  One might have expected this entry to start with a definition of ‘category mistake’. However, giving an explicit informative definition of category mistakes is no easy task. A typical dictionary definition looks like this: “The error of assigning to something a quality or action which can only properly be assigned to things of another category, for example treating abstract concepts as though they had a physical location” (Stevenson 2010). But such definitions are at best too vague to be useful, and at worst simply incorrect. For example, if ‘properly assigned’ is interpreted as meaning truly assigned, then the definition massively over-generates: the sentence ‘Two is odd’ assigns to something (the number two) a quality (being odd) that can only be truly assigned to things of another category (odd numbers), but the sentence clearly isn’t a category mistake. Alternatively, if ‘properly assigned’ is understood as ‘grammatically assigned’, then we risk classifying obviously ungrammatical strings such as ‘the boys eats’ as category mistakes.