O'brien says that Winston is the last man because Winston is the last person to know that this is wrong and should be defeated. Everyone else in the society has bought into the version of reality that the Party is laying down, but Winston is a man in the sense of the a fully aware human whose spirit is still intact, who still has the spirit of man that will defeat the party. Winston thought two plus two is four but big brother make people to think two plus two is five.


O'brien is villain because he tricks Winston into believing that he is a member of the anti-Party Brotherhood. O'brien approaches and inducts Winston into the group, but does that in order to set Winston up for the ultimate crime. O’Brien was essentially toying with him, seeing how far a man would go to rebel against the state and he tortured Winston.