The philosophy explained in Goldstein’s book is that war is necessary. The Inner Party, those who know much of the truth, who are aware that many things they are told are lies, are expected to show hysteria and hatred of the enemy the strongest.
Those who are members of the Inner Party know that an item of war news is untruthful, often aware the entire war is spurious and they manage this by the technique of doublethink.
Doublethink is one of the most striking aspects of Nineteen Eighty Four. It is the act of simultaneously accepting two mutually contradictory beliefs as correct, often in distinct social contexts.
The concept of Doublethink is one of the most important ‘take-aways ‘ of Nineteen EightyFour