And when memory failed and written records were falsified—when that happened, the claim of the Party to have improved the conditions of human life had got to be accepted, because there did not exist, and never again could exist, any standard against which it could be tested.
This quote from Book One, Chapter VIII, emphasizes how one’s understanding of the past affects one’s attitude about the present. Winston has just had a frustrating conversation with an old man about life before the Revolution, and he realizes that the Party has deliberately set out to weaken people’s memories in order to render them unable to challenge what the Party claims about the present. If no one remembers life before the Revolution, then no one can say that the Party has failed mankind by forcing people to live in conditions of poverty, filth, ignorance, and hunger. Rather, the Party uses rewritten history books and falsified records to prove its good deeds.