Monday, April 02, 2007

What is wrong with Luskin's attack on Sober?

In "What is wrong with Intelligent Design?", Elliot Sober details why ID can not be considered to be scientific. Casey Luskin has responded to this article in four separate posts and I want to give a response to the second of those. In order to understand my writings, it would help if you have read both Sober's and Luskin's writings beforehand.

Writes Luskin:
Thus, in Sober's view, ID must make predictions with respect to neo-Darwinism in order for ID to be testable: “If ID is to be tested, it must be tested against one or more competing hypotheses.” His method might be called "relative testability," and it has clear implications for the scientific status of ID: Since Sober measures ID’s testability by comparing it to neo-Darwinism, the implication is that Sober should measure the comparative testability of neo-Darwinism by trying to test it against ID. The unavoidable conclusion is that under Sober’s methodology, ID and neo-Darwinism must have equal, relative testability with respect to one-another. Obviously Sober believes that neo-Darwinian evolution is a scientific theory, so doesn't that mean ID must also qualify as a scientific theory? Yet Sober implies ID is not a scientific theory, revealing a possible double-standard.

Luskin's claim that Sober applies (possible) double-standards regarding the scientific validity/testability of ID vs "neo-Darwinism"(ND) is wrong. While comparative testing is a good thing, it does not follow that ND should be tested against ID at all or that ID is science. What Luskins seems to fail to realize is that there are more hypoteses (although ID is not a hypothesis, of course) than ND and ID (this is a common IDist fallacy, btw). Lamarkism, for example, can be tested against ND. In fact, Lamarkism has been tested and found wanting since ND explains observed phenomena better. So, the unavoidable conclusion is NOT that ID and ND have equal, relative testability with respect to one-another or that ID is a scientific theory - although a lack of a logical train of thought might make you think so

Writes Luskin:
Sober writes: “It is crucial to the scientific enterprise that auxiliary propositions not simply be invented. By inventing assumptions, we can equip a theory with favorable auxiliary propositions that allow it to fit the data.” Auxiliary assumptions, when misused, are like the epicycles used to defend the long-discarded geocentric model of the solar system: they are post-hoc explanations used to square a theory with contrary data. I agree with Sober's statement here, which makes it all the more curious that Sober fails to recognize how often Darwinists have made auxiliary propositions to square their theory with the data:"

First of all, auxilliary assumptions are not post-hoc, although they could potentially be ad hoc (as when they are simply invented) - hopefully Luskin knows what the difference between these terms is. As Sober writes, the auxiliary propositions we use have to be "independently justified" in the sense that our reasons for accepting them do not depend on (i) assuming that the theory being tested is true or (ii) using the data for arriving at the hypothesis. Luskin agrees when Sober says that auxiliary propositions should not simply be invented which is interesting - mainly for the reason than Luskin doesn't even try to deny that IDists do anything but "simply invent" them (as Sober argues, they have to). Instead Luskin gives what he thinks are instances of Darwinists making "auxiliary propositions to square their theory with the data". Luskin simply throws out a few instances of new scientific discoveries and doesn't even try to justify why these are not justified propositions (how ironic). Problem for Luskin is that the examples he give are "independently justifiable" (and I would say that the third one he lists is simply a straw-man; Co-option and exaptation don't replace natural selection - the features that were "co-opted" and "exapted" would have been subject to selection.).

So, if you accept Sober's writings regarding auxiliary propositions, it would follow that you don't consider ID to be science. Given that Luskin doesn't even try to deny that ID simply invents it's auxiliary propositions (and given that he thinks that that they shouldn't simply be invented) it is quite safe to say that Luskin doesn't think that ID is science either. He doesn't seem to care about that and instead tries to claim that evolution is not science either. Here, as I noted above, he fails. Luskin's attempt at responing to Sober's claims seems to have failed as well.


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