The mutability of the past is the central tenet of Ingsoc....

The mutability of the past is the central tenet of Ingsoc. Past events, it is argued, have no objective existance, but survive only in written records and in human memories. The past is whatever the records and the memories agree upon. And since the Party is in full control of all records, and in equally full control of the minds of its members, it follows that the past is whatever the Party chooses to make it.