So what is the mark of genuine science? To attack this question, Popper examined several theories he thought were inherently unscientific but had a vague allure of science about them. His favorites were Marx’s theory of history and Freud’s theory of human behavior. Both attempted to describe the world without appeal to super-natural phenomena, but yet seem fundamentally different from, say, the theory of relativity or the gene theory.
What Popper noticed was that, in both cases, there was no way to prove to proponents of the theory that they were wrong. Suppose Jim’s parents moved around a lot when Jim was a child. If Jim also moves around a lot as an adult, the Freudian explains that this was predictable given the patterns of behavior Jim grew up with. If Jim never moves, the Freudian explains — with equal confidence — that this was predictable as a reaction to Jim’s unpleasant experiences of a rootless childhood. Either way the Freudian has a ready-made answer and cannot be refuted. Likewise, however much history seemed to diverge from Marx’s model, Marxists would always introduce new modifications and roundabout excuses for their theory, never allowing it to be proven false.
Popper concluded that the mark of true science was falsifiability: a theory is genuinely scientific only if it’s possible in principle to refute it. This may sound paradoxical, since science is about seeking truth, not falsehood. But Popper showed that it was precisely the willingness to be proven false, the critical mindset of being open to the possibility that you’re wrong, that makes for progress toward truth.
I agree with this 100%. In fact, this is actually enshrined in American jurisprudence as the Daubert standard. This is the standard that courts apply to expert testimony, and the ultimate question on it is falsifiability.
If we examine ID in this light, it becomes pretty clear that the theory isn’t scientific. It is impossible to refute ID, because if an animal shows one characteristic, IDers can explain that the intelligent designer made it this way, and if the animal shows the opposite characteristic, IDers can explain with equal confidence that the designer made it that way. For that matter, it is fully consistent with ID that the supreme intelligence designed the world to evolve according to Darwin’s laws of natural selection. Given this, there is no conceivable experiment that can prove ID false.
And this is where I disagree. ID (which isn’t yet a theory, simply a collection of hypothesis) proposes that design can be detected mathematically (the signal in the noise) and should therefore be falsifiable. In fact, the techniques they are proposing have already been shown to work in fields like cryptography.
On the other hand, Evolution falls squarely on the Freudian example above. What does Evolution do when new evidence is found? It simply shoehorns it in with whatever looks like the best fit. It makes the presumption of common decent and then shoves the jigsaw puzzle together in whatever way seems to fit closest (regardless of whether it is a proper fit or not.)
Evolution has failed to account for the apparent error-checking functions that weed out mutation in genetic material. Evolution has failed to show a way to perform a regression analysis on genetic material and show common decent. Evolution has failed to show any significant speciation.
It is sometimes complained that IDers resemble the Marxist historians who always found a way to modify and reframe their theory so it evades any possible falsification, never offering an experimental procedure by which ID could in principle be falsified. To my mind, this complaint is warranted indeed. But the primary problem is not with the intellectual honesty of IDers, but with the nature of their theory. The theory simply cannot be fashioned to make any potentially falsified predictions, and therefore cannot earn entry into the game of science.
This is flat wrong. The entire premise of the ID thought is that you cannot design something without leaving evidence of that design. The evidence is the very unlikelihood of it having occurred by random chance and selection.