Professor Moody seems upset that I bring up formuli. In response to "SETI also cannot calculate the probability of ETI existing," I had noted "SETI does in fact have a formula for calculating the likelihood of an ETI." Moody responds, "Did I say anything about a formula? No. I said that SETI cannot cannot calculate the probability. Swan says the same thing, but calls it a 'difference.'" But this is the point. Moody did not mention formulae, and that is a problem. I do not say the same thing as he does about SETI, rather I do point out a major difference: SETI cannot calculate the probabilities, knows it, says so, and shows a formula showing precisely what some of the problems are. SETI puts for the formula, the Drake Equation: http://www.seti.org/science/drake-bg.html. Now, where is ID's formula? Is it in Dembski's No Free Lunch? No, there a probability calculation is done based on unreasonable assumptions (for the evolution of bacterial flagella) that no evolutionary biologist would accept (the assumption the flagellum came together randomly, all at once), and this is justified on the basis of the point that Dembski is attempting to make (the the flagellum is irreducibly complex, so could not be assembled piecemeal). There is the contrast between ID and SETI: on the one side, from SETI, an admission with precision as to why a probability calculation cannot be done; on the other, from ID, a probability calculation done on the basis of unsupportable assumptions.

"SETI does not claim ETI on the basis of calculating, or asserting, a low probability the nonexistence of ETI. Well, first of all, SETI does not yet claim ETI at all." Yes, as I said, SETI does not claim ETI on the basis of low probability of the opposite claim; ID does. ID tries to establish criteria for nondesign, show that nondesign has low probability, and claim that design therefore wins by default. I argue that this is an illogical, antiscientific way of proceeding, that instead criteria for design should be provided. All that is received in return from ID advocates, as the "design inference," is more verbiage on disproving nondesign.

So, what is Moody's response regarding SETI? "But if and when it does make such a claim, it will be based on a low probability that the signal came from anything other than an intelligent source." And what is Moody's source for this? What does this mean in the first place? Does Moody mean that in general science says that its conclusions are open-ended, that there is always a possibility that it is wrong. If that is what Moody means, I dismiss it as trivial. Does Moody mean that statistical analysis will be used to reject a null hypothesis of no ETI? Note that in science, such tests are often done but that what they do is provide support for a hypothesis only by showing that it was not falsified. It does not establish the hypothesis as true. Does the hypothesis win by default? No, many possible hypotheses will be compatible with any specific result. What gives a tested hypothesis heightened support is that it was previously stated and was then not falsified. This in no way guarantees that it will survive the next test. In fact, the ideal is that the hypothesis is elaborated, is altered to explain more-complex phenomena, and is subjected to testing for that. By contrast, ID is claimed to win by default, with no strategy for further elaboration.

Now, what does SETI actually say? Here's step one (http://www.seti.org/science/principles.html): "Any individual, public or private research institution, or governmental agency that believes it has detected a signal from or other evidence of extraterrestrial intelligence (the discoverer) should seek to verify that the most plausible explanation for the evidence is the existence of extraterrestrial intelligence rather than some other natural phenomenon or anthropogenic phenomenon before making any public announcement." In other words, ETI is to be at first accepted as "the most plausible explanation" after ruling out other explanations as less likely, so Moody's probability. Step two: "Prior to making a public announcement that evidence of extraterrestrial intelligence has been detected, the discoverer should promptly inform all other observers or research organizations that are parties to this declaration, so that those other parties may seek to confirm the discovery by independent observations at other sites and so that a network can be established to enable continuous monitoring of the signal or phenomenon. Parties to this declaration should not make any public announcement of this information until it is determined whether this information is or is not credible evidence of the existence of extraterrestrial intelligence." In short, independent confirmation will be essential before determination of ETI as a source. Will the only evidence be the signal itself? SETI doesn't know, but where prior possible detections have occurred, other criteria have been successfully applied (http://www.seti.org/science/eqpeg.html).

I have noted that SETI rejects some scenarios not on the basis of asserting a low probability, rather by setting criteria that exclude them -- e.g. (http://www.seti.org/faq.html#a1): "Narrow-band signals, say those that are only a few Hertz or less wide, are the mark of a purposely built transmitter. Natural cosmic noisemakers, such as pulsars, quasars, and the turbulent, thin interstellar gas of our own Milky Way, do not make radio signals that are this narrow. The static from these objects is spread all across the dial. Š In terrestrial radio practice, narrow-band signals are often called 'carriers.' They pack a lot of energy into a small amount of spectral space, and consequently are the easiest type of signal to find for any given power level. If E.T. is a decent (or at least competent) engineer, he'll use narrow-band signals as beacons to get our attention." That is, assumptions are made on the basis of knowledge of possible design and of a designer (human engineers). This is further explained (same URL): "Every radio astronomer (including extraterrestrial ones) will know about this hydrogen emission. It may serve as a universal 'marker' on the radio dial. Consequently, it makes sense to use nearby frequencies for interstellar "hailing" signals." Again, explicit assumptions are made about ETI designers. And further (same URL): "Any signal less than about 300 Hz wide must be, as far as we know, artificially produced. Such narrow-band signals are what all SETI experiments look for." Yes, detection is made on the basis of the signal, but based on assumptions. There are assumptions about possible designers. There are also assumptions that possible signals from possible designers should not be looked for because they could be CONFUSED WITH NATURAL PROCESSES. Note, this is not more or less likely than natural processes, but that they could be confused with them.

