April 15, 2005

Paul Nelson covers a "golden oldie" - The SETI analogy

Paul Nelson is one of the less familiar stars in the ID firmament, but he still receives his share of attention. Although I'm not as familiar with Nelson as some of the more prominent ID proponents, the little I've read by him has impressed me as just a bit more measured, and just a bit less breathless than the standard ID fare. Unfortunately, his most recent entry at Idthefuture is a disappointing rehash of an extremely tired argument. In the post, Nelson attempts to clean up a mess of an answer he gave following a debate held at the University of Minnesota-Morris. After a student suggested that all he had done is poke at evolution, she asked "...what evidence can you show me for intelligent design?"

When I read an account that includes something like the above question I always sit up a bit in my seat, hoping that I’ll see something new and intriguing. Needless to say my desires are seldom satisfied, but since I hadn’t read that much from Nelson I remained expectant. So with what sparkling recitation of data was my attention rewarded? One of the most bedraggled of all ID arguments, the SETI analogy.
"Suppose we are SETI researchers, I continued. One day, our radio telescopes detect a narrow-band pattern. What’s more, it is an amplitude-modulated, pulsed narrow band, carrying, let’s say, a series of prime numbers (2, 3, 5, 7, 11, 13...).

I become ecstatic, start jumping around the room, and reach for the phone...but you say No, hang on. You haven’t left the computer screen, and you’re frowning.

Come on, I say, this is evidence of extraterrestrial intelligence! But you point out, quite correctly, that we haven’t eliminated every possible natural cause for the narrow band or for the series of prime numbers it is carrying. And we don’t want to be hasty. After all, intelligent causation was a live candidate for some months following the discovery of pulsars, until it was eliminated in favor of a plausible physical mechanism. Let’s not go down in scientific history for a colossal error of impatience."
Nelson continues with this story, which eventually ends in uncertainty,
"If you’re right, what we see on the computer screen is not evidence of intelligence, and we should keep looking for a natural mechanism. If I’m right, however, the patterns are evidence, and the search for a natural mechanism is ill-founded. Impasse.

So evidence is a funny thing. End of thought experiment."
I would observe that evidence is actually a provisional thing. There is nothing in the above story that should prompt us to pause and thoughtfully reflect on the mysterious nature of evidence and its interpretation by well-meaning but, perhaps, partisan researchers. I suspect most of us would accept that Nelson’s story is a reasonable speculation on the process by which a SETI investigation might develop. I’d further suspect that most would have no trouble accepting that more evidence could tip the investigation one way or the other (toward or away from intelligent agency), or continued lack of evidence might leave this inquiry unresolved. What is important to recognize, however, is that this tale is in no way analogous to the question of whether "Intelligent design" can be inferred in any particular case.

In Nelson’s thought experiment the researchers are dealing with natural phenomena. They are phenomena, in fact, for which SETI has chosen to look precisely because they reflect human design. "Amplitude-modulated, pulsed narrow band" signals are, for the purposes of SETI investigation, considered diagnostic of intelligent agency and are completely acceptable as evidential support for the same because they exist within the universe of natural processes. They are therefore, entirely scientific and perfectly legitimate data that, should they receive further support causally connecting the evidence to non-terrestrial agency, could legitimately lead to intelligent design.

No one argues this. No one disagrees with this. No one resisting the intrusion of ID into matters of science has a problem with this concept.

Apparently, though, most ID proponents still do not get it. "Intelligent design" proposes to legitimize inference to non-natural agency. [Stephen Meyer has explicitly asserted this (Scientific Status of Intelligent Design), Phillip Johnson has defended this (pick a book) and Jonathan Witt has accepted this view. Most others, like Dembski and Behe and Wells, have made arguments from which this position is reasonably inferred.] But inference to non-natural agency is not testable, not demonstrable, and not scientific. There is nothing in either Nelson’s thought experiment, or SETI’s protocols that allows for the search target, a putative intelligent agency, to be inferred to be non-natural. And similarly there is nothing in the analogy with SETI that expresses support for "Intelligent design" or defense of its methodology.

Many of us would be jumping up and down with Nelson should such signals be detected. None of us would conclude they came from God.

Nelson tries to expand on the analogy by adding a few comments,
"1. Note that the data themselves in my thought experiment are exactly the same for the design skeptic and the design proponent. What renders the narrow band and primes evidence of intelligence is a causal impotence claim –- no natural mechanism exists to cause x –- coupled with a causal sufficiency claim –- intelligence, uniquely in our experience, produces narrow band radio transmissions and prime numbers. Because of its logical form, however (a universal negation), the causal impotence claim cannot be proven. No failed search for a natural mechanism, a necessarily finite search in any instance, can turn back one’s prior conviction that a mechanism nevertheless exists, lying perhaps just beyond the horizon of our current investigations. Until we find that natural mechanism, say the design skeptics, (Wilkins & Elsberry, Biology & Philosophy 16 [2001]:721)."
Read the above carefully. Note Nelson’s citation of the design skeptic’s claim that "we can content ourselves with regularities, chance, and ‘don’t know’ explanations." Now look back a bit for the context to which he refers. Nelson conflates a design skeptic’s logical response to an unwarranted inference of non-natural agency with a SETI scientist’s empirical attempt to distinguish between competing natural hypotheses. In this case researchers are looking for evidence pointing toward either undirected natural cause (uNC) or directed natural cause (dNC, or intelligence) in the proposed case of received signals.

No researcher in this position would suggest that there must be an exclusion of all (either uNC or dNC) before one could accept the alternate proposition. Either is a legitimate causal hypothesis. The argument - that one must exhaustively rule out all possible natural mechanisms - is offered only in the case that non-scientific non-natural agency is suggested as a sufficient explanation. Nelson has connected two dialectically unrelated positions. This is either exceedingly sloppy argumentation or deliberate misdirection (or both). It’s illogical and irrelevant.
"2. Here’s the last piece of the UM-Morris story. The fragility of RNA, I said to the UM-Morris chemist, might be just the evidence you’re seeking of intelligent design. And why not? The molecule at the very heart of Terran biochemistry appears from current knowledge to be exactly the sort of entity that would never arise naturally on the early Earth."
This would be an interesting argument if Nelson would simply supply some evidence that RNA is "exactly the sort of entity that would never arise naturally on the early Earth." In fact, what evidence we have would appear to suggest that RNA could easily qualify as an earthly biological precursor that one might expect to extend the continuum from non-living to alive. Nelson’s point here stands as evidence for nothing but the fact that ID proponents are willing to build their rhetoric upon the flimsiest of assertions.

He finishes up by noting that,
"She shook her head No –- that’s still not evidence, Paul –- but I thought I saw the glimmer of curiosity in her face."
Given the quality of Nelson’s responses, I have no trouble believing he saw curiosity in her face. I think he and I would differ, though, on the subject of her scrutiny.


Anonymous Anonymous said...

Some thoughts and essays on ID versus SETI can be found here:


or just google "seti evolinks"

11:51 PM  

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