Part one

In part one we learn about Big Brother and Winston Smith. The whole dynamic in which they live in is completely corrupt. To have basically a caste system would obviously lead to some type of underground resistance which is the Brotherhood. Keeping lower, middle and upper class seperated is a good idea for control, and Big Brother certainly keeps these people in check by establishing rules to make them less human and more like sheep. 

FAV QUOTE: A nation of sheep will beget a government of wolves. 

The tedious jobs in which the outer party is involved in keeps their minds busy, lack of physical and sensual release makes them become more involved into their work and the hate against Goldstein. 

Being afraid to speak your mind can lead to two answers: 1. Becoming angry and revolting which requires brain energy. 2. Listening blindly so you don't have to put forth an effort. The second option is what many people flock to. 

Paranoia is a main reason of vaporization. People who are intelligent and can understand what's going on need to be gotten rid of. With the bombings among the proletariats, it is to keep population down to prevent a revolt.