Structuralism

Derrida:

Meaning includes identity (what it is) and difference (what it isn't) and is therefore continuously being 'deferred'. Derrida invented a word for this process, combining difference and deferral - différance.

 'THERE'S NEVER ONLY ONE MEANING'

Rejects the dogmatic representation of Reason as timeless and certainty.

Foucault: 

epistemology = the verification theory of knowledge concerned with distinguishing genuine from spurious knowledge.
An episteme dictates what counts as knowledge and truth and what doesn't.

'There is no history but a multiple, overlapping and interactive series of legitimate vs. excluded histories.'

Art: meta-epistemic; it is about the episteme as a whole, an allegory of the deep arrangements that make knowledge possible.