Randal Rauser

“One does so by eliminating all non-intelligent causal explanations so that the only plausible causal explanation that remains is an intelligent one.”

That may be a valid way to demonstrate the truth of something, but it’s not a test in the scientific sense of the word. One can build the case for arson by providing both positive and negative evidence; the evidence for ID is entirely negative. In science a hypothesis is tested by attempting to nullify it, which is generally done by trying to demonstrate the failure of positive evidence to uphold the hypothesis. So when the hypothesis can only be inferred from the failure of other hypotheses, it can’t really be tested per se. The only theoretical way to prove its truth would be to demonstrate that it is the only remaining possible explanation, which is not really possible in the case of origins questions.

This is highly problematic from a scientific point of view. However, as I believe you’ve pointed out, ID is not really a question of science but of philosophy of science. Scientific testability is not the criterion for truth; it’s just a way of making it easy to test whether a belief is true. ID may very well be true in some cases, but it’s going to be impossible to demonstrate that in the typical scientific manner.

“… how did the investigators conclude that the fire was the product of arson? The answer, of course, is really quite simple: they eliminated all the other explanations.”

A scientific arson investigator (and the field is sadly rife with the unscientific sort) would first try to determine the cause. Failing to find a cause would simultaneously mean finding no natural/accidental cause and finding no deliberate cause, and the case would simply be logged as undetermined cause–an entirely legitimate finding in arson investigation. It would be the worst sort of arson investigator who can’t find any cause at all, and thereby concludes it must have been arson.

“And there you have it: a straightforward answer to your question of how one tests for intelligent design. One does so by eliminating all non-intelligent causal explanations so that the only plausible causal explanation that remains is an intelligent one.”

For an example of how quickly this can go wrong, consider the case of seemingly spontaneous atomic decay. In adding up all the energies that emerge from such a decay event, we find no surplus, and there is nothing in atomic theory which suggests an internal cause, so for the time being, we are logging this phenomenon as having no known cause. What the principle above suggests is that we should say we have eliminated all non-intelligent causal explanations, so intelligence remains as the only plausible causal explanation, which is just dumb. In the first place, we can only eliminate known causes. There always remains the possibility of unknown causes. In the second place, even if it were possible to eliminate all causes, that would eliminate all intelligent causes right along with all the non-intelligent causes.

“Now this brings us to the depth of irony of those who critique intelligent design. You know what they commonly say? “Appealing to intelligence is a science stopper!” Oh really? Try telling that to the investigators of the Slave Lake fire. Do you think that once they’ve identified intelligence as the cause of the fire that they are going to call off their investigation? On the contrary, it is at this point that the investigation kicks into high gear as the RCMP (Canada’s national police service) are called in.”

Which strongly indicates they found a cause for the fire, and the cause has properties common to deliberately set fires. Because if all they truly have is the lack of a finding of a cause, that would leave the RCMP with nothing to investigate.

“In closing, note one more point: it is still possible that the fire could turn out to be the result of non-intelligent causes. Perhaps it is not arson after all.”

This is a serious risk when dealing with an animal which has a propensity to see agency, even when it isn’t there. (see the Cameron Todd Willingham case for a particularly egregious example of how far things can go wrong when an investigation is conducted without sufficient scientific rigor.)

“So we recognize that for now the inference to an intelligent cause is a provisional one. But we also recognize that in light of all the data it is the best causal explanation available.”

In the case of arson, we are usually dealing with probable causes. Deliberately set fires are included among the candidate possibilities because we know they happen, they happen a lot, and humans have several common ways of setting fires which have characteristics readily distinguishable from natural causes. When you find chemical trace and burn patterns consistent with gasoline being splashed on the walls of a home, and the burned remains of a gasoline can in the living room, we don’t conclude that was a deliberately set fire on the basis of it being utterly impossible for natural causes to have left that evidence (since we don’t know that), but because the arson explanation is the most probable and least remarkable of any of the more common explanations. We don’t have an analog to that in biology.

But there is another sort of error which can occur in arson investigation. A skilled arsonist can set a fire in a manner which leaves evidence that is entirely consistent with natural or accidental causes, so there is always a possibility that what looks unintelligent is actually intelligence intelligently concealing itself. And if humans have the ability to conceal their tracks from humans, how much moreso could a cosmic intelligence?

“once we make that inference to intelligence we can expect the investigation not to stall but rather to intensify.”

If ID proponents would care to lay out exactly how such an investigation could proceed, maybe they would actually get somewhere in the scientific community.