An ideological problematic turns around certain eloquent silences and elisions; and it is so constructed that the questions which are posable within it already presuppose certain kinds of answer. Its fundamental structure is thus closed, circular and self-confirming: wherever one moves within it, one will always be ultimately returned to what is securely known, of which what is unknown is merely an extension or repetition.
-Terry Eagleton
(on Althusser)