Twice in the last 12 hours I've encountered the concept of "omniscience."
In the first case, I was watching the film "The Lives of Others," which is set in East Germany before the Wall fell. The "stasi" had as its stated goal "to know everything." This was not the main theme of the film, but it is one that was highlighted frequently. In one example, the stasi are noticed by a nosy neighbor as they set up surveillance on a citizen. Unflustered, the lead stasi agent knocked on her door, referred to her by name, and threatened her with personalized consequences should she reveal that they had been there.
In the second case, Ayaan Hirsi Ali recounts in her book "Infidel," being criticized by one of her teachers:
We were not true Muslims, Sister Aziza sadly informed the abashed and suddenly silent classroom. Allah did not look on us with delight. He could see into our hearts, and He knew we were not dedicated to him. The goal of prayer was awareness--constant awareness of the presence of God and the angels--and an inward submission to God's will that permeated every thought and action every day.
Sister Aziza reminded us of the angels we had learned about in school in Saudi Arabia, who hovered above each of our shoulders. On the left and the right they recorded our thoughts, intentions, and ideas--bad and good. Even if we did cover ourselves and pray, that was not sufficiently meaningful for God. What counted was the intention. If your mind strayed--if you were doing it for the wrong reasons--God and the angels would look into your heart and know. (pg 80, hardback, emphasis in original)
The idea that struck me upon reading this is that the goal behind the concept of omniscience is the same: the utter subjugation of the individual to the ruling authority.
In the case of religion, omniscience is used as a threat to inculcate guilt for thoughts and feelings, thereby turning the individual into an informant against himself. In a religious context, omniscience is a mystical concept where some outside judges our privy to one's inner thoughts and feelings. One lives one's live in paranoid fear that some unbidden thought will come to mind and that Allah will hear it, and damn you for eternity.
In the case of the Stasi, omniscience is given a kind of metaphysical reality: the State spends enormous sums of money to spy on its citizens, to learn as much as they can about them, so that it can threaten them accordingly. Once again, the citizenry live their lives in paranoid fear that their private conversations might be overheard by a stasi informant. They are not even safe in their own homes, with their own spouses and children. True trusted friendships are impossible in a state where 1/3 of the citizens are informants, and the rest can be threatened into becoming informants.
Coming across these two examples in such close proximity to one another highlighted the way that "omniscience" is used in practice. It's not just an irrational concept--it's an irrational concept with a purpose.