Category Mistake / Category Error: 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. A semantic or ontological error in which “things of one kind are presented as if they belonged to another”, or, alternatively, a property is ascribed to a thing that could not possibly have that property. For example, “how much does the number six weigh?”1