Aristotle thought that there could be no lasting void in the natural order, that any emptiness would be instantaneously filled. Of course Aristotle was full of batty ideas. But this one came to be rephrased by philosophers and Vulcans alike as “nature abhors a vacuum,” enduring as a powerful metaphor if not a precisely factual truth. In terms of critical thinking, scientists too abhor a vacuum, and are usually eager to fill in the blanks. On Pharyngula, PZ Myers criticizes a review of long-established brain anatomy, freshened with primary colors and a hypothesis that makes no sense. Describing the original purpose of an apparently useless neuron, PZ writes “It’s like sending a kite string across a chasm, then using the string to pull a rope across, and then using the rope to pull a cable across, and pretty soon you’ve got a bridge.” On EvolutionBlog, Jason Rosenhouse glimpses the formlessness underlying the arguments of Intelligent Design proponents, saying “there is ultimately nothing more to their argument than the claim that at some point in natural history, an unnamed intelligent designer did something.” Can we be a little more specific, please?