“In their propaganda today’s dictators rely for the most part on repetition, suppression and rationalization — the repetition of catchwords which they wish to be accepted as true, the suppression of facts which they wish to be ignored, the arousal and rationalization of passions which may be used in the interests of the Party or the State.

As the art and science of manipulation come to be better understood, the dictators of the future will doubtless learn to combine these techniques with the non-stop distractions which, in the West, are now threatening to drown in a sea of irrelevance the rational propaganda essential to the maintenance of individual liberty and the survival of democratic institutions.”

• Brave New World Revisited (1958) by Aldous Huxley

"Political language... is designed to make lies sound truthful and murder respectable, and to give an appearance of solidity to pure wind.

“The imagination and the spiritual strength of Shakespeare’s villains stopped short at a dozen corpses because they had no ideology. Ideology – that is what gives villainy its long-sought justification and gives the villain the necessary steadfastness and determination. Thanks to ideology, the twentieth century was fated to experience villainy on a scale calculated in the millions.”

― Aleksandr Solzhenitsyn, The Gulag Archipelago

I think Alexander Solzhenitsyn, in his Warning to the West speech summarized communism well.

“Communism is as crude an attempt to explain society and the individual as if a surgeon were to perform his delicate operations with a meat ax. All that is subtle in human psychology and in the structure of society (which is even more complex), all of this is reduced to crude economic processes. The whole created being—man—is reduced to matter. It is characteristic that Communism is so devoid of arguments that it has none to advance against its opponents in our Communist countries. It lacks arguments and hence there is the club, the prison, the concentration camp, and insane asylums with forced confinement.”

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To accomplish this they also brainwash people , children when they are young, they engage in endless censorship and propaganda and they have to erase history because again it could be used as reference from which to judge the party. That is why they put effort in rewriting history, tearing down statues etc.

Language matters because whoever controls the words controls the conversation, because whoever controls the conversation controls its outcome, because whoever frames the debate has already won it, because telling the truth has become harder and harder to achieve in an America drowning in Orwellian Newspeak. -- Erica Jong

"Every record has been destroyed or falsified, every book has been rewritten, every picture has been repainted, every statue and street building has been renamed, every date has been altered. And that process is continuing day be day and minute by minute. History has stopped. Nothing exists except the endless present in which the party is always right." -- George Orwell

In George Orwell's dystopian classic 1984, doublethink is the act of holding, simultaneously, two opposite, individually exclusive ideas or opinions and believing in both simultaneously and absolutely. Doublethink requires using logic against logic or suspending disbelief in the contradiction.

The three slogans of the party — "War Is Peace; Freedom Is Slavery; Ignorance Is Strength" — are obvious examples of doublethink. The act of doublethink also occurs in more subtle details throughout the novel.