>>>RS>This is how the "argument from imperfection" arose. Creationists
>>>have been talking for a long time about how life must have been
>>>designed, because it works so perfectly. Then others responded by
>>>pointing out many instances in which the fucntioning of organisms
>>>is (sometimes significantly) less than perfect.
>>>
>>
>>BH>This is undoubtedly true for many creationists but is certainly
>>not true for all. For example Beheian design is based on the
>>idea of irreducible complexity which may or may not involve
>>"perfection" or even optimality in function.
>
>RS>This argument is effectively answered in a talk.origins FAQ. It
>can be found at:
>
>http://www.talkorigins.org/faqs/behe.html
>
Yes, I've read Robison's review and several others and would tend
to agree with your assessment. I hope I'm not being too immodest
in saying that I've made my own attempts at answering Behe's
argument on this reflector. This has always been a little difficult
for me since I have a great admiration and respect for Behe. Hopefully
my disagreements with him will not overshadow this.
Anyway, my point was that not all design arguments are based
on "perfection" or on optimality of function. To say something
is badly designed simply because it could be made to function
better is a strawman. It applies only to one specific "model"
of design. Its kind of like the argument from improbability
being a strawman since it addresses only one possibility for
the origin of life. Creationists who give the argument from
improbability seldom mention this important point. This could be
due either to ignorance or to the recognition that such an
admission severely weakens their argument. In any event, the
creationist certainly should mention that the argument from
improbability applies only to one specific model for the origin
of life and not to abiogenesis in general. Likewise, the
evolutionist should mention that the argument from imperfection
applies only to one specific notion of "designedness" and not
to the concept of design in general. This is my main point.
Failure to do this puts the burden of proof on the evolutionist.
They must perform the task often demanded from creationists.
They must provide a precise, objective, scientific definition
of design. Otherwise, talk of bad design is just rambling.
Perhaps I should clarify another point since I think you are
relatively new to the reflector. I'm not a Creationist or
Intelligent Design advocate myself, though I used to play
one on t.o ;-). At the time of the "eye" discussions on t.o
I was a progressive creationist but have since changed my
position to theistic evolution.
>>BH>As another example, let's look at your statement:
>>
>> 'This is how the "argument from imperfection" arose'
>>
>>I'm not enough of an historian to attempt a guess at when the
>>argument from imperfection arose. If we go as far back as Darwin
>>we'll find one of Darwin's contemporaries, Richard Owen, making
>>extensive use of the argument.
>
>RS>This makes sense. At and before Darwin's time, it was quite common
>for people to believe in literal Creation; much more common than it
>is today. Therefore, the "argument from imperfection" arose as a
>response to the claims that life is so well-designed that it must
>have been intelligently created.
>
>>BH>It is clear that Darwin borrowed
>>some of his examples of imperfections from Owen. Interestingly,
>>Owen was a creationist who used the argument from imperfection
>>as an argument *for* design. It seems quite possible then that
>>the argument from imperfection originated with creationists ;-).
>
>RS>Well, now I'm really confused... <g>
>
And well you should be ;-). Just kidding. This is my fault for
not giving enough details. There were two design schools in
Darwin's day. There were the "utilitarian-creationists" whose
ideas about design seem to match pretty well with present day
special creationists. Optimal (near perfect) match between form
and function. Then there were the "idealists" of whom Owen was
probably the most prominant member. Two main points to the
idealist view of design (1) form takes precedence over function.
Using the same form for many different functions necessitates
sub-optimalities and imperfections. (2) Purposeful design can
be seen in the overall pattern of creation and not in the
specifics. Imperfections in organs or organisms are expected
compromises in maintaining the global design.
Perhaps its a little clearer now why I say that the argument from
imperfection may well have originated with creationists. Owen
used the argument from imperfection against his rivals, the
utilitarian-creationists, in much the same way as modern day
evolutionists use the argument.
>>The point of these examples is that context is essential. For
>>someone like Owen, the argument from imperfection is obviously
>>knocking down a strawman.
