When working with Nineteen Eighty-Four, it is important to understand the social and political realities of the society the book describes. Some of these are described more or less directly throughout the narrative itself, but you can also find a more systematic description in the sections of Goldstein’s book that Winston reads towards the end of Part II. If you want to brush up on the social setting, pages 192-226 might therefore be particularly useful to re-read.
Of course, since it is revealed that Goldstein’s book was in fact written by Party members, you should always keep in mind that some of its information could be untrustworthy, as the book’s narrator is unreliable (p. 274). However, the fact that Winston feels that the book does not tell him anything he does not already know (p. 208) indicates that the social structures it describes match those that Winston observes in his everyday life.
Oceanian society is divided into three social classes, centred around the political party INGSOC (short for “English Socialism”), which has complete control of society: Members of the Inner Party, members of the Outer Party, and ‘proles’ (who do not directly belong to the Party but are still under its control). Above everything is the mysterious Big Brother, the leader of the Party and therefore of the state. Finally, we are told of a mysterious resistance group known as the Brotherhood (but it is unclear whether this really exists).
Goldstein’s book reveals that this social structure is carefully designed to eliminate any possibility of rebellion. The proles are kept uneducated and therefore never realise that society might have a different structure, while Party members are systematically indoctrinated to wish to keep the Party in power - and also constantly watched to ensure that no one tries to do anything different. Those who attempt to rebel, or who are seen to hold views that are inimical to the Party are eliminated or ‘vaporised’.
The leader of the Party is simply known as Big Brother, an imposing figure who is displayed on posters all around London, and who frequently appears at the end of propaganda videos: “[The poster] depicted simply an enormous face, more than a metre wide: the face of a man of about forty-five, with a heavy black moustache and ruggedly handsome features” (p. 3).
It is strongly implied that Big Brother is simply a useful symbol of leadership (pp. 216-217) and does not really exist, since he only ever appears on posters and telescreens. O’Brien even freely admits that Big Brother will never die (p. 272), which is another argument that points to his non-existence. Instead, Oceania is ruled by a collective group of people who together make up the Inner Party.
The Inner Party
Members of the Inner Party form the upper class of society and in practice act as the rulers of the state, collectively. They clearly enjoy more luxuries than the other classes, as we learn that they live in better buildings, have more reliable access to electricity and get food and drink of much better quality. They also typically have a few personal servants to tend to their needs.
Since the economy of Oceania is collectivised, the...