You do not exist

'What have you done with Julia?' said Winston.

O'Brien smiled again. 'She betrayed you, Winston. Immediately -- unreservedly. I have seldom seen anyone come over to us so promptly. You would hardly recognize her if you saw her. All her rebelliousness, her deceit, her folly, her dirty-mindedness -- everything has been burned out of her. It was a perfect conversion, a textbook case.'

'You tortured her?'

O'Brien left this unanswered. 'Next question,' he said.

'Does Big Brother exist?'

'Of course he exists. The Party exists. Big Brother is the embodiment of the Party.'

'Does he exist in the same way as I exist?'

'You do not exist,' said O'Brien.

Once again the sense of helplessness assailed him. He knew, or he could imagine, the arguments which proved his own nonexistence; but they were nonsense, they were only a play on words. Did not the statement, 'You do not exist', contain a logical absurdity? But what use was it to say so? His mind shrivelled as he thought of the unanswerable, mad arguments with which O'Brien would demolish him.

- 1984
George Orwell