Doublethink is the act of simultaneously accepting two mutually contradictory beliefs as correct, often in distinct social contexts. Doublethink is related to, but differs from, hypocrisy and neutrality. Also related is cognitive dissonance, in which contradictory beliefs cause conflict in one's mind. Doublethink is notable due to a lack of cognitive dissonance — thus the person is completely unaware of any conflict or contradiction.
George Orwell created the word in his dystopian novel Nineteen Eighty-Four (published in 1949); doublethink is part of newspeak. In the novel, its origin within the typical citizen is unclear; while it could be partly a product of Big Brother's formal brainwashing programmes, the novel explicitly shows people learning doublethink and newspeak due to peer pressure and a desire to "fit in", or gain status within the Party — to be seen as a loyal Party Member. In the novel, for someone to even recognize — let alone mention — any contradiction within the context of the Party line was akin to blasphemy, and could subject that someone to disciplinary action and to the instant social disapproval of fellow Party Members.
Like many aspects of the dystopian societies reflected in Orwell's writings, Orwell considered doublethink to be a feature of Soviet-style totalitarianism, as reflected in this statement from a speech by Joseph Stalin: We are for the withering away of the state, and at the same time we stand for the strengthening of the dictatorship of the proletariat, which represents the most powerful and mighty of all forms of the state which have existed up to the present day. The highest development of the power of the state, with the object of preparing the conditions of the withering away of the state: that is the Marxist formula. Is it "contradictory"? Yes, it is "contradictory." But this contradiction is a living thing and wholly reflects the Marxist dialectic.