design hypotheses, not by considering the merits of the
design hypothesis.
So I think your statement that "Dembski says that he is not proposing
`design' as an hypothesis" is misleading, and is just introducing an
unnecessary element of confusion.
>> IY>His approach is better characterized as philosophical rather than
>> >scientific.
>>
>> Not really. The same methodology of inferring intelligent cause by
>> eliminating unintelligent natural causes underlies the *sciences* of
>> archaeology and SETI.
>
>The scientific approach is to propose hypotheses and then seek to
>confirm or refute them. Dembski isn't doing this. Rather, he is
>attempting to show that an intelligent being, hitherto unknown to
>science, is logically necessary. He is making a kind of ontological
>argument for God.
I don't agree with you. I think that in any inference of design where we
don't have positive proof (like having actually seen the object being made),
we must use a process of elimination, and, beyond a certain point, we must
simply say "We consider it inconceivable that any natural process could have
created this object, so it must be designed." Suppose, for example, that
SETI receives an extraterrestrial message like the one in the book Contact.
We cannot prove that the message was not produced by some unknown natural
process, i.e. in accordance with some unknown chance hypothesis.
Nevertheless, because we can't conceive of any natural process producing
such an effect, we reject all such unknown hypotheses.
Effectively this is what has happened in the past. Before Darwin, a natural
explanation for the complexity of life seemed inconceivable, so most people
did accept the existence of a designer. Even Dawkins says that he could not
have been an intellectually fulfilled atheist before Darwin. But, now that
we have a natural explanation, the complexity of life cannot be offered as
scientific evidence for a designer without ruling out that explanation.
If Dembski was able to rule out the theory of evolution, that wouldn't prove
that life was designed, but it would strongly support the case. Even Dawkins
has said something to the effect that Darwinian evolution is the only
possible natural explanation for the complexity of life. I think some other
people (like Kaufmann) would disagree. Anyway, it would certainly give a
massive boost to ID. However it's important to bear in mind that the theory
of evolution does not yield a single chance hypothesis, but a whole family
of them. There are many unknowns in the theory, and Dembski would have to
rule out all possible variations.
Given the difficulty of applying the design inference to living organisms,
perhaps IDers would prefer to apply it to the origin of the first
self-replicating entity. (I think this is what DNAUnion would like.) But it
can only be applied to certain simplistic chance hypotheses, such as a
complex molecule being formed by the random accumulation of amino acids. But
we do not know that this is the only possibility. Cairns-Smith for
example has proposed that the first self-replicating entities were crystals.
Other OOL researchers are working on other possibilities. DNAUnion argues
that, because we currently have no viable natural explanations, we must
accept ID. But ID researchers do not find the possibility of a natural
explanation to be inconceivable, and frankly I'll put their judgement ahead
of DNAUnion's (or the small minority of scientists who share DNAUnion's
opinion).
>Archaeologists know that man exists. They are proposing hypotheses
>that certain objects were made or modified by man.
But suppose they found relics of a pre-Cambrian alien civilization. They
might be able to recognize those as designed objects, i.e. they might
conclude that there is no conceivable natural explanation for such objects.
Richard Wein (Tich)
--------------------------------
"Do the calculation. Take the numbers seriously. See if the underlying
probabilities really are small enough to yield design."
-- W. A. Dembski, who has never presented any calculation to back up his
claim to have detected Intelligent Design in life.
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