I want to say freedom, independence. But such things are illusions. Ironically, freedom from illusion may be the thing which most drives me, but it's a quicksand battle. The harder one fights the deeper one is lost.
I think ideas are imbued with a life that ensures someone, somewhere, will bring them to light, no matter how many heretics are burned along the way. If one vessel fails another will bear. Oh. Heretics. If any human is worth fighting for, it's the heretic that carries the thought-form that can change the landscape of man.