… This kind of thing is frightening to me, because it often gives me the feeling that the very concept of objective truth is fading out of the world. After all, the chances are that those lies, or at any rate similar lies, will pass into history. … The implied objective … is a nightmare world in which the Leader, or some ruling clique, controls not only the future but the past. if the Leader says of such and such an event, ‘It never happened’ – well, it never happened. If he says that two and two are five – well, two and two are five.
-George Orwell, Looking Back on the Spanish War