A "Declaration of Reasonable Doubt" (Guardian, 9 September) is the latest reminder of the persistence of controversy over who wrote Shakespeare. But the skeptics' case depends on a logical slip. The starting point is always some close variant of the claim that while Shakspere (a common spelling...

I introduce the notion of "neglect defaulting", which labels the propensity to neglect possibilities which are ordinarily sensibly neglected. In familiar contexts we are well-tuned to recognize when to override the default. But outside the range of familiar experience – here in the artificial...