Another set of excellent quotes from an article that was published alongside Behe’s.
Irreducible Incoherence and Intelligent Design: A Look into the Conceptual Toolbox of a Pseudoscience. https://www.researchgate.net/publication/49764027_Irreducible_Incoherence_and_Intelligent_Design_A_Look_into_the_Conceptual_Toolbox_of_a_Pseudoscience
In his initial definition, Behe seems to intend the weak interpretation, but he then proceeds to use the concept in a line of reasoning that only makes sense under the strong interpretation. Precisely because the bacterial flagellum is IC, Behe tells us, it could not have evolved by means of random mutation and natural selection. However, when critics object that the system’s components may well be able to perform other functions in other contexts, or when they point to the possibility of indirect evolutionary pathways, Behe switches back to the weak definition and blames his critics for misrepresenting his argument.
Not, how this author also sees the switching between definitions in IC. The “weak” and “strong” versions correspond to IC1 and IC2, in the parlance we have used here. IC1 is very easy too measure, but IC2 is nearly impossible to measure.
This allows for an interesting bait-and-switch strategy, which one could describe as follows: ‘First present evidence for weak IC in the living world, then pretend that strong IC has been demonstrated and continue to equate IC with “unevolvability”. If challenged on empirical grounds, jump back to the weak version and accuse your critics of misrepresenting your argument. Switch the IC claim to subsystems and assembly of components, keep raising the standards of evidence, and reassert that all this directly follows from the simple objective criterion of IC. Finally, when really pressed against the wall, give up this particular system and quickly find a new one. Repeat the circle ad libitum.’ Further equivocations
In any case, what is disingenuous in Behe’s presentation is that this challenge to offer a complete and step-by-step evolutionary account of IC systems is not spelled out from the beginning, but is a belated revision of his original claim (based on ambiguities in his definition). In Darwin’s black box, Behe leaves us with the impression that the concept of IC is in principle easy to challenge, but when his critics actually set out to do so, as we saw in the discussion with Pennock and Miller, Behe dodges and weaves like a hunted rabbit.
Behe’s claim has indeed been tested against the facts and found wanting (Miller, 2000; Lenski et al., 2003; Young and Edis, 2006; Forrest and Gross, 2007a). In response to these demonstrations, however, IDC proponents belatedly ‘reinterpret’ their initial claims in order to lift them out of the critic’s reach. A first strategy to this end consists in shifting the burden of proof from plausible evolutionary pathways to the actual evolutionary story, maintaining that the broad outlines of a plausible evolutionary account amounts to nothing more than Darwinian wishful thinking and speculation. The same bait-and-switch technique can be discerned here: IC is constantly boasted as a point of principle for ruling out the possibility of evolutionary explanations, but as soon as it is challenged on that ground, through a discussion of plausible evolutionary scenarios, ID creationists pretend that they were talking about actual evolutionary pathways all along.
This is an important point too, that came up just yesterday. The IC argument is merely a logical argument about plausibility, but when plausible pathways are supposed, there is a shift to demand evidence for what actually happened. This creates a large asymmetry in the argument, where a logical argument about implausibility does not tolerate a logical argument that demonstrates it is wrong. This dismissal is merely on the grounds that it is not empirically demonstrated, no matter the fact that it shows logical errors in the original argument it is disputing.