"It was not you that ate the idea, but the idea that ate you."
From Demons, also known less accurately as The Possessed.
While in the territory, a great line from The Brothers Karamazov uttered as a throwaway by Dmitri Karamazov, and a kind of prefiguring on the philosophy of the societal mechanisms of control in the technological era:
"Man is broad, too broad even. I would narrow him down."