Since all occurrences of human language are manifested as physically immediate artifacts (visible and tactile gestures, sound vibrations in the air, marks on a page, etc.), language itself, and its use, can be represented by still further recursion of language. Representing language is no different in kind than representing knives and lightning and hair. But this doubling back of language upon itself—alluring like a forbidden fruit—is almost invariably done without sensible purpose.
The normal purpose of language is to make use of a biologically immediate artifact to represent something that is not biologically immediate. But when language represents language, it becomes the use of a biologically immediate artifact to represent something already biologically immediate, and thus confusion easily abounds. Meta-language too often betrays a misuse, and a misunderstanding, of the tool.