And perhaps you might pretend, afterwards, that it was only a trick and that you just said it to make them stop and didn’t really mean it. But that isn’t true. At the time when it happens you do mean it. You think there’s no other way of saving yourself and you’re quite ready to save yourself that way. You want it to happen to the other person. You don’t give a damn what they suffer. All you care about is yourself.
Julia speaks these lines to Winston in Book Three, Chapter VI, as they discuss what happened to them in Room 101. She tells him that she wanted her torture to be shifted to him, and he responds that he felt exactly the same way. These acts of mutual betrayal represent the Party’s final psychological victory. Soon after their respective experiences in Room 101, Winston and Julia are set free as they no longer pose a threat to the Party. Here, Julia says that despite her efforts to make herself feel better, she knows that in order to save herself she really did want the Party to torture Winston. In the end, the Party proves to Winston and Julia that no moral conviction or emotional loyalty is strong enough to withstand torture. Physical pain and fear will always cause people to betray their convictions if doing so will end their suffering.
Winston comes to a similar conclusion during his own stint at the Ministry of Love, bringing to its culmination the novel’s theme of physical control: control over the body ultimately grants the Party control over the mind. As with most of the Party’s techniques, there is an extremely ironic strain of doublethink running underneath: self-love and self-preservation, the underlying components of individualism and independence, lead one to fear pain and suffering, ultimately causing one to accept the principles of anti-individualist collectivism that allows the Party to thrive.