Moody seems not to like my statement that one of his assertions was laughable. What did I say was laughable? Here is my quote (http://chronicle.com/colloquy/2001/design/403.htm): "What is laughable is his next assertion: 'This argument, again, is refuted by SETI. If and when SETI gets positive results, those results will likely be the only evidence we have for ETI.'" Apparently Moody did not find my laughter so exceptional, in that he quickly retreats: "He points out that positive results could be verified by other procedures. I agree that this is possible, but my point was simply that it is not necessary for a valid design inference." Now, how is a "those results will likely be the only evidence we have for ETI" the same as "positive results could be verified by other procedures. I agree that this is possible?" I have argued that it is not only possible but also essential. Moody finds it only possible, but contradicts his earlier statement by allowing it to be possible. Moody explains 'my point was simply that it is not necessary for a valid design inference.' But that is the point that he is trying to support.

"What he should have said is that SETI has obtained what at first appeared to be positive results but which, on closer analysis, turned out not to be positive." No, I said what I intended. SETI had a false positive from its first scan. It tested further and identified these are false positives. How did it test? By getting independent information from another source. Scientific testing often gets false positives. The issue is that it then tests further and seeks independent confirmation. Moody's real intent comes later: "Let's take the set of all irreducibly complex systems that we know of and divide them into two classes." The two are said to be things we know humans designed and things identified as IC but of unknown provenance. He then argues that design is the preferred explanation for the second groups because it is known to hold for the first. But how do we know that these two groups are similar? The second group is asserted to be known to be IC. Is it? The debate on this board has led to a number of alternatives for some biological structures: (1) IC and not clearly explainable by "natural forces," (2) IC but explainable by "natural forces," including evolution, or (3) not IC. Thus, there is in the first place not agreement that these structures are IC. Further, the term "IC" is fuzzy enough that it may encompass structures that are too complex to operate with parts removed but that could have come about through step-like additions, with full functionality of organisms at each step. Finally, there is no assurance that what is not currently explainable with reference to nondesign will always be unexplainable in this way - alternative #1 may simply reveal our current ignorance, not an inherent characteristic of any such IC phenomena. So, does the fact that we know that humans have designed some complex things mean that design must be accepted for other things asserted to be IC?

"The often-repeated accusations of ID critics that ID wants to 'win by default' always strategically ignore the inductive knowledge base that we have about IC systems." No, it explicitly takes into account the inductive knowledge base that we have about human-designed phenomena. Thus, when confronted with something that is difficult to explain, we can ask: could humans have done this? In some additional cases (rocks chipped in particular ways), this is a plausible inductive inference. In other cases, the phenomena are known to be beyond human capacity as far as it existed (so finding BMW radiator at a Neanderthal site would be not just a surprise but a reason to be very suspicious). In the case of biological phenomena of the type ID talks about, the phenomena made their appearance before there were humans. Therefore, any inference of design necessitates a very conjectural assumption that some other type of designer existed, had the capacity, had the motivation, and in fact produced the phenomena. That is hardly a matter of simple induction.

Moody asserts a rather-illogical case: "My point is simply that the claim that in order to detect ID we have to have independent information about the designer is false, and SETI shows that to be the case." He has just admitted that SETI does make assumptions about ETI senders of signals. But the crux of the argument is in his 'independent information.' In fact, what I argued about SETI is that it must make explicit assumptions about ETI, based on independent information about known, earthly intelligence, as well as independent information about he universe. Thus, he does not answer the charge but tries to knock down a strawman.

"That's fine. Assume away. Assumptions are not knowledge." But those assumptions are based upon knowledge. Where are ID's assumptions about any Intelligent Designer(s), and on what knowledge are they based? ID advocates have been asked this repeatedly. The answer has been that no such assumptions need be made. The response to that is that in the absence of such assumptions, criteria for the detection of design are meaningless verbiage.

Moody creates another strawman in discussing "signals" that could be natural: "Yes, this shows that the claim that ETIs exist is not strongly falsifiable. Imagine that." I suppose that that applies to some, unspecified assertion that ETIs exist - of the type that leads to chasing UFOs. However, it does not apply to SETI, which in fact eschews such an assertion. SETI, which is what Moody compared to ID, excludes possible signals that could come from unintelligent, natural sources. Moody's strawman is something like UFO-ology, not SETI. Yes, indeed, his arguments could probably be usefully employed in refuting Big Foot, as well.

Moody finally loses it. In response to my statement that "Many of ID's claims look more like a hypothetical claim for SETI that it had detected a signal from an ETI civilization that acted like my hypothetical star-mimicking ETIs," he responds: "Those ID claims that turn out to be in that category would have to be regarded as (weakly) falsified, just as analogous ETI claims would be." What Moody here calls weakly falsified, I would call nonsensical. The issue is that SETI does not make claims of this type. Moody seems to admit that ID does make such claims.

-- James Swan, Professor, Wichita State University (posted 2/12, 9:35 a.m., U.S. Eastern time)

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