That was the ultimate subtlety: consciously to induce unconsciousness, and then, once again, to become unconscious of the act of hypnosis you had just performed. Even to understand the word ‘doublethink’ involved the use of doublethink.
George Orwell, Nineteen Eighty-four (1949), chapter 3.
Note: illustration by Bernd Pohlenz — CC BY-SA 3.0.