In a thought-provoking paper from the March issue of The Quarterly Review of Biology , Elliott Sober (University of Wisconsin) clearly discusses the problems with two standard criticisms of intelligent design: that it is unfalsifiable and that the many imperfect adaptations found in nature refute the hypothesis of intelligent design.

Biologists from Charles Darwin to Stephen Jay Gould have advanced this second type of argument. Stephen Jay Gould's well-known example of a trait of this type is the panda's thumb. If a truly intelligent designer were responsible for the panda, Gould argues, it would have provided a more useful tool than the stubby proto-thumb that pandas use to laboriously strip bamboo in order to eat it.

ID proponents have a ready reply to this objection. We do not know whether an intelligent designer intended for pandas to be able to efficiently strip bamboo. The "no designer worth his salt" argument assumes the designer would want pandas to have better eating implements, but the objection has no justification for this assumption. In addition, Sober points out, this criticism of ID also concedes that creationism is testable.

A second common criticism of ID is that it is untestable. To develop this point, scientists often turn to the philosopher Karl Popper's idea of falsifiability. According to Popper, a scientific statement must allow the possibility of an observation that would disprove it. For example, the statement "all swans are white" is falsifiable, since observing even one swan that isn't white would disprove it. Sober points out that this criterion entails that many ID statements are falsifiable; for example, the statement that an intelligent designer created the vertebrate eye entails that vertebrates have eyes, which is an observation.

This leads Sober to jettison the concept of falsifiability and to provide a different account of testability. "If ID is to be tested," he says, "it must be teste
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Contact: Suzanne Wu
swu@press.uchicago.edu
773-834-0386
University of Chicago Press Journals
22-Feb-2007