I don't think theory adds to criticism. (Methodology does, for better or worse.) Theory's function is to make criticism self-conscious, maybe even a little sheepish, about its ex cathedra pronouncements.

The 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.

The effect of reading literary non-fiction that matters most to me is when the coin drops, and this happens in the company of the great, mercuric, encyclopedic minds: Empson, Kenneth Burke, Northrop Frye.

I 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.

Authors we are in danger of accepting as gospel, whereas founders of discursivity provide permeable ideas that we can elaborate upon in a tradition of constructive dialogue.

The rhetoric of theory is always in a bind. It pronounces ideas and denounces failures to accept or grasp them while insisting that there are no grounds either for accepting or grasping ideas.

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.