grammatical fiction

Rubashov had always believed that he knew himself rather well. Being without moral prejudices, he had no illusions about the phenomenon called the ‘first person singular’, and had taken for granted, without particular emotion, that this phenomenon was endowed with certain impulses which people are generally reluctant to admit. Now, when he stood with his forehead against the window or suddenly stopped on the third black tile, he made unexpected discoveries. He found out that those processes wrongly known as ‘monologues’ are really dialogues of a special kind; dialogues in which one partner remains silent while the other, against all grammatical rules, addresses him as ‘I’ instead of ‘you’, in order to creep into his confidence and to fathom his intentions; but the silent partner just remains silent, shuns observations and even refuses to be localized in time and space.
Now, however, it seemed to Rubashov that the habitually silent partner spoke sometimes, without being addressed and without any visible pretext; his voice sounded totally unfamiliar to Rubashov, who listened in honest wonder and found that his own lips were moving. These experiences held nothing mystic or mysterious; they were of a quite concrete character; and by his observations Rubashov gradually became convinced that there was a thoroughly tangible component in this first person singular, which had remained silent through all these years and now had started to speak.
...
Rubashov tried to study this newly discovered entity very thoroughly during his wanderings through the cell; with the shyness of emphasizing the first person singular customary to the Party, he had christened it the ‘grammatical fiction.’ He probably had only a few weeks left to live, and he felt a compelling urge to clear up this matter, to ‘think it to a logical conclusion.’ But the realm of the ‘grammatical fiction’ seemed to begin just where the ‘thinking to a conclusion’ ended. It was obviously an essential part of its being, to remain out of the reach of logical thought, and then to take one unawares, as from an ambush, and attack one with day-dreams and toothache.