Glossary of Literary Theory by Greig E. Henderson and Christopher Brown

Aporia:

A term used by deconstructionists to describe the point of impasse or undecidability to which reading a text necessarily gives rise. Because all texts undo or dismantle the philosophical system to which they adhere by revealing its rhetorical nature, all texts are riven by indeterminacies, and the clash between the referential or literal and the rhetorical or figural levels of discourse inevitably produces aporia. The reader is thereby left in the double bind of trying to master a self-subverting text. (See also Deconstruction.)