Taken from two postings in the thread
"The Multi-Design Inference" over at the Internet Infidels.
This is an inference that multiple designers had designed some entities; this is a natural extension of Dembski's "Design Inference". And it is an inference often made about human designers.
This is an essential part of efforts to detect forged signatures; handwriting styles are individualized, and a close examination of a signature may reveal whether it was written with an imperfect imitation of someone else's style.
Handwriting analysis has also been useful in archeology; by that means, it was shown that the various
Mycenaean Linear B tablets had been written by several scribes, each of whom had written several tablets.
Such stylistic analyses have been used in other fields; much of the debate about the authorship of various parts of the Bible has been based on stylistic analyses -- characteristic vocabulary, preoccupations, etc. More recently, the Unabomber was identified when someone recognized some familiar styling in the text of his manifesto.
Applying that to the world of life, one concludes that if many features had been designed, then there had likely been more than one designer. Camera-like eyes are sometimes pointed to as examples of design, but those of vertebrates have one characteristic architecture and those of cephalopods have another. So could there have been a separate designer for each? Charles Darwin himself, in his creationist years, had concluded that Australia's distinctive fauna might suggest that "there had been two Creators at work."
Likewise, predator-prey relationships suggest multiple designers, one for the predators and one for the prey, because predators are adapted for finding and catching prey, and prey are adapted for avoiding and resisting predators. Multiple food-chain levels suggest additional designers. Thus, in a grass-deer-wolf food chain, with deer eating grass and wolves eating deer, the grass, deer, and wolves had had separate designers.
Host-parasite relationships are a close analogue of predator-prey relationships, with parasites being adapted to live off of their hosts and hosts being adapted to resist their parasites. Thus, in this example, the wolves can be afflicted with fleas, heartworms, and distemper viruses, adding yet another designer to the list.
In an attempted rebuttal, Walter ReMine has claimed to have demonstrated that there had only been one designer, but I've yet to see his "proof".
The multi-design inference must be an embarrassment for the Intelligent Design movement, because it goes against the theological predilections of many of its participants. However, I doubt that those like the Raelians would be terribly bothered by a multi-design inference.
However, it must be conceded that single superpowerful designer can imitate several less-powerful designers. But the trouble is that such a hypothesis tends to lack falsifiability; for sufficiently powerful designers, it would be difficult to rule out hypotheses like creation with apparent age, like Philip Gosse's
Omphalos hypothesis.
Also, there is a parallel to the single-powerful-designer hypothesis in Biblical criticism.
Among present-day scholars, the favorite hypothesis of the authorship of its first five books is the JEDP hypothesis, which posits four separate sets of authors, each with a characteristic vocabulary and preoccupations.
The traditional hypothesis, however, is that all those five books had been written by Moses and only Moses, and its present-day defenders maintain that he had repeatedly switched stylistic gears as he wrote.
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