Criticism is concerned with evaluation. There may be evaluative principles implicit in this or that form of theory, but theory in and of itself is not prescriptive.
Paul FryI do identify the escape hatch through which Foucault eludes the charge that he himself is an author/authority, hence a tyrant. He establishes the category of "founder of discursivity" for the authors he likes. Slippery, perhaps, but you can see what he means.
Paul FryThe basic change in the landscape since my salad days started with the defensive rediscovery of history and politics by all the theoretically-oriented academics in the late seventies and eighties.
Paul Fry