"To know and not to know, to be conscious of complete truthfulness while telling carefully constructed lies, to hold simultaneously two opinions which cancelled out, knowing them to be contradictory and believing in both of them, to use logic against logic, to repudiate morality while laying claim to it, to believe that democracy was impossible and that the Party was the guardian of democracy, to forget whatever it was necessary to forget, then to draw it back into memory again at the moment when it was needed, and then promptly to forget it again: and above all, to apply the same process to the process itself
That was the ultimate subtlety: consciously to induce unconsciousness, and then, once again, to become unconscious of the act of hypnosis you had just performed. Even to understand the word "doublethink" involved the use of doublethink. (1.3.20)" Here Big Brother subtlety tries to put a total stop to any thought that could be different from the universal truths that they're trying to put forward.
One of Orwell's most important messages in 1984 is that language is of great importance to human thought because it structures and limits the ideas that individuals are capable of formulating and expressing. If language was controlled by a small group of individuals, Orwell poses such a question, that such a group would be able to alter language to make it impossible to even think of disobedient or inappropriate thoughts as deemed by the group in power. The concept of doublethink is an important result of the Party's extremely extensive campaign of psychological control. Doublethink is the ability to have two contradictory "truths" within ones mind and still believe both. The Party uses this to make it possible for the individual to believe anything that the Party tells them, even while having a contradicting idea at the same time.
