"The author assumes authority to propose a readily available course of study, indicated in a set of drawings by the author, together with directions, explanations and comment based upon his observation and experience." (Oliver Senior, How to Draw Hands)
In my response to Randy Westgren's comment on my last post, I came up with a formulation that has a more general application. I think our thinking about society should begin with an assumption of political sovereignty, not scientific ignorance. We should approach social problems from the vantage of the power we have, not the knowledge we lack. I have said before that a "knowledge society" is, in an important sense, founded on the opposite assumption, always trying to solve our social problems by ameliorating a knowledge deficit.
It gives a particular meaning to the old adage "ignorance is bliss". When faced with an obvious injustice, like poverty, we immediately absolve ourselves of guilt by invoking our ignorance. We tell ourselves we don't know how to fix the problem. I think the same thing happens in writing instruction, which is why I proposed a "counter-revolution". It's not that we don't know how students can become better writers. It's that we don't want to tell them what to do.