The dilemma that Foucault is coming up against at the end of The Order of Things and the end of The Archaeology of Knowledge is a problem that hangs over all the earlier Superstructuralists. It is easy enough for the theory of epistēmēs to encompass the thought of other historical periods; but when it encompasses the thought of our own present-day period, it also encompasses the thought of the thinker of the theory of epistēmēs. The power of received social discourse suddenly becomes an embarrassment when Foucault himself has to submit to its control. I t is a classic case of a deterministic theory that reflexively determines itself out of existence.