Originally a comment by Bjarte Foshaug on That turning of the tide has been slow.
To me the most memorable and useful concept from 1984 was Doublethink (I believe the closest You get to a synonym in Oldspeak is “compartmetalization”):
… Read the restDOUBLETHINK means the power of holding two contradictory beliefs in one’s mind simultaneously, and accepting both of them. The Party intellectual knows in which direction his memories must be altered; he therefore knows that he is playing tricks with reality; but by the exercise of DOUBLETHINK he also satisfies himself that reality is not violated. The process has to be conscious, or it would not be carried out with sufficient precision, but it also has to be unconscious, or
