‘How many fingers am I holding up, Winston?’
‘Four.’
‘And if the party says that it is not four but five — then how many?’
“You believe that reality is something objective, external, existing in its own right. You also believe that the nature of reality is self-evident. When you delude yourself into thinking that you see something, you assume that everyone else sees the same thing as you. But I tell you, Winston, that reality is not external. Reality exists in the human mind, and nowhere else. Not in the individual mind, which can make mistakes, and in any case soon perishes; only in the mind of the Party, which is collective and immortal. Whatever the Party holds to be truth is truth. It is impossible to see reality except by looking through the eyes of the Party.”
George Orwell, 1984