This article examines how both scientists and creationists, as they argue over intelligent design, invoke and quote the fictional character of Sherlock Holmes to support their opposed positions. Rhetorical analysis ofHolmes's repeated contributions to the debate reveals not only how the argument for design falls apart, but also how the argument for Darwin compromises itself when following the detective onto shaky logical ground. The sciences and the humanities must work together to combat the corrosive influence ofpseudoscientific reasoning on our students and the general public; this article contributes to that joint enterprise.