RDehaan237@aol.com wrote:
>
> In a message dated 7/1/2000 8:40:16 AM, gmurphy@raex.com writes:
>
> << Your examples which I snip) point out the possibility of studying a
> subject
> without being able to give a precise & unambiguous definition of the subject
> matter. An example even closer to the ID debate can be given - "life".
> Biology studies living
> things, yet a precise & unambiguous definition of "life" or "living" is
> difficult. You
> can get a good debate going among some scientists by asking whether viruses
> are alive. But in reality biologists don't worry about the lack of such a
> precise definition and operate a "If it walks like a duck ..." understanding
> of life.
> Now is "intelligent design" the same sort of thing? It depends on what
> types of
> phenomena are being considered. Art critics or historians of technology
> recognize quite explicitly that they are studying the products of ID & don't
> have to worry about defining just what ID _is_: "Everybody" knows that there
> have been human beings around to produce paintings, clocks, &c & only a few
> people on the fringes of those fields are going to argue that these things
> were produced by dolphins or ETs.
> The situation is different when we ask study living things, because here
> there
> definitely is NOT a tacit consensus that they have been "intelligently
> designed". The
> claim that they have been is precisely the point at issue. Thus a more
> explicit &
> careful definition is needed, which is what Howard is asking for. This is
> especially so because what the term "intelligent design" in fact connotes for
> most people on both sides of the debate is "made by God in a way science
> can't explain."
> Shalom,
> George >>
>
> Thanks, George, for your clarifying remarks. Of course, I agree that
> intelligent design is an inference, a judgment. But I fail to see that it
> requires a prior definition of the term. Let me give an example and you tell
> me why it requires a prior definition of design.
>
> This has to do with the biconvex lens of the trilobite eye. (Taken from
> _Trilobites_ Riccardo Levi-Straus, 1993, pp. 44-57 passim). Levi-Straus
> wrote:
>
> "The biconvex lenses of trilobites are made up of the doublet structures that
> were constructed for an unmistakable purpose: to correct for the large
> spherical distortion (aberration) of simple thick lenses....
>
> "When we humans construct optical elements, we sometimes cement together two
> lenses that have different refracting indices, as a means of correcting
> particular lens defects. In fact, this doublet is a device so typically
> associated with human invention that its discovery in trilobites comes as
> something of a shock. The realization that trilobites developed and used
> such devices half a billion years ago makes the shock even greater. And a
> final discovery--that the refracting interface between the two lens elements
> in a trilobite's eye was designed in accordance with optical constructions
> worked out by Descartes and Huygens in the mid-seventeenth century--borders
> on sheer science fiction....
>
> "By comparing the shape of the aspheric lens exit surfaces constructed by
> Huygens and Descartes with the two lens structures identified by Clarkson
> [figures are added in the text showing the lens structure, DH] little doubt
> remains that trilobites utilized the properties of Cartesian Ovals more than
> 400 million years before the seventeenth-century masters discovered the
> principle..."
>
> And finally,
>
> "The design of the trilobite's eye could well qualify for a patent
> disclosure."
>
> Levi-Straus tried to provide a Darwinian explanation. He suggested, "What we
> would like to hear, to appease our Darwinian upbringing, is that new visual
> structures were evolved in response to new environmental pressures as a means
> of survival." As possibilities he suggests that it "allowed the trilobite
> to see at some depth in sea, at dusk, or in turbid water." He added the
> advantage that they provided a prompter recognition of and response to
> impending danger. To this hypothetical mix he adds “mating may have proven
> more effective with sharper images". (p. 59)
>
> These suggestions of his do not even touch on how natural selection might
> have constructed such a biconvex lens.
>
> Levi-Straus clearly admits that the biconvex lens is designed, and long
> before human beings understood or were able to construct such a lens. Do you
> demand of him that "a more explicit & careful definition is needed"?
>
> When evolutionary authors themselves use design concepts, isn't that clear
> evidence that the term is understood, that it doesn't need the precise
> definition that Howard demands, and that only the ascription of causality is
> at issue?
>
> If you have a choice between saying that the biconvex lens of the trilobite
> is designed by an intelligent agent or Levi-Straus' Darwinian explanation,
> (or some other more sophisticated one) which would you choose?
>
> I submit that the design inference of the trilobite convex lens is more
> heuristic than Darwinian theory. The logical steps for an ID researcher
> would be to ask how it was designed. What should follow would be some kind
> of reverse engineering of the biconvex lens, trying to determine what steps
> went into its construction. A flow chart of the construction steps might
> eventually be forthcoming. Perhaps the puzzle of the construction of the
> biconvex lens may never be solved. Reverse engineering probably works better
> for complex biochemical and biomechanical systems than for the biconvex lens.
> IMHO a reverse engineering approach to biological design, as IDer Scott
> Minnich advocates, will become the method of choice for ID research, and will
> prove to be more productive than trying to create Darwinian scenarios to
> account for it.
Bob -
I think we all recognize that there are a lot of biological structures (a)
whose origin has not been explained in neo-Darwinian termas 7 (2) bear strong analogies
to things constructed by human beings. & in an informal way we may say that they were
"designed" for certain functions. But that need not be taken as an explanation of how
they came about any more than does the phrase from your post, "The realization that
trilobites developed and used such devices ..." has to be taken to mean that the
trilobites themselves designed & constructed their eyes as a human telescope maker would
design & construct an instrument.
Granted, we can sometimes operate with tacit understanding of certain terms.
But when the concepts associated with those terms become matters of scientific debate,
they need more careful definition. Before ~1905 "everybody knew" what absolute time
was. When Einstein began examining basic issues associated with space & time he had to
ask himself what absolute time meant & found that the concept had to be dropped.
The question of definition of ID has been raised, & I agree with Howard in
thinking it striking that ID proponents are so coy about trying to provide
non-circular definitions which contribute to clarification of the debate.
Shalom,
George
George L. Murphy
gmurphy@raex.com
http://web.raex.com/~gmurphy/
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