The theories of Darwinian evolution and Intelligent Design appear to be locked in an intractable debate, partly because they offer rival scientific explanations for the phenomenon of descent with modification in biology. This paper analyses the dispute in two ways: firstly, it seeks to clarify the exact nature of the logical flaw that has been alleged to lie at the heart of Intelligent Design theory. Secondly, it proposes that, in spite of this error, the Intelligent Design theory advocated by Michael (...) Behe takes at least one significant step in the right direction. Although Behe's suggestion is promising, it is shown to be not nearly radical enough. (shrink)