>>
>>The problem as I see it is that appropriate context is
>>practically never given. For example, the talk.origins FAQ
>><Evidence for Jury-Rigged Design in Nature> has the following
>>as its opening paragraph:
>>
>> Many organisms show features of appallingly bad design.
>> This is because evolution via natural selection cannot
>> construct traits from scratch; new traits must be
>> modifications of previously existing traits. This is
>> called historical constraint. A few examples of bad
>> design imposed by historical constraint:
>>
>>There is no mention whatsoever of the appropriate context of
>>the argument from imperfection here. We do, however, see a
>>very strong claim being made "appallingly bad design" with
>>absolutely no supporting analysis except stuff like "looks
>>like bad design to me".
>
>I've read that FAQ too. The analyses give not only examples of
>why the designs are bad, but how they could have been improved.
>
>>BH>If the writers of this FAQ want to
>>maintain their position of "appallingly bad design", then
>>they also need to define exactly what design is and how its
>>idntified and measured objectively.
>
>RS>That is exactly what people have been asking Creationists
>to do for decades, considering that it is the Cre'ists who
>are claiming that there is a "design".
>
And the FAQ claims "appallingly bad design".
>>Otherwise they're just
>>giving their opinions,
>
>RS>No, they're giving specific examples of how certain features
>are less than optimal, and how they could be more effectively
>optimized.
>
>>>>BH>For example, one says "the eye would obviously be better designed
>>>>without a blind spot". This involves the implicit (and ridiculous)
>>>>assumption that one can change one aspect of a complicated design
>>>>keeping everything else constant.
>>>
>>>RS>It was done with the squid. Squids don't have a blind spot.
>>>
>>>>BH>Of course, one could say that
>>>>God could accomplish this feat if he wished. But now you're supporting
>>>>your argument with theology. This is taking the easy way out that
>>>>creationists are so often condemned for. To really support the
>>>>case that the blind spot is bad, one has to come up with an alternate
>>>>design and demonstrate that it is better. No one has done this.
>>>
>>>RS>Nature has. We have merely pointed it out.
>>>
>>
>>Are you saying squid eyes are actually better than
>>human eyes?
>
>Yes.
>
>>If so, by what criteria?
>
>Because they don't have a blind spot.
>
This is exactly what I mean by a naive view of design. Are
you really going to say squid eyes are better than human
eyes based on only one criteria? This seems rather silly
especially in view of the fact that the blind spot has
an almost negligible effect on the performance of the eye.
If you have a copy of <Climbing Mount I> you may want to
see what Dawkins has to say about the blind spot starting
on page 170.
>>>>BH>What I mean here, of course, is an alternate design of a human
>>>>eye, and not something completely different like a cephalopod
>>>>eye.
>>>
>>>RS>Why not? The designs (so to speak) are very similar.
>>>
>>>>BH>I'm pretty sure that I still have all the relevant posts from the
>>>>t.o thread that I could forward to you if you are interested in
>>>>all the gory details. If memory serves the crucial points were:
>>>>
>>>>1) a complicated interdependence between the various structures.
>>>>included in this is the importance of the relative locations of
>>>>some of the structures. One cannot simply change or move one thing
>>>>without producing a whole host of changes in other things. To
>>>>remove the blind spot one would have to move a lot of stuff.
>>>
>>>RS>So it is your argument that it would be impossible to make this
>>>minor change in the layout of blood vessels in the retina?
>>>
>>
>>BH>No. My argument is that the consequences of this change upon the
>>performance of the eye are not known.
>
>RS>The consequences are known, because it is known to occur in the squid.
>And it doesn't seem to be a problem.
>
But the claim is that a human eye would be better "designed" if the
wiring were modified so that there is no blind spot. The consequences
of this re-wiring on the performance of a human eye is not known.
The point I've been trying to get across here is that you are
displaying a real naive view of design. It goes like this: look,
I think component X is sub-otimal, let's change X. Unfortumately,
the functioning of A, B, and C depend on X being as it is. If you
change X you'll simulataneously change A, B, and C. What are the
consequences of these changes on the performance?
Brian Harper
Associate Professor
Applied Mechanics
The Ohio State University
"Because there's no primordial soup;
we all know that, right?" -- Leo Buss