Quote Originally Posted by Light Mage
I think it's implying that there's nothing in the mind that isn't a pre-created thought pattern designed by the consiousness, as opposed to unique phenomenal experiences caused on-the-moment by the act of percieving.
I think it's got a lot to do that, and with "the unknowability of absolute truth", or the subjectivity of each person's perception of reality - since basically everything we see, think, feel, read, experience etc is influenced, in our thoughts, by cultural factors and constructs.

This quote, an excerpt from this, was brought up in my jurisprudence class during a discussion of modernism, structuralism, post-structuralism and postmodernism.