My literary theory professor uses the Derridian phrase "there's nothing outside the text" at least once per class. I'm constantly tempted to challenge this epistemological relativism, but then someone goes and says it better than I could.
Roger Kimball, one of my favorite contemporary essayists, nails it:
"Even if deconstruction cannot be defined, it can be described. For one thing, deconstruction comes with a lifetime guarantee to render discussion of any subject completely unintelligible. It does this by linguistic subterfuge. One of the central slogans of deconstruction is "il n'y a pas de hors-texte", i.e., "there is nothing outside the text." (It sounds better in French.) In other words, deconstruction is an updated version of nominalism, the view that the meanings of words are completely arbitrary and that, at bottom, reality is unknowable."
To say that "there is nothing outside the text" begs the question of how anyone could ever know that in the first place. (Are you in the Matrix or not?) But that little philosophical conundrum doesn't seem to bother too many of my classmates....