Not necessarily. Sometimes it flows from other theories, sometimes from situations where there is no practice.
> and I
> think it's high time that our theorists and thinkers on the left also made
> themselves useful to grassroots movements
As much as I bash mainstream academia for being worthless, sinecured and clueless, I have to disagree. Theory should not and cannot be useful. Theory should critique -- which means, grappling with what exists. (Sometimes that will be useful to a campaign, sometimes not.) The academic norm is already frightening close to the ethos of "being useful" - it's called the corporate university, where everything is measured by enrollments and tuition dollars.
If you teach three classes a quarter, you're feeding 360 young minds a year with vital information, narratives, stories, concepts, etc. they otherwise would never have. That could be just as revolutionary an act as an anti-war demo, or organizing a union.
-- DRR