  I take issue with AI formalizations of context, primarily the formalization
by McCarthy and Buvac, that regard context as an undefined primitive whose
formalization can be the same in many different kinds of AI tasks. In
particular, any theory of context in natural language must take the special
nature of natural language into account and cannot regard context simply as an
undefined primitive. I show that there is no such thing as a coherent theory of
context simpliciter -- context pure and simple -- and that context in natural
language is not the same kind of thing as context in KR. In natural language,
context is constructed by the speaker and the interpreter, and both have
considerable discretion in so doing. Therefore, a formalization based on
pre-defined contexts and pre-defined `lifting axioms' cannot account for how
context is used in real-world language.
