Manipulation is a very big part of the book 1984 because the party (Big brother) uses manipulation to completely rewrite history. Big brother also removes words form their language in hopes that it may eliminate the possibility of the proles rebelling against Big brother. Also if anyone does commit a thought crime or take part in any type of rebellion against Big brother that person or group of people are taken and eliminated or tortured until they actually believe that they love Big brother.
The party used manipulation when they captured Winston and took him to room 101 O'Brien says "sometimes pain is not always enough. There occasions when a human being will stand out against pain, even to the point of death. But for everyone there is something unendurable".
"in this way every prediction made by the party could be shown by documentary evidence to have been correct; nor was any item of news, or any expression of opinion, which conflicted with the needs of the movement, ever allowed to remain on record". Winston's job was to change and rewrite the history of Oceania.