"You don’t have to know what the thought is or where it came from or who gave it to you (all this karma/Miasm stuff). You just have to know how it feels to think that thought. If it feels good, try and stay on the same vibe with it; if it feels bad, try and distract yourself or find a better feeling thought."
Much happens before (and in relative exclusion from) thought.
It depends where one is, I s'pose: what form the filters take. The Truth doesn't need as much defense as any of us think. Everything else, well, it's all a relative stew.