The mutability of the past is the central tenet of Ingsoc. Past events, it is argued, have no objective existence, 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. It also follows that though the past is alterable, it never has been altered in any specific instance. For when it has been recreated in whatever shape is needed at the moment, then this new version is the past, and no different past can ever have existed. This holds good even when, as often happens, the same event has to be altered out of recognition several times in the course of a year. At all times the Party is in possession of absolute truth, and clearly the absolute can never have been different from what it is now. It will be seen that the control of the past depends above all on the training of memory. To make sure that all written records agree with the orthodoxy of the moment is merely a mechanical act. But it is also necessary to remember that events happened in the desired manner. And if it is necessary to re-arrange one’s memories or to tamper with written records, then it is necessary to forget that one has done so. The trick of doing this can be learned like any other mental technique. It is learned by the majority of Party members, and certainly by all who are intelligent as well as orthodox. In Oldspeak it is called, quite frankly, ‘reality control’. In Newspeak it is called doublethink , though doublethink comprises much else as